Detailed Anatomy of the Human Skull! The cranial, and facial bones and structures! New and Improved!

Summary

This educational video script delves into the intricate anatomy of the human skull, detailing the cranial bones such as the frontal, parietal, sphenoid, temporal, occipital, and ethmoid bones. It highlights the unique structures associated with each bone, like the frontal sinuses, parietal sutures, temporal bone's mandibular fossa, and the sphenoid bone's sella turcica. The script also explores the ethmoid bone's nasal conchae and crista galli, the occipital bone's foramen magnum, and the mandible's features. It concludes with a look at the fetal skull, emphasizing the soft spots known as fontanelles, providing a comprehensive guide for students of anatomy.

Takeaways

• 💀 The skull is composed of cranial and facial bones, with the cranial bones including the frontal, parietal, sphenoid, temporal, and occipital bones.
• 🗺️ The occipital bone is the largest and surrounds the foramen magnum, which is the hole for the spinal cord.
• 👥 The frontal bone contains the frontal sinuses, which are visible in a sagittal section of the skull.
• 🔍 The parietal bones are separated by the sagittal suture and bordered by the coronal suture.
• 🦴 The temporal bone features the mandibular fossa, which articulates with the jaw, and the external and internal auditory meati.
• 👂 The sphenoid bone, located in the temple region, has a distinctive butterfly shape and includes the sella turcica, which houses the pituitary gland.
• 👃 The ethmoid bone, part of the nasal region, contains the ethmoid sinuses and the crista galli with the cribriform plate on either side.
• 🦷 The mandible, or jaw, has the mandibular fossa that articulates with the temporal bone and the mandibular foramen.
• 👁️ The maxilla and zygomatic bones form the major part of the face, with the zygomatic bone also having a temporal process.
• 👶 The fetal skull differs from the adult skull, featuring soft spots like the anterior and posterior fontanelles where the bones are not yet fused.

Q & A

What are the primary bones that make up the cranial portion of the skull?

The primary bones that make up the cranial portion of the skull include the frontal bone, two parietal bones, sphenoid bone, temporal bone, and occipital bone.

What is the occipital bone's relation to the foramen magnum?

The occipital bone is large and includes the area around the foramen magnum, which is the hole through which the spinal cord passes.

What structures are associated with the frontal bone?

The frontal bone is associated with the frontal sinuses, which are visible in a sagittal section of the skull.

How are the parietal bones related to each other?

The parietal bones are separated by the sagittal suture and bordered by the coronal suture.

What are the key features of the temporal bone?

The temporal bone features the squamous suture, mandibular fossa, external auditory meatus, and zygomatic process.

What is the function of the mandibular fossa on the temporal bone?

The mandibular fossa is the articulation point for the temporomandibular joint, where it connects with the mandibular condyle of the jaw.

What is the sphenoid bone's location in relation to other skull bones?

The sphenoid bone is located over the temple area and in front of the temporal bone, beneath the squamosal suture.

What is the sella turcica and its significance?

The sella turcica is a chamber in the sphenoid bone that houses the pituitary gland, which is an important endocrine gland.

What are the nasal conchae and their location?

The nasal conchae are round structures on the walls of the nasal cavity and are part of the ethmoid bone.

What is the crista galli and its relation to the ethmoid bone?

The crista galli is a protruding structure in the middle of the ethmoid bone, which is also known as the rooster comb.

What is the foramen magnum and its role in the skull?

The foramen magnum is a large hole at the base of the skull in the occipital bone, through which the spinal cord passes to connect with the brain.

What are the occipital condyles and their function?

The occipital condyles are protrusions on the occipital bone that articulate with the first vertebra (C1), allowing for head movement.

What is the mandibular foramen and its significance?

The mandibular foramen is a structure in the mandible that provides a pathway for the nerves and blood vessels that supply the lower jaw.

What is the difference between the anterior and posterior fontanelles in a fetal skull?

