Chapter 7 - Skeletal: Axial System Flashcards
(134 cards)
0
Q
What is the musculoskeletal system?
A
The combination of bones, muscles, and joints
1
Q
How does the axial skeleton contribute to homeostasis?
A
By protecting many of the body’s organs (brain, spinal cord, heart, lungs)
Important in support and calcium storage and release
2
Q
What is orthopedics?
A
Prevention and correction of disorders of the musculoskeletal system
3
Q
How many bones does an adult have?
A
206
Children have more b/c some of their bone haven’t fused yet
4
Q
What are the two principle divisions of the skeletal system?
A
- Axial skeleton - 80 bones
2. Appendicular skeleton - 126 bones
5
Q
What bones make up the axial skeleton?
A
Skull (cranium and face) Hyoid Auditory ossicles Vertebral column Thorax (sternum and ribs)
6
Q
What bones make up the appendicular skeleton?
A
Pectoral girdles
Upper limbs
Lower limbs
Pelvic girdle
7
Q
What are the 5 main types of bones based on shape?
A
Long Short Flat Irregular Sesamoid
8
Q
What are the characteristics of long bones?
A
Greater length than width Consist of a shaft and a variable number of extremities or epiphyses (ends) Slightly curved for strength Compact bone tissue in their diaphyses Spongy bone tissue in their epiphyses
9
Q
Give some examples of long bones.
A
Femur (thigh bone) Tibia and fibula (leg bones) Humerus (arm bone) Ulna and radius (forearm bones) Phalanges (finger and toe bones)
10
Q
What are the characteristics of short bones?
A
Somewhat cube-shaped
Nearly equal in length and width
Consist of spongy bone tissue except at the surface (thin layer of compact bond)
11
Q
What are some examples of short bones?
A
Carpal (wrist bones)
Tarsal (ankle bones)
12
Q
What are the characteristics of flat bones?
A
Generally thin and composed of two nearly parallel plates of compact bone tissue enclosing a layer of spongy bone tissue
Provide protection and extensive areas for muscle attachment
13
Q
Give some examples of flat bones.
A
Cranial bones
Sternum
Ribs
Scapulae
14
Q
What are the characteristics of irregular bones?
A
Complex shapes and cannot be grouped into any other previous category
15
Q
Give some examples of irregular bones.
A
Vertebrae (backbones)
Hip bones
Certain facial bones
Calcaneus
16
Q
What are the characteristics of sesamoid bones?
A
Develop in certain tendons where there is considerable friction, tension, physical stress
Very small! A few mm in diameter
May vary in number from person to person, may not be completely ossified
17
Q
What are the functions of sesamoid bones?
A
Protect tendons from excessive wear
Often change the direction of pull of a tendon
Improves mechanical advantage at a joint
18
Q
What are the notable exceptions of sesamoid bones? (Not small, and present in everyone)
A
Two patellae (kneecaps) Large sesamoid bones located in the quadriceps femoris tendon
19
Q
What is another type of classification of bone based on location, not shape?
A
Sutural bones
20
Q
What are sutural bones?
A
Small bones located in sutures (joints) between certain cranial bones
Their numbers vary from person to person
21
Q
Where is red bone marrow found? Which bones?
A
Ribs Sternum Skull Vertebrae Hip bones Femur (the proximal epiphyses) Humerus Some short bones
22
Q
What are surface markings?
A
Structural features adapted for specific functions
Develop in response to certain forces
Most prominent in the adult skeleton
23
Q
What are two major types of surface markings?
A
- Depressions and openings
2. Processes
24
Describe the characteristics of "depressions and openings" (surface markings)
Allow the passage of soft tissues (such as blood vessels, nerves, ligaments, and tendons) and
Form joints
25
What are processes (surface markings)?
Projections or outgrowths that either help form joints or serve as attachment points for connective tissue
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What is a fissure? What kind of surface marking is it?
Narrow slit between adjacent parts of bones through which blood vessels or nerves pass
*depression or opening
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What is a foramen? What kind of surface marking is it?
Opening through which blood vessels, nerves or ligaments pass
*depression or opening
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What is a fossa? What kind of surface marking is it?
Shallow depression
| *depression or opening
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What is a sulcus? What kind of surface marking is it?
