Axial Skeleton (Ch 7) Flashcards Preview

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Flashcards in Axial Skeleton (Ch 7) Deck (85):
1

What are the parts of the axial skeleton?

skull
hyoid bone
vertebral column
thoracic cage
-80 named bones

2

What are the functions of the axial skeleton?

1. supports head, neck, and trunk
2. protects brain, spinal cord, and thoracic organs

3

Foramen

a hole in a bone
--> typically for nerves/blood vessels

4

Fossa

a depression in a bone

5

Process

projection from a bone, narrow or wide, protrudes from surrounding bone

6

Meatus

hole/tube-like structure

7

Canal

a groove/tube-like structure, passageway for nerves/blood vessels

8

The Skull

-28 bones (complex!)
-mostly flat bones formed via intramembranous ossification
-bones united by sutures
-subdivides into cranial and facial divisions

9

What are sutures?

interlocking, immoveable joints

10

What are the functions of the cranial bones?

1. protect brain
2. provide attachment for some head/neck muscles

11

What are the functions of the facial bones?

1. form framework of face
2. openings for passage of food/air
3. hold the teeth
4. anchor muscles of the teeth

12

What are the subdivisions of the cranium?

1. Vault: superior, lateral, and posterior bones of the skull (including the forehead)
2. Base: inferior part of the crainum

13

What are the bones of the cranium?

1. Frontal
2. Occipital
3. Sphenoid
4. Ethmoid
5. Parietals (2)
6. Temporals (2)

14

Coronal Suture

between the frontal and two parietal bones

15

Squamous Sutures

between temporal and parietal bones (lateral)

16

Lambdoid Suture

between parietal bones and occipital bone

17

Saggital Suture

runs along midline of skull, between parietal bones

18

Frontal Bone

-makes up forehead
1. Superciliary Arches: deep to eyebrows at superior edge of orbit
2. Labella: superior to bridge of nose, smooth medial part

19

Parietal Bones

-posterior to frontal bone, make up most of superior part of skull
-touch saggital/lambdoid sutures

20

Occipital Bone

-bone at back of head, posterior to cranium/cranial base
-foramen magnum
-occipital condyles

21

foramen magnum

large opening of occipital bone the allows spinal cord to pass and connect with the brain

22

occipital condyles

where the skull articulates with the vertebral column

23

Temporal Bones

-paired temporal bones house opening to ear, base of cheekbone
-3 main regions: petrous, tympanic, squamous
--> petrous best seen internally (contains middle/inner ear cavities)
-External Acoustic Meatus
-mastoid/styloid processes: sites of muscle attachment
-TMJ

24

External Acoustic Meatus

opening in tympanic region leading to middle/inner ear

25

Temporomandibular Joint

the condylar process of the lower jaw fits into a depression in the temporal bone (mandibular fossa) --> creates jaw joint

26

Middle Ear Cavity

3 ossicles in middle ear
1. Malleus (lateral) "hammer"
2. Incus "anvil"
3. Stapes (medial) "stirrup"
--> sound waves cause vibrations that are transmitted to the inner ear

27

Sphenoid Bone

large/wing-shaped bone
-landmark: sella turcica
-only cranial bone that articulates with every other cranial bone

28

Sella Turcica

in sphenoid bone
-bony depression that holds pituitary gland ("master gland")

29

Ethmoid Bone

-just anterior to the sphenoid --> forms roof of nasal cavity
-takes up most of area between nasal cavity and orbits
-forms some boundaries of nasal cavity = separates nasal cavity from brain
-peaks up into frontal bone
-includes: cribriform plate and crista galli

30

cribriform plate

in ethmoid bone
-helps form roof of nasal cavities; foramina allow passage of olfactory nerves into brain = smell
*superior

31

crista galli

in ethmoid bone
-attaches to cribriform plate; separates nasal cavity from brain
-site of attachment for dura mater (brain membrane)
*inferior

32

Nasal Cavity

-lateral walls made up of nasal bones
-nasal conchae (superior, middle, inferior)
-frontal process of maxillae
-perpendicular plate of the palatines
-floor made up of hard palates --> formed by palatine process of maxillae and horizontal plate of palatine

33

What are the bones of the facial skeleton?

*14 bones
1. Mandible
2. Vomer
3. Two Nasals
4. Two Lacrimals
5. Two Maxillae
6. Two Zygomatic
7. Two Palatine
8. Two Inferior Nasal Conchae

34

Maxilla

-makes up part of nasal cavity, oral cavity, and orbit
-forms upper jaw
-articulates with ALL facial bones (except mandible)
Includes:
-alveolar, frontal, zygomatic processes
-infraorbital foramen

35

What is the alveolar process?

part of maxilla- contains teeth

36

What are the frontal processes?

part of maxilla- extend upward to reach frontal bone

37

What are the zygomatic processes?

part of maxilla- articulate with zygomatic bone

38

What is the infraorbital foramen?

part of maxilla- provides passage for infraorbital artery, vein, and nerve (below orbit)

39

The Orbit (what bones are the walls formed by?)

