in this video I walk you through some of the important structures that we see in the cranial base recall cranial base is exactly where brain sets on I start with the anterior bone which is frontal bone deep inside the frontal bone where I'm pointing at we must find some air filled cavities which we named them frontal sinuses this is not a real skull so we do not actually see the frontal sinuses we just locate where they're supposed to be recall frontal sinuses are lined by ciliated pseudostratified columnar epithelium the epithelial tissue contains goblet cells that secrete mucus and then mucus from frontal sinuses should be emptied into the nasal cavities so from the frontal sinuses we find frontal duct that open these cavities into the nasal cavities exactly below Middle East or concave in the spaces that we refer to them as middle nasal meal statuses then in the middle I can see a very small part of the ethmoid bone which is called crib reform plate this is a very thin partition that separates nasal cavities from cranial cavity we can say that criboform plate forms the roof of the nasal cavities and in the creep reform plate we find about 20 openings that we refer to them as olfactory foramina clearly these are passage for olfactory fibers cranial nerves number one to exit the nasal cavities and enter the cranial fossa in general pre-perform plate is thin and mechanically weak so a blow to the frontal region can easily fracture the crew perform plate and please keep in mind if critiform played due to trauma is fractured it also causes usually laceration of durometer recalled Dura Mudder is the outer of the three meninges that surround the rain and the reason that laceration of the raw mother happens is simply because that elevation here which is called Crystal Galley is the attachment point for false cerebral that would be part of the dura mother that he separates cerebrum into two cerebral Hemisphere and when cribriform plate is fractured that simply means that cerebrospinal fluid can leak into the nose so in the patients that we have a blow to especially the frontal region and we see that the patient has a runny nose that could be an indication that cerebral spinal fluid is leaking from the cranial cavity into the nasal cavities that's something that we have to take it very seriously because as we know insulin for spinal fluid we are not supposed to find any microorganisms but the moment nasal cavities are open and connected to the cranial cavity so easily due to the fracture of this creeper from plate bacteria from nostrils into the cerebral spinal fluid and cause infectious diseases such as meningitis so after learning about the cribriform plate of ethmoid olfactory foramina incredible form plate and the Crystal Galley that elevation I move to the butterfly shaped bone which is fenuate bone this is one of the most complex bones that we find in the skull this is the bone that articulate with all other cranial bones and we divide it into different sections we named this part of sphenoid bone body of this fenui we name these two small triangular shaped Parts lesser wings of svenoid bone and we name this very large areas greater Winds of sphenoid bone so body lesser Wings greater Wings in the body of the sphenoid bone we find a saddle-shaped structure which forms by two elevations and a depression between these two projections we named the posterior projection dorsum Cella we named the depression that I'm pointing at right now hypophyseal fossa and we named the anterior projection tuberculum Cella and we refer to tubercolumbsella hypophyseal fossa and dorsum Cella all three together as Cella torsica this is the place that we find pituitary gland so pituitary gland literally sits inside the hypophyseal fossa and we can say that somehow is protected by tuberculum Cella and dorsum Cella between body of this phenoid and lesser Wings we find these two openings we refer to them as either optic canals or Optic foramina these are passage for optic nerves cranial nerves number two recall optic nerves transmit visual signals from the eyeballs to the brain so now it makes sense whenever we have for example tumor of the pituitary gland why the patient experiences some visual problems simply because the optic nerves very close by to the pituitary gland so enlargement of the pituitary gland can easily press and put pressure on the optic nerves then I focus on what I see between lesser wing and greater wing we can see some long triangular shape openings on both sides we name the opening between lesser and greater wings Superior orbital fissure many important structures pass through Superior orbital features for example several of our cranial nerves pass through Superior orbital fissure such as oculomotor nerves abducens nerves trochlear nerves and even ophthalmic nerves which are branches of trigeminal nerves so the two Superior orbital fissures which clearly we can see them also when we look inside the orbits in the anterior view are important Pathways for many anatomical structures that we have