so our learning goals for this particular area of the course are to learn and utilize directional terminology learn the components of the axial and appendicular skeleton understand and identify the differences between carnivore equine and bovine skeletal Anatomy further to that I'll also add understanding the different joints and classifications of joints so looking at directional terminology the reason that we use this specifically is in order to describe what we're seeing and where we're seeing it on an animal so as an RVT our role typically is when an animal comes into a clinic we're going to have a look at the animal do a physical exam and start identifying normals and abnormals and when we're writing up our medical records and describing this to the doctor to have a look at the animal we have to be able to tell them exactly where we're seeing something that's abnormal so we can't just say somewhere on the left side of the chest of this dog we're going to use other terminology such as the lateral aspect medial cranial caudal rostral etc so we'll go through this in class quite significantly but this is how we break the animal components down into directional terminology so all this highlight here when we are talking to word the tail on an animal and we start right from the bridge of the nose so right from the stout if we're talking about toward the tail we're talking about the caudal aspect if we are talking about toward the head we're talking about the cranial aspect where that changes is if we're looking at the face of an animal and it's toward the nose we'll use the term rostral and we'll continue to use the word caudal if it's away from the nose and toward the tail and then we move on we have the dorsal aspect of the animal so that runs along the spine and the way I think but that is the dorsal fin of a dolphin so it runs along the spine of the animal and then we have ways that we break up the limbs specifically so we have proximal which means closer to the body toward the body and distal is the aspect of the limb specifically that's away from the body moving on again so we like I said before we have dorsal which is toward the spine like the dorsal fin of a dolphin and then we have ventral and ventral is toward the Abdo I'm sorry toward the toward the floor and when an animal is standing so toward the lower aspect of their abdomen is is ventral and then when we break it into this plane here our transverse plane we can see we have lateral which is toward the outer edges of the animal and then we have medial which refers to the midline so medial I like to think of as toward our belly buttons if we're thinking about it in regard to people and lateral is sort of toward our sides all right furthermore getting specific once again to the feet we have plantar and Palmer so plantar refers to the aspect of the foot that is touching the ground and specifically plantar refers only to the back legs so the aspect of the foot that's touching the ground on the back legs Palmer is the aspect of the foot that's touching the ground on the front legs now a good way to remember that find helpful is Palmer front legs when we look at our hands we talk about the palms of our hands so it refers to front to tour our arms which are the dog's front legs plantar it's kind of lame but I'd like to think that I stopped on plants with my feet okay so a plantar is referring to back legs the the aspect of the feet that touches the ground on the back legs now to talk about the tops of the feet this aspect here that's dorsal so the dorsal aspect of the hind left foot is what we're looking at here so if there is here let's say so I would refer that to that as the cranial thorax and it would be sort of cranial dorsal thorax on the left hand side so what I'm saying is that it's more toward the head on the thorax of the chest than it is the tail and then it's more toward the dorsum than it is the ventral aspect and it's the left hand side which is also really important so the transverse plane cuts the animal I know it sounds awful but cuts the animal into cranial and caudal as transverse plane that we're talking about their dorsal is the dorsal and ventral and then the sagittal which is here oops sorry pardon me sagittal our median is into the lateral and medial aspects so that's just another image to give you a bit more further in-depth understanding okay so just remembering that proximal and distal is specifically referring to limbs only and then when we're looking at animals we always have to remember that they get their own left and right so we don't mirror or why don't know yeah we don't mirror ourselves onto them so if I'm looking at the table what I put if I put my hand on an aspect of the table I put my right hand down it means that's the right side of the table whereas if it's an animal they have their own left and right so if we're looking at them dead on of course that's going to be opposites so this kitty cats looking at us I'm pointing to this ears right here that's it's right here same with this little guy this is moose he's my very special cat that I loved very much who's no longer with me that's mooses left ear and this is how moose used to distract me when I was marking papers and this is another little guy his name's Ringo and he was adopted from the vet tech program he was really fabulous unfortunately he died a few years ago as well but went back to this that's his left front foot all right so we're get into talking a little bit about bones as that's our main goal for today so there are five functions of bones I don't know if anybody's seen this Family Guy episode but I'll always remember it it's when Peter Griffin wishes he has no bones and it's really weird and hilarious so let's go into bone function there are five functions of bones number one support an example is the spinal processes processes support the cranium number twos protection rims protect the lungs and the heart likewise the spinal processes will protect the spinal cord to leverage so attached to muscles bones allow us to walk jump and run storage we store calcium various minerals as well as blood and then there's also blood cell formation hemolytic tissue in the bone marrow produces new blood cells so that's why we'll talk about the anatomy of about anatomy of a bone but if an animal or a human breaks a large bone they do have the potential to bleed to death because of that significant blood cell formation in storage so then we have various types of bones as well there are flat bones short bones irregular bones long bones and then sort of this miscellaneous or other category a couple examples of flat bones and we'll get into all of these in a bit more detail we have the scapula so on humans we call it the shoulder blade dogs and cats horses cows call it the scapula and then a lot of the bones that make up the cranium the aspect of the skulls skull itself are flat bones as well so we look at the bridal bones frontal bone they're all flat bones short bones make up the carpus and the Tarsus so they are the bones within the carpal joint and within the tarsal joint and we'll go into the skeleton a little bit later on but Karpis is of course the wrist and Tarsus is the angle if we're comparing it to humans and then we have irregular bones so such as the spinal vertebrae the patella with Bella and the navicular bone as well and then we have these cute little guys which are you oh that's my desktop these cute little guys that are irregular bones they're called sesamoid bones is I I didn't quit say yet so sesamoid bones are found where a tendon passes over a joint and they prevent the tendon from flattening and sticking to the joint so sesamoid bones you'll find various numbers of sesamoid bones depending on the species within the feet and for us within our hands these are long bones we've got an example of a femur right there here's our femur and here are two radius bones and then we have this hackathon category called other and within that is this interesting bone which is called an AWS penis and I'll talk about those bones in a little bit so the structure of a long bone we talk about the outer structure and then the inner workings of the bone as well as just how the bone is laid out in general so when we're describing changes