Chapter 3 - The Muscular System

Question 1

What are the two types of muscles?

Answer 1

Voluntary and involuntary

Question 2

What are voluntary muscles?

Answer 2

They are under conscious control and can be activated at will as they are required. These are also referred to as skeletal muscles as they attach to the skeleton and are capable of producing movement.

Question 3

What are involuntary muscles?

Answer 3

They are not controlled consciously and therefore function independently from a person’s awareness. These muscles perform a wide range of essential bodily functions like digestion, urination and circulation.

Question 4

What are skeletal muscles?

Answer 4

These are also called striated muscles. Have many forms eg. Flat, long, short, fat etc.
Made up of 75% water and 20% protein. 5% consists of salt and high energy phosphates.

Question 5

Give six functions of skeletal muscles…

Answer 5

1. Movement
2. Circulation - assisting the cardiovascular system with transport of blood, help to push blood back towards the heart
3. Energy storage - store energy in form of glycogen and ATP
4. Shape and structure - muscular system holds the skeletal system together and gives it its shape
5. Upright position - muscles pull/contract in such a way to allow the body to remain upright
6. Heat production - when skeletal muscles contract they give off heat which helps to maintain body temperature. In cold conditions, this is why we shiver.

Question 6

Where would you find smooth (involuntary) muscle types?

Answer 6

In the walls of the blood vessels and surrounds many of the internal organs. Also found in digestive tract.

Question 7

Where would you find cardiac (involuntary) muscle?

Answer 7

Wall of the heart. Pumps blood around the body.

Question 8

Where would you find skeletal (voluntary) muscle?

Answer 8

Attached to the skeleton and are located throughout the body.

Question 9

What do you call the external wall of muscle?

Answer 9

Fascia (or sheath)

Question 10

Where are the bundles of muscle fibres?

Answer 10

Bound together by the ‘sheath’ (fascia)

Question 11

Along individual muscle fibres there are a number of smaller fibres known as……?

Answer 11

Myofibrils

Question 12

Myofibrils are made up of a series of worm like segments that form the contractile units of the muscle. These are called…..

Answer 12

Sarcomeres

Question 13

Which two types of protein filament form the sarcomere?

Answer 13

Actin and Myosin

Question 14

Muscles contract as a result of the overlapping nature of actin and myosin, which enables sarcomeres to shorten. The entire muscle fibres becomes shorter and this is what causes muscles to contract.

True or false?

Answer 14

True

Question 15

What are tendons made from?

Answer 15

Dense, regular collagen fibres.

Question 16

What is the primary role of the tendon?

Answer 16

Connect the muscle to the bone.

Sometimes the tendons do attach to connective tissues.

Question 17

What is a motor unit?

Answer 17

It is made from a nerve, or neuron, and all of the muscle fibres under the control of that nerve.

Question 18

During heavy exercise (eg. Weights) when the muscles need to generate large forces, what will the brain signal the muscles to do?

Answer 18

Recruit more motor units which employs more muscle fibres.

Question 19

What is the all or nothing principle?

Answer 19

This law states that when a muscle is stimulated, every contractile unit within that fibre will contract. There is no partial recruitment of a muscle fibre because all the contractile units (myofibril and sarcomere) are controlled by the same nerve.

Question 20

Skeletal muscle fibres can be broadly classified as ________ twitch or ________ twitch.

Answer 20

Fast or slow twitch

Question 21

Fast twitch fibres are larger, stronger and more explosive whereas slow twitch fibres are larger, stronger and more enduring.

True or false?

Answer 21

True

Question 22

A persons muscle fibre type is determined……?

Answer 22

Genetically

Question 23

During exercise, where large forces are required, the body normally recruits which type of fibres?

Answer 23

Fast twitch fibres

Question 24

Which type of fibre is more fatigue resistant - slow or fast twitch?

Answer 24

Slow twitch

Question 25

What are mitochondria?

Answer 25

Specialised cells which are located in between muscle fibres, predominantly the slow twitch variety, and which possess the unique about to burn oxygen along with other nutrients.

Question 26

What does regular cardiovascular endurance exercise do to mitochondria?

Answer 26

Stimulates an increase in size and number of these cells, allowing the muscles to generate even more aerobic energy

Question 27

What is myoglobin?

Answer 27

An oxygen carrying protein that is located within muscle tissue and which is responsible for shuttling the oxygen from the blood vessel to the mitochondria cells where it can be used to release ATP from nutrients consumed.

Question 28

How is muscle glycogen formed?

Answer 28

From chains of glucose that are bound together and packed within the muscle and liver for use as an energy source. At rest, and during exercise, glycogen is broken down and deposited into the blood as glucose, which is then transported through the body for use as energy.

Regular exercise can enhance the muscles ability to store glycogen.

Question 29

When a muscle contracts, movement will occur if:

Answer 29

1. The muscle crosses a joint - muscles pull across moveable joints to create movement
2. The opposing muscle relaxes - muscles work in pairs. For one to shorten, it’s opposing muscle (the antagonist) must relax

(Remember, muscles can only pull along the direction in which the muscle fibres run)

Question 30

What happens during the concentric phase of an isotonic muscle contraction?

Answer 30

First stage of an exercise and takes place when the muscle becomes shorter and fatter.

Question 31

What happens during the eccentric phase of an isotonic muscle contraction?

