Axial Skeleton 1 Flashcards
Describe the bones of the skull. Describe the associated features (e.g., processes, foramina) of the skull bones.
1
Q
what are most of the bones in the skull fused together by?
A
immovable joints called sutures
2
Q
What are the main functions and features of the skull bones?
A
protect the brain (cranial cavity)
3
Q
what is the purposed of the surface markings on the skull?
A
muscle attachment sites and passageways for blood vessels and nerves.
4
Q
In addition to the cranial cavity, some skull bones form ____
A
the orbits and nasal cavity
5
Q
Some skull bones also contain _____
A
smaller cavities (e.g., paranasal sinuses, middle and inner ear structures)
6
Q
how many cranial bones are there?
How many facial bones are there?
A
8 and 14
7
Q
purpose of cranial bones:
A
form the cranial cavity, in which the brain sits
8
Q
purpose of facial bones:
A
for the structure of the face
9
Q
list the cranial bones:
A
frontal
parietal (2)
temporal (2)
occipital
sphenoid
ethmoid
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10
Q
what forms the frontal bone?
A
The forehead
The anterior portion of the cranial cavity
Part of each orbit
11
Q
features of the frontal bone
A
Supraorbital margin (2)
Supraorbital foramen (2
12
Q
what passes through the supraorbital foramen of the frontal bone?
A
artery and nerve
13
Q
what forms the parietal bones (2)
A
The top and upper part of the sides of the head
Most of the superolateral portion of the cranial cavity
14
Q
what forms the temporal bones (2)
A
The lower part of the sides of the head (“temples”)
Most of the inferolateral portion of the cranial cavity
15
Q
what are the features of the temporal bone?
A
Styloid process
Mastoid process
Stylomastoid foramen
Carotid foramen
Jugular foramen
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16
Q
what nerve passes through the stylomastoid foramen?
A
CN VII
17
Q
what artery passes through the carotid foramen?
A
Internal carotid artery
18
Q
what vein passes through the jugular foramen?
A
Internal jugular vein, CN IX, CN X, CN XI
19
Q
features of the temporal bone:
A
Zygomatic process
Mandibular fossa
External auditory meatus
Internal auditory meatus
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20
Q
Zygomatic process:
A
A finger-like projection that extends anteriorly to meet the zygomatic bone.
21
Q
Mandibular fossa:
A
A depression that articulates or forms a joint with the condylar process of the mandible.
22
Q
External auditory meatus:
A
A passage or opening leading to a canal for sound transmission.
23
Q
Internal auditory meatus:
A
A passageway for cranial nerves 7 & 8.
24
Q
What are the structures found between the external auditory meatus and internal auditory meatus in the temporal bone?
A
two cavities: the middle ear and inner ear.
25
The boundary between the external auditory meatus and the middle ear is covered by___
the tympanic membrane or eardrum.
26
There is a small opening between the middle and inner ears called:
the oval window.
27
The middle ear contains three small bones called the ____ and consists of ___, ____, and ___.
The middle ear contains three small bones called the auditory ossicles: the malleus, incus, and stapes.
28
The malleus is attached to ____, while the stapes is attached to the ____.
the tympanic membrane
membrane covering the oval window.
29
How are sound waves transmitted from the outer ear to the inner ear, and what is their significance?
Sound waves vibrate the tympanic membrane, which then vibrates the auditory ossicles in the middle ear.
30
where are vibrations in the ear transmitted?
These vibrations are transmitted to the cochlea in the inner ear, enabling us to hear. Damage to the tympanic membrane, auditory ossicles, or middle ear cavity can result in diminished hearing.
31
what is the structure of occipital bone?
The back of the head
The posteroinferior portion of the cranial cavity
32
features of the occipital bone:
Foramen magnum
Occipital condyle (2)
External occipital protuberance
Superior nuchal line (2)
Inferior nuchal line (2)
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33
External occipital protuberance:
A bump on the back of the head in the midline.
34
Superior nuchal lines:
Small ridges extending laterally from the external occipital protuberance.
35
Inferior nuchal lines:
Ridges located a couple of centimeters inferior to the superior nuchal lines.
36
Foramen magnum:
A large hole in the base of the occipital bone through which structures like the medulla oblongata (brain stem), cranial nerve 11, and vertebral arteries pass.
