Muscle and tendon Flashcards
What are the three types of muscle
Skeletal striated
cardiac striated
smooth
Importance of skeletal muscle
Posture and locomotion
controlling body cavity and orifices sizes
venous and lymphatic return
is the end product of the production line (food)
1 muscle =
many fascicles
1 fascicle =
many fibres
1 fibre =
1 multinucleate syncytium - a long cylindrical tube
many intracellular, longitudinal myofibrils each divided into repeating transverse sarcomeres
what is contraction range proportional to
number of sarcomeres in series
what is forces applied when contract proportional to
number of myofibrils in parallel
what are the three types of skeletal muscle that have fibres parallel to each other
strap, pennate, bipennate
name a strap muscle
omotransversarius
Give a property of pennate and bipennate relating to their contraction
don’t contract very far but contract with a high force
Name the eight gross shapes of skeltal muscle
Strap
Pennate
Bipennate
Oblique
Spiral
Digastric
Multihead
Constrictor
Dilator
Name the 8 gross structures of skeletal muscle
Strap
Pennate
Bipennate
Oblique
Spiral
Digastric
Multihead
Constrictor
Dilator
Name the 8 gross structures of skeletal muscle
Strap
Pennate
Bipennate
Oblique
Spiral
Digastric
Multihead
Constrictor
Dilator
Describe structure of pennate muscle
long tendons connected by short muscle fibres
Name an oblique muscle
serratus ventralis
Name a spiral muscle
Supinator
Describe extrinsic muscles
strap like since no leverage avaliable
Describe intrinsic muscles
pennate - strong with little range but lots of leverage
What is an agonist
prime mover - carries out the main function
What is an antagonist
carries out the opposing function to the agonist
What is a synergist
muscle that prevents other muscles from being impaired
Two types of synergists
Capsular muscles - stabilise joint capsule (anconeus)
Ligamentar muscles - constrain movement (subscapularis)
Mono-articular muscles
only cross one joint
Brachialis only crosses one joint = the elbow
Polyarticular muscles
Cross multiple joints
act at the most distal joint they cross
common digital extensor
What is torque
the ability of a force (muscle) to cause rotation of a mass (limb segment) about a pivot (joint)
Tendons
strong fibrous continuation of the epi, peri and endomysia at the ends of muscle - dense collagen
more injury prone than muscle
Types of tendon
Funicular - chord
Aponeurotic - broad sheet
Functions of tendons
direct muscular force
Store and release elastic potential energy
Absorb sudden forces that would usually tear muscle appart
What is a fascicle surrounded by
perimysium
Fascial tunnels
bundle of fibrous connective tissue surrounding the whole muscle
muscle contained in a fixed volume, allows venous and lymphatic return
makes the muscle tough and rigid when contracted
Torque =
force x perpendicular distance from pivot
movement of inertia x angular acceleration
Units for torque
Nm
Four acessory structures
Sheaths
Scuta
Retinacula
Sesamoid bones
Sheaths
areolar fibrous tissue sleave - peritendon
synovial bursa lie between bone and tendon may connect to joint space or not
synovial sheath wraps around tendon
mesotendon gap for vessels and nerves
Scuta
tough pad of fibrocartilage over a tendon
Retinacula
transverse bands that straps the tendon in place
decreases perpendicular distance between tendon and pivot so decreases torque
Sesamoid bones
bones that form within tendons
prevent flattening of tendon, reduce friction
increases perpendicular distance from tendon and pivot increasing torque