Answer 31

This is the reverse of the concentric phase and takes place as the muscle lengthens under tension.

Eccentric muscle actions are linked with DOMS.

Question 32

What is an isometric muscle contraction?

Answer 32

A static muscle contraction where the length of the muscle does not alter, and so the distance between the origin and the insertion remains relatively constant.

(These have an effect on internal pressure and should be used carefully)

Question 33

During exercise, what is the role of the prime mover?

Answer 33

Prime mover (also know as the agonist) is the muscle primarily responsible for creating the movement.

Question 34

During exercise, what is the role of the synergistic muscle?

Answer 34

An assisting muscle that is working in conjunction with the prime mover.

Question 35

What is the role of the fixator muscle in exercise?

Answer 35

A muscle that contracts statically (without moving) to resist or prevent movement

Question 36

What is the role of the antagonist muscle during exercise?

Answer 36

This is the muscle that must relax in order to allow the movement to take place.

Question 37

Muscle contractions are governed by two primary factors: A and B. What are they?

Answer 37

Energy availability and nervous impulses

Question 38

Muscle contractions can only take place when they are signalled to do so by….?

Answer 38

A nervous impulse or twitch.

The brain sends a signal via a motor neuron, a nerve, towards the muscle. Skeletal muscles are voluntary and can only act when instructed to do so.

Question 39

What is momentary muscle failure?

Answer 39

When the muscles become exhausted and this lack of available energy prevents the contraction from continuing

Question 40

Where are the abductors situated and give an example of an exercise for these.

Answer 40

Lateral surface of hip joint.

Side lying leg raises.

Question 41

Where are the adductors situated and give an exercise for these.

Answer 41

Medial surface of the hip and upper leg region. 4 individual muscles.

Inside lying leg raises.

Question 42

Where are the biceps situated and give an exercise for these.

Answer 42

Front of the upper arm.

Standing barbell curl.

Question 43

Where is the deltoid situated and give an exercise for these.

Answer 43

Outside of the upper arm and shoulder area.

Seated shoulder press machine, dumbbell lateral raise.

Question 44

Where is the erector spinae situated and give an exercise for these.

Answer 44

Lower back region and becomes smaller as it moves up the spine.

Seated back extensions, prone back extensions/dorsal raises

Question 45

Where is the gastrocnemius situated and give an exercise for these.

Answer 45

Rear surface of the lower leg and affects both the knee and the ankle.

Standing calf raises.

Question 46

Where is the gluteus maximum situated and give an exercise for this.

Answer 46

Bum.

Squats and leg press

Question 47

Where are the hamstrings situated and give an exercise for these.

Answer 47

Rear surface of the upper leg and are composed of three individual muscles.

Lying leg curls.

Question 48

Where are the hip flexors situated and give an exercise for these.

Answer 48

Span the front surface of the hip joint.

Hanging knee tucks, leg raises

Question 49

Where is the latissimus dorsi situated and give an exercise for these.

Answer 49

Large sheet of muscle that spans the mid lateral region of the spine. Crossing the shoulder.

Lateral pull down, seated row

Question 50

Where are the obliques situated and give an exercise for these.

Answer 50

Abdominal muscles - internal and external. Connect ribs to pelvis.

Side bends, twisting crunches

Question 51

Where is the pectoralis major situated and give an exercise for these.

Answer 51

Forms the chest area are crosses the shoulder joint.

Bench press, flyes

Question 52

Where are the pelvic floor muscles situated and give an exercise for these.

Answer 52

3 layers of flat muscle and connective tissue which form a sling in the base of the pelvis. They support the pelvic organs, control bladder and bowel movements, facilitate child birth and stabilise the pelvis and lower spine.

Kegals - often advised for women after giving birth vaginally

Question 53

Where are the quadriceps situated and give an exercise for these.

Answer 53

Front of the upper leg. Four separate muscles.

Leg press, squats, leg extensions

Question 54

Where is the rectus abdominis situated and give an exercise for these.

Answer 54

Front of the torso.

Crunch, plank

Question 55

Where are the rhomboids situated and give an exercise for these.

Answer 55

Sitting deep to the trapezius muscle in the upper back region of the torso. Key stabilisers of the shoulder complex.

Seated row, reverse press up

Question 56

Where are the soleus situated and give an exercise for these.

Answer 56

Rear surface of the lower leg and only acts at the ankle. Becomes more dominant when the knee is flexed.

Seated calf raises

Question 57

Where are the tibialis anterior situated and give an exercise for these.

Answer 57

Long sheet of muscle situated on the front of the lower leg.

Resisted dorsi flexion

Question 58

Where Is the transverse abdominis situated and give an exercise for these.

Answer 58

Deep to the rectus abdominis, this muscle acts like a corset supporting the visceral organs. When contracted, it pulls in the naval.

Plank, side plank, any core exercise

Question 59

Where is the trapezius situated and give an exercise for these.

Answer 59

Large, strong muscle situated across the upper back, shoulder and neck region. Upper tends to be involved in shrugging and lower in pulling the shoulders down.

Upright rows, shrugs, seated rows

Question 60

Where are the triceps situated and give an exercise for these.

Answer 60

Rear of the upper arm and constitutes 2/3 of the muscle in that area.

Tricep push down, tricep kick backs