The anterior fontanelle is a soft spot on the skull of a fetus where the bones have not yet fused, located at the front, while the posterior fontanelle is a similar but less pronounced area at the back of the skull.

Outlines

00:00

💀 Anatomy of the Skull: Cranial Bones

The video segment begins with an exploration of the skull's anatomy, focusing on the cranial bones. These include the frontal bone, two parietal bones, sphenoid bone, temporal bone, and occipital bone. The occipital bone is highlighted as being particularly large, encompassing the area around the foramen magnum. The frontal bone is associated with the frontal sinuses, which are visible in a sagittal section of the skull. The parietal bones are separated by the sagittal suture and bordered by the coronal suture. The temporal bone features the squamous suture, mandibular fossa, and external auditory meatus, which are essential for understanding the skull's structure.

05:05

👂 Temporal Bone and Sphenoid Bone Structures

This part of the script delves deeper into the structures of the temporal bone, such as the zygomatic process and internal auditory meatus, which are crucial for the bone's function and identification. The sphenoid bone, located at the temple area and in front of the temporal bone, is described with its characteristic butterfly shape. Key features of the sphenoid bone include the sella turcica, which houses the pituitary gland, and the optic foramina, which are essential for the passage of the optic nerves.

10:13

👃 Ethmoid Bone and Occipital Bone Features

The ethmoid bone, with its intricate features within the nasal cavity, is discussed, including the nasal conchae and the perpendicular plate. The ethmoid sinuses are noted for their honeycomb-like structure. The video then shifts focus to the occipital bone, emphasizing its large size and the presence of the foramen magnum, through which the spinal cord passes. The occipital condyles, which articulate with the first vertebra, are also mentioned as important for head movement.

15:18

🦴 Mandible and Maxilla: Jaw and Cheekbone Structures

The script continues with an examination of the mandible, or jaw, detailing its features such as the mandibular fossa and condyle, which are essential for jaw articulation. The mandibular foramen, visible in an unattached jawbone, is also discussed. The zygomatic bone, or cheekbone, and its relationship with the temporal bone through the zygomatic process are highlighted. The maxilla, the major facial bone, and the vomer, a thin bone at the nasal septum, are also covered.

20:21

👶 Fetal Skull Characteristics

The final part of the script contrasts the fetal skull with that of an adult, pointing out the presence of soft spots known as fontanelles, which are the anterior and posterior fontanelles. These areas are significant as they indicate the skull's flexibility in infants. The script concludes with a brief mention of the other bones present in the fetal skull, such as the occipital and parietal bones, which are similar to those in adults but smaller and less developed.

Keywords

💡Cranial bones

Cranial bones are the bones that make up the skull, protecting the brain. In the video, the speaker goes over each of these bones, emphasizing their importance in the anatomy class. The frontal bone, parietal bones, sphenoid bone, temporal bone, and occipital bone are all part of the cranial bones. The occipital bone, for instance, is highlighted as being very large and includes the area around the foramen magnum, which is a significant structure for the passage of the spinal cord.

💡Frontal sinuses

The frontal sinuses are air-filled spaces within the frontal bone. The script mentions that they are only viewable with a sagittal section of the skull, indicating their location within the forehead area. They are part of the structures associated with the frontal bone and are important for understanding the anatomy of the skull.

💡Sagittal suture

The sagittal suture is a fibrous joint that separates the two parietal bones in the skull. It is mentioned in the context of discussing the parietal bones and their relation to other skull bones. Understanding the sutures is crucial for recognizing how the bones of the skull are connected and how they change during growth and development.

💡Temporal bone

The temporal bone is one of the cranial bones and is discussed in detail in the script. It includes several structures such as the squamous suture, mandibular fossa, external auditory meatus, and zygomatic process. The temporal bone plays a significant role in the anatomy of the skull, housing the structures related to hearing and jaw movement.

💡Mandibular fossa

The mandibular fossa is an indentation on the temporal bone that articulates with the mandibular condyle of the jaw. It is a key structure for the movement of the jaw and is mentioned as part of the temporal bone's features. Understanding the mandibular fossa is essential for comprehending the mechanics of the jaw joint.

