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Flashcards in test 2 ch 6 Deck (33):
1

5 primary functions of the skeletal system

1. support 2. storage of minerals (calcium) and lipids (yellow marrow) 3. blood cell production (red marrow) 4. protection 5. leverage (force of motion)

2

sutural bones

small irregular bones found between the flat bones of the skull

3

irregular bones

complex shapes
vertebrae, pelvis

4

short bones

small and thick
ankle and wrist

5

long bones

long, thin, with rounded ends
arms, legs, fingers, toes

6

sesamoid bones

small, flat, and develop inside tendons
minisci

7

diaphysis

shaft of bone has a heavy wall of compact bone around a central medullary cavity

8

epiphysis

wide part at each end of bone that articulates w other bones. Made up of mostly spongy bone (cancellous) covered with compact bone (cortex)

9

metaphysis

where diaphysis and epiphysis meet

10

structure of flat bone

resembles a sandwich of spongy bone between 2 layers of compact bone; parietal bone

11

diploe

layer of spongy bone between the compact bone in the cranium

12

osseous tissue characteristics

dense, supportive connective tissue that contains specialized cells; produces solid matrix of calcium salt deposits around collagen fibers

13

osteocytes

bone cells within lacunae organized around blood vessels; do not divide; are between lamellae (layers) of matrix and connect by cytoplasmic extensions through canaliculi

14

canaliculi

form pathways for blood vessels to exchange nutrients and waste

15

periosteum

covers outer surface of bone and consists of outer fibrous and inner cellular layers

16

osteoblasts

immature bone cells that secrete matrix compounds (osteogenesis)

17

osteoid

matrix produced by osteoblasts, but not yet calcified to form bone

18

osteoprogenitor cells

mesenchymal stem cells that divide to produce osteoblasts; located in endosteum; assist in fracture repair

19

osteoclasts

giant multinucleated cells that dissolve bone matrix and release stored minerals (osteolysis)

20

trabeculae

open form of matrix found in spongy bone

21

endochondral ossification

ossifies bone that originates from hyaline cartilage

22

appositional growth

compact bone thickens and strengthens long bone w layers of circumferential lamellae

23

epiphyseal lines

when long bones stop growing after puberty

24

intramembraneous ossification

occurs in the dermis and produces dermal bones-mandible and clavicle

25

hormone calcitrol

made in the kidneys and helps absorb calcium and phosphorus from digestive tract; requires vitamin D3 (cholecalciferol)

26

bone growth vit C

collagen synthesis and stimulation of osteoblast defferentiation

27

bone growth vit A

osteoblast activity

28

growth hormone and thyroxine

stimulat bone growth

29

estrogens and androgens

stimulate osteoblasts

30

calcitonin and parathyroid horemone (PTH)

regulate calcium and phosphate levels- increases

31

parathyroid hormone

stimulates osteoblast and osteoclast activity

32

hormone calcitonin

made in thyroid gland; inhibits osteoclast activity, decreases calcium in blood

33

4 step fracture repair

1. bleeding 2. cells of periosteum and endosteum divide and make external and internal callus 3. osteoblasts replace central cartilage of external callus with spongy bone 4.osteoblasts and osteoclasts remodel fracture for up to a year