1.1 Skeletal And Muscular Systems Flashcards
What is a joint
Area of body where two or more bones articulate to create movement
What is a ligament
Tough band of slightly elastic connective fibrous tissue that connects bone to bone
What is the articulate cartrilidge
Smooth tissue which covers the surface of the articulating bones to absorb shock and allow friction free movement.
What is a plane of movement
Three dimensional movements at a joint
Flexion
Decreasing the angle at a joint
What is extension
Increasing the angle at a joint
What is abduction
Movement of the limbs away from the midline of the body
What is adduction
Movement of bringing limbs towards the midline of the body
What is horizontal flexion
Movement of the limbs towards from the midline of the body parallel to the ground
What is horizontal extension
Movement of the limbs away the midline of the body parallel to the ground
What is an agonist
Muscle responsible for creating movement
What is an antagonist
Muscle that opposes the agonist providing a resistance for a co-ordinated movement
What is a fixator
Muscle that stabilises one part of a body while another moves
What is a motor neuron
A nerve cell which conducts a nerve impulse to a group of muscle fibres
What is the delayed onset of muscle soreness
Pain and stiffness felt in the muscle which peaks 24-72 hours after exercise
What is a motor unit
A motor neuron and the muscle fibres stimulated by its axon
What is action potential
Positive electrical electrical charge inside the nerve and muscle cells which conducts the nerve impulse down the neruon and into the muscle fibre
What is a neurotransmitter
A chemical produced and secreted by a neuron which transmits the nerve impulse across the synaptic cleft to the muscle fibre
What is the All-or-none law
Depending on whether a stimulus is above a threshold, all muscle fibres will give a contraction or no contraction at all.
What are slow oxidative muscle fibres
Muscle fibres which are rich in mitochondria , myoglobin and capillaries which produce little force over a long period of time
Name 3 characteristics of slow oxidative muscle fibres
Rich in mitochondria
Work aerobically
Have high resistance to fatigue
Have high endurance
Have slow contractions
What are fast glycolytic muscle fibres
Rich in phosphocreatine which produces maximal force over a short period of time
Name 3 characteristics of fast glycolytic muscle fibres
Work anaerobically
Have large stores of phosphocreatine
Low resistance to fatigue
Low endurance
Powerful contractions
What is phosphocreatine
High energy compound stored in muscle cell, used as fuel for very high intensity energy production
What is mitochondria
Structure in the sarcoplasm responsible for aerobic energy production
Define isotonic contraction
Contractions that cause the muscle to change length creating movement.
Define concentric contraction
Contraction that causes the muscle to shorten
