Paper 1 - Musculoskeletal Systems Flashcards
What is the structure and function of a ligament?
Is a connective tissue that connects bone to bone.
It binds the ends of the bones together to prevent dislocation and increase stability.
What is the structure and function of a tendon?
It is connective tissue that attaches skeletal muscle to bone.
Strong attachment of muscle to bone allow for movement and improves stability.
What is the structure and function of articular cartilage?
Smooth, slightly spongy cartilage that covers the ends of bones in a joint.
To prevent friction between bones at a joint and to act as a shock absorber.
What is the structure and function of fibrocartilage?
Cartilage made up of many thick collagen fibres.
Acts as a shock absorber between bones. (E.g. between vertebrae)
What is the structure and function of synovial fluid?
Viscous fluid contained within a synovial membrane.
To reduce friction between articulate cartilage in a joint.
What is the structure and function of a joint capsule?
Tough fibrous tissue that lies outside the synovial membrane.
Helps to strengthen the joint and the synovial membrane secretes the synovial fluid.
What is the structure and function of a bursa?
Flattened fibrous sac containing a thin layer of synovial fluid.
To prevent friction between a ligament/tendon and a bone.
What is the structure and function of meniscus?
A wedge of fibrocartilage.
Improves the fit between bones - improving stability, acting as a shock absorber and reducing friction.
What is the structure and function of a pad of fat?
A fatty pad located between the joint capsule and muscle or bone.
Provides cushioning to improve stability and prevent friction between muscles and the joint capsule.
What is a joint?
Two or more bones articulate to create movement.
What is flexion?
Movement that decreases the joint angle.
What is extension?
Movement that increases the joint angle.
What is Doris-flexion?
Decreases angle at the angle (bringing toe towards the tibia).
What is plantar-flexion?
Increase joint angle at ankle (moving toe down onto tiptoes).
What is abduction?
Lateral movement of the limbs away from the midline of the body.
What is adduction?
Lateral movements of the limbs towards the midline of the body.
What is horizontal extension?
Movement of a limb away from the midline of the body parallel to the ground (backwards).
What is horizontal flexion?
Movement of a limb towards the midline of the body parallel to the ground (across chest).
What is rotation? What are the 2 specific types?
Bones turn about their longitudinal axis in a screwdriver action.
Medial (towards body), Lateral (away from body).
What movements happen during a sagittal plane (left - right)?
Flexion, Extension, Doris-flexion, Plantar-flexion.
What movements happen during a frontal plane (back - front)?
Abduction, Adduction.
What movements happen during a transverse plane (top - bottom)?
Horizontal Flexion, Horizontal Extension, Rotation, Pronation, Supination.
What are the names of all of the 22 bones in the body (label the diagram)?
Answers in bamboo paper.
What are the names of all of the muscles (label the diagram)?
Answers in bamboo paper.
What is pronation and supination?
Pronation = palm up (twisting from the radio-ulnar joint).
Supination = palm down (twisting from the radio-ulnar joint).
What type of joint is the wrist?
Condyloid
What is the agonist?
The muscle responsible for the movement at a joint (e.g. bicep brachii during flexion at the elbow).
What is an antagonist?
The muscle that lengthens by relaxing as the agonist contracts. This allows the agonist action to take place. (e.g. tricep brachii during flexion at the elbow).
What is a fixator?
The muscle(s) that stabilise the joint at the origin (connected to none moving part) of the agonist. It helps the agonist function efficiently and prevents unwanted movement. (e.g. rotator cuff muscles, guardians of the shoulder joint, or the deltoid/trapezius during flexion at the elbow).
What are isometric contractions?
The muscle is not changing length while exerting a force
What are isotonic concentric contractions?
The muscle shortens while exerting a force
What are isotonic eccentric contractions?
The muscle lengthens while exerting a force
True or false : Any weighted moment (weight or body weight) has the same agonist during an upwards and downwards phase of a movement which allows controlled movements.
True
What are type 1 muscle fibres?
Slow oxidative fibres
Endurance fibres (aerobic)
What are type 2A muscle fibres?
Fast oxidative glycolytic
Speed endurance fibres
Aerobic + anaerobic (closer to type 2B)
What are type 2B muscle fibres?
Fast glycolytic fibres
Speed/power fibres
Anaerobic
What are the structural and functional characteristics of all 3 muscle fibres?
Answer on docs - muscle fibres type - in musculoskeletal systems folder
What is a motor unit and how does it function?
A motor neuron plus all the muscle fibres it innervates (stimulate)
To carry impulses from the central nervous system (the brain and the spinal cord) to the muscle fibres to initiate muscular contraction
What are the effect of number of motor units recruited?
The greater the strength of the stimulus from the central nervous system = greater number of motor units recruited and greater force of contraction in the muscles.
In practice : brain sends weak stimulus to bicep brachii, recruit low number of motor units to lift feather and very large stimulus to bicep brachii to recruit high number of motor unit to lift bar bell
What are the effects if the type of motor unit recruited?
Muscles constrain combination of 3 types of motor unit
Type 1 (small + produce low force of contraction over long period of time)
Type 2a (force and time of contraction between type 1 and type 2b motor units)
Type 2b (large + produce greatest force of contraction over short period of time)
In practice : lift feather = brain recruit only type 1 to produce small force in bicep brachii. Lift bar bell = brain recruit type 1, 2a and 2b motor units to produce large force in bicep brachii
What are the effect of synchronisation of motor units recruited?
Not all motor units recruited at same time
1st motor unit recruited = type 1 (force of contraction low)
2nd motor unit recruited = type 2a (force of contraction increase)
3rd motor unit recruited = type 2b (force of contraction increase further)
In practice : brain recruits type 1 in bicep brachii immediately to lift feather. Very tiny delay before recruits type 2a and 2b motor units in bicep brachii to lift barbell
What is a neuron?
A nerve cell that transmits the action potential
What is an axon?
Carried the electrical impulse from cell body to neuromuscular junction
What is a neuromuscular junction?
The point where motor neuron communications with muscle fibre across a space called the synapse
What is the synapse?
The space between a motor neuron and skeletal muscle
What is a motor end plate?
The area of muscle fibre that establishes synaptic contact with motor neuron.
Fill in the diagram of a motor unit
Bamboo paper
What is the resting potential?
The neuron at rest (no positive charge). There is a lower charge inside the neuron than outside.
What is the action potential?
The electrical activity carried down the axon (positive charge).
What is the neurotransmitter?
Chemical messenger that transmits across synapse and binds to muscle fibres to initiate contraction
What is acetylcholine?
The neurotransmitter released at neuromuscular junction that travels across synapse (chemical + electrical impulse)
What is the all or none law?
If the action potential threshold is reached, all muscle fibres in the motor unit are activated. If it is not reached, no muscle fibres are activated.
What is the flow diagram of a motor unit?
Bamboo paper
