The Axial Skeleton Flashcards
(125 cards)
1
Q
How many bones are found in an adult human body?
A
~206
2
Q
What is the axial skeleton?
A
Forms longitudinal axis of body
3
Q
What are the bones of the axial skeleton
A
Skull, hyoid bone, vertebral column, and thoracic cage
It is the framework that supports the brain, spinal cord, and organs of the ventral body cavity
4
Q
What is the appendicular skeleton?
A
Bones of the limbs and girdles that connect them to axial skeleton
5
Q
What is the function of bone markings?
A
Attachment of muscles, grooves for nerves & blood vessels, bone articulations s
6
Q
Bone markings
What is a projection or process?
A
Any projection or bump
7
Q
Explain what a head projection/process is
A
The expanded articular end of an epiphysis, seperated from the shaft by a neck
8
Q
Explain what a tuberosity process is, it attaches what?
A
Process formed where tendons or ligaments attach
A smaller rough projection
9
Q
Explain what a tubercle process is, it attaches what?
A
Processes formed where tendons or ligaments attach
A small rounded projection
10
Q
Explain what a condyle process is, it attaches to what?
A
Processes formed for articulation with adjacent bones
A smooth, rounded articular process
11
Q
What is a fossa
A
A depression
12
Q
What is a foramen?
A
An opening, rounded passageway for blood vessels or nerves
13
Q
How many frontal bones does an adult skeleton have?
A
1
14
Q
What is the frontal bones function
A
Forms forehead and upper parts of orbits
15
Q
What are some special features or landmarks of the frontal bone?
A
Contains frontal-sinus mucus cavity
Formed by the union of 2 bones at metopic suture: usually disappears by age 8 when bones fuse
16
Q
What is the metopic suture?
A
Forms the frontal bone usually disappears by age 8
17
Q
How many parietal bones does an adult skeleton have?
A
2
18
Q
What does the parietal bone form?
A
Forms sides and roof of cranium
19
Q
How many temporal bones does an adult skeleton have?
A
2
20
Q
What is the function of the temporal bones?
A
Forms lateral wall of cranium and part of cranial floor
21
Q
What are the specific processes of the temporal bone?
A
Zygomatic process Mastoid process Styloid process External auditory canal Mandibular fossa
22
Q
Explain what the zygomatic process of the temporal bone does
A
Forms posterior part of the zygomatic arch
23
Q
Explain what the mastoid process of the temporal bone does
A
Rounded projection behind ear is a muscle attachment site
24
Q
Explain what the styloid process of the temporal bone does
A
Slender spike extending downward
Where ligaments attach that support hyoid bone
25
Explain what external auditory canal in the temporal bone does?
Canal leading to middle ear
26
Explain what the mandibular fossa of the temporal bone does
Depression on inferior surface which forms socket for mandible
27
How many occipital bones does an adult human skeleton have
1
28
What is the function of the occipital bone
Forms much of the posterior and inferior surfaces of the cranium
29
What are the special features of the occipital bone?
Occipital condyles
| Foramen magnum
30
Explain what the occipital condyles of the occipital bone does
Oval processes that articulate with the first cervical vertebra knuckle like projection
31
Explain what the foramen magnum of the occipital bone does
Large hole, connects the cranial cavity to the spinal cavity; surrounds connection between brain and spinal cord
32
How many ethmoid bones can be found in an adult skeleton?
1
33
What is the function of the ethmoid bone
Irregularly shaped; forms inner surface of cranial floor, medial walls of orbit, roof of nasal cavity, and superior part of nasal septum
34
What are the special features or landmarks of the ethmoid bone? (5)
```
Cribiform plate
Crista galli
Superior and Middle Nasal conchae
Perpendicular plate
Ethmoid sinus
```
35
Explain what the cribiform plate of the ethmoid bone does
Forms floor of cranium and roof nasal cavity, contains perforations= olfactory bulb
36
Explain what the crista galli of the ethmoid bone does
Upward projecting triangular process, attachment site for meninges of brain
37
Explain what the superior and middle nasal conchae of the ethmoid bone does
Forms lateral masses that form walls of nasal cavity
38
Explain what the perpendicular plate of the ethmoid bone does
Slender process in midline that forms upper part of nasal septum
39
Explain what the ethmoid sinus of the ethmoid bone does
Mucus lined cavities
40
How many sphenoid bones does the adult skeleton have
1
41
What is the function of the sphenoid bone?