to the outside of a bone just looking at an x-ray etc the ends of the bone are called the epiphysis and then the shank of the bone is called the diaphysis and then looking at our long bones as specifically as a long bone there's articular cartilage and that's cartilage that sits along the joint surface there is spongy bone also called cancellous bones epiphyseal plate red marrow cavities compact bone and ostium medullary canal yellow marrow periosteum and then the epiphysis eel plate which is a growth plate so the spongy bone like I said is also called to cancellous bone and it looks like it's sorry it looks like a sponge that's why it's called spongy bone as well as cancellous and it's made up of tiny spicules of bone so tiny tiny little spicules of bone the way I think of it is the game of pick-up sticks if you ever played that when you're a little kid if not I'm dating myself but pick-up sticks were they all sort of stick together and sit up one against another those are spicules so that that's what this the cancellous bone looks like are just a ton of tiny little bone sticks that are sticking up together and there are little spaces in between those little bone spicules and within those little spaces it's filled with red marrow and that's the formation of red marrow helps reduce the weight of the bone without impending function so that's they sorry the formation of the spongy the spicules and then it creates red marrow i'm sorry i'm totally going off on a tangent anyways carrying on down so the cancellous bone is quite light it reduces the weight the way it's set up with this little spicules going down the way we have compact bone which is a lot heavier a lot more densely packed and then past deep to the compact bone we have this medullary cavity that contains the yellow marrow so the red marrow typically creates red blood cells various blood cells and then the yellow marrow is used for different aspects of the body and it's sent out to assist with connective tissue and create connective tissue throughout the body the periosteum is the hardest part of the bone and it covers all bone except for the articular surfaces so again going back up to the epiphysis of the bone here the articular cartilage at the top it's sitting along the articular surface that's the joint surface essentially periosteum covers all other aspects of the bone now the periosteum it's really important to know that the periosteum is extremely sensitive to - pain - pain specifically so when an animal is having anything done to their bones whether it's resetting of a fracture or if it's drilling into a bone whatever it might be a lot of referral doctors will actually freeze the periosteum and provide local anaesthetic along and sort of bathe the periosteum with local anesthetic because it's extremely sensitive to pain and I once had a cat scratch me in my finger and it hurt like heck well what was its name Constantinople oh no that was another key anyways scratch me the hand and it hooked its thing it's little nail into my hand and it hit the periosteum of my bone so it just tapped the periosteum it was insanely painful it just quickly tapped my bone right down to the bone and it was grossly painful I didn't like it the inner layer of the periosteum contains bone forming cells and it's really important for fracture Helium healing sorry the endosteum lines hollow surface it lines the hollow surface inside the bone and that's about it the pivot steel plates are growth plates if you ever look at a puppy or a kitten x-ray it's really hard to tell if it's broken legs or not if they have broken bones or not because their growth plates look so interesting on x-ray and they can be really tricky to see and that's again the Epiphany on plates growth plates are when it's cartilage slowly changing into bone as the animal grows so we're going to go through the entire skeleton and I've broken it up into the axial and appendicular skeleton as well as the visceral skeleton just as a way to get your head around it a little bit easier or classify I won't be too concerned about what belongs to axial which belongs to appendicular but I think it helps some people when they're trying to figure out which is which so the axial skeleton one way that it was put to me is very small murderers have really small axes that's one that way that you can help remember it if you're having some trouble remembering the specific bones and within that we have the vertebrae the spinal processes the mandible hyoid bone ribs sternum and that equals the axial skeleton so again I won't be too specific on which belongs to which sections but it might help you in your studying so that overall is the axial skeleton is what I'm saying there easier for me appendicular skeleton i think of appendages so your arms your legs on a dog and a cat just legs those are all appendicular or appendages so right which equates to the appendicular skeleton all right axial skeleton let's start with the skull as part of the axial skeleton so we have three types of skull formations that I want you to get to know right away we have brachycephalic masada cephalic and doko cephalic and these are various types of skulls that are referring to the ratio between the cranium and the snout okay so our brachycephalic that's our pug face dog so squishy face dog shih tzus pugs Pekinese persians Himalayans anything that you can hear breathing about a kilometer away guarantee that's a brachycephalic these animals need to not be bred anymore because unfortunately right now people are really really wanting that brachycephalic look for their animal and it creates massive problems actually quite often problems that cause the animal to die earlier than others because their faces are just too squished and what that means is that all that soft tissue that's involved in their mouth at the back of their throat is crammed with in a very small space they get stenotic Airways so they actually physically can't breathe out of their noses they can't regulate their body temperatures very well I have a friend with a little pug cross who is so interesting the way he's bred to look but we went for a walk on a somewhat humid day and he was blue within a couple of minutes so we had to turn around it's just not just not meant to be anyways that's my rant about brachycephalic dogs that should not be bred anymore and cats to mossad offense if Alec are your typical ratio of cranium to snow and that's your labs golden retrievers more or less but your typical border collie etc doko cephalic are quite often the sight hounds and the collies really really long sort of needle like snout and with a smaller head smaller cranium and then when worlds collide so this was brownie I believe was his name cute little Pomeranian who is a brachycephalic and then this is Leia I'm a big beautiful meatball of a great pyrenees when they met she was a big big sweet dog okay so let's get into the nitty-gritty about the skull this is a nice painted skull in our anatomy labs we have a couple other painted skulls which I find are really really helpful for getting to know the various bones of the skull now there are lots and lots of bones in the skull we are not going to learn them all we're going to learn the ones that might be clinically relevant when we're discussing setting up for an x-ray how to capture specific images things you might note on an x-ray that you need to report to the doctor etc so we'll go through the external bones of the skull now the skull is mainly flat bones as I mentioned earlier it contains or consists of the cranium and the lower jaw so that's essentially the dentary bones the cranium function is to protect the brain the eyes the ear structures and then the maxilla and the mandible are to provide attachment for muscles that allow for mastication and that of course is eating so this is in your colville textbook it's a great chart of all the bones in the skull so we've got external bones and internal bones of the skull now I did say that we wouldn't learn all the bones there are quite a few bones that you need to know about but look lots of them are duplicated okay too frontal bones to interpret Oh bones buh buh buh buh bah so just need to know where they are in general on the skull and then some of them have