b3.3- muscle and mobility Flashcards
motile
can move from one place to another
sessile
cant move from one place to another
how sacromere contracts
- action potential causes release of calcium ions
- calcium ions bind to troponin
- causing tropomyosin to be released from the binding sites
- exposing binding sites for actin filaments
- ATP binds to myosin heads and breaking the cross bridges
- ATP is hydrolysed to ADP and phosphate
- energy from ATP causes myosin heads to cock (swivel outwards)
- myosin heads form new cross bridges to new actin binding sites
- myosin head swivel inwards while releasing ADP and phosphate
- myosin filaments move actin filaments towards the centre of the sacromere
- sliding of filament shortens the sacromere
A Chloe Tryin Expose Acrobatic Ahoy Excepts Makes Minimum Movement Slayed
role of protein titin [3]
- holds the myosin filament in place
- prevents over stretching of the sacromere
- helps sacromeres to recoil after stretching
antagonistic muscles
- work together: contraction of one provides energy needed for the titin molecules in the other as it relaxes
- cause opposite movements
role of antagonistic muscles
- needed because muscle tissue can only exert force when it contracts
- joint angle becomes smaller: flexor muscle
- joint angle becomes larger: extensor muscle
motor neuron
carries electrical impulse to muscles
muscle fibres
- one motor neuron with all the muscle fibres it stimulates
- acetylcholine as neurotransmitter
neuromuscular junctions
synapse between a motor neuron and muscle fibres
type of skeleton arthopods have
exoskeleton
type of skeleton vertebrates have
endoskeletons
fulcrum
middle part below lever
effort applied nearer to the fulcrum
force decreases but increases distance moved
synovial joints
- capsules that surround the articulating surfaces of two bones (i.e. where the bones connect)
eg. shoulder
role of bones [2]
- provides anchorage for muscle and ligaments
- act as levers
cartilage
tough, smooth tissue that covers the bone at the joint
role of cartilage [2]
- prevents friction
- absorbs shocks
synovial fluid
fills a cavity in the joint between the cartilages on the ends of the bones
role of synovial fluid [2]
- lubricates the joint- prevent friction
- provides oxygen and nutrition to the cartilage
ligaments
tough cords of tissue containing large quantities of protein collagen
role of ligaments
prevent aberrant movements- wont dislocate/damage the joint
role of muscles
provides forces that cause movement at the joint
role of tendons
attaches muscle to bone
hinge joint
- one direction
eg. elbow joint
pivot joint
simple rotation: nodding and turning
eg. neck
internal and external intercostal muscles
muscle fibres orientated differently- alternating contraction of the different layers
- moves the ribcage in opposite directions
reasons for locomotion [4]
- foraging for food
- escaping from danger
- searching for a mate
- migration
adaptions for swimming in marine mammal [4]
- streamlining
- fins, tail and flukes for swimming
- blowhole- allow periodic diving
- hairless, smooth skin surface
what are troponin and tropomyosin
regulatory porteins
structure of muscle fibre
- myofibrils contain repeating units called sacromeres
- sacromeres contain actin filaments and myosin filaments
- actin fibres are thin and myosin fibres are thick
function of joint capsule [2]
- seals the joint space
- provides stability by restricting the range of possible movements
what happens when the external intercostal muscle contracts
inhalation
- ribcage expands
- stretches internal intercostal muscles
stretching a muscle
stores potential energy in the titin in the msucle
function of neurones [2]
- stimulate muscles to contract
- control the timing of muscle contraction
function of joints
control the range of movement