Keystone of cranial floor; acts as a cross brace to strengthen skull by extending from one side of cranium to other; resembles bat with wings extended; forms side of skull, most of cranial floor and part of the orbit
42
What are the special features or landmarks of sphenoid bone? (4)
Body
Sella turcica
Greater wing
Sphenoidal sinus
43
Explain what the body of the sphenoid bone does
Central portion
44
Explain what the sella turcica of the sphenoid bone does
Saddle shaped depression on superior surface
| Pituitary gland sits here
45
Explain what the greater wing of the sphenoid bone does
Lateral projections that form part of orbit and lateral walls of skull anterior to temporal bone
46
Explain what the sphenoidal sinus of the sphenoid bone does
Mucus lined cavities
47
Facial bones
| How many nasal bones does an adult human skeleton have?
2
48
What is the function of the nasal bone
Forms bridge of nose
49
How many maxillary bones will you find in an adult skeleton?
2
50
What is the function of the maxillary bones? What does it form
Forms upper jaw and parts of orbit, anterior part of roof of mouth (hard palate)
51
How many zygomatic bones will you find in an adult skeleton?
2
52
Explain the function of the zygomatic bone what does it form?
Forms part of zygomatic arch and part of outer wall and floor of orbit
53
What are the 2 special features/landmarks of the maxillary bone?
Maxillary sinus
| Palatine process
54
Explain what the maxillary sinus of the maxillary bone does
Mucus lined cavity
55
Explain what the palatine process of the maxillary bone does
Horizontal projection that forms bony roof of mouth anterior 2/3 hard palate
56
How many mandibles can you find in an adult skeleton?
1
57
What is the function of the mandible?
Lower jaw main horizontal part forms chin
58
What are the two special features of the mandible?
Alveolar process
| Mandibular condyle
59
Explain what the alveolar process of the mandible does
Sockets for teeth
60
Explain what the mandibular condyle does
Articulates with mandibular fossa of temporal bone
61
What is the function of the palatine bone?
Forms posterior part of hard and small part of orbit floor
62
What is the function of the inferior nasal conchae?
Forms lower part of lateral walls of nasal cavity
63
What is the function of the vomer bone?
Forms lower part of nasal septum
64
Explain what a suture is
Immovable joints between skull bones
65
What is a wormian (sutural bones)
Usually present along a lambdoid suture
66
What is a an orbit
| Special features of the skull
Made up of several bones bony recesses that contain the eyes
67
What forms the superior portion of the nasal septum
Perpendicular plates of ethmoid bone
68
What forms the perpendicular plate of the nasal septum
Ethmoid
69
What forms the perpendicular plate of the inferior portion of the nasal septum
Vomer
70
What are the three main qualities brought about by the paranasal sinuses
Lightens the skull
Extensive area of mucous epithelium
Sound quality of voice
71
What are fontanels what are their function?
Fetal skulls large fibrous areas between cranial bones
Distortion of skull for delivery
Allows for brain growth to continue after birth
72
What is the function of the hyoid bone
Horseshoe shaped bone in neck between mandible and larynx
73
What are the special features or landmarks of the hyoid bone
Supports tongue and serves as attachment for muscles
74
What is the vertebral column
A flexible segmented rod that is shaped like an elongated "S"
75
What is the function of the vertebral column
Forms axis of body and encloses spinal cord
76
Why is the spinal column curved
Allows body to remain in balance when standing upright
77
Name the four curves of the spinal column
Cervical, thoracic, lumbar, sacral
78
When curves in the spine are posterior it's called ___
Concave
79
When curves in the spine are anterior it's called ___
Convex
80
What are the primary curves
Ones you are born with
| Thoracic and sacral
81
What are secondary curves
Ones you develop after birth
| Cervical & lumbar
82
What is kyphosis?