Furrow along bone surface that accommodates blood vessel, nerve or tendon
*depression or opening
30
What is a meatus? What kind of surface marking is it?
Tubelike opening
| *depression or opening
31
What is a condyle? What kind of surface marking is it?
Large, round protuberance with a smooth articular surface at end of bone
* process that form joints
32
What is a facet? What kind of surface marking is it?
Smooth, flat, slightly concave or convex articular surface
| * process that forms joints
33
What is a head? What kind of surface marking is it?
Usually round articular projection supported on neck (constricted portion) of bone
* process that forms joints
34
What is a epicondyle? What kind of surface marking is it?
Typically roughened projection above condyle
| * process that form attachment points for connective tissue
35
What is a crest? What kind of surface marking is it?
Prominent ridge or elongated projection
| * process that form attachment points for connective tissue
36
What is a line? What kind of surface marking is it?
Long, narrow ridge or border (less prominent than crest)
| * process that form attachment points for connective tissue
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What is a spinous process? What kind of surface marking is it?
Sharp, slender projection
| * process that form attachment points for connective tissue
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What is a trochanter? What kind of surface marking is it?
Very large projection
| * process that form attachment points for connective tissue
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What is a tubercle? What kind of surface marking is it?
Variably sized rounded projection
| * process that form attachment points for connective tissue
40
What is a tuberosity? What kind of surface marking is it?
Variably sized projection that has a rough, bumpy surface
| * process that form attachment points for connective tissue
41
What is the skull?
Bony framework of the head
42
How many bones are in the skull?
22 bones (not counting the bones in the middle ears)
43
What are the two categories of skull bones?
1. Cranial bones
| 2. Facial bones
44
What is the function of the cranial bones?
Form the cranial cavity
| Enclose and protect the brain
45
Name the 8 cranial bones.
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Frontal bone
2 parietal bones
2 temporal bones
Occipital bone
Sphenoid bone
Ethmoid bone
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46
Name the 14 facial bones.
```
2 nasal bones
2 maxillae
2 zygomatic bones
Mandible
2 lacrimal bones
2 palatine bones
2 inferior nasal conchae
Vomar
```
47
What is the frontal bone?
Forms the forehead (anterior part of the cranium)
48
Where are the 2 parietal bones?
Sides and roof of the cranial cavity (form a large part of it)
49
What is in the internal surface of the parietal bones?
Many protrusions and depressions that accommodate the blood vessels supplying the dura mater
50
How is the zygomatic arch formed?
By the zygomatic process of the temporal bone and the temporal process of the zygomatic bone
51
Where is the mandibular fossa located?
On the inferior posterior surface of the zygomatic process of each temporal bone
52
What forms the temporomandibular joint (TMJ)?
The mandibular fossa and the articular tubercle
| Also articulates the mandible
53
What serves as an attachment point of muscle and ligaments of the tongue and neck?
The styloid process
54
What houses the middle and internal ear?
The petrous portion of the temporal bone
55
What passes through the carotid foramen?
Carotid artery
56
What is the passageway for the jugular vein?
Jugular foramen
57
With which bones does the temporal bone articulate?
The mandible, parietal, sphenoid, zygomatic, occipital
58
What forms the most of the posterior and inferior portions of the cranium?
Occipital bone
59
What connects within the foramen magnum?
Medulla oblongata connects with the spinal cord
60
What forms the atlanto-occipital joint?
The occipital condyles and the depressions of the first cervical vertebrae
61
What allows you to nod your head "yes"?
The atlanto-occipital joint
62
What is the most prominent midline projection on the posterior surface of the bone just above the foramen magnum?
The external occipital protuberance
63
What ligament extends from the external occipital protuberance to the 7th cervical vertebrae?
Ligamentum nuchae
64
What bone is called the keystone and why?
The sphenoid bone, b/c it articulates with all other cranial bones - holding them together
65
What contains the pituitary gland?
Hypophyseal fossa
66
What passes through the optic foramen?
Optic (II) nerve and the ophthalmic artery
67
What is the nasal septum?
A partition that divides the nasal cavity into right and left sides
68
What is the lacrimal sac? Where is it located?
