1a1-chapter 8 skeletal system 2 Flashcards Preview

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Flashcards in 1a1-chapter 8 skeletal system 2 Deck (147):
1

Vertebral Column

functions

–supports the skull and trunk
–allows for their movement
–protects the spinal cord
–absorbs stress of walking, running, and lifting
–provides attachments for limbs thoracic cage, and postural muscles

2

Vertebral Column

33 vertebrae with intervertebral discs of fibrocartilage between most of them

3

five vertebral groups

–7 cervical in the neck
–12 thoracic in the chest
–5 lumbar in lower back
–5 fused sacral at base of spine
–4 fused coccygeal

4

Newborn Spinal Curvature

•spine exhibits one continuous C-shaped curve at birth
•known as primary curvature

5

Adult Spinal Curvatures
four normal curvatures

four normal curvatures
–cervical
–thoracic
–lumbar
–pelvic

6

primary curvatures

–present at birth
–thoracic and pelvic

7

secondary curvatures

–develop later
–cervical and lumbar
–lifting head as it begins to crawl develops cervical curvature
–walking upright develops lumbar curvature

8

Abnormal Spinal Curvatures

from disease, paralysis of trunk muscles, poor posture, pregnancy, or congenital defect

9

scoliosis

abnormal lateral curvature
–most common
–usually in thoracic region
–particularly of adolescent girls
–developmental abnormality in which the body and arch fail to develop on one side of the vertebrae

10

kyphosis

kyphosis(hunchback) –exaggerated thoracic curvature
–usually from osteoporosis, also osteomalacia or spinal tuberculosis, or wrestling or weightlifting in young boys

11

lordosis

lordosis(swayback) –exaggerated lumbar curvature
–is from pregnancy or obesity

12

body

body(centrum)
–mass of spongy bone that contains red bone marrow
–covered with thin shell of compact bone
–weight bearing portion
–rough superior and inferior surfaces provide firm attachment for intervertebral discs

13

vertebral foramina

collectively form vertebral canal for spinal cord

14

vertebral arch

–composed of two parts on each side
–pedicle–pillarlike and lamina-platelike

15

spinous process

–projection extending from the apex of arch
–extends posteriorly and downward

16

transverse process

–extends laterally from point where pedicle and lamina meet

17

superior articular processes

project upward from one vertebra and meets inferior articular processes from the vertebra above

18

facets

–flat articular surfaces covered with hyaline cartilage

19

intervertebral foramen

–when two vertebrae are joined they exhibit and opening between their pedicles
–passageway for spinal nerves
–inferior vertebral notch in the pedicle of the upper vertebra
–superior vertebral notch in the pedicle of the lower vertebra

20

intervertebral discs

(23)
–first one between C2 and C3
–last one between L5 and sacrum
–bind vertebrae together
–support weight of the body
–absorb shock

21

intervertebral discs

consisting of:

pad consisting of:
•nucleus pulposus -inner gelatinous mass
•anulus fibrosus –outer ring of fibrocartilage

22

herniated disc

(‘ruptured’ or ‘slipped’ disc) puts painful pressure on spinal nerve or spinal cord

23

Cervical Vertebra C1

atlas (C1)
–supports the head
–has no body
–a delicate ring surrounding a large vertebral foramen
–lateral masses with superior articular facets
•articulates with occipital condyles
•allows nodding motion of skull gesturing ‘yes’
–inferior articular facets articulate with C2
–anterior and posterior arches
–anterior and posterior tubercles

24

lateral masses with superior articular facets

•articulates with occipital condyles
•allows nodding motion of skull gesturing ‘yes’

25

inferior articular facets

articulate with C2

26

Cervical Vertebra C2

axis (C2)
–allows rotation of the head gesturing ‘no’

27

dens

dens or odontoid process –prominent knob on its anterosuperior side
•forms as an independent ossification center during first year of life
•fuses with axis by age 3 to 6 years
•projects into vertebral foramen of the atlas
•held in place by a transverse ligament

28

atlanto-occipital joint

joint between atlas and cranium

29

atlantoaxial joint

joint between the atlas and axis

30

transverse ligament

holds dens in place

31

Typical Cervical Vertebrae

•C1-C7 are the smallest and lightest vertebrae, other than the coccygeals
•bifid or forked spinous process in C2 to C6
•small body and larger vertebral foramen
•transverse foramen in each short transverse process

32

transverse foramen

provides passage and protection for:
•vertebral arteries –supply blood to the brain
•vertebral veins –drain blood from various neck structures
–transverse foramen only found in cervical vertebrae

33

C7 vertebra prominens

spinous process not bifid and especially long
–prominent bump on the lower back of the neck
–convenient landmark for counting vertebrae