unique features that we'll talk about as well points of interest okay so this is a good one to get to know oh and I just realized I did not check that link to see if it still works but this image in particular as my students is a really good image to get to know because this describes essentially most of the bones that we're going to talk about and let's go and I can go through each of them with their interesting little components okay so starting at the most rostral aspect we have the incisive bone notice how I use that directional terminology just like that so the incisive bone is what attaches the front teeth to the incisors to the skull and then we have the nasal bone I should just go in order and the nasal bone is very small on most of our cat models it's missing the nasal bone because it's very delicate very thin and it often pops off of skulls I'm talking about skulls that aren't alive they don't just pop off of animals so the nasal bone protects a lot of the the internal structures of the nose including the nasal turbinates and when we look at our skulls in class you'll see that when you look directly into the nasal cavity of the animal you'll see these little scroll like bones these really thin paper-thin ruled up little bones those are called nasal turbinates and they are covered in mucosa and beautiful soft tissue with mucous all over it and they help warm and humidify the air they help moisten the air that's coming in through the nose I'm just gonna take my shoe away from my dog she's creeping around the house stealing shoes so the nasal bone houses the needle nasal termen turbinates I'm sorry I can't speak and that helps moisten the air before it's breathed into the skull going on the the maxillary bone attaches to the canine teeth all the way back to the premolars and molars and it also contains a sinus so a sinus is a small pocket within bone and again it contains mucosa and it contains lots of mucous and it allows that mucous to enter into the nasal cavity so to keep everything nice and moist and humidified as it enters into the respiratory system the lacrimal bone there is a tiny little bone where the lacrimal ducked is located and that's of course where tears come out and enter into the orbit of the eye the zygomatic bone and the temporal bone create this large arch at the lateral on the lateral surface of dog and cats faces actually nameless faces in general in a cat it's very predominant and in a cat we use this zygomatic arch as an easy way to pill a cat so we use our hands along the zygomatic arch to gently lift the cat's head upward toward the ceiling and then allowing their lower jaw to relax and we can pop a pill in pretty easily we also use the zygomatic arch a lot for examinations so looking at an animal's head specifically cats we we tend to use the zygomatic arch sort of as a handle to their head which sounds really weird but it makes sense when you do it the frontal bone is a really big flat bone at the dorsal the dorsal cranium walls dorsal rostral aspect of the head the frontal bone is interesting because it also contains another sinus so another pocket and in cow's as well sheep that have horns growing out the horns themselves grow essentially through not through the frontal bone but they they come out of the frontal bone of an aspect of the frontal bone so that being said cow or bull or cow whatever it might be if it is the horned on a very cold day sometimes a little piece of the frontal bone will come off with the dehorning and what that allows is an open sinus all of a sudden so what these cows look like in the dead of winter is a cow that's standing out in the field and it's as its breathing in and out that air is circulating in and out of their frontal sinus and they release steam from their head and it looks really strange so the horns come in at the frontal bone essentially for animals with horns and sometimes we open up that frontal sinus a little when we dehorn animals pride Oh bone and enterprise Oh bone form the majority of the caudal aspect of the the dorsal caudal aspect of the skull the occipital bone is really important because that's what connects to the Atlas the atlanto-occipital joint and that creates a yes motion so the atlanto-occipital joint that is created when the Atlas and the occipital bone connect when they are connected they allow for an up-and-down motion of the head that is saying yes yes yes yes temporal temporal bone assists with the formation of the zygomatic arch and then we'll talk a little bit about this area of the temporal bone as well called the tympanic bulla plural is tympanic Bolle we'll talk about that in just a minute span wide I won't get into too much detail Bo and then of course the mandible we talk about the in this the lower aspect of the jaw has beautiful attachments from muscle from musculature that allows for mass diffic or mastication and of course it houses the lower teeth I can't remember if I just said that or not that's essentially it all right carrying on so I talked about the occipital bone a little bit going back to the occipital bone it has these two beautiful processes called the occipital condyles and those are the two processes that connect to the atlas of the spine which allow it to create the atlanto-occipital joint and then likewise i said i would talk about the tympanic bulla so when we talk about plural it's Bolle with an AE and these how's the middle ear organelles which are really interesting the tiny little organelles within the ear really really really important and on certain skulls you'll see see quite large tympanic boules such as guinea pigs and it all depends on the acuteness of their hearing so oftentimes if they have a more developed sense of then auditory sense so a sense of hearing then they'll have a highly developed two pennant ball in order to house their inner ear or their middle ear organelles this big hole in the skull is called the foramen magnum and that of course is where the spinal cord exits the skull and enters into the vertebra one thing that can go wrong with that is called key or key re like formation ie scratchers syndrome and that is a disease most often of brachycephalic dogs quite often King Charles Cavalier spaniel whereby the brain is essentially too big for the cranium so it starts to create inflammation and tissue being pushed crowding the foramen magnum and crowding the spinal cord and they start to get a strange neurological itchy sensation in the back of their head and there's nothing there to cause it so these poor little dogs will be scratching and scratching and scratching the back of their head like crazy and it's because they have a neurological problem that needs to be fixed was there anything else I was going to say I believe that's it oh yes no that's fine that's good now okay a little bit of a review what is the difference between cancellous and compact bone provide a breed example of brachycephalic masada cephalic and de la cosa phallic type head shapes what is one important feature of the following bones in the skull and that's the Jim panic boy occipital condyles foramen magnum and maxilla and frontal bone all right carrying on with the axial skeleton so this is another little one it's it actually not so much one bone it's called the hyoid apparatus and I'd like you to get to know what it's all about you can read it up in your textbook and then we're going to move on to spinal processes so here's a weird little formulating whole bunch of formulae that I'm going to give you so carnivore c7 tea thirteen l7s three CD five to twenty equine C 7 T 18 L five to six s 5 CD 15 to 21 bovine C 7 T 13 l5 classify CD 16 d-18 what the heck does this mean well when we open up those words it means carnivore cervical seven thoracic 13 lumbar seven sacral three caudal or coccygeal five to twenty and what the heck is this well this identifies the various sections of the spinal processes and how many individual vertebra are in each section of the spinal column so we have a cervical section a thoracic section a lumbar section sacral section and a coccygeal section and then this is telling us exactly how many vertebrae are within each of those sections for carnivore equine and bovine so just going back you as my student will definitely want to