Week 10 - Muscle Anatomy Flashcards
muscle
bundles of fibre that can only stretch/contract in one direction
movement accomplished by a muscle depends on:
type of joint, orientation of muscle fibres, action of other muscles, muscle tension
abduction
moving a part away from the medial plane
adduction
moving a part towards the medial plane
supination
palm upwards
pronation
palm downwards
dorsiflexion
foot towards anterior tibia
plantar flexion
foot away from tibia
eversion
foot moves laterally (aka pronation)
inversion
foot moves medially (aka supination)
elevation
moving a part upwards
depression
moving a part downwards
protraction
outward on a plane parallel to the ground
retraction
inward
each muscle fiber (containing myofibrils) is surrounded by…
an endomysium layer
a group of fibres (fascicle) is wrapped by…r
a perimysium layer
a group of fascicles is wrapped by…
an epimysium
sarcoplasmic reticulum
similar to the smooth ER, contains high levels of calcium ions
Z line
separates one sarcomere from another
I band
lighter portion of sarcomere that contains only the thin filaments
A band
covers the whole length of the thick filament
H zone
contains only thick filaments
M line
the “middle line” of the sarcomere
thick filaments
composed of several myosin molecules linked together
thin filaments
actin, tropomyosin, troponin
-actin molecules twist together to form a thin filament with several myosin-binding sites
-myosin-binding sites are covered by a protein called tropomyosin
-tropomyosin is held in place by troponin
what’s required for a muscle to contract?
calcium ions and ATP
sources of ATP for muscle contraction
aerobic respiration, anaerobic respiration, creatine phosphate