34

Typical Thoracic Vertebrae

•12 thoracic vertebrae (T1 –T12)
–corresponds to the 12 pairs of ribs attached to them
•spinous processes pointed and angled sharply downward
•larger body than cervical but, smaller than lumbar

35

costal facets

for attachment of ribs
–on body as small, smooth, slightly concave spots

36

transverse costal facets

at end of each transverse process on T1 –T10
–provide second point of articulation for ribs 1 to 10

37

inferior and superior costal facets

on vertebral body
–in most cases, ribs insert between the two vertebra

38

Lumbar Vertebrae

•5 lumbar vertebrae (L1 –L5)
•thick, stout body
•blunt, squarish spinous process

39

superior articular processes

face medially
–lumbar region resistant to twisting movements

40

Sacrum

bony plate that forms the posterior wall of the pelvic cavity
•once considered the seat of the soul

41

Sacrum

anterior surface

–smooth and concave
–4 transverse lines indicate line of fusion of vertebrae
–4 pair of large anterior sacral (pelvic) foramina
•allow for passage of nerves and arteries into the pelvic organs
•sacral promontory on S1 supports L5

42

Sacrum (Posterior View)

posterior surface very rough

43

median sacral crest

formed from fusion of spinous processes

44

lateral sacral crest

less prominent, and on either side of median sacral crest
–formed from the fusion of the transverse processes

45

posterior sacral foramina

4 pairs of openings for spinal nerves that supply gluteal region and lower limbs

46

sacral canal

runs through sacrum and ends as sacral hiatus
–contains spinal nerve roots

47

Coccyx

usually consists of four small vertebrae (Co1 –Co4)
–sometimes five
•fuse into a single, triangular bone by age 20 –30

48

horns

(cornua) on Co1
–serves as attachment points for ligaments that bind the coccyx to the sacrum

49

Thoracic Cage

consists of thoracic vertebrae, sternum and ribs
•forms conical enclosure for lungs and heart
•provides attachment for pectoral girdle and upper limbs
•broad base and narrower apex
protect thoracic organs, but also the spleen, most of the liver, and to some extent the kidneys

50

costal margin

inferior border of thoracic cage formed by the downward arc of ribs

51

sternum

(breastbone) –bony plate anterior to the heart

52

sternum

divided into three regions

manubrium
body
xiphoid

53

manubrium

•broad superior portion
•suprasternal (jugular) notch medially
•clavicular notches –articulate with clavicle
•ribs attach along scalloped lateral margins

54

body

•longest part of sternum
•sternal angle –point where body joins manubrium
•ribs attach along scalloped lateral margins

55

xiphoid

•inferior end of sternum
•attachment for some of abdominal muscles

56

Ribs

12 pairs of ribs
–no difference between sexes
–posterior (proximal) end attached to vertebral column
–anterior (distal) ends mostly attached to the sternum
–costal cartilages composed of hyaline cartilage attach anterior ends to sternum

57

head

portion of the rib that articulates with the thoracic vertebrae
–superior articular facet
–inferior articular facet

58

neck–

narrow portion distal to the head

59

tubercle–

wider rough area distal to the neck
–articulates with transverse costal facet of vertebra

60

angle

lateral curve of rib

61

shaft

long, gentle sloping, bladelike portion of rib

62

costal groove

on inferior margin of shaft

63

true ribs

(ribs 1 to 7)
–each has its own costal cartilage connecting it to the sternum

64

false ribs

(ribs 8-12)
–lack independent cartilaginous connection to the sternum

65

floating ribs

(ribs 11 –12)
•articulate with bodies of vertebrae T11 and T12
•do not have tubercles
•do not attach to transverse processes of the vertebra
•no cartilaginous connection to the sternum or any of the higher costal cartilages

66

pectoral girdle

(shoulder girdle) –supports the arm
•consists of two bones on each side of the body
–clavicle(collarbone) and scapula(shoulder blade)
•clavicle articulates medially to the sternum and laterally to the scapula

67

sternoclavicular joint

clavicle articulates medially to the sternum

68

acromioclavicular joint

articulates laterally to the scapula

69

glenohumeral joint

scapula articulates with the humerus
shoulder joint

70

clavicle

S-shaped, somewhat flattened bone

71

inferior

grooves and ridges for muscle attachment

72

rounded head

rounded head

73

acromial end

flattened

74

conoid tubercle

roughened tuberosity near acromial end

75

scapula

named for its resemblance to a spade or shovel
•triangular plate that posteriorly overlies ribs 2 to 7
–three sides -superior, medial (vertebral) and lateral (axillary) borders
–three angles –superior, inferior, and lateral angles

