Chapter 3- Effects Of Ageing -the Muscular System Flashcards
What are the 3 types of cartilage? Give properties for each.
Hyaline cartilage. It has a smooth and solid matrix which sits on the end of bones, and forms the exact surfaces which are in contacts and move across one another when a joint is used
White fibro-cartilage. Tough and slightly elastic, sits between vertebrae.
Yellow elastic cartilage. Is soft and elastic, exists in ear lobes.
What are the 3 functions of the skeletal system?
To act as a lever system
To act as a surface area for attachment of muscles, ligaments and tendons
To give shape and support to the body
How does hyaline cartilage operate?
It absorbs synovial fluid from the joint spaces when not under pressure, then expels his fluid when in contact with another cartilaginous substance, meaning that when a high impact activity is taken, the articular surfaces at each end of the joint effectively mould themselves together as this fluid is expelled. The cartilage can then absorb the fluid when pressure is off.
What is the periosteum?
An outer protective covering of bone, providing attachment for muscle tendons and ligaments
What is the epiphyseal disc?
The segment of bone in which an increase in bone length takes place
What is compact bone?
Dense, tightly packed, ring shaped calcium phosphate plates. Forms solid bone tissue, providing strength and support.
What is cancellous bone?
Light weight, occurring at the end of a long bone.
Define articulation
A place where two or more bones meet to form a joint
What are the short term responses of the skeletal system to exercise?
Lever systems provided by bones at joints enables the skeletal system to exert forces on its surroundings. Bone and cartilage are slightly elastic when subject to force, so they don’t shatter or break
What are the long term responses of the skeletal system to exercise?
Bones respond to force by becoming stronger. Therefore the chance of osteoporosis is reduced if mechanical stress is regularly exerted.
List some adaptations of the skeletal system to exercise
Thickening of articular(hyaline) cartilage provides greater cushioning and protects bone ends
Improvement of the capability of the hyaline cartilage to absorb and release synovial fluid when pressure is reduced and increased
Increased range of movement at a joint.
What do ligaments attach?
Bone to bone, to limit range of movement of joints
What do tendons attach?
Muscle to bones across joints, to transmit the muscle force.
Describe the antagonist muscle action
The agonist is the active muscle. Th antagonist relaxes to allow the agonist to work as movement occurs.
What is a synergistic muscle?
A muscle which holds the body in position so an antagonist muscle can operate. This prevents any unwanted movement.
What are the three types of muscle tissue in the human body? Describe each
Involuntary. Smooth muscle, found within walls of blood vessels
Cardiac muscle. Forms walls of heart
Skeletal muscle. Muscle type concerned with human movement and activity
What are the 4 functions of skeletal muscle tissue?
Producing movement by exerting a force.
Maintaining body posture and changing body shape
Generating heat to keep us warm
Storage of glycogen for energy
What are the long term adaptations of muscle fibres of endurance training?
Type 11b muscle fibres are converted to type 11a. The aerobic capacity of slow twitch increases. Efficiency of blood supply to these muscles will improve with endurance training, enabling slow twitch muscle to function effectively
What are the long term adaptations to muscle fibres of high intensity anaerobic training?
Increased size of fast twitch fibres(hypertrophy). Increased number of type 11b fibres
What is an isometric contraction?
When the length of the muscle doesn’t change shape, but the tension does.
What is dynamic contraction, and what are the 2 types?
When a muscle changes it’s length.
Concentric is when the muscle shortens, eccentric is when the muscle lengthens.
What are the long term adaptations to ligaments and tendons to dynamic exercise?
They will become thicker and stronger. However they will become slightly less elastic, so flexibility can be lost.
Describe how skeletal muscle is caused to contract, neurologically.
Neve impulses sent from cerebellum are sent down a motor neurone, which terminates at a synaptic end bulb, which is a junction to the muscle fibre. On the muscle fibre side there is a motor end plate. A signal is transmitted between the motor end plate and the muscle fibre, causing the muscle to contract
Define a motor unit
A single block of muscle fibres and it’s neurone
What happened when a motor unit is stimulated?
All fibres connected to that neurone are activated at once.
What are dendrites?
Highly branched processes which extend from cell body, specialised to receive stimuli from sensory organs or other neurones
What does the axon do?
Conducts nerve impulses to other cells
What does the myelin sheath do?
Electrically insulates the nerve
What are the nodes of ranvier?
Gaps in the myelin sheath where the action potential jumps from node to node
When is an action potential initiated? Describe the following process.
When sufficient numbers of sodium ions diffuse into the neurone. This depolarises the axon to a level called the all or none law. The axon is then depolarised. This process forms an electrical impulse, which is transmitted down the axon, which is insulated by the myelin sheath. The action potential can then travel from node to node in the nodes of ranvier. The nerve action potential is then followed by a muscle action potential
What is a synapse?
A junction where the axon of one neurone interacts with another neurone
What is wave summation?
When a fibre is repeatedly fired, causing the force to build up.
How is control of an action achieved?
By varying the number of motor units in operation.
List some adaptations to muscle cells following anaerobic exercise.
Fast twitch muscle hypertrophy Increased number of myofibrils Hyperplasia Increase in size and strength of contractile proteins Increase in muscle cell stores of substances such as ATP, PC and glycogen. Improves tolerance of lactate Increased rate of response of cns Reduced doms
List some adaptations to muscle cells produced by aerobic training.
Body fat proportion is reduced
More myoglobin in muscle cells
More and bigger mitochondria created in muscle cells
Increased utilisation of fat as an energy source
Conversion of 11b to 11a fibres so more aerobically active fibres
Reduced DOMS
better recruitment of slow twitch fibre motor units
