The Skull - Lecture 5 Flashcards
1
Q
How many bones are in the skull? How many paired and how many unpaired?
A
- there are 28 bones in the skull
- there are 11 paired bones
- there are 6 unpaired bones
2
Q
Name the paired bones of the skull
A
- the Parietal bones
- the Temporals
- the Zygomatic bones
- the Nasals
- the Nasal Conchae
- the Palatines
- the Lacrimals
- the Maxillae
- the Ear bones (Malleus, Incus, Stapes)
3
Q
Name the unpaired bones of the skull
A
- the Occipital
- the Frontal
- the Sphenoid
- the Ethmoid
- the Vomer
- the Mandible (adult)
4
Q
Where are the Parietal bones?
A
the sides of the brain case
5
Q
Where are the Temporal bones?
A
the temples
6
Q
Where are the Zygomatic bones?
A
the cheeks
7
Q
Where are the Nasal bones?
A
the bony bridge of your nose
8
Q
Where are the Nasal Conchae? What does the term Conchae refer to?
A
- inside the nasal aperture (opening) on the lateral side
- the term refers to the fact that they are shell shaped
9
Q
Where are the Palatine bones?
A
they are right behind the maxilla and make up the hard palette of the roof of your mouth
10
Q
Where are the Lacrimals?
A
inside your eye surrounding the tear duct
11
Q
Where are the Maxillae?
A
- the upper jaw just under your nose
- upper teeth fit in here
12
Q
Where do the ear bones sit? What do they do?
A
- inside the temporal bones
- help support your ear drum
13
Q
What is the Petrous Pyramid? Where is it?
A
the place in the temporal bones where the ear bones sit
14
Q
Where is the Occipital bone?
A
the back of your head
15
Q
Where is the Frontal bone?
A
the front of your head (the forehead)
16
Q
Where is the Sphenoid bone? What shape is it?
A
- right under your brain and extends to under the Palatines and a thin area right beside the eye
- looks like a pterodactyl or stingray
17
Q
Where is the Ethmoid bone?
A
deep part of the skull that is behind the nose
18
Q
Where is the Vomer?
A
is your nasal septum that splits the nose into right and left
19
Q
Where is the Mandible?
A
the lower jaw
20
Q
What is the ear hole called?
A
External Auditory Meatus (outside ear hole)
21
Q
What are cranial sutures?
A
a sort of zipper that connects the different cranial bones together
22
Q
What are the two different kinds of Cranial Sutures? Explain them.
A
- Interdigitating: like a zipper
- Squamosal: where one is on top of the other (like velcro)
23
Q
Give an example of an Interdigitating suture.
A
the coronal suture
24
Q
How many Squamosal sutures are there? Which bones connect with a Squamosal suture?
A
- two
- the Squamosal sutures are where the parietal and the temporal bones articulate on either side of the skull
25
What is the Orbit?
the Orbit is what holds the eye
26
What is the Nasal Aperture?
the nose hole
27
Where is the Coronal suture? What cranial bones does it connect?
- in the middle of the head running transversely and it is where the coronal plane divides the body
- it is where the frontal bone articulates with the parietal bones
28
What and where is the Mastoid process?
a feature of the temporal bone that is located under the External Auditory Meatus
29
What and where is the Brow Ridge?
a feature of the skull that is where your eyebrows are
30
What is the nasal?
a feature of the skull where the nose is
31
Name all the Cranial features that can be seen from the Frontal and Lateral views of the skull.
- frontal bone
- nasal aperture
- maxilla
- zygomatic
- orbit
- parietal
- temporal
- mastoid process
- external auditory meatus
- nasal
- brow ridge
- coronal suture
32
Name all the Cranial features that can be seen from the Dorsal (Posterior) and Inferior views of the skull.
- sagittal suture
- lambdoidal suture
- parietal
- occipital
- external occipital protuberance
- nuchal area
- foramen magnum
- basilar portion of the occipital
- maxilla
- vomer
- occipital condyles
33
What and where is the Sagittal suture?
- on the Sagittal plane that separates the body into right and left halves
- connects the right and left parietal bones
- an interdigitating suture
34
What and where is the Lambdoidal suture?
- an interdigitating suture
- connects the right and left parietal bones to the occipital bone
35
What and where is the External Occipital Protuberance?
- a feature on the occipital bone
- a bit of bone that sticks out and is a place for muscle attachments
36
What and where is the Nuchal Area?
- runs out on either side of the External Occipital Protuberance and it looks a bit like a child's drawing of a bird
- place for muscle attachments
37
What and where is the Foramen Magnum?
- the hole at the base of the skull where the brain stem goes
38
What and where is the Basilar Portion of the Occipital?
- part of the Occipital and is in front of the Foramen Magnum and connects to the Sphenoid
39
What and where are the Occipital Condyles?
