physiology

Question 1

what are the 3 types of cartilage?

Answer 1

hyaline – fine collagen fibres. Has perichondrium (weakest one)

fibrocartilage – alternating layers of hyaline + thick dense collagen (strongest)

elastic – chondrites in thread like network. provides strength, elasticity + maintains shape

Question 2

what is a joint?

Answer 2

link between bones; can a t to allow movement + stability

Question 3

what are the 3 types of joints? give examples

Answer 3

fibrous – joints interlock + bonded by tough fibre (skull)

cartilaginous – bones held by a ligament straps + joined by pads of cartilage (vertebral joints)

synovial – bones articulate about a fluid filled joint (shoulder)

Question 4

what are the types of synovial joints?

Answer 4

hinge (knee)
pivot (neck)
saddle (thumb)
condyloid (wrist)
ball + socket (hip)
gliding (spine)

Question 5

what is the structure of synovial joints?

Answer 5

ligament – strong fibrous, connects bone

synovial fluid – slippery fluid in joint cavity, decreases friction between joint and cartilage

articular cartilage – covers bones in joint, absorbs shock + decreases friction

joint capsule –tough + fibrous tissue; 2 layers, fibrous capsule strengthens, synovial fluid lines joint.

Question 6

what is the weeping lubrication theory?

Answer 6

when a joint compressed, synovial fluid is released to reduce friction between articular cartilage - when movement stops, fluid is reabsorbed.

Question 7

3 additional features of synovial joints?

Answer 7

bursa – sac of synovial fluid

meniscus – improves fit between adjacent bone ends, increases stability.

pad of fat – provides cushioning between fibrous capsule + bone/ muscle

Question 8

what are the types of movement?

Answer 8

flexion – narrowing angle at joint
extension – increasing angle at joint
abduction – away from midline
adduction – towards midline
circumduction – movement that outlines a cone, consists of all of the above
dorsi flexion + plantar flexion – unique to ankle.

Question 9

what are the 3 planes of movement?

Answer 9

sagital – ÷ body from left to right
frontal – ÷ body from front to back
transverse – ÷ body from top to bottom

Question 10

what are the 4 types of muscle contraction?

what do each mean?

Answer 10

concentric – contraction causing shortening of muscle
eccentric – contraction causing lengthening of muscle
isotonic – contraction causing change in muscle length
isometric – contraction where muscle stays same length

Question 11

what are the 3 roles of a muscle?

what do each do?

Answer 11

agonist – creates the movement

antagonist – creates resistance, against coordinated movement

fixator – a stabilising muscle

Question 12

what is a motor unit?

Answer 12

a motor neuron + muscle fibres stimulated by its axon; impulse conducted down axon of synaptic cleft by action potential. if electrical charge reaches threshold, muscle will conduct, in all or none fashion.

Question 13

what is a motor neuron?

Answer 13

a nerve cell that conducts a nerve impulse to a group of muscle fibres.

Question 14

what is action potential?

Answer 14

a positive electrical charge inside a nerve + muscle cells that conducts the nerve impulse.

Question 15

what does a neurotransmitter do?

Answer 15

carries the action potential across the synaptic gap.

Question 16

what is the all or none law?

Answer 16

all muscle fibres will contract if a threshold is met, if it is not, there will no contraction.

Question 17

1) what is a muscle fibre?

2) what are the 2 main types?

Answer 17

1) they’re long cylindrical muscle cells, held by bundles
forming individual muscles.
2) slow twitch (type 1)+ fast twitch (type 2)

Question 18

what are slow twitch fibres used for?

Answer 18

aerobic/ endurance athletes – o2 used to small tension over a long period of time.

Question 19

what are fast twitch fibres used for?

Answer 19

anaerobic/power athletes – produce large force in a short time; fatigue easily.

Question 20

what are the 2 types of fast twitch?

Answer 20

fast oxidative glycolytic – less force but more resistant to fatigue.
fast glycolytic – greatest anaerobic capacity; generates large amount of force.

Question 21

what are the recovery rates of type 1 and type 2 fibres?

Answer 21

type 1 – recover quickly + available in 90 seconds - traing rates of 1:1 - damage not associated to aerobic work.
type 2 – used in the last 2-20 seconds of contraction - DOMS felt 24-48 hours after exercise; training rates of 1:3 - if used to exhaustion, 48 hour rest is needed.