get to know this now let's just show you here how it looks so we've got our skull and then we have seven serve cervical vertebrae we have thirteen thoracic vertebrae seven lumbar three sacral and then caudal the proper term is coccygeal is five to twenty why the heck do we need to know how many numbers of vertebrae are in each specific section of the the spine so really important for a few reasons we always need to know normals in order to know our abnormals so again if an animal is born within some sort of congenital defect etc also when we are performing radiographs as an RVT registered vet tech our job is definitely to set an animal up for x-rays and take the x-rays and we want to be able to the various sections of the spine to ensure that we have the vertebrae in there that the doctor is requesting okay so for me that's typical number one number two a doctor often uses accounting so counting whether it's on x-ray or physically by hat by hand the cervical number or not cervical number sorry the vertebra number so calling it c3 would be cervical vertebra vertebra number three and the reason they'll do that is to indicate specifically where they see an injury so maybe they'll say between c6 and c7 so that might be on an x-ray or where an animal is sensitive if they're walking their hands up their back sort of calculating the spine as they go they'll be able to say between l1 T 13 that's where they start to get sensitive we also use it when we either as rvts or when the doctors are giving epidurals and a local anaesthetic goes in between the epidural space between two specific vertebrae they need to be able to landmark those specific vertebrae all right and then here's looking at the equine vertebrae so again cervical they have seven thoracic they have 18 lumbar five to six depending on the breed sacral they have five and then they have fifteen to twenty one oxygen and then likewise with the bovine as well okay so then we'll look at each individual spinal vertebra so when we're talking about one we're saying vertebra when we're talking about plural its vertebrae ae so the anatomy of a spinal process or a spinal vertebra we have the spinous process the cranial articular process the caudal articular process the arch the body the vertebral foramen and the transverse process now these specifically I don't need you to go into extremely high levels of knowing the anatomy of a spinal process I just need she'd be able to know what I'm talking about so if I say it has an elongated transverse process or it has a long gated spinous process hint hint those are the two that I'll use all the time then you get to know what I'm talking about but this is the general anatomy of a spinal process so the vertebrae are separated by intervertebral discs made of fibro cartilage on the outside and gel on the inside the spinal cord runs down the center of the vertebrae through the vertebral foramen and the Atlas and axis are unique to ensure appropriate support for the cranium and we'll get into those two right now so remember how I was saying that the various areas of the spine have specific numbers of vertebrae within them so the very first the most cranial aspect of the spine is called the cervical spine and it has seven vertebrae within it and that's for everybody that's every mammal ever has seven vertebrae a giraffe they have seven very large vertebrae so the first two vertebrae are very unique different than any other vertebrae in the body and it's specifically to allow for a yes and no movement of the head as well as supporting the cranium as it's the most vital part of the body so they very first cervical vertebra c1 or cervical vertebra one is also called the atlas and in the textbook it identifies the atlas was named because of the Greek god who held the globe over his head the world over his head so you think about the atlas holding the globe over it over itself so holding the brain over itself so it's the very first cervical vertebra and the atlas to me looks like a weird little butterfly or a stingray wherever you want to picture it but definitely a butterfly in my head and when you pick up your cat next time or if you have a dog that doesn't have a giant muscular neck just put them behind the back of the skull and then down to their neck and right behind the skull so right just caudal to the skull you should be able to feel these two processes sticking out laterally on either side and that is the Atlas the axis is also very different it has a dens which is this small process that connects to the atlas and it also has this very large ax light acts like transverse prose or spinous process which is unlike any other vertebrae in the body so that being said when the atlas connects to the skull so when it connects to the occipital condyles it allows the head to make to bob up and down and that's a yes a yes motion that it's able to make so if you do it yes with your head that's what the atlanto-occipital joint allows for motion wise the axis connects with the atlas and allows the head to solve all the other way allowing for an o-type movement which i think is kind of cool now a couple ways that you can remember which ones which because we've got the atlas and the axis and one of them is c1 one of them see to the for me it works best that the atlas comes before the axis in the dictionary alphabetical for me works best and then this is something that you'd probably get on a test hit nod nod I use this for testing all the time so this is the cervical spine this is an a radiograph of the cervical spine and it identifies when we would start to use sort of that counting mechanism to identify areas on the spine so this is cervical vertebra one also called the Atlas cervical vertebra - called the axis and you can see that big overhanging spinous process and then cervical vertebra three cervical vertebra four all the way down six and then seven and seven in fact is covered up by the scapula so it's difficult to see some thoracic spine that's a thoracic vertebra we'll talk about in class they are significantly different in many ways from other vertebra they look extremely unique they have this immense transverse nope I lied they have this immense spinous process really immense spinous process and there's a certain I kind of look up what kind of dinosaur this is that's in my head but there's a certain dinosaur that these guys always remind me of and it's got this big thing on the back of its head I'll look it up I'll bring it to class hopefully so the thoracic vertebrae are very different they have really short transverse processes on the sides and then they have a really long spinous process and we'll talk about that in class but that's mainly to attach a significant amount of muscle up near the shoulder and then around through the ribs and the abdominal muscles as well they're not so much the well toward the abdominal muscles but definitely the shoulders and through the ribs lumbar muscle or lumbar vertebrae nothing particularly spectacular about the looks of these one thing that is different in some areas of the lumbar vertebrae are there significant transverse processes okay so the side processes here transverse processes and they are typically much more extensive than the spinous process in the lumbar vertebrae because again they attach to muscle say they really attach to all that abdominal muscle that really cool abdominal muscle and you can see those transverse processes here goes sticking it in the x-ray just gonna go back to thoracic and I'll talk about a little bit later but just to note that within each thoracic vertebra ribs articulate so ribs will create a joint with thoracic vertebrae so the sacral and coccygeal a a a.k.a the caudal so I like the term Cox you only feel it's a little bit more anatomically correct you'll sometimes see it noted as coddles but Cox a Jules but I'll typically use so we have the sacrum is a and B is the caudal vertebra so the sacrum is fused and I think yeah we'll go into that next so the sacrum is made up of various sacral vertebrae but they're fused together to create one big plate one big bone plate so they're unique in that sense and dog and cat these are not dog and cat these are definitely cow but they are all fused in mammals the the sacrum and for us