Skeletal and muscular systems Flashcards
joint
an area of the body where 2 or more bones articulate to create human movement
ligament
a tough band of fibrous, slightly elastic connective tissue that attaches bone to bone
articular cartilage
smooth tissue which covers the surface of articulating bones to absorb shock and allow friction free movement
synovial joint
allow free movement
sagittal plane
divides body into left and right parts
frontal plane
divides the body into front and back parts
transverse plane
divides body into upper and lower parts
pivot joint
a rounded bone articulates with a ring-shaped bone which restricts motion to one plane
ball and socket joint
ball-shaped head articulates with a cup-shaped socket to give large range of motion in al three planes
hinge joint
a cylindrical bone articulates with a trough-shaped bone help tightly by ligaments which limit sideways movement, motion restricted to one plane
condyloid joint
flatter bone surface to allow motion in 2 planes
flexion
decreases the joint angle
extension
increases joint angle
doris-flexion
ankle joint as the toes move up
plantar flexion
ankle joint the toes move down
abduction
limbs away from the midline of the body
adduction
limbs towards the midline of the body
rotation
articulating bones turn about their longitudinal axis in a screwdriver action
tendon
a fibrous connective tissue that attaches a muscle to bone
origin
the point of muscular attachment to stationary bone which stays relatively fixed during muscular contraction
insertion
the point of muscular attachment to movable bone which gets closer to the origin during muscular conraction
agonist
muscle responsible for creating movement at a joint
antagonist
muscle that opposes the agonist providing a resistance for co-ordinated movement
fixator
muscle that stabilises one part of a body while another moves
isotonic contraction
muscular contraction which changes length during its contraction
concentric contraction
muscular contraction which shortens while producing tension
eccentric contraction
muscular contraction which lengthens while producing tensions
isometric contraction
muscular contraction which stays the same length while producing tension
DOMS - delayed onset muscle soreness
pain and stiffness felt in the muscle which peaks 24-72 hours after exercise associated with eccentric contractions
motor neuron
a nerve cell which conducts a nerve impulse to a group of muscle fibres
motor unit
a motor neuron and the muscle fibres stimulated by its axon
action potential
positive electrical charge inside the nerve and muscle cells which conducts the nerve impulse down the neuron and into the muscle fibre
all-or-none law
depending on whether the stimulus is above a threshold, all muscle fibres will give a complete contraction or no contraction at all
slow oxidative muscle fibres
rich in mitochondria, myoglobin and capillaries which produces a small amount of force over a long period of time
fast glycolytic muscle fibres
rich in phosphocreatine which produces a maximal force over a short period of time
fast oxidative glycolytic muscle fibres
designed to produce a large amount of force quickly, however they also have the capacity to resist fatigue
work: relief ratio
the volume of relief in relation to the volume of work performed