37
Occipital condyles:
Bony projections on either side of the foramen magnum that articulate with the superior facets of the first cervical vertebra (C1) to form the atlanto-occipital joints.
38
what is the structure associated with the sphenoid bone?
The middle part of the inferior portion of the cranial cavity
Part of each orbit
Part of the nasal cavity
39
_____ is derived from the Greek word for “wedge”, because it sits in the middle of the cranial cavity and articulates with every other cranial bone.
the sphenoid bone
40
what are the features of the sphenoid bone?
Body
Sella turcica (“Turkish saddle”)
Sphenoid sinus
41
When the sphenoid bone is removed from the skull it resembles _____.
a bird or bat like creature with a central body for wings projecting laterally, and four wing like processes projecting inferiorly.
42
what is the central portion of the sphenoid bone called?
the body
43
what structure is within the body of the sphenoid?
the sphenoid sinus (one of the paranasal sinuses).
44
what is the superior portion of the sphenoid bone referred to
the Sella turcica
45
features of the sphenoid process:
Features:
Greater wing (2)
Lesser wing (2)
Pterygoid process (4)
46
Describe the four wing-like processes of the sphenoid bone and the forward leg projections.
The sphenoid bone has two greater wings and two lesser wings projecting laterally from its body. Additionally, it has forward leg projections called pterygoid processes. These processes serve as attachment points for some of the muscles that attach onto the base of the skull
47
features of the sphnoid bone:
Optic foramen (2)
Superior orbital fissure (2)
48
What are the two openings within the back of each orbit of the sphenoid bone, and what structures pass through them?
Optic foramen: This small opening allows cranial nerve 2 (optic nerve) to pass out of the orbit.
Superior orbital fissure: This larger opening allows cranial nerves 3, 4, and 6, as well as a portion of cranial nerve 5, to pass between the orbit and cranial cavity.
49
features of the sphenoid:
Foramen ovale (2)
Foramen rotundum (2
50
What are the two additional openings within each greater wing of the sphenoid bone, and what cranial nerve utilizes them?
Foramen rotundum: Located on the anterior surface of the greater wing.
Foramen ovale: Located on the inferior surface of the greater wing.
Both openings are used by cranial nerve 5 (trigeminal nerve) to exit the cranial cavity.
51
features of the ethmoid bone?
Cribriform plate
Olfactory foramina
Crista Galli
52
What structures does the ethmoid bone form?
Portion of the medial wall of each orbit.
Much of the roof and lateral walls of the nasal cavity.
A large part of the nasal septum, which separates the nasal cavity into left and right sides.
53
The portion of the ethmoid bone that separates the cranial cavity above from the nasal cavity below is called___
the cribriform plate.
54
Within this plate are numerous small openings called ___ and are innervated by which nerve?
Olfactory foramina
innervated by CN I
55
What structures within the nasal cavity are associated with olfaction, and how do they connect to cranial nerve 1?
Olfactory or smell receptors within the nasal cavity have nerve roots that extend through the olfactory foramina. These nerve roots form the first part of cranial nerve 1, also known as the olfactory nerve.
56
Extending superiorly, from the cribriform plate, is a bony projection called _____.
the Crista Galli
57
a feature of the ethmoid bone; extending inferiorly from the cribriform plate is the ____
perpendicular plate, which forms part of the nasal septum
58
a feature of the ethmoid bone; extending laterally from the cribriform plater are the ____
two lateral masses, which form the walls of the nasal cavity
59
what is within the lateral mass of the ethmoid bone?
a series of small spaces called the ethmoid sinuses, which form a group of paranasal sinuses.
60
a feature of the ethmoid bone; what extends medially from each lateral mass?
a superior nasal concha and a middle nasal concha.
61
what is the purpose of the nasal concha of the ethmoid bone?
create turbulence as air passes into the nasal cavity, which allows the air to warm and be moistened before it passes into the lungs.
62
features of the facial bones:
nasal bones (2)
lacrimal bones (2)
zygomatic bones (2)
maxillae (2)
palatine bones (2)
vomer
inferior nasal conchae (2)
mandible
63
Where are the nasal bones located, and what do they form?
The nasal bones lie inferior to the frontal bone on either side of the midline. They form the superior border of the opening to the nasal cavity.
64
Where are the lacrimal bones located, and what is their function?
