Chapter 3- Effects Of Ageing -the Muscular System

Question 0

What are the 3 types of cartilage? Give properties for each.

Answer 0

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.

Question 1

What are the 3 functions of the skeletal system?

Answer 1

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

Question 2

How does hyaline cartilage operate?

Answer 2

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.

Question 3

What is the periosteum?

Answer 3

An outer protective covering of bone, providing attachment for muscle tendons and ligaments

Question 4

What is the epiphyseal disc?

Answer 4

The segment of bone in which an increase in bone length takes place

Question 5

What is compact bone?

Answer 5

Dense, tightly packed, ring shaped calcium phosphate plates. Forms solid bone tissue, providing strength and support.

Question 6

What is cancellous bone?

Answer 6

Light weight, occurring at the end of a long bone.

Question 7

Define articulation

Answer 7

A place where two or more bones meet to form a joint

Question 8

What are the short term responses of the skeletal system to exercise?

Answer 8

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

Question 9

What are the long term responses of the skeletal system to exercise?

Answer 9

Bones respond to force by becoming stronger. Therefore the chance of osteoporosis is reduced if mechanical stress is regularly exerted.

Question 10

List some adaptations of the skeletal system to exercise

Answer 10

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.

Question 11

What do ligaments attach?

Answer 11

Bone to bone, to limit range of movement of joints

Question 12

What do tendons attach?

Answer 12

Muscle to bones across joints, to transmit the muscle force.

Question 13

Describe the antagonist muscle action

Answer 13

The agonist is the active muscle. Th antagonist relaxes to allow the agonist to work as movement occurs.

Question 14

What is a synergistic muscle?

Answer 14

A muscle which holds the body in position so an antagonist muscle can operate. This prevents any unwanted movement.

Question 15

What are the three types of muscle tissue in the human body? Describe each

Answer 15

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

Question 16

What are the 4 functions of skeletal muscle tissue?

Answer 16

Producing movement by exerting a force.
Maintaining body posture and changing body shape
Generating heat to keep us warm
Storage of glycogen for energy

Question 17

What are the long term adaptations of muscle fibres of endurance training?

Answer 17

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

Question 18

What are the long term adaptations to muscle fibres of high intensity anaerobic training?

Answer 18

Increased size of fast twitch fibres(hypertrophy). Increased number of type 11b fibres

Question 19

What is an isometric contraction?

Answer 19

When the length of the muscle doesn’t change shape, but the tension does.

Question 20

What is dynamic contraction, and what are the 2 types?

Answer 20

When a muscle changes it’s length.

Concentric is when the muscle shortens, eccentric is when the muscle lengthens.

Question 21

What are the long term adaptations to ligaments and tendons to dynamic exercise?

Answer 21

They will become thicker and stronger. However they will become slightly less elastic, so flexibility can be lost.

Question 22

Describe how skeletal muscle is caused to contract, neurologically.

Answer 22

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

Question 23

Define a motor unit

Answer 23

A single block of muscle fibres and it’s neurone

Question 24

What happened when a motor unit is stimulated?

Answer 24

All fibres connected to that neurone are activated at once.

Question 25

What are dendrites?

Answer 25

Highly branched processes which extend from cell body, specialised to receive stimuli from sensory organs or other neurones

Question 26

What does the axon do?

Answer 26

Conducts nerve impulses to other cells

Question 27

What does the myelin sheath do?

Answer 27

Electrically insulates the nerve

Question 28

What are the nodes of ranvier?

Answer 28

Gaps in the myelin sheath where the action potential jumps from node to node

Question 29

When is an action potential initiated? Describe the following process.

Answer 29

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

Question 30

What is a synapse?

Answer 30

A junction where the axon of one neurone interacts with another neurone

Question 31

What is wave summation?

Answer 31

When a fibre is repeatedly fired, causing the force to build up.

Question 32

How is control of an action achieved?

Answer 32

By varying the number of motor units in operation.

Question 33

List some adaptations to muscle cells following anaerobic exercise.

Answer 33

``` 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 ```

Question 34

List some adaptations to muscle cells produced by aerobic training.

Answer 34

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