know I was gonna say something that did not make sense ignore it but as they get down toward the tail when we're talking about the coccygeal vertebrae they're going to vary in number depending on the breed of animal that it is depending on whether or not they've had their tails docked or just whether or not that breed reborn without a long tail so they can vary quite significantly that being said it's important to know that when a tail is being docked on a puppy or a kitten or horse or cow or lamb in general it is now I say lamb but they're done typically a little bit differently but let's say it's a puppy or kitten that a tail is being docked it is really dis articulating two bones so it's cutting between two bones cutting the tail off between two bones so there are some complications that can happen number one it's painful don't ever let a vet or anybody I say a vet because it happened to me but don't lay if I tell you that cutting a puppy's tail off when it's newborn is not painful it's terribly painful they have significant nerve endings within that tail area so that's one point to always keep in mind when you're an RVT in the field that it is painful and if it's being done definitely locally anesthetic or more should be used and then number two if it's being done even if it's for like a medical reason not so much in a static reason it's really important then the vet would know this to ensure disarticulation so that the the incisions being made in between two bones and not taking a piece of one bone and leaving a piece of a bone because if you split a bone then you've got open nerves and potential blood supply but definitely open nerves that can be extremely painful as that animal gets older all right review list the vertebral of vertebral sorry formulate for a carnivore equine and bovine c1 and c2 are also known as what the atlanto-occipital joint is responsible for which head movement and what the heck is the purpose of the hyoid bone ribs alright moving on let's talk a little bit about ribs so the ribs their overall goal is to protect the thoracic cavity and then they also allow for muscle attachment and various attachments to allow for breathing so to allow for inhalation and an exhalation each rib has a bony part and a cartilaginous area so I like this image this is the ventral aspect okay so right here we're looking at the sternum which I'll talk about in a moment and this is the cartilage that's attached to the sternum so each rib starts off as bone okay this is the dorsal aspect it's the head of the rib it's all bone all bone all bone and as it works its way ventually it turns into costal cartilage and that cartilage connects to the sternum and that allows for some flexibility within the ribs and that does vary by species as well but typically definitely carnivore if we've got beautiful cartilaginous ribs about two-thirds of the way down so the where their bone and the cartilage meets right here is called the costo chondral Junction okay I will definitely ask you that on a test at some point and rib pairs um all the wait what was he gonna say nope that's it so carnivores have 13 rooms equine has 18 and we have this costal arch so we have let's count them starting from cranial so this is where the head would be up here and then this is caudal we have rib one two three four five six seven eight nine ten eleven twelve thirteen now what do you notice about 13 12 11 10 and that's it so those ribs in particular create this costal arch so they are linked together and held together via cartilage whereas the others the cartilage actually connects into the sternum itself so it's just something to note oh yeah sneaky trick technically technically there are 26 rings not 13 because there are two of each just be aware of that but I'll accept 13 that's accepted as 13 pairs so the 13th rib on carnivores is called the floating rib and it's sort of like a little half rib or a third of a rib it ends abruptly and you can feel it so we typically use that again why do we need to know the numbers of the ribs because they are literally labeled rib one all the way through to rib 13 on the left and right side we use that often for land marking so it's really important for us as rvts to be able to count ribs on dogs and cats at least if not horses and cows in order to count backwards because I'll go into that in a minute but we count backwards from 13 toward the cranial aspect to start landmarking for various procedures so various procedures that we might be landmarking for could be for placement appropriate placement of a feeding tube so how far are the feeding tube how far we should measure the feeding tube to go in for cardiac injection so which is often a euthanasia and also where to place the stethoscope okay so where to specifically find the heart on the animals body so that being said when we're counting ribs that I'll show you this in class because it's really hard to describe without showing you is the hands but we count from the caudal aspect up toward the cranial aspect because the cranial ribs up here are covered by their scapula on either side as well as heaps of muscle so we really can only count up to about room for rib three four okay so we'll start with thirteen and then we sort of tickle the animal as we count from caudal to cranial alright let's get back into this because apparently just trying to shut my computer down alright I also just wanted to point out I was talking earlier about the little joint that the rib creates with the thoracic vertebra so see here the head of the rib right here sorry and the tubercle which is another process projection of the rib bone create this cute little okay it's not that cute but it is kind of cute a cute little joint so in articulation with the thoracic vertebrae the various thoracic vertebrae alright this is the sternum so if we go back to the other picture this is how the sternum is truly laid out this is the cranial aspect this is the caudal so again this is cranial caudal and in carnivores there are eight sterna Brahe now in carnivores this Turner Bray are not fused together whereas bovine equine they're fused together to form one big bone plate so here is our sternum which is made up of eight little sternal brace so eight little bones so again we count in this case we're going to count and label them from cranial to caudal so this is sterna bra number one sterna bra two three four five six seven eight now other names for these we have the most cranial sternum is also called the manubrium and the most caudal sterna bra is also called the xiphoid and the manubrium clinical significance the manubrium we often can feel on dogs and cats again as long as they're not heavily muscled in that thoracic girdle area we can often feel the manubrium and if we can touch them a new rim we place our thumb the left or right of it and that's our land marking that we use for jugular withdrawal the xiphoid on the other hand extending from the xiphoid is what's called the xiphoid cartilage and we can feel that and some animals as well and the xiphoid cartilage attaches to the Linea Alba which is a large piece of connective tissue that attaches right down to the pelvis we often use it for land marking for shaving for abdominal surgeries and then I'll talk about the Linea Alba in lectures to come appendicular skeleton what does that mean we're talking about the appendages so we've got the front limbs that include the scapula or scapulae if it's plural humerus radius ulna Karpis metacarpal bones and phalanges and know the difference between canine and large animal because they vary significantly so looking at fluffy here we've got the scapula and we have you can see on the scapula it's a nice big flat bone and then we have the spine of the scapula runs down the center of the bone and that again is another process that allows for massive muscle attachment around the shoulder the scapula we have the humerus the olecranon process definitely get to know that one it's the elbow okay we don't call it the elbow with animals we call it the well we I lied I totally just lied we often do call it the elbow I'm sorry but it's the olecranon process that attaches to a lot of the musculature to allow flexion flexion and extension of that leg so a leopard on process