-supports the eyes and muscles that move them
-include fat and tear producing glands
-walls formed by frontal, sphenoid, zygomatic, maxillary, palatine, lacrimal, and ethmoid bones

40

Palate

-hard palate = ventral maxillary bones (anteriorly) and the palatine bones (posteriorly)

41

Inferior Nasal Septum

-vomer forms inferior portion of nasal septum

42

Cleft Palate

failure of the two sides of palate to join during development
-opening between mouth and nasal cavity makes nursing hard
-surgery --> good outcomes

43

Mandible

-largest/strongest bone in face
-body contains lower teeth
-tooth sockets on superior border
Two parts: ramus (superior/inferior) and body (anterior/posterior)

Includes:
-mandibular symphysis
-mental protuberance
-mental foramen
-condylar process
-coronoid process

44

mandibular symphysis

in mandible- where two halves of body join to form the chin (mental protuberance)

45

mental protuberance

on mandible- chin

46

mental foramen

in mandible- opening below teeth for vessels/nerves

47

condylar process

in mandible- articulate with temporal bone to form the TMJ (on both sides of jaw)

48

coronoid process

in mandible- serves as attachment site for temporalis (chewing) muscle

49

Fetal/Infant Skull

-skull bones not yet fully joined --> allows head to deform as it passes through the birth canal/allows brain growth
-fontanelles: sturdy membranous covering between cranial joints
-bones fuse over time
-cranium is proportionally huge relative to face in infancy

50

Craniosynostosis

fetal sutures fuse too early, surgically correctable

51

The Hyoid

-"free floating" bone in neck inferior to mandible
-only bone in skeleton that doesn't articulate with another bone
-acts as base for tongue, site for muscle attachments for muscles that move larynx/tongue muscles

52

Thoracic Cage parts

includes: thoracic vertebrae, ribs, sternum, and costal cartilages

53

What are the functions of the thoracic cage?

1. protect heart, lungs, and other organs
2. supports pectoral girdle
3. provides attachment points for upper limb and trunk muscles
4. intercostal spaces hold muscles that aid in breathing

54

Sternum

3 bones: manubrium, body, xiphoid process
-articulates with clavicles and ribs/costal cartilage
Includes:
-jugular notch
-sternal angle

55

Rib Cage

Function: protects internal organs, aids in respiration
-12 pairs of ribs
-all ribs attached posteriorly to thoracic vertebrae
1. true ribs: attach to sternum by costal cartilage
2. false ribs: no direct attachment to sternum
3. floating ribs: do not attach anteriorly (just to vertebrae)

56

Rib Structure

-main part = shaft (body)
-articulates with vertebrae at head and tubercle
-"neck" = thinner region between head and tubercle
-"head" = two demifacets (one attaches to body of "its" vertebra and one attaches to the superior vertebra)
-tubercle articulates with a facet on the transverse process of vertebrae

57

The Vertebral Column

*26 vertebrae (7-12-5-5-4)
-7 cervical
-12 thoracic
-5 lumbar
-5 sacral (fuse into 1)
-4 coccyx (fuse into 1)

58

Functions of the vertebral column

1. protect spinal cord
2. support body axis
3. attachment points for ribs/muscles of neck/back
4. anchor pectoral and pelvic girdles

59

"Typical" Vertebra

-vertebral arch (includes pedicles/lamina)
-spinous process
-transverse process
-articular processes/facets

60

vertebral arch

-around vertebral foramen
-protects spinal cord passing through vertebral foramen and spinal nerves traveling through INTERvertebral foramen
--> includes: pedicles (between transverse process/body) and lamina (between spinous/transverse process)

61

spinous process

attachment site for muscles, most posterior

62

transverse process

attachment sites for muscles (on lateral sides)

63

articular processes/facets

where vertebrae articulate (joints)

64

Vertebral Column/Spinal Cord

-spinal cord passes through and is protected by the spinal canal
-spinal nerves exit between body of the vertebra and neural arch in intervertebral disc (between each vertebra)

65

Laminectomy

removal of one or more lamina in vertebrae
-take pressure off spinal cord = pain relief for pt with herniated disc

66

Cervial Vertebrae

*7 (C1-C7)
-transverse foramen on transverse process (major head artery goes through here)
-articular facts face superior/inferior
-bifid (split) spinous process
--> atlas/axis are unusual

67

Atlas

*C1
-no body or spinous process
-articulates with occipital condyles --> allows flexion/extension of head (nodding yes)

68

Axis

*C2
-dens articulates with Atlas --> allows rotational movement on anterior midline (shaking head no)

69

Thoracic Vertebrae

*12 (T1-T12)
-COSTAL FACETS for ribs, on body/transverse processes
-articular facets face anterior/posterior
-spinous processes are long/project inferiorly

70

Lumbar Vertebrae

*5 (L1-L5)
-in lower back
-large bodies, support LOTS of weight
-articular facets face medial/lateral
-short/flat spinous processes, project almost anteriorly

71

Sacrum

*5 fused vertebrae
-forms posterior wall of pelvis
-Ala: "wings" on lateral sacrum articulate with hip bones to form SI joints

72

Coccyx

*4 fused vertebrae
-"tailbone"

73

Curves of the spine

-increase flexibility and maintain center of gravity over body axis
-curvature for each region (ex. sacral curvature)

74

Scoliosis

lateral curvature of spine
*abnormal
-usually treated with braces/surgery when young

75

Kyphosis

*excessive curvature of thoracic spine
-typically result of spinal fractures caused by osteoporosis
("Dowager's Hump")

76

Lordosis

*excessive curvature of lumbar spine
-usually temporary and resulting from shift in larger front load (ex. pregnancy/beer belly)

77

cranial stenosis

early fusion of skull plates

78

Where does the action of nodding happen?

between skull and axis

79

Where does the action of shaking head "no" happen?

between atlas and axis

80

What vertebrae has 3 holes?

cervical

81

What vertebra has no body?

atlas

82

What vertebra has a dens?

axis

83

What vertebrae have one hole only?

thoracic and lumbar

84

What vertebrae have costal facets?

thoracic

85

What sinus is only completely drained when laying down?

maxillary sinus