Exaggeration of thoracic curve
83
What is lordosis
Exaggeration of lumbar curve
84
What is scoliosis?
Abnormal lateral curvature of spine
85
Features of a Typical Vertebra
| Explain what the body of typical vertebra is?
Thick, disc-shaped anterior part of vertebrae
86
The vertebral arch of a typical vertebra is formed by what 2 things?
Pedicles and lamina
87
Explain what a pedicicle is within the vertebral arch
Two short thick projections which extend posteriorly from body
88
Explain what a lamina is within the vertebral arch
Flat part that joins to form the dorsal wall of the vertebral arch
89
What is the vertebral foramen
Hole in the center of a vertebra formed by the union of the body, pedicels and lamina
90
What are the 3 characteristics that make the cervical vertebra unique?
Small
Spinous process is split
Transverse foramen in transverse processes
91
What are the things that make the atlas or C1 unique
No body
No spinous process
Large round vertebral foramen
Contains superior articular surfaces
92
How does the atlas get its name
Holds up head
93
What action is provided by the joint between the atlas and the occipital condyles?
Nod head
94
Explain what defines the C2 or axis
Has a body
| Contains a peg-like projection called the odontoid process or dens that extends into the atlas
95
What action is provided by the joint between the axis and the atlas?
Rotate head
96
In babies the dens is not fully fused to the axis. Why is shaking dangerous to a baby?
Dens can break go into brain
97
Why is the C7 the vertebra prominens unique?
Long non-bifid process (does not have transverse foramina)
| Largest cervical vertebra
98
How many thoracic vertebra are there
12
99
Explain the size of the thoracic vertebra
Larger than cervical vertebra
100
Explain what the spinous process is like in the thoracic vertebra
Spinous process is long, pointed, and directed inferiorly
101
Explain the transverse processes in the thoracic cavity
Long and heavy transverse processes that have facets for articulations with ribs
Bodies have facets or partial facets (Demi-facets) for articulation with ribs
102
What function do the lumbar vertebra do?
Largest and strongest vertebra supports weight if body
103
Explain the spinous process of the lumbar vertebra
Square projects posteriorly
104
Explain what the transverse lines on the anterior side of the sacrum are
Points where vertebrae have fused
105
Explain what the thorax is
Bony cage formed by sternum, costal cartilages, ribs, and bodies of thoracic vertebra
106
What are the three different parts of the sternum
Manubrium
Body
Xiphoid
107
Explain what the manubrium is
Triangular superior portion
108
Explain what the body of the sternum is
Middle, tongue shaped, largest portion
109
Explain what the xiphoid process of the sternum is
Inferior, smallest portion
110
How many pairs of ribs do most people have
12 pairs= 24 pairs
111
What are the three main features of ribs
Head
Tubercle
Body/shaft
112
Explain what the head on the rib is
Projection at posterior end of rib
113
Explain what the tubercle of the rib is
Knoblike elevation
114
Explain what the body/shaft of the rib is
Flat, main part of rib
115
What is the real name for true ribs
Vertebrosternal
116
How many pairs are in the vertebrosternal ribs
1-7
117
What is the anterior articulation of vertebrosternal ribs
Costal cartilages of sternum
118
What is the posterior articulation of the vertebrosternal ribs
Thoracic vertebrae
119
What are the two kinds of vertebrochondral ribs
Vertebrochondral
| Vertebral/floating
120
Which sets of ribs are the vertebrochondral ribs
8-10
121
Where is the anterior articulation of the vertebrochondral ribs
Costal cartilage of rib 7
122
What is the posterior articulation of the vertebrochondral ribs
Thoracic vertebrae
123
Which of the ribs are the vertebral/floating
11,12
124
What is the anterior articulation of the vertebral/floating ribs
Not attached directly
125
What is the posterior articulation of the vertebral/floating ribs
Thoracic vertebrae