💡Sphenoid bone

The sphenoid bone is a complex bone located in the skull, in front of the temporal bones and underneath the squamosal suture. It is described as having a butterfly-like shape with important structures such as the sella turcica, which houses the pituitary gland, and the optic foramina, through which the optic nerves pass. The sphenoid bone's features are critical for understanding the skull's internal structures.

💡Ethmoid bone

The ethmoid bone is a light, spongy bone that forms the roof of the nasal cavity and the upper part of the nasal septum. It contains the ethmoid sinuses and has a structure called the crista galli, which is a protrusion that supports the dura mater of the brain. The ethmoid bone's features are essential for understanding the nasal region's anatomy and the connection to the brain.

💡Foramen magnum

The foramen magnum is the large hole at the base of the skull through which the spinal cord passes. It is a critical structure in the occipital bone and is mentioned as a key feature of the skull's anatomy. The foramen magnum's size and position are vital for the connection between the brain and the spinal cord.

💡Mandible

The mandible, also known as the lower jawbone, is a crucial part of the skull's anatomy. It is discussed in relation to the mandibular fossa and the mandibular condyle, which are points of articulation with the temporal bone. The mandible's structure and movement are essential for understanding facial expressions and the mechanics of chewing.

💡Zygomatic bone

The zygomatic bone, also known as the cheekbone, is part of the facial skeleton that forms the prominence of the cheek and contributes to the orbit's lateral wall. It is mentioned in the context of the zygomatic process, which articulates with the temporal bone. The zygomatic bone's structure is important for understanding the shape and support of the face.

💡Maxilla

The maxilla is the upper jawbone that contributes to the formation of the hard palate and the floor of the orbit. It is mentioned as the major area of the face and is crucial for understanding the structure of the midface and the support it provides to the oral and nasal cavities.

Highlights

Introduction to the anatomy of the skull, covering various bones and structures.

Description of the cranial bones, including the frontal, parietal, sphenoid, temporal, and occipital bones.

Explanation of the frontal bone and its associated frontal sinuses, viewable in a sagittal section.

Discussion on the parietal bones, their separation by the sagittal suture, and their border with the coronal suture.

Details on the temporal bone, including the squamous suture, mandibular fossa, and external auditory meatus.

Identification of the zygomatic process of the temporal bone and its role in the structure of the skull.

Description of the internal auditory meatus as part of the temporal bone, important for hearing.

Overview of the sphenoid bone, its location, and its distinctive butterfly shape.

Mention of the sella turcica, a chamber in the sphenoid bone that houses the pituitary gland.

Explanation of the optic foramina in the sphenoid bone, which are pathways for the optic nerves.

Discussion on the ethmoid bone, its features, and its role in the nasal cavity and sinuses.

Identification of the crista galli and cribriform plate of the ethmoid bone, important for olfactory function.

Description of the occipital bone, its large size, and its features like the foramen magnum and occipital condyles.

Explanation of the mandible, its features, and its articulation with the temporal bone.

Mention of the mandibular foramen, a key structure for the jaw's blood supply and nerve.

Identification of the zygomatic bone, or cheekbone, and its connection with the temporal bone.

Discussion on the maxilla, the major bone of the face, and its role in the structure of the skull.

Introduction to the fetal skull, highlighting differences from the adult skull, such as the anterior and posterior fontanelles.

