chapter 7 and 8 skeletal system

Question 1

human skeleton

Answer 1

206 bones

Question 2

longitudinal axis

Answer 2

80 bones

Question 3

appendicular skeleton limbs

Answer 3

126 bones

Question 4

axial skeleton functions

Answer 4

1. support and protect organs in dorsal and ventral body cavities.
2. provide surface area for muscle attachment:
   A. adjust position of head, neck and trunk
   B. Perform respiratory movements
   C. stabilize appendicular skeleton

Question 5

skull bones interconnect at immovable joints called sutures (dense fibrous CT). Four major sutures:

Answer 5

1. Lambdoid
2. Coronal
3. Sagittal
   4 Squamous

Question 5

skull

Answer 5

22 bones

Question 6

Lambdoid

Answer 6

separates occipital bone from parietal bones

Question 6

coronal

Answer 6

separates frontal bone from parietal bones

Question 7

sagittal

Answer 7

separates pareital bones

Question 8

squamous

Answer 8

separates temporal bone from parietal bone

Question 9

sinuses

Answer 9

air filled chambers inside flat bones

Question 10

Function of sinuses

Answer 10

1. reduce weight of bone
2. house mucus membranes that moisten and clean incoming air
   Found in: sphendoid, Ethmoid Frontal, palatine and maxillary bones

Question 11

Skull development

Answer 11

-intramembranous ossification from many centers of ossification
-during development brain grows more rapidly than cranial bones
-growing skull bones held together by bands of fibrous CT to provide flexibility (expansion of brain, compression for birth)
-large intersections of CT between bones=fontanels (soft spots), persist until age 5
-around age 5 brain stops growing in size solid sutures form between cranial bones

Question 12

craniostenosis

Answer 12

premature closure of fontanels w/o surgery brain is crushed

Question 13

microcephaly

Answer 13

brain fails to enlarge cranium remains small

Question 14

Vertebral column (26 bones)

Answer 14

7 cervical vertebrae (c1-c7)
12 thoracic vertebrae (t1-t12)
5 lumbar vertebrae (L1-L5)
1 sacrum ( 5 fused)
1 coccyx (3-5 fused)
-vertebral column not straight: 4 curves bring weight of body in line with central axis

Question 15

Primary curves

Answer 15

-thoracic and sacral
-present at birth
-accomodate organs

Question 16

secondary curves

Answer 16

-lumbar and cervical
-appear in first year
-necessary for bipedalism
-cervical= hold head up
-lumbar= standing

Question 17

kyphosis

Answer 17

exaggerated thoracic curvature

Question 18

lordosis

Answer 18

exaggerated lumbar curvature

Question 19

scoliosis

Answer 19

abnormal lateral curvature

Question 20

construction of column

Answer 20

-vertebral body: stacking
-intervertebral disc: spacing between bodies (not c1 and c2) annulus fibrosus: fibrocartilage, outside nucleus pulposus: gel inside (cushion) (loss of water from discs= shrinking height)

Question 21

elastic ligaments

Answer 21

link bodies for alignment

Question 22

intervertebral foramen

Answer 22

holes formed by spacing from discs allow spinal nerves to exit column

Question 23

vertebral arch

Answer 23

bone attached to vertebral body, with body forms vertebral foramen

Question 24

vertebral foramen

Answer 24

hole for spinal cord

Question 25

vertebral canal

Answer 25

bony canal for spinal cord formed by stacking of vertebral foramen

Question 26

spina bifida

Answer 26

vertebral arch fails to develop correctly at 3 weeks 9fetus) and spinal cord is unprotected or even exposed. 4/1000 births show some degree (due to lack of folic acid)

Question 27

Thoracic cage (25 bones)

Answer 27

1 sternum
24 ribs:
7 pair true ribs: separate costal cartilage to attach to sternum
3 pair false ribs: common shared costal cartilage to attach to sternum
2 pair floating ribs: no cartilage no attachment to sternum

Question 28

Appendicular skeleton

Answer 28

126 bones
-consists of limbs and limb girdles to provide movement
1. pectoral girdle: 4 bones
2. upper limbs: 60 bones

Question 29

carpal tunnel syndrome

Answer 29

-carpals arranged in two rows of four bones
-creates a U shape enclosed by the flexor retinaculum (ligament)
-all tendons, vessels and nerves of hand must pass through channel between bones and ligament ( no extra space)
-any inflammation= pressure on nerves leading to pain

Question 30

Pelvic girdle

Answer 30

2 bones 2 os coxae
note: “pelvis ( not anatomical) = pelvic girdle (2 os coxae) + sacrum + coccyx

Question 31

lower limbs

Answer 31

60 bones
*individual bones and bone markings will be examined in detail in lab