musculoskeletal system

Question 1

3 major components of the musculoskeletal system and from where they are derived

Answer 1

bone, connective tissue and skeletal muscle all derived from the mesoderm

Question 2

functions of the bone

Answer 2

support, protect e.g thorax protects the lungs, metabolic e.g strokes ca2+ and phosphate, movement and heamatopoiesis

Question 3

functions of skeletal muscle

Answer 3

locomotion, posture metabolic (store of glycogen), venous return especially in lower veins where low pressure, cheat production (shivering) and continence (sphincters)

Question 4

functions of the connective tissue

Answer 4

tendon- muscle to bone force transmission
ligament- support bone-bone
fascia- very tough, protects and compartmentalises
cartilage- prevents fictions acts, as shock absorber
(synovial membrane)- lubricates by secreting fluid
(bursa)- synovial fluid scar to protect tendons from friction

Question 5

composition of bone

Answer 5

osteoblasts, casts and cites. some fibroblasts, macrophages, mast cells and adipocytes.fibre include collagen and elastin. ground substance with water and GAG/PG. calcium and phosphate give it compressive strength and collagen fibre gives it tensile strength

Question 6

what happens if the balance of the action of osteoblast ad clasts is disrupted

Answer 6

causes disease. the levels are controlled in the blood and more calcium and phosphate can be excrted if needed

Question 7

types of bone and their function + examples

Answer 7

irregular(skull), sesamoid (protect from friction in patella), long(levers e.g femur), short(range of movement in wrist) and flat(protection e.g skull)

Question 8

name some surface features of bones

Answer 8

bones have prominences which bones can attach to, the larger the prominence the more powerful the muscle attached. also have groves, notches feraminas(holes) and nutrient feraminas found on the surface where blood vessels and nerves are found

Question 9

how is the bone supplied with blood

Answer 9

via nutrient artery and blood supplies at epiphyses.

Question 10

what happens when fracture before blood supplies at epiphyses and nutrient artery are connected

Answer 10

can lead to avascular necrosis (only in children)

Question 11

how is bone deposition regulated

Answer 11

increased/ decreased depending on how much its used. osteocytes detect force passing through bone and communicate with osetoblasts/calsts to increase or their activity

Question 12

what are joints

Answer 12

connect bone to bone and their role Is to maximise stability and keep range of movement

Question 13

what are the 3 types of joints +draw diagram of one

Answer 13

fibrous- highly stable, glued by collagen and found in voucher between skull. movement v limited
cartilaginous- held by cartilage, movement limited
synovial- with synovial, highly mobile and found everywhere

Question 14

types of synovial joint

Answer 14

plane- sliding of 1 bone over another
hinge- flexes and extends like door
pivot- movement around 1 axis
saddle- movement in oval shape, hinge+side to side (thumb)
condyloid- movement around 2 axes (wrist)
ball and socket- around multiple axes e.g hip

Question 15

development of synovial joint

Answer 15

kill chondrocytes at site of joint. space (joint cavity) formed. synovial joint is an interception in cartilage. perichondrium is constant with joint capsule

Question 16

types of levers and draw them

Answer 16

first class - like seesaw e.g neck
second class- like wheel barrow e.g standing on tiptoes
third class- like forceps e.g biceps

Question 17

what is the origin of a muscle

Answer 17

stationary anchor point for muscle, sits proximally

Question 18

what is the point of insertion of a muscle

Answer 18

mobile/distal attachment

Question 19

types of movements of muscles

Answer 19

they only pull, they don’t push and they always work together

Question 20

types of muscle contraction

Answer 20

concentric contraction- pulls and shortens
eccentric contraction- pulls and lengthens e.g lowering weight
isometric contraction- muscle pulls while staying the same length e.g carrying box
muscles never push

Question 21

where are muscles found?

Answer 21

they are found in fascial compartments and within they share common function e.g have same nerve

Question 22

types of muscles and the differences. +draw

Answer 22

parallel, fusiform, circular, triangular and pennate(feather shaped). pennate are found in calf and exert much more force than parallel because they can pack many more fibres into their structures for greater power but can’t shorten as much as parallel muscle

Question 23

what is the tendon (connective tissue)

Answer 23

connects muscle to bone = dense regular tissue

Question 24

what are ligaments (connective tissue)

Answer 24

connect bone to bone. are pretty much thickened areas of joint capsule. many ligaments found in knee

Question 25

what are aponeurosis (connective tissue)

Answer 25

flattened tendons that connect muscle to muscle e.g in skull

Question 26

what are fascia

Answer 26

compartments of muscle in which muscles have similar action, same innervation and a similar blood supply

Question 27

what is hiltons law

Answer 27

nerve is sensitive to skin , muscle and joint that it crosses. controls it all

Question 28

what are hox genes

Answer 28

they determine different types of vertebrae that form in each body segment and which limbs will come from each limb bud

Question 29

what are homeotic mutations

Answer 29

mutations that causes tissues to alter their normal differentiation producing structure in unusual locations e.g production of an extra lumbar or 6 toes

Question 30

explain limb development

Answer 30

limbs develop from limbs buds formation of an apical ectodermal ridge (promotes growth of limbs) by ectodermal cells and then elongates through the proliferation of mesenchyme. then bones develop by ossification. the libs then rate in opposite directions.