Transcripts

[Music]

okay so today let me go over the anatomy

of the skull I'm gonna go over each of

the bones and each of the structures

associated with each of those bones that

you need to know for this class so first

let's start with the cranial cranial

bones you've got your frontal bone here

your two parietal bones your spin ID

bone temporal bone and the occipital

bone the occipital bone is very large

and it includes all of this area here

around the magnum foramen so all of this

is occipital bone

[Music]

okay so this is the frontal bone mmm the

structures that you need to know that

are associated with the frontal bone

only include the frontal sinuses which

is only viewable with this sagittal

section of the skull so here we have our

sagittal section and this area here

would be the frontal sinus so this is

the frontal bone and the structure here

is the frontal sinus of the frontal bone

we have the two parietal bones now the

parietal bones are separated with the

sagittal suture and they are also

bordered with the coronal suture which

is shown here so this is the coronal

suture coronal suture and sagittal

suture for the temporal bone which is

shown here the temporal bone has several

structures you need to know there is a

suture that runs horizontally this is

the squamous suture squamous suture

another feature that the temporal bone

has

is right here where it articulates with

the jawbone the indentation here that is

on the temporal bone this is the

mandibular fossa the mandibular fossa is

the articulation point for the and

emulator on dial which is on the

mandible or jaw

right here this is the external auditory

meatus otherwise known as the acoustic

canal or the external auditory canal so

this is also considered to be a

structure of the temporal bone so this

portion here is still considered part of

the temporal bone and this is the

zygomatic process of the temporal bone

so that is another structure of the

temporal bone that you need to know

now there's another structure that you

need to know hmm that is part of the

temporal bone and that is the internal

auditory meatus okay so here is the

external auditory meatus that I showed

you earlier and this travels quite a

distance actually through the bone and

it will come out in a small structure

right there so this is the internal

auditory meatus

you

so this is the internal auditory meatus

okay and that is the bone associated

with that is still the temporal bone

even though now we're on the inside of

the skull okay so temporal bone we've

got your squamous suture your zygomatic

process of the temporal bone

we've got your external auditory meatus

your where did it go

area your internal auditory meatus

there and there

and your mandibular fossa which is the

indentation for the articulation point

of the jaw next let's look at the

sphenoidal and the structures associated

with the sphenoid bone so from the

outside the sphenoid bone is going to

lie over the tent the area where you

have your temple and it's going to be in

front of the in front of the temporal

bone it's going to be this area right

here it's also going to be underneath

the squamosal suture so this is the spin

wide bone when we take an internal view

of the sphenoid bone we can really see

it in all of its glory the sphenoidal

this area right here which kind of looks

like a happy face to me like that would

be an eye that would be an eye and

there's a little smiley face here and

then it has these wings his winged

structure so if you were to just isolate

the area of the sphenoid bone you would

see this butterfly shape okay there are

a couple of structures that are part of

the spinet bone that you need to know

the first one is if you go right in the

middle of the happy face there is

actually a little chamber right here let

me see if I can give you guys a close-up

there mm-hmm

so if you could imagine this is an eye

and that's an eye and this is a little

smiley face right here there's a little

chamber this chamber is called the sella

turcica now the sella turcica is a

little chamber that houses your

pituitary gland

which lies at the inferior most point of

the of that section of the brain okay so

there would be the sella turcica also

associated with the spin white bone

would be your optic foramen plural would

be optic foramina so this here actually

gonna try to stick my stick my stick

through it there you go so this right

here would be the optic foramen foramen

and the optic foramen comes out here and

so basically the eyeballs that I pointed

out to you earlier on my imaginary moth

or butterfly of the sphenoid bone these

would be the optic foramen or I could

say optic foramina for being plural next

let's go ahead and look at the ethmoid

bone the ethmoid bone has a lot of

wonderful features from a few different

viewpoints so we're gonna start with the

viewpoint where we're just looking up

the of the nasal region here of our

skeleton all of these structures that we

see here inside of the nose are all part

of the ethmoid bone these are all part

of the ethmoid bone when you look very

closely hmm

this one doesn't have it quite as

pronounced as some other ones do there

are some round structures that are on

the walls of the nasal cavity here those

would be the nasal Concha Concha me