is this you can see it really well here that's the electronoggin process okay and it's actually the point of the ulna so it's the dorsal most aspect of or the proximal most aspect of the ulna and this is the ulna here so here's the ulna and then the radius it's essentially cranial - the ulna sort of sits on top of the ulna and that creates a lower for them and then we have the carpals which is the carpus joint the metacarpals and the phalanges we'll work our way back we've got the pelvis we've got the femur the patella is the kneecap and then we have the fibia note the tibia sorry the fibula note the spelling tibia fibula and together the femur the patella and the tibia create the stifle joint and on us it's called the knee joint then we go down we've got the tibia fibula as I said the tarsals as are the tarsal bones also known as the tarsal joint so ie the ankle on humans and the calcaneal on us is our heel so and it's it's an extension of a meta car metatarsal bone so calcaneus is something that we use on dogs and cats as a landmarking calcaneus or calcaneal is entirely acceptable how it varies on horses and on cows is of course at the distal aspect of their joints they only have one to two toes so horses have one cows have two also on these big guys the metacarpal bones are fused and the metatarsal bones are fused the tibia and fibula are fused as well as the radius and ulna are fused likewise going back to the ribs the sternum is fused as well ok so here's an example of an equine front limb so I've got the scapula the humerus the point of the elbow which is also called the Olmec or not and then the ulna and radius are combined there's a Karpis which in a horse it's referred to as the knee and then we have the third metacarpal which is also called the cannon bone and then this second and fourth metacarpals which are called the splint bones and those three are essentially fused together with a fibrous joint and then we have the first phalanx the second phalanx and the third phalanx as well as the proximal sesamoid bones and then distally which you can't really see on this image are the distal sesamoid bones as well okay lots of differences lots of differences and we'll talk about these a lot in the lab and then moving on to the front feet of a dog and a cat so a carnivore front feet this is your typical structure and this is something that you'll want to get to know would be able to label now why the heck do we need to know all this information about front feet let me just check my battery here I'm still good all right why do we need to know how to label all these little bones on the front feet what it comes down to for us as registered vet techs again is to be able to identify abnormalities so for performing a physical exam or a treatment on an animal and we see something abnormal we need to be able to report it accurately so we need to make sure that regardless of how many people are going to look at that medical record no matter how many people are going to interpret it they all have to be able to grasp the same information from that medical record so they need to all be able to understand where that wound is or where you think it has a broken toe or where the toenail has come off going through this so I won't be too specific about the carpal bones okay don't worry about those too much if you'd like to get to know them you definitely can my main focus starts with the metacarpal bones so if we look at our hands if you put your hand flat out on the table in front of you the if you if you do jazz fingers with your fingers if you wiggle your fingers around you'll see the long bones in your hands so between your wrist and your knuckles dancing around those are your metacarpal bones and in the hind foot or the high end like hindfoot they're callin metatarsal bones okay so dogs and cats carnivores have five metacarpal bones five minute carpal bones working our way distally next we have the phalanx bones well we have sesamoid bones which are those little bones that help create what am I trying to say lubrication between tendons and bones so don't worry about the sesamoid for now but moving down from the metacarpal bones moving distally we have the Phalanx or phalanges is plural so typically on most toes there are three phalanges so if you make a claw with your four fingers you'll see three individual bones if you make a claw with your thumb you only have two specific individual bones so how we label those we've got balance the the first phalanx that we come across and when let's go talk with the four main toes to start with so we have proximal phalanx middle phalanx and distal phalanx okay if you're talking plural proximal phalanges middle phalanges distal phalanges also called phalanx one sounds too felling's three so P 1 P 2 P 3 okay we're getting there P 3 always holds the nail okay so P 3 is the most distal so phalanx 3 is the most distal it always holds the nail the nail bed is coming away from P 3 so let's have a look at how we number the digits and the metacarpal bones because they're the same so the digits so if we have a dog or cat that comes in it's got a torn up nail and you need to identify which toe the torn up nail is on are you gonna say the middle one well they've got 2-minute ones that doesn't make sense so your acceptor number them so how it works we have digit 1 is the most medial and we work our way from medial to letter digit one digit 2 digit 3 digit 4 digit 5 likewise that's replicated with the metacarpal bones some metacarpal bone 1 2 3 4 5 now one thing that you should note the most medial toe is called the dewclaw and what do we know about the dewclaw well what I know is that it's a heck of a lot shorter than the other toes specifically so dewclaws on most animals are on the animal when they're born some animals when they're born somebody cuts them off and there are various reasons for that some people say that it's likely if it has poor attachment because some dogs specifically have poorly attached dewclaws people get worried that it will get caught in the snow or the ice and be painful and rip off I had a great pyrenees she had two sets of hind dewclaws that were very very floppy it didn't happen I know it can't happen so it's up to you sort of where your head goes with that but I'm not one to take things off ahead of time anyways that being said do claw so the dewclaw please note that the do claw only has two phalanges it doesn't have a middle phalanx so it has P 1 and it has P 3 now how does this compare to the back foot behind foot how does this compare to the hind foot the hind foot only has four toes all together some dogs some cats have an have a do claw on the back foot but it's it's rare it's not as common so most dogs and cats have four digits now we always account for the fact that that digit at some point in evolution was there so if it's a hind foot and we're counting let's say it's this toe that the nails broken and we have to tell the doctor which digit has a broken toenail and they don't have this new claw what number digit would this be it would still be digit number two it's like we got to do a little throwback to the evolution that at one point there was Duke law that was number one so the first most medial digit that we see is still digit number two and then digit three four five okay lateral and then media always account for the fact that it existed let's just do a little throwback here to the horse equine okay check out the horse go get the dog and cat pretty intense pretty crazy look at the horse so differences with the horse again radius and ulna are fused and then these beautiful metacarpal bones they have a second a fourth and a third metacarpal bone they're fuse together well they're they're fused together with a fibrous joint and then they have a links one filings to balance three but they only have one digit so horses are always always always dancing around on their tippy toes okay again horses have one digit so on the right that's of us that's mr. Joe that's old that's an old fossil of an old ancient horse where you can see that they had various metacarpal bones over time over evolution they fuse these metacarpal bones on horse so then me and metacarpal bone number three is also called the cannon bone and then the to