A structure that gathers tears and passes them into the nasal cavity
Lacrimal fossa
69
What are the 5 openings associated with each orbit?
1. Optic foramen
2. Superior orbital fissure
3. Inferior orbital fissure
4. Supraorbital foramen
5. Lacrimal fossa
70
What is a suture?
An immovable joint, holds skull bones together
71
What are the 4 prominent sutures?
1. Coronal suture - unites frontal and parietal bones
2. Sagittal suture - unites the two parietal bones (top of the skull)
3. Lambdoid suture - parietal bones to occipital bone
4. Squamous suture - unite the parietal and temporal bones
72
What are the functions of the paranasal sinuses?
Produce mucus and serve as resonating chambers for vocalization
73
What are fontanels?
Soft spots
Areas where unossified mesenchyme develops into dense connective tissue of the skull
Serve as spacers for growth
74
What are the six main fontanels?
1. Anterior fontanel
2. Posterior fontanel
3. Paired anterolateral fontanels
4. Paired posterolateral fontanels
75
What does the hyoid bone do?
Supports the tongue, providing attachment sites for some tongue muscles and for muscles of the neck and pharynx
76
How is the vertebral column distributed?
```
7 cervical vertebrae
12 thoracic vertebrae
5 lumbar vertebrae
1 sacrum
1 coccyx
```
77
How many curves are in a normal adult spine? In a fetus?
4 in an adult
| 1 in a fetus
78
What is special about the hyoid bone? How is it different?
Does not articulate with any other bone
| It is suspended by ligaments and muscles
79
Which normal curves are convex? Which are concave in an adult spine?
Cervical and lumbar are convex
| Thoracic and sacral are concave
80
What are the primary curves?
Thoracic and sacral curves b/c they retain their original curvature of the embryonic vertebral column
81
What are the secondary curves?
Cervical and lumbar b/c they begin to form several months after birth
82
What are the names of three abnormal curves of the spine?
Kyphosis
Lordosis
Scoliosis
83
What are intervertebral discs?
Found between the bodies of adjacent vertebrae from the second cervical vertebrae to the sacrum
84
What are the two parts of an intervertebral disc?
1. Annulus fibrosus - outer fibrous ring consisting of fibrocartilage
2. Nucleus pulposus - inner soft, pulpy, highly elastic substance
85
What are the functions of the intervertebral discs?
Form strong joints, permit various movements, absorb vertical shock
86
Why do we get shorter during the day?
During the course of the day, the discs compress and lose water in their cartilage
Sleeping, there is less compression and rehydration occurs
87
Are intervertebral discs vascular or avascular?
Avascular - they rely on blood vessels from the bodies of the vertebrae
88
What is the vertebral body?
The thick, disc-shaped anterior portion
| Weight bearing portion
89
What is on the anterior and lateral surfaces of the vertebral body?
Nutrient foramina, openings through which blood vessels deliver nutrients and remove wastes
90
What is a vertebral arch?
Two short, thick processes (the pedicles) project posteriorly from the vertebral body and then unite with the flat laminae
91
What does the vertebral foramen contain?
Spinal cord, adipose tissue, areolar connective tissue, blood vessels
92
How many processes arise from the vertebral arch?
7
93
Name the 7 processes of the vertebral arch.
Transverse process (x2) - where lamina and pedicle join
Spinous process - projects posteriorly from the junction of the laminae
Superior articular process (x2) - join with inferior articular processes
Inferior articular process (x2) - join with superior articular processes
94
What are osteophytes?
Bony growths around intervertebral discs
Can lead to a narrowing of the vertebral canal
Happens as you age
95
What are the three main parts of a typical vertebra?
1. Vertebral body
2. Vertebral arch
3. 7 vertebral processes
96
What is the thorax?
Refers to the entire chest region
97
What makes up the thoracic cage?
Formed by the sternum, ribs, and their costal cartilage and the bodies of the thoracic vertebrae
98
What does costal cartilage do?
Attach the ribs to the sternum
99
What is the function of the thoracic cage?
Protects the organs in the thoracic and superior abdominal cavities
Provides support for the upper limbs
Plays a role in breathing
100
Identify the location and surface features of the cervical vertebrae.
