Transcript for:
Overview of Human Bones

there are a lot of bones in the human body but today we're going to run through them all in less than 10 minutes my name's connor and this is anatomy 101 let's start by taking a look at the lower limb this consists of four bones arranged to support the weight of the body when standing as well as allow enough range of motion to permit walking the most distal part of the lower limb is known as the leg and is composed of two long bones the first of these is the large tibia also known as the shin bone this takes most of the weight in the lower limb and can be easily palpated through your skin lateral to this is the fibula this is a very thin bone that articulates with the tibia both proximally and distally the fibula takes very little weight in the leg and is largely vestigial it derives its name from the latin word for broach as it is attached to the side of the tibia acting like the pin in a clasp brooch anterior and superior to the tibia is the flat kneecap or patella this forms an integral part of the knee joint and transmits energy from the quadriceps tendon in the thigh to the leg the patella gets its name from the latin word for shallow dish due to its flatness finally in the lower limb is the femur which articulates with the pelvis at the hip joint and the tibia and patella at the knee joint on the right here we have the knee joint as seen from the side now let's move upwards to examine the upper limb the anatomy here is pretty similar to the lower limb with two bones in the forearm and one in the arm the first of the forearm bones is the medial ulna which gets its name from the greek word elaine which means elbow the same root leads to the word olecranon which is the posterior projection of the ulna at the elbow joint the upper limb equivalent of the fibula is the radius which gets its name from the latin word for staph unlike the fibula the radius performs a key function in articulating with the ulna and wrist joints to allow the hand to supinate and pronate the uppermost bone of the upper limb is the humerus which articulates at the shoulder and elbow joints taking a closer look at the elbow joint we can see that the ulna wraps around the back of the humerus producing the electron process this provides an immense amount of stability but restricts the elbow to move only as a hinge joint here we have a side by side view of the upper and lower limbs these two have a lot of similarities owing to the fact that evolutionarily we use them both for similar jobs gripping and climbing nowadays they clearly serve different functions but it's fun to notice the similarities clearly the head of the humerus is a very similar articular surface as the head of the femur but the femur has a more pronounced neck the radius and fibula clearly resemble one another and even the ankle and wrist joints are very similar in their composition however the wrist has a much greater number of bones articulating in it okay now we've got the limbs let's have a look at the peripheries first we have the foot this is a very complex structure that is composed of 26 individual bones articulating together first let's look at the short bones these are the seven tassels we have the talus which is the only part of the foot to connect directly to the leg then we have the calcaneus which is better known as the heel bone these two connect the rest of the foot via the navicular tassel finally we have four cuboidal bones from lateral to medial these are the cuboid tarsal the lateral cane form intermediate cuneiform and medial canal form the word cuneiform derives from the latin kunais which means wedge the 19 long bones of the foot are comprised of the five metatarsals which project into the toes the five proximal phalanges the four intermediate phalanges and the five distal phalanges remember that the big toe does not have an intermediate phalange only a proximal and distal one now the bones of the hand are super similar to the bones of the feet with only a couple of small differences first of course their arrangement is different this allows you to have long fingers with a lot of mobility for gripping and interacting with objects secondly there's one additional bone which we'll cover in a minute looking at the long bones first we have five metacarpals similar to the five metatarsals in the feet then five proximal phalanges four intermediate phalanges and five distal phalanges like the big toe the thumb only has a proximal and distal phalange now let's look at the short bones in the hand these are known as the carpal bones and there are eight they're arranged into two rows the proximal row which articulates at the wrist joint has the scaphoid lunate triquetral and pisiform bones and the distal row has the tribesium trapezoid capitate and hamate bones these are all named according to their shape for example the scaphoid is boat shaped so comes from the greek word for boat and the lunate is moon shaped so it gets its name from the latin word for moon the pisiform is p shaped and the triquetral three-sided the capitate gets its name from the latin word for head and the trapezium and trapezoid both get their names from the greek root for table the trapezium carpal articulates with the base of the thumb via a saddle joint between them the hands and feet include 106 bones which is half the bones in the entire human body like with the upper and lower limbs we can see that the foot and hand both clearly come from similar origins they both have a group of small bones at their proximal pole and 19 long bones projecting from these into the peripheries it's interesting to think how different their functions have become in modern day humans next let's look at the pelvis this is composed of two large bones known as the innominate bones or the two hemi pelvises these two large bones are themselves formed of three smaller bones which fuse in childhood these bones are the ielium which has a large wing-shaped body the istium which is the bone you use to sit down on and the pubis which forms the anterior part of the pelvis as well as the pelvis the central or axial skeleton is formed of the vertebral column this is a vertical pillar of 26 bones that articulate with one another mostly using fibrocartilaginous intervertebral discs there are seven vertebrae in the cervical or neck spine twelve vertebrae in the thoracic or chest spine and five vertebra in the lower or lumbar spine additionally there are five fused vertebrae in the inferior vertebral column forming the sacrum which articulates directly with the pelvis and finally the small triangular coccyx which is the remainder of our evolutionary tailbone from the thoracic spine comes the 12 long straight bones which form the ribcage there are seven pairs of true ribs which articulate directly with the sternum three pairs of false ribs which articulate with the sternum via the costal cartilage and two pairs of floating ribs which do not articulate with a sternum at all the sternum itself is composed of three parts the manubrium the body and the xiphoid process joining onto the most proximal part of the upper limb is the shoulder girdle this is composed of two bones only the collar bone or clavicle and the shoulder blade or scapula these serve as the only point of connection between the upper limb and the axial skeleton let's finish by examining the many bones forming the skull most would think the skull to be composed of only two bones but it's actually a complex structure made up of 22 flat bones connected together mostly by suture joints forming the forehead and anterior cranium is the single frontal bone the sides of the cranium are made up of the two parietal bones connecting to the parietal bones are the two temporal bones which get their name from their close relation to the temporal lobes of the brain connecting to these and forming most of the cheekbone are the two zygomatic bones which themselves connect to the two maxillae the maxillae form the upper jaw with the mandible forming the lower jaw all 32 teeth are set into these two bones the remaining bones of the skull are mostly clustered in the center forming part of the eye socket are the sphenoid ethmoid and lacrimal bones and forming parts of the nose are the nasal bones the inferior nasal conchae the palatine bones and the voma the only bone we can't see here is the occipital bone which forms the back of the head and encloses the occipital lobe of the brain inside the ear there are three tiny bones the smallest in the entire body these are the malleus incus and stapes we'll cover them in more detail in a later session finally the only bone left to cover is a small c-shaped bone in the neck known as the hyoid bone this is the only bone in the human body not to articulate directly with another bone okay we've covered everything let's see just how many bones that was the two lower limbs have eight bones between them the upper limbs six bones the shoulder girdle four bones the hands have 27 bones each and the feet both have 26 bones each the pelvis has six fused bones the vertebral column has 26 bones the ribcage 27 bones the skull 22 bones the inner ear has two pairs of three bones and finally the unpaired hyoid in the neck that gives us a grand total of 212 bones in the human body plus 32 teeth wow great i hope you've learned something today if you did remember to like the video and subscribe to our channel see you next time and have a great day