muscle and tendon Flashcards
types of muscle
skeletal striated, cardiac striated, smooth muscle non striated
what are intrinsic muscles
often pennate, strong, little range, lots of leverage
what are extrinsic muscles
often strap since no leverage available
name some muscles
strap, pennate, bipennate, oblique, spiral, diagastric, multi head, constrictor, dilator
which muscles have great range of movements
strap
which muscles have greatest force
pennate
which has a lower range
bipennate
what is a agonist
prime mover, concentrically active
what is an antagonist
eccentrically active, less strong
what are the features of antagonist
muscles cannot push, often action must be actively reversed, control of smooth muscle
what is a synergist
prevents others being impaired
features of synergist muscle
capsular by stabilising joint capsule or ligamentar by constraining movement
what is monoarticular muscle
crosses over one joint only e.g. brachialis
what is polyarticular muscle
crosses over two or more joints e.g. digit extensor
what is the importance of skeletal muscle 4
1 posture and locomotion, 2 controlling body cavities and orifices, 3 venous and lymphatic return 4 food
what is a fascicle
many muscle fibres
what does one muscle fibre contain
1 multinucleate syncytinum which has many intracellular, longitudinal myofibrils each divided into repeating transverse sarcomeres
what determines range of contraction
number of sarcomeres in series
what determines force of contraction
number of myofibrils in parallel
epimysium
connective tissue outside of muscle
perimysium
connective tissue divides muscle into tube, surrounds a fasicle
endomysium
further divides the tubes
what are fascicle funnels
muscles contained in fixed volume enabling venous and lymphatic return, diverts semi sharp trauma if muscles are contracted to prevent injury
what is torque
ability of a force to cause rotation of a mass about a pivot
2 formulae for torque
t = force x perpendicular d from pivot or t = movement of inertia x angular acceleration
what is torque measured in
newton metre
the ability of a muscle to turn a limb around the pivot of the joint is dependent on 3 things…
1 the force it exerts 2 perpendicular distance 3 must be able to act against the weight or inertia of the limb
what are tendons
strong fibrous continuation of the epi peri and endo mysia at the ends of the muscle, they are collagenous
what are the two categories of tendons
funicular (chord) or aponeurotic (broad sheet like)
what are the 3 main functions of tendons
1 direct muscular force (telegraph, focus, distribute). 2 store and release elastic energy. 3 absorb sudden force
what are the 3 accessory sheath structures of tendons
1 areola fibrous tissue sleeve like peritendon. 2 synovial bursa fluid between bone and tendon. 3 synovial sheath fluid wraps around mesotendon
what is the retinacula
ring like angular ligaments that decrease the perpendicular distance and decrease torque
what is the scuta
fibrocartilage sheet, smooth resilient surface to shield underlying tissues
what are sesamoid bones
form in tendons to prevent flattening from force of tendon, reduce friction from between bones
do sesamoid bones increase or decrease torque
increase, they increase the perpendicular distance form the pivot
