skeleton

Question 1

functions of skeletal system

Answer 1

• support
• body shape
• protects vital organs e.g. skull and vertebral column
• important of haematopoiesis (formation of blood cellular components)
  
  • RBC formation and protects RBC and WBC
• mineral store for calcium and phosphates (metabolic processes and hormonal demand)

Question 2

the 2 functional parts of the skeletal system

Answer 2

Axial skeleton

appendicular skeleton

Question 3

describe axial skeleton

Answer 3

bones of head, neck and trunk

• located in midline
• flat and long bones
• protection (vital organs)
• forms attachment for muscles that move arms/legs

Question 4

describe appendicular skeleton

Answer 4

bones of limbs inc pectoral and pelvic girdles (attaches limbs to central body)

• upper limbs = dexterity
• lower limbs = support and movement

Question 5

how many bones in the body

Answer 5

206

350 but fuse over time (stops late 20s/early 30s)

Question 6

long bone

Answer 6

found in limbs

leavers = longitudinal forces

Question 7

short bones

Answer 7

cuboidal
found only in tarsus (ankle) and carpus (wrist)
support
small movement between collection of them

Question 8

flat bones

Answer 8

protective functions e.g. cranium
large SA for muscle attachment
normally slightly curved

Question 9

irregular bones

Answer 9

unusual shapes

Question 10

sesamoid bones

Answer 10

• develop in certain tendons and located where tendons cross the end of long bones in the limbs
• protect tendons from excessive wear
• change the angle of tendons as they pass to their attachments

Question 11

the types of bone cells

Answer 11

osteoblasts
osteoclasts
osteocytes

Question 12

osteoblasts

Answer 12

• immature bone cells
• on bones surface (periosteum and some in endosteum)
• secrete organic bone matrix: turns osteoids to bone via calcification

Question 13

osteoclasts

Answer 13

• secrete acids and enzymes that remove bone by reabsorbing
• multinucleate and derived from monocytes (WBCs)
• in the endosteum

Question 14

osteocytes

Answer 14

• mature bone cell
• stellate (starshaped) processes stick out into bone matrix
• sense loading: communicate with osteoclasts to absorb more or less

Question 15

osteoporosis

Answer 15

when the bone becomes too hollow. number of osteoclasts too high

Question 16

osteopetrosis

Answer 16

bone becomes too thick. number of osteoclasts too low

Question 17

diaphysis

Answer 17

the central part of the bone/shaft

Question 18

epiphysis

Answer 18

the end of the long bone

Question 19

metaphysis

Answer 19

where diaphysis meets the epiphysis. often has growth plate that allows elongation of the bone during maturity

Question 20

medullary cavity

Answer 20

hollow centre of the bone that contains yellow marrow

Question 21

endosteum

Answer 21

connective tissue between the bone and medullary cavity

-highly cellular

Question 22

periosteum

Answer 22

connective tissue on the outside of the bone

• vascular and fibrous
• important in healing e.g. during fractures

Question 23

compact bone

Answer 23

varies in thickness

Question 24

spongey bone

Answer 24

strong and minimises weight

tend to follow lines and these are called trabeculae

Question 25

trabeculae

Answer 25

aligned along lines of principle stress | -help to take load and prevents from bending

Question 26

wolffs law of functional adaptation

Answer 26

trabeculae can evolve depending on individuals own direction of stressors

Question 27

describe bone matrix

Answer 27

67% inorganic -causes rigidity -without inorganic (addition of vinegar) = bones overly flexible and cant support weight 33% organic (90% of the collagen) - without organic (addition of bleach) bones too brittle and would snap with force

Question 28

joint types

Answer 28

fibrous cartilaginous synovial

Question 29

fibrous joints

Answer 29

- collagen (DFCT) between the 2 pieces of bone | - allows for little movement e.g. used at sutures between bones of skull

Question 30

cartilaginous joints

Answer 30

- cartilage between 2 bones - hyaline cartilage = not much movement - fibrocartilage = more movement

Question 31

synovial joints

Answer 31

- gives the most movement - 2 ends of the bone aren't in contact (lined by hyaline cartilage: causes arthritis when hyaline wears away) - has synovial cavity containing synovial fluid

Question 32

describe the ribs

Answer 32

12 pairs total 7 true: attached to sternum 5 false: attach indirectly or not attached to sternum - 2 floating

Question 33

the vertebral column

Answer 33

- support and flexibility for head and appendicular skeleton - contains and protects spinal cord - 4 curvatures: cervical (7), thoracic (12), lumbar (5) and sacral/coccyx : isn't present at birth, instead c shaped

Question 34

cervical vertebrae

Answer 34

small body = little weight bearing/ range of movement develops as you learn to hold up your head 1st cervical vertebrae: Atlas C1 - hold up head -doesn't have central body 2nd cervical vertebrae: Axis C2 -has long process articulation between the 2 allow you to shake head

Question 35

lumbar vertebrae

Answer 35

large body = weight bearing | develops when you learn to walk

Question 36

describe the skull

Answer 36

contains and protects brain separate bones fused together by sutures approx. 22 bones all together