The lacrimal bones lie anterior to the ethmoid bone within the medial wall of each orbit. They contribute to the formation of the tear duct system. Lacrimation refers to the production of tears, and excess tears flow through ducts into the nasal cavity, leading to a runny nose during crying.
65
What are the functions of the zygomatic bones?
The zygomatic bones form much of the bony portion of each cheek and the lateral walls of each orbit. They also have temporal processes that extend posteriorly to the temporal bone.
66
What structures collectively form the zygomatic arch, and what bones do they belong to?
The zygomatic arch is formed by the temporal process of the zygomatic bone and the zygomatic process of the temporal bone. It's important to note that the temporal process is a feature of the zygomatic bone, while the zygomatic process is a feature of the temporal bone.
67
Where are the maxillae bones located within the skull?
The maxillae bones are in the middle of the face.
68
What do the maxillae bones articulate with?
The maxillae bones articulate with the upper teeth.
69
What is the infraorbital foramen and what passes through it?
The infraorbital foramen is a small opening in each maxilla bone. It allows the passage of a small artery and nerve.
70
What structure do the maxillae collectively form?
The maxillae collectively form most of the hard palate, which separates the nasal cavity above from the oral cavity below.
71
What is contained within each maxilla bone?
Each maxilla bone contains a maxillary sinus, which is one of the paranasal sinuses.
72
What bones are posterior to the maxillae, and what structure do they form?
The palatine bones are posterior to the maxillae, and they form the posterior part of the hard palate.
73
What are the additional bones associated with the nasal cavity?
Vomer: lies inferior to the perpendicular plate of the ethmoid bone
inferior nasal concha: lies along the lateral walls of the nasal cavity, inferior to the middle nasal concha of the ethmoid bone
74
What is the portion of the mandible that articulates with the lower teeth called?
The body.
75
What are the two processes found on each ramus of the mandible?
The coronoid process anteriorly and the condylar process posteriorly, with a mandibular notch in-between.
76
What structures do the condylar processes of the mandible articulate with?
The condylar processes articulate with the mandibular fossa of the temporal bone to form the temporomandibular joints.
77
What is the mandibular foramen used for?
The mandibular foramen serves as the entranceway to a passage that nerves and blood vessels use to reach the lower teeth.
78
What is the significance of the mandible in the skull?
Other than the auditory ossicles, the mandible is the only movable bone in the skull.
79
bone and contents of olfactory foramina
ethmoid
CNI
80
bone and contents of the optic foramen
sphenoid
CNII
81
bone and contents of the superior orbital fissure
sphenoid
CN III, CN IV, CN V, CN VI
82
foramen ovale bone and contents
Sphenoid, CN V
83
foramen rotundum bone and contents
sphenoid and CN V
84
internal auditory meatus bone and contents
temporal
CN VII, CN VIII
85
stylomastoid foramen bone and contents
temporal
CN IX, CN X, CN XI, internal jugular vein
86
Carotid foramen bone and contents
temporal, internal carotid artery
87
foramen magnum bone and contents
occipital
medulla oblongata, CN XI, vertebral arteries
88
what forms the roof of the orbits?
Frontal bone
Sphenoid bone
89
what forms the medial wall of the orbits?
Maxilla
Lacrimal bone
Ethmoid bone
Sphenoid bone
90
what forms the floor of each orbit?
Maxilla
Zygomatic bone
Sphenoid bone
91
what forms the lateral wall of each orbit?
Zygomatic bone
Sphenoid bone
92
What separates the nasal cavity into left and right sides?
nasal septum
93
what is the nasal septum composed of?
Composed of cartilage (anteriorly) and bone (posteriorly)
94
What structures form the posterior portion of the nasal septum?
The posterior portion of the nasal septum is formed by the perpendicular plate of the ethmoid bone and the vomer.
95
Paranasal Sinuses:
Cavities within certain bones lined with mucous membranes that are continuous with the nasal cavity
96
function of the paranasal sinuses
decrease the weight of the skull and increase the surface area of the nasal mucosa (moisten/clean inhaled air)
97
which bones have sinuses?
the frontal bone, sphenoid bone, ethmoid bone, and maxillae
98
where is the hyoid bone located?
anterior neck between the mandible and larynx
99
what attaches to the hyoid bone?
muscles of the tongue, pharynx, and anterior neck
100
what is the purpose of the hyoid bone?
Assists in tongue movements and swallowing
