Unit 1- Muscles And Movement KO Flashcards
Muscle origin
The point of muscle attachment to a stationary bone which stays relatively fixed during muscle contraction.
Muscle insertion
The point of muscle attachment to a moveable bone which moves closer to the origin during muscle contraction.
Agonist
Muscle responsible for creating movement at a joint by contracting
Also known as the prime mover
Antagonist
Muscle that relaxes to coordinate movement
Fixator
Muscle that stabilises a body part to prevent unwanted movement and allow the agonist to create the desired movement
Antagonistic muscle action
A pair of muscles at a joint
When one muscle contracts another relaxes to create joint movement
Isotonic contraction
Muscle contraction where a muscle changes length under tension to create movement
Concentric contraction
Muscle contraction where a muscle shortens under tension
Eccentric contraction
Muscle contraction where a muscle lengthens under tension
Isometric contraction
Muscle contraction where a muscle remains the same length and no movement occurs
Core stability
Muscles of the abdomen and lower back that stabilise the spine and allow for efficient movement
Rotator cuff
4 muscles that stabilises the shoulder joint and allow for rotational movements
Motor neuron
Nerve cell which conducts an nerve impulse to a group of muscle fibres
Motor unit
Motor neuron and muscle fibres stimulated by axon
Action potential
Positive electrical charge which conducts a nerve impulse down a neuron to muscle fibres
Axon
Long nerve cell responsible for conducting an impulse from cell body to muscle fibres
Neuromuscular junction
The point where the axon’s motor end plates meet muscle fibres
Synaptic cleft
Small gap between axon’s motor end plates and muscle fibres
All or none law
Depending on whether a stimulus is above or below a threshold, either all muscle fibres in a motor unit contract or none contract
Type 1 slow oxidative muscle fibres
Produce low force for a long period of time
Type 2a fast oxidative glycolytic fibres
Produce high force over a moderate period of time
Type 2b fast glycolytic fibres
Produce a very high for a short amount of time
Phosphocreatine (PC)
High energy compound required to produce muscle contraction for fast and explosive movements
Mitochondria
Structure responsible for aerobic energy production
Myoglobin
Muscle protein responsible for accepting oxygen into muscle cell
Joint
Two or more bones articulate to create movement
Ligament
Connective tissue that joins bone to bone preventing dislocation and increasing joint stability
Tendon
Connective tissue that attaches skeletal muscle to bone
Synovial fluid
Viscous fluid contained within the synovial membrane that reduces friction between Articular cartilage
Articular cartilage
Smooth, slightly spongy cartilage that covers the ends of bones in a joint preventing friction and absorbing shock
Joint capsule
Tough, fibrous tissue that lies outside the synovial membrane
Helps to strengthen the joint
Synovial membrane secrets synovial fluid
Bursa
Flattened fibrous sac containing a thin layer of synovial fluid
Prevents friction between ligaments/ tendons and bone
Meniscus
Wedge of fibrocartilage
Improves fit between bones
Improves stability
Acts as a shock absorber and reduces friction
Sagittal plane
Runs vertically, dividing body into left and right
Frontal plane
Runs vertically, dividing body into front and back
Transverse plane
Runs horizontally, dividing body into upper and lower parts
Flexion
Movement that decreased the angle at a joint
Extension
Movement that increases the angle at a joint
Dorsi flexion
Decreases angle at the ankle, bringing toes towards tibia
Sagittal plane
Plantar flexion
Increases joint angle at ankle, moving toes down
Sagittal plane
Abduction
Moves limb away from the midline of the body
Frontal plane
Adduction
Moves a limb closer to the midline of the body
Frontal plane
Horizontal extension
Movement of a limb away from the midline of the body parallel to the ground
Transverse
Horizontal flexion
Movement of a limb towards the midline of the body parallel to the ground
Transverse
Rotation
Bones turn about their longitudinal axis in a screwdriver action
Transverse