76

three sides

superior, medial (vertebral) and lateral (axillary) borders

77

three angles

superior, inferior, and lateral angles

78

suprascapular notch

conspicuous notch on superior border
–provides passage for a nerve

79

spine–

transverse ridge on posterior surface

80

supraspinous fossa

indentation superior to the spine

81

infraspinous fossa –

broad surface inferior to the spine

82

subscapular fossa

concave, anterior surface of scapula

83

lateral angle of scapula has three main features

acromion
coracoid process

84

acromion

platelike extension of the spine
•forms apex of the shoulder

85

coracoid process

shaped like a bent finger
•provides attachment for tendons of the biceps brachii and other arm muscles

86

glenoid cavity

shallow socket that articulates with the head of the humerus
•forming glenohumeral joint

87

Upper Limb

upper limb is divided into four regions containing a total of 30 bones per limb

88

brachium

(arm proper) –extends from shoulder to elbow
•contains only one bone -humerus

89

antebrachium

(forearm) –extends from elbow to wrist
•contains two bones -radiusand ulna

90

carpus

(wrist)
•contains 8 small bones arranged in 2 rows

91

manus

(hand)
•19 bones in 2 groups
–5 metacarpals in palm
–14 phalanges in fingers

92

Humerus

proximal end

–hemispherical head that articulates with the glenoid cavity of scapula
–anatomical neck
–greater and lesser tubercles and deltoid tuberosity
–intertubercular sulcus holds biceps tendon
–surgical neck

93

Humerus

distal end

–rounded capitulum articulates with head of radius
–trochlea articulates with ulna
–lateral and medial epicondyles
–lateral and medial supracondylar ridges
–olecranon fossa holds olecranon process of ulna
–coronoid fossa
–radial fossa

94

Radius

head –disc-shape, allows for rotation around the longitudinal axis of the bone during pronation and supination of hand
•superior surface articulates with capitulum on humerus
•side of disc spins on radial notch on ulna
–neck
–radial tuberosity for biceps muscle
–styloid process can be palpated near thumb
–ulnar notch

95

ulna

–trochlear notch articulates with trochlea of humerus
–olecranon–bony point at back of elbow
–coronoid process
–radial notch holds head of radius
–styloid process

96

interosseous membrane

–ligament attaches radius to ulna along interosseous margin of each bone
–enables the two elbow joints to share the load

97

Carpal Bones

8 bones form wrist
–allow movements of flexion, extension, abduction and adduction
•2 rows (4 bones each)

98

proximal row

scaphoid, lunate, triquetrum, and pisiform
•pisiform is a sesamoid developed by age 9 to12 in tendon of flexor carpi ulnaris muscle

99

distal row

trapezium, trapezoid, capitate, and hamate

100

metacarpals

bones of the palm
–metacarpal I proximal to base of thumb
–metacarpal V proximal to base of little finger
–proximal base, body, and distal head

101

phalanges

bones of the fingers
–thumb or pollex has two phalanges
•proximal and distal phalanx
–fingers have three phalanges
•proximal, middle and distal phalanx

102

pisiform

Sesamoid Bone
–develops around age 9 –12 years
–in tendon of flexor carpi ulnaris muscle

103

pelvic girdle

consists of a complete ring composed of three bones
–two hip (coxal) bones
•also called ossa coxae or innominate bones
–sacrum that is also part of the vertebral column

104

pelvis

bowl-shaped structure composed of the two coxal bones and sacrum as well as their ligaments and muscles that line the pelvic cavity and form its floor
–supports trunk on the lower limbs and protects viscera, lower colon, urinary bladder, and internal reproductive organs

105

sacroiliac joint

joins hipbone to the vertebral column
–auricular surface of ileum to auricular surface of sacrum

106

interpubic disc

–pad of fibrocartilage joins pubic bones

107

pubic symphysis

the interpubic disc and adjacent regions of the pubic bone on each side

108

greater (false) pelvis

between flare of the hips

109

lesser (true) pelvis

narrower and below

110

pelvic brim

round margin that separates the two

111

pelvic inlet

opening circumscribed by brim that infant’s head must pass during birth

112

pelvic outlet

lower margin of the lesser pelvis

113

three distinct features of hip bone

iliac crest –superior crest of hip
–acetabulum–the hip socket
–obturator foramen –large hole below acetabulum

114

each adult hip bone is formed by the fusion of three childhood bones

ileum
ischium
pubis (pubic bone)

115

ileum

the largest
•extends from the iliac crest to the center of the acetabulum
•anterior and posterior superior spine
•anterior and posterior inferior spines
•greater sciatic notch and iliac fossa

116

ischium

•inferioposterior portion of hip
•heavy body with prominent spine
•lesser sciatic notch
•ischial tuberosity
•ramus