supporting metacarpal bones which are metacarpal bone two and metacarpal bone one those are called splint bones and then on a horse we have to get really complicated so p1 p2 p3 ie phalanx one Fehlings two felons three also called proximal phalanx middle phalanx distal phalanx also on a horse because they can't be simple it's called the long posture and bone short posture and bone and the coffin bone good times can't keep it simple this is cow so they have two digits same idea they have fused metacarpal bones metacarpal bone three I'm in a carpal bone for they have the three phalanges but they have two digits specifically now this picture is nice because it illustrates the proximal sesamoid bones and the distal sesamoid bones in the horse and the cow up here proximal and then distal and in the horse we'll talk about specific names that they have for those so in horses let's just skip back just because we can one more yeah okay so in horses right here proximal sesamoid bone is also called oh no it's out of my head oh the fetlock sorry having a brain brain go so it's also called the fetlock and then the distal which you can't really see but essentially is right here the distal sesamoid bone is called navicular and they can get a lot of issues with their navicular bone and it's essentially if they're overworked or whatnot they can get swelling of the tendons and the soft tissue that's around the navicular bone and it can cause a horse to go very lame very quickly and it's often a very long course of treatment and not always curative so review how many metacarpal bones do dogs and cats have in their front feet what does the declaw process involve what is a common name for metacarpal bone number three and the horse and what is the common name for metacarpal bones two and four in the horse what's navicular navicular is that condition I was just explaining now I should go into detail the one thing I did not discuss is a declawed procedure so I talked about removing a dewclaw from a dog or a cat so declaw is another procedure that's done most often in cats I've only ever seen it done in cats and I'm thinking that it's on its way out it's actually illegal in most countries except for Canada in the United States due to humane reasons so decline what happens is they actually disarticulate the middle phalanx and the distal phalanx so they cut away phalanx number three which is a bone and they toss it aside so always keep in mind that cats that are declawed it's not just cutting the nail back really far it's not taking the nail off it's actually cutting the ends of their toes off so again if you curl your fingers up like a claw it's that last little bone that your fingernail sits on that would all be removed with a d' claw and some people still do it a lot of people are changing the ways and not doing it anymore and rather educating clients about alternatives to decline and i think that's a really important aspect for us as our VPS to learn about the alternatives to decline to get really comfortable helping clients learn how to cut their cat's nails talking about environmental enrichment keeping their cats with lots of scratching posts soft paws etc because what they're finding now as we get more in tune to chronic pain in felines is that there is a lot of phantom pain so chronic phantom pain associated with d claws done 10 years ago or or more even sometimes and even if that's done really really well by a really great surgeon it's you know you have to remember that it's cutting the bones off of a cat's it's cutting the ends of their toes off so there they are finding that there is increasing rates of phantom pain with kitties who have d claws something to think about all right moving along we're getting over to the hind limbs so we've got we're gonna start with the pelvis which is a large structure made up of about six bones so we have three pairs of bones we have the ilium which includes the wing of the ilium the wing of the ilium is the dorsal most process of the ilium and that allows for massive amounts of muscle attachment and then the ilium the body of the ilium essentially is what that arrow is pointing to and then working our way down about halfway down the hip socket also called the acetabulum is the hip socket so the acetabulum about halfway down the acetabulum creating a bit of a tea is the pubis so this area I met learning halfway through is the pubis okay so that's the pubis and then we have the ischium is essentially what an animal standing it is the most caudal aspect of the pelvis so the ischium and on the issue we have the ischial tuberosities which allow again muscle attachment to their large processes that allow muscle attachment the ischial tuberosities you can see on a lot of dogs as well and sometimes on cat if you lift up their tail and just have a feel at the top of their thigh essentially you'll start to feel their ischial tuberosities on really emaciated animals it's a very predominant which is really unfortunate so going back the acetabulum is where the head of the femur connects to create the hip joint and then other unique features we have this obturator foramen or obturator foramen however you like to say it pronounced it and that is a hole two holes essentially within the pelvis purpose of that a lot of nerves and vasculature run through the obturator foramen and also it's in part to lighten the weight of the pelvis the pelvis is giant I'll show you a cow pelvis in class it's really giant it's really really heavy so over time these holes have developed in part to lighten the load of the pelvis and also they allow for a lot of nerves to pass through sometimes animals can get into trouble with those nerves specifically cows that have irregular births a long time with a with the calf being stuck in the birth canal they can get nerve damage to those obturator nerves that are running through now they're interesting point here is the pubic symphysis not synthesis so it's not like photosynthesis it doesn't turn green with chlorophyll its pubic symphysis and this is a cartilaginous joint that allows just small amounts of flexibility of the pelvis all right we're here away distally down the leg we have the femur an important points of the femur we have the head of the femur which again is very large very specific connects with the acetabulum to create that hip joint we have the neck of the femur the greater trochanter trochanter allows for muscle attachment on the lateral aspect of the hind leg and then at the bottom we have the Chokey trochlea and the medial and lateral condyles so we'll talk about those in class the keenan tibia and fibula note the spelling fibula it's not fibia so at the top here we've got here at the proximal aspect we've got the patella which is a small sesamoid bone so it's patella and then we have the head of the fibula the head of the tibia one thing I'll point out in class is the tibial crest which is quite beautiful allowing for muscle attachment and that's a specific area I'll talk about in class all right now here's the hind feet of the canine and feline so one thing that's really important to note are the metatarsal bones so again looking at the number of digits there are only four digits but we still count okay if this is the medial aspect we're still going to count for the missing the missing toe so it would be digit one two three four okay so four digit but note that they don't have that metacarpal bone one and they don't have digit one some animals do have hind do claws but it's fairly rare somewhat rare this is a really blurry picture identifying the hind limb of a horse really beautiful blurry picture so again it's identifying a couple things that are a bit different the tibia and fibula are fused in the horse and cow this is the calcaneus that we talked about earlier by this I'm saying this calcaneus and then again they've got the splint bone Oh which is the second and fourth metatarsals as well as cannon bone of use together with a fibrous joint and then we have the long posture and short posture and coffin bone so those are the common terms the anatomical terms would be proximal phalanx middle phalanx distal phalanx here's a better illustration of the proximal sesamoid so the fetlock essentially is areas fetlock and then the