from Superior orbital feature I start moving posteriorly walking through the greater Wing right behind posterior to Superior orbital fissure I can find these two foramina that we refer to them as rotundum for example maxillary branch of the trigeminal passes through foramen rotundum and then from foramen rotunda I move again walk through the greater wing posteriorly and I see the oval shape opening that is called foramen or Valley for example mandibular branch of the trigeminal passes through foramen or Valley and then when I move more posteriorly near the end the edge of the greater Wing I find foramen spinosum so if I walk through the greater Wing we have Rotunda or Valley spinozum r o s so remember Ross all three are located on the greater wing of this phenoid bone and then I noticed this opening that is located between sphenoid bone temporal bone and occipital bone that would be called foramen lacerum so if I look at the other foramen later on I see that lacerone sits medial to ovali and Spinoza and if you connect or Valley to La serum lacerone to spinosum spinozum to ovale you see a triangle and hopefully this helps lacerone ovale spinozum l-o-s loss please keep in mind La Serum is open only in a dried skull in a living human lacerum is covered by a layer of fibrocartilage only we see it open if it's a dried skull and we have lost the fibrocartilage layer after sphenuate bone I go through the two temporal bones so that would be the right temporal bone this is the left temporal bone we have a projection in the internal view of the temporal bone that is called Petrus portion of the temporal bone for example inner ear middle ear they are deeply located inside the Petrus portion of the temporal bone and then when I look at the medial wall of the Petrus portion we find internal acoustic meatus many important structures pass through internal acoustic meatus for example facial nerves vestibular cochlear nerves pass through internal acoustic meatus when we say a structure a neurovascular structure passes through one of these openings it doesn't mean that definitely that structure gets out of the opening in the other side of the skull in a separate video I walk you through the inferior view of the skull but in general please know some of these neurovascular structures enter an opening here but they exit a different opening when we get to the inferior view for example when facial nerves enter the internal acoustic meatus when we learn about the inferior view of the skull we see that most of their branches of facial nerves exit through the Stylo mastoid foramen so that's something to note about the detail of the anatomy is more complex than what we explained in this video and then from internal acoustic meters when I move posteriorly I see this very large opening which actually sits between the Petrus portion of the temporal bone and the occipital bone so this opening is located between temporal and occipital and we name this opening jugular foramen clearly we know that the jugular vein passes through this and also some of our cranial nerves for example cranial nerves number nine glossopharyngeal Vegas number 10 accessory they all pass through the jugular foramina and recall that the flat section of the temporal bone would be referred to as temporal squamous so I'm pointing at the internal view of the temporal squamous after temporal bone then I walk through the occipital bone first I locate foramen magnum recall that exactly in frame and Magnum part of the brain name medulla oblongata fuses to spinal cord so that explains why this area has to be protected for example when we want to transfer a patient to the hospital first thing that we do we stabilize the neck we do not want any inflammation or any pressure on that section that is located in foramen magnum because in medulla oblongata of the brain that is sitting very close to frame and Magnum we have some important visceral control centers including the neurons that control breathing lateral to foramen magnum we can locate hypoglossal canals so I can see the two hypoglossal canals lateral to frame and Magnum and Superior to foramen magnum obviously we know that hypoglossal nerves pass through the hypoglossal furamina and when they exit then we know that hypoglossal nerves mostly Supply the muscles of tongue so the movement of the Hong depends on the nerves that pass through the hypoglossal canals and then inside the occipital bone I can see this large elevation that is called internal occipital protuberance and please note that inside the cranial base we can see a small section of parietal bones so those are the parietal bonds that I'm pointing at but in general these are the details that we can see in this skull which I emphasize this is not a real skull so some of the anatomical structures that we can see in a real skull are missing here but at least in this video we were able to go through some important structures and also name some of the neurovascular structures that pass through them or are attached to them I hope you find this helpful