she'll cuz they kind of look she'll like

area here would be the perpendicular

plate of the ethmoid bone

so the sagittal section is the only

section of the skull that you would be

able to identify the ethmoid sinuses

much of it has been broken off however

you can see here some very thin brittle

honeycomb-like structures so these

structures here that would be the

ethmoid sinuses the ethmoid sinuses of

the ethmoid bone

you

so up here you have a a coma-like

structure that is protruding upwards or

superiorly

so this whole area that I'm outlining

right here is the is still ethmoid so

this is still the ethmoid bone the

structure here right in the middle that

is more pronounced that is going to be

the crista galli crista galli

which means rooster comb and then the

areas on the left and right sides of the

crista galli you're going to have the

cribriform plate the cribriform plate on

either side and that would be the

cribriform plate of the ethmoid bone and

the crista galli

of the ethmoid bone

so this region back here this is the

occipital bone and this suture here that

lines the occipital bone is the

lambdoidal suture the lambdoidal suture

and you might recall that the occipital

bone is deceivingly large because as we

as we look inferior lis all of this area

as well is all also going to be the

occipital bone

there are two more structures you need

to know associated with the occipital

bone this hole here this is the foramen

magnum meaning large hole this is the

hole that your spinal cord travels

through foramen magnum so this would be

the foramen magnum of the occipital bone

and there are two articulation points

one here and one here and these are like

little knuckles if you will that kind of

protrude out these are the occipital

condyles the occipital condyles and

these points are going to articulate

with the c1 vertebra so that your head

can move around which is always a good

thing so this is the jaw

now the jaw is called the mandible okay

so this is the mandible and the mandible

has has a couple of features that you

need to know about now you might

remember you might remember that we

talked briefly before about the

mandibular fossa and the mandibular

fossa is this indentation right here

that articulates with the jaw right so

this is the mandibular the mandibular

fossa articulates with the mandibular

condyle which is actually this

protruding point here on the mandible so

this is the mandibular condyle and this

on the temporal bone is the mandibular

fossa

you

yep there's one more thing you need to

know which is the mandibular foramen the

mandibular foramen you really need to

have a unattached jawbone in order to

really be able to see this and I'm

hoping that you'll be able to see this

through the video if not when you look

at it in person it's pretty easy to tell

so if you look at an angle actually I

can even put my stick right there so

that's kind of nice alright so this is

the mandibular foramen okay you have one

on either sides there's one there so

they kind of go at an angle and the

other one the bones that you feel on

your cheeks here and here

these cheekbones this area is the zygoma

it also call it the zygomatic bone or

the zygoma okay your cheekbones the

major area of the face here is going to

be the maxilla

now the zygoma also has a process right

so this is the zygoma right and you

might remember that this right here is

the zygomatic process of the temporal

bone well there's something similar

going on here we've got the zygomatic

bone which is protruding and having out

this process fishing back to the area of

the temporal bone so this is called the

temporal process of the zygomatic bone

or the temporal process of the zygomatic

bone the nasal bone whereas so this is

your perpendicular plate of the ethmoid

bone which I mentioned before this right

here at the bottom is the vomer that is

the vomer okay so you I mentioned the

vomer earlier and let's go ahead and

take another view of the vomer looking

at it inferior lis here

this Center structure here is the vomer

and then we can also see the maxilla and

the Palatine bone as well when you look

inside of the orbital region the bone

that is inside of the orbital region but

very very anterior here this is your

lacrimal bone this is where your

lacrimal gland lacrimal duct that allows

you to cry which you might be wanting to

cry right now is located so this is the

lacrimal bone okay so lastly so next

we'll go ahead and take a look at the

fetal skull the skull of the fetus has

some features that is not seen in the

adult skull and you can see a wonderful

wonderful illustration of that here so

this is what's commonly known as a soft

spot so we always want to make sure

we're careful of this area the

anatomical correct anatomical term for

this is the anterior fontanelle the

anterior fontanelle okay now you also

you also have this front area which is

the frontal suture this is the frontal

suture

now if I were to turn this around we

also have another soft spot that is less

pronounced but the bones are not fused

yet here either and this would be the

posterior fontanelle the posterior

fontanelle and the rest of this is very

similar to the adults you know we've got

our occipital bone parietal bone

temporal bones really tiny and way down

spin away

[Music]