navicular bone which is the distal sesamoid okay horses we really get into common terms and then anatomical terms visceral bones viscera bones are super cool they are essentially embedded in tissue or organs of the animal they are not attached to other bones which is extremely rare they're extremely interesting rarity it depends on the species so some mammals have penises dogs are really good example that male dogs always have an auskey 'no sand this is a bone that lies to the side of the urethra within their penis the aw score dis is a bovine bone that's within their heart certain species of bovine breeds know its species certain types of bovine breeds have the oscar de s-- in their heart to support the vows and the austrie is in some pigs notes to support the snow during that rooting behavior so while they're searching for things and leaves turning up ground etc now the ospina s-- is totally under the impression as in the textbook that there are only a few types of mammals that have awesome penises and i can't list them from a textbook off my head but what I found out last year thanks to a student is that cats they're finding also some cats have ospina PSA's as well so what they were finding is that in radiography this is the study that was done when a radiograph was taken of the cat of the penis of the cat it was sometimes being identified as calculus so as like a urinary crystal or stone stuck in the penis of a cat and they were thinking that it's more of an obstruction waiting to happen but instead what they're finding out with better quality radiographs and digital radiographs is that some cats actually have tiny tiny tiny little oz penises probably not that interesting to you I was really interested so that's the study if you want to read it okay moving along we're getting out of here joints the goals know the common terms for the joints identify the commonly utilized joints on equine bovine and canine species and classify the joints into one of the three types I also want you to sub classify the joints as well so the three types of joints we've got fibrous cartilaginous and synovial so fibrous do not allow for movement very firm fibrous tissue that unites two areas the examples are the joints that unite the flat bones in the skull and there are little sutures between that cut or that unites these bones and keep them solid they do not move there have been studies to prove that they do not move there is a theory of thought that they do move slightly but so far it's been unproven and that's to do with another medical area um also fibrous joint example are the split bones they are attached to the cannon bone with a fibrous joint cartilaginous they allow for slight movement so a very slight rocking movement is permitted example the joints between the vertebrae and the spine as well as the pubic symphysis in the pelvis and the manipular symphysis in the mandible synovial are beautiful freely movable joints so these are the ones that we really think about all the time in regard to joints so the Stifel the carpus the Tarsus the shoulder etc etc etc so the elbow the big joints now another word for saiful for talking about humans it's the knee but for animals always the stifle Karpis and Tarsus for us that's the wrist and the ankle shoulder is the shoulder there are three key characteristics of synovial joints they have an articular surface that's present on the surface of the bone so it's present on the distal and proximal end of the bone the cartilage is present on the articular surface and there's a presence it should just say presence of a fluid-filled joint cavity called a fluid earth that's right called a joint capsule now articular surface means the joint surface itself okay this is just a good picture of what a typical synovial joint looks like so if you're ever involved in the synovial joint surgery or if you are taking fluid out of a synovial joint for testing it's a sterile sterile sterile procedure because this is all very well protected so the synovial joint is extremely well protected within the bursa within the cavity itself and you can see here so here's the epiphysis of the bone it has this is the articular surface so the joint surface of the bone it's covered in articular cartilage and that reduces friction it allows for a smooth smooth moving surface and then it has this synovial cavity with synovial fluid which again allows for lubrication allows for low friction in order to allow that point to point that joint to move without any any concerns all right we are so almost done it's very exciting so ligaments versus tendons I just want to point out a few things because we'll go through them in class so both are thick bands of connective tissue ligaments they both that they point they join bones to other bones and tendons join bone to muscle so a good example I like to think of cruciate ligaments are all within the knee so within the Stifel there are various cruciate ligaments it's one that you'll often hear if dogs quote blowing their cruciate ie blowing their cruciate ligaments whether it's the lateral collateral etc tendons I like to think of your Achilles tendon and that is the muscle joining to bone so this is the crew ship this is the Stifel itself so that is here's your tibia not yours the dog's tibia the distal aspect of the femur and that's the stifle right that's the knee so these are all the beautiful beautiful ligaments that connect the femur to the tibia and create the knee joint and allow for flexibility and extension now my big beautiful dog Leia was such a sweet dog she had about 45 issues with her but I loved her very much she unfortunately blew her right cruciate first so she blew her right one and she had to have surgery and she was this really big sad dog for a really really long time but you can see it's all shaved it looks like a little chicken leg she had surgery and she had an IV in there it's all bruised unfortunately okay so they did a t PLO which is a surgery that changes the angle of the tibial plateau so the tibial plateau which you can't really see in this image so they insert screws and plates to adjust for this level and ensure that she won't have blown cruciate anymore no no with this x-ray please note this is also layout this is my big beautiful great pyrenees dog note that she has two plates in so she blew both of her crew sheets she blew one had it done had it fixed and then about six months later she blew the other cruciate so the other leg which is very common because they're suddenly overusing that other leg and weakening all these little ligaments that connect those bones together my poor big dog and that's what it looked like from the side view so this is the tibia fibula and this is the dis loss effect of the femur and there's the patella and that's the flow Bella and those are some wide bones did not stop her from digging holes I know it's my fault it's my fault but she wasn't crate trained it's all my fault but she dug big holes and it was I just let her do it anyways so that's essentially it and I don't know what's going on with that I'll show you that one across oh yes this is an interesting image one that I found on the web just to show you some things that again you need to know the normals before you can know what abnormal looks like what the heck is wrong with this picture this is a radiograph of a pelvis and the femur so pelvis femur femur vertebrae look at this poor animal has a broken pelvis a severely broken pelvis and then it's shifted as well you can see the pubic symphysis is all shifted so again you need to know that when you take an x-ray you can look at it and say yeah we took it we got what we need you know show it to the vet feeling proud knowing that you can see the anatomy knowing which Anatomy you needed to get in that radiograph and then of course being able to look at this and not you know being able to look at this and clearly see that there's something wrong then it's something major going on and handle the animal appropriately so some review list one example of each of the following joints fibrous cartilaginous synovial what's the significance of the obturator foramen provided an example of a hinge joint a pivot joint a gliding joint and a ball-and-socket joint secret those are in your textbook