- a raised area that articulates with the first cervical vertebra
40
What is a Condyle?
a raised area that articulates with another bone
41
Name all the Cranial features that can be seen inside the skull
- petrous bone (or petrous pyramid)
- internal occipital protuberance
- sphenoid
- internal auditory meatus
- frontal sinus
- ethmoid
- maxillary sinus
42
What and where is the Petrous Bone (or Petrous Pyramid)?
- on the inside of the temporal bone where the auditory ossicles (ear bones) are
- very dense and is usually one of the only cranial bones to survive being burned
43
What and where is the Internal Occipital Protuberance?
a bit of bone that sticks out a bit into the skull
44
What and where is the Internal Auditory Meatus?
same place and thing as the External Auditory Meatus just on the inside
45
What and where is the Frontal Sinus?
- just above the nose between the eyebrow area and it is just another space where puss build up can happen
- not everyone has one
46
What and where is the Maxillary Sinus?
it is a space (what sinus is) just above the maxilla
47
What are the tiniest bones in the body?
the auditory ossicles (ear bones)
48
What are the Auditory Ossicles?
the ear bones
49
How many Auditory Ossicles are there? Name them.
1. Malleus (outermost bone)
2. Incus (middle)
3. Stapes (innermost bone)
50
Which of the Auditory Ossicles does the eardrum rest on?
the Malleus
51
Name the features of the Mandible.
- mandibular condyle
- ramus
- body
- mental foramen
- mental protuberance
- alveolus
52
What and where is the Mandibular Condyle?
where the mandible connects with the temporal bone
53
What and where is the Ramus?
the upper portion of the jaw
54
What and where is the Mental Foramen?
a hole/dimple in the mandible
55
What and where is the Mental Protuberance?
- the very tip of your chin
- important for sex identification
56
What and where is the Alveolus?
the sockets in the mandible where the roots of the teeth are connected
57
What are the different terms used to refer to the skull that are based on its completeness?
1. Skull - whole thing, everything present
2. Mandible - just the lower jaw
3. Cranium - skull without lower jaw
4. Calvaria - cranium without the face (ie just the brain case
5. Calotte - Calvaria without the base (ie just the top half of the brain case)
6. Splanchnocranium - just the face
58
What part of the skull is usually found in isolation?
the Mandible
59
What is another name for the soft spots on baby's heads that are a result of the sutures being unossified?
Fontanelles
60
What is a Fontanelle?
- the soft spots on baby's heads
- the membrane where the bone of the sutures is going to develop
61
How can the fusion of the crania and the appearance of cranial sutures help with age estimation?
you can tell if its still in utero, has just been born, or has already been born
62
What is a Bone Ossicle and how does it form? Where are they usually found?
- a "bone island" in a cranial suture grew from within the membrane and not from the sides
- on the lambdoidal suture though they can be found in any suture
63
How can cranial sutures be individualizing?
because they can have crazy and unique patterns that are unique to an individual person or family trait
64
What cranial bone that was originally two completely fuses together?
the frontal bone, though sometimes there can be a visible suture
65
What is a metopic suture?
- a suture in the frontal bone that can appear instead of a complete fusion
- only called this if it is maintained into adulthood
66
What are Meningeal Grooves?
lines on the inner side of the parietal bones that are spaces for the blood vessels that run over the meninges of your brain
67
What is a good identifying factor of the Parietal bone? How can it also help you orient it?
- the Meningeal Grooves since they have a very distinct pattern with one long meninge along the coronal suture
- the large meningeal groove along the coronal suture is at the front of the parietal bone and the rest of the grooves go posteriorly after that
68
What way do the Meningeal Grooves go?
they go posteriorly
69
What and where is the Sagittal Sulcus?
- a sulcus is a bit of a dip
- runs along either side of the sagittal suture
- where the meningeal grooves begin to disappear
70
What and where is the Sigmoid Sulcus?
another bit of a dip that is near the lambdoidal suture
71
What is the Hyoid Bone?
- the bone that supports your tongue and the thyroid cartilage
- doesn't touch any other bone
- not technically a cranial bone but very close
- very tiny
72
Name all the Cranial Sutures seen in a Lateral view of the cranium.
- Coronal suture
- Squamosal suture(s)
- Lambdoid suture
73
Name all the Cranial Sutures seen in a Superior view of the cranium.
- Coronal suture
- Sagittal suture
74
Name all the Cranial Sutures seen in a Posterior view of the cranium.
- Sagittal suture
- Lambdoid suture
75
Is the Coronal suture more anterior or posterior?
Anterior
76
Is the Lambdoidal suture more anterior or posterior?
Posterior
77
Is the Squamosal suture medial or lateral?
Lateral
78
Is the Sagittal suture medial or lateral?
Medial
79
What is a bone ossicle?
a small bone
80
What is another word for a bone ossicle?
Wormian bones or accessory bones
81
What kind of bone growth are the cranial bones, cranial sutures, and possible bone ossicles formed by?
Intramembranous ossification