C1-C7
Smaller than all other vertebrae (except coccyx)
Vertebrae arches are larger
Have three foramina
101
What is contained in the vertebral foramina and in the 2 transverse foramina?
Vertebral foramina - spinal cord
| Transverse foramina - vertebral arteries and veins, and nerves
102
What is the atlas?
C1
First cervical vertebra inferior to the skull
Lacks a body and spinous process
103
What is the axis?
C2
| Has a vertebral body
104
What allows you to move your head to signify "no"?
The dens (a peglike process) makes a pivot on which the atlas and head rotate
105
What is the usual cause of death in whiplash injuries?
The dens of the axis is driven into the medulla oblongata of the brain
106
Identify the location and surface features of the thoracic vertebrae.
T1-T12
Larger and stronger than cervical vertebrae
Spinous processes on T1-T10 are long, laterally flattened and directed inferiorly
107
How is the spinous process on T11 and T12 different?
Shorter, broader, and directed more posteriorly
108
What are costal facets? Which vertebrae have them?
```
Articular surfaces for the ribs
Thoracic vertebrae (except for T11 and T12)
```
109
What is a facet?
Is formed when the head of a rib articulates with the body of one vertebra
110
What is a demifacet?
Is formed when the head of a rib articulates with two adjacent vertebral bodies
111
Identify the location and surface features of the lumbar vertebrae.
L1-L5
Largest and strongest of the unfused bones in the vertebral column
Projections are short and thick
112
Describe the spinous processes of the lumbar vertebrae
Quadrilateral in shape, thick and broad and project nearly straight posteriorly
Well adapted for the attachment of the large back muscles
113
What is the sacrum?
A triangular bone formed by the Union of five sacral vertebrae
S1-S5
114
When do the sacral vertebrae begin to fuse?
Between 16-18 years of age, completed by age 30
115
What does the sacrum serve as?
A strong foundation for the pelvic girdle
| Female - shorter, wider and more curved
116
What is the sacral canal?
A continuation of the vertebral cavity
117
What is the sacral hiatus?
When the 4th and 5th sacral vertebrae fail to meet, it leaves an inferior entrance to the vertebral canal
118
What is the coccyx?
Triangular in shape
Formed by the fusion of 4 coccygeal vertebrae
Co1-Co4
Fuse between the ages of 20-30
119
What is the sternum?
A flat, narrow bone located in the centre of the anterior thoracic wall
Consists of three parts
120
What are the three parts of the sternum?
1. Manubrium - superior part
2. Body - middle and largest
3. Xiphoid process - inferior, smallest
Typically fuse by age 25
121
Describe the xiphoid process in detail.
Does not completely ossify till age 40
No ribs are attached to it
Provides attachment for some abdominal muscles
Incorrect positioning during CPR, may fracture the xiphoid process
122
With which ribs does the body of the sternum articulate?
Directly or indirectly with ribs 2-10
123
How many ribs do we have?
Twelve pairs of ribs
124
Describe the length of the ribs.
1-7 increase in length
| 8-12 decrease in length
125
Which ribs have a direct anterior attachment to the sternum?
1-7
By a strip of hyaline cartilage called costal cartilage
Called TRUE ribs
126
Why are some ribs called false ribs?
8-12
B/c their costal cartilage either attach indirectly to the sternum or do not attach to the sternum at all
Called vertebrochondral ribs
127
Which are the floating ribs? Why?
11-12
| B/c their costal cartilage at their anterior ends do not attach to the sternum at all
128
How does a rib articulate with a thoracic vertebra?
The facet on the head of a rib fits into a facet on the body of a vertebra, and the articular part of the tubercle of a rib articulates with the fact of the transverse process of the vertebra
129
What is a herniated disc?
Pressure that ruptures the surrounding fibrocartilage
| The nucleus pulposus may protrude (herniate) posteriorly or into one of the adjacent vertebral bodies
130
What is scoliosis?
Most common
Lateral bending of the vertebral column
Usually in the thoracic region
131
What is kyphosis?
Increase in the thoracic curve
Hunchback
Common in females with osteoporosis
132
What is lordosis?
Hollow back
Increase in the lumbar curve
From increased weight of pregnancy or extreme obesity
133
What is spina bifida?
Laminae of L5 and/or S1 fail to develop normally and unite at the midline