117

pubis (pubic bone)

•most anterior portion of the hip bone
•body, superior and inferior ramus

118

male

male -heavier and thicker due to forces exerted by stronger muscles

119

female

wider and shallower, and adapted to the needs of pregnancy and childbirth, larger pelvic inlet and outlet for passage of infant’s head

120

Lower Limb

lower limb divided into four regions containing 30 bones per limb

121

four regions

femoral
crural region
tarsal region
pedal region

122

femoral region

(thigh) –extends from hip to knee region
•contains the femur and patella

123

crural region

(leg proper) –extends from knee to ankle
•contains medial tibiaand lateral fibula

124

tarsal region

(tarsus) –ankle –the union of the crural region with the foot
•tarsal bones are considered part of the foot

125

pedal region

(pes) -foot
•composed of 7 tarsal bones, 5 metatarsals, and 14 phalanges in the toes

126

Femur

•longest and strongest bone of the body
•hemispherical head that articulates with the acetabulum of the pelvis
–forms ball-and-socket joint
–fovea capitis –pit in head of femur for attachment of a ligament

127

Femur

features

greater and lesser trochanters for muscle attachment
•intertrochanteric crest –thick oblique ridge on the posterior surface that connects the trochanters
•intertrochanteric line –more delicate ridge on the anterior surface that connects trochanters
•linea aspera –ridge on posterior of the shaft
•spiral (pectineal) line and gluteal tuberosity
•medial and lateral condyles and epicondyles found distally
•intercondylar fossa
•patellar andpopliteal surface

128

Patella

triangular sesamoid bone embedded in tendon of the knee
•cartilaginous at birth
–ossifies at 3 to 6 year
•base–broad, superior portion
•apex–pointed, inferior portion
•articular facets –shallow, posterior portion

129

quadriceps femoris tendon

extends from the anterior muscle of the thigh to the patella
–continues as the patellar ligament from the patella to the tibia

130

tibia

thick, medial, weight-bearing bone
–only weight bearing bone of the crural region
–broad superiorhead

131

tibia

features

–medial and lateral condyles
•fairly flat articular surfaces
•articulate with condyle of femur
–intercondylar eminence –ridge separating condyles
–tibial tuberosity –attachment of quadricep muscles
–anterior crest –sharp, angular
–medial malleolus –bony knob on inside of ankle

132

fibula

slender, lateral strut that helps stabilizes ankle
•does not bear any body weight
–spare bone tissue for grafts
•head -proximal end
•apex–point of the head
•lateral malleolus -distal expansion, bony knob on lateral side of ankle
•joined to tibia by interosseous membrane

133

tarsal bones

arranged in proximal and distal groups
•tarsal bones are shaped and arranged differently from carpal bones due to load-bearing role of the ankle

134

calcaneus

largest tarsal bone
–forms heel
–distal portion is point of attachment for calcaneal (Achilles) tendon

135

talus

talusis most superior tarsal bone
–forms ankle joint with tibia and fibula
–sits upon calcaneus and articulates with navicular

136

proximal row of tarsal bones

talus, calcaneus, and navicular

137

distal row of tarsal bones

medial, intermediate and lateral cuneiforms and cuboid

138

Foot

remaining bones of foot are similar in name and arrangement to the hand

139

metatarsals

–metatarsal I is proximal to the great toe (hallux)
–metatarsal V is proximal to the little toe
–proximal base, intermediate shaft, and distal head

140

phalanges

2 in great toe
•proximal and distal phalanx
–3 in all other toes
•proximal, middle and distal phalanx

141

rotation of upper and lower limbs in opposite directions

–starts seventh week of embryonic development
–largest digit medial in foot and lateral in hand
–each limb rotates about 90°in opposite directions
–rotation also explains why elbow flexes posteriorly and knee flexes anteriorly

142

Foot Arches

sole of foot is not flat on ground
–3 springy arches absorb stress
arches held together by short, strong ligaments

143

medial longitudinal arch

–from heel to hallux
–formed from the calcaneus, talus, navicular, cuneiforms and metatarsals I and III

144

lateral longitudinal arch

–from heel to little toe
–includes calcaneus, cuboid ,and metatarsals IV and V

145

transverse arch

–across middle of foot
–includes the cuboid, cuneiforms, and proximal heads of metatarsals

146

pes planus

(flat feet) –excessive weight, repetitious stress, or congenital weakness(

147

46Skeletal Adaptations for Bipedalism

–strong, springy foot arches
–great toe not opposable
–femurs angle inward so knees are closer together –erect posture requires less muscular effort
–viscera supported in bowl-shaped pelvis
–insertions of gluteal muscles differ from other primates