physiology Flashcards
what are the 3 types of cartilage?
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
what is a joint?
link between bones; can a t to allow movement + stability
what are the 3 types of joints? give examples
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)
what are the types of synovial joints?
hinge (knee) pivot (neck) saddle (thumb) condyloid (wrist) ball + socket (hip) gliding (spine)
what is the structure of synovial joints?
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.
what is the weeping lubrication theory?
when a joint compressed, synovial fluid is released to reduce friction between articular cartilage - when movement stops, fluid is reabsorbed.
3 additional features of synovial joints?
bursa – sac of synovial fluid
meniscus – improves fit between adjacent bone ends, increases stability.
pad of fat – provides cushioning between fibrous capsule + bone/ muscle
what are the types of movement?
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.
what are the 3 planes of movement?
sagital – ÷ body from left to right
frontal – ÷ body from front to back
transverse – ÷ body from top to bottom
what are the 4 types of muscle contraction?
what do each mean?
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
what are the 3 roles of a muscle?
what do each do?
agonist – creates the movement
antagonist – creates resistance, against coordinated movement
fixator – a stabilising muscle
what is a motor unit?
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.
what is a motor neuron?
a nerve cell that conducts a nerve impulse to a group of muscle fibres.
what is action potential?
a positive electrical charge inside a nerve + muscle cells that conducts the nerve impulse.
what does a neurotransmitter do?
carries the action potential across the synaptic gap.
what is the all or none law?
all muscle fibres will contract if a threshold is met, if it is not, there will no contraction.
1) what is a muscle fibre?
2) what are the 2 main types?
1) they’re long cylindrical muscle cells, held by bundles
forming individual muscles.
2) slow twitch (type 1)+ fast twitch (type 2)
what are slow twitch fibres used for?
aerobic/ endurance athletes – o2 used to small tension over a long period of time.
what are fast twitch fibres used for?
anaerobic/power athletes – produce large force in a short time; fatigue easily.
what are the 2 types of fast twitch?
fast oxidative glycolytic – less force but more resistant to fatigue.
fast glycolytic – greatest anaerobic capacity; generates large amount of force.
what are the recovery rates of type 1 and type 2 fibres?
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.
