Muscle

Question 1

What types of contraction are there?

Answer 1

Isometric, cocentric and eccentric

Question 2

What’s isometric contraction?

Answer 2

When the muscle is held at a constant length

When force increases with no change in muscle length

Question 3

The force generated during an isometric contraction is dependent on?

Answer 3

The length of the muscle while contracting

Question 4

Max isometric contraction is produced ?

Answer 4

At the muscles optimum length

Question 5

What’s a concentric contraction ?

Answer 5

When the muscle shortens

Question 6

What’s an eccentric contraction and how does it work?

Answer 6

This is when the muscle lengthens.

When the muscle is generating force but it’s not enough to shorten the muscle so the muscle extends instead

Question 7

All these types of contraction are ..?

Answer 7

Isotonic contractions. Where the length of the muscle changes

Question 8

What’s the functional unit of the skeletal muscle ?

Answer 8

Motor unit

Question 9

What’s the motor unit made of ?

Answer 9

-alpha motor neurons (located in spinal cord)
-it’s axon
Muscle fibres

Question 10

What are the types of skeletal muscle fibres?

Answer 10

• slow twitch oxidative fibres (type 1)-
• fast twitch oxidative
• fast twitch glycolytic

Question 11

What’s slow twitch oxidative fibres ?

Answer 11

Contract slowly and use aerobic respiration (glucose and oxygen) to produce ATP

Question 12

What are fast twitch oxidative fibres?

Answer 12

They have fast contractions and primarily use aerobic respiration but can switch to anaerobic respiration so fatigue quicker than SO fibres.
(Type 2a)
Generate force quickly

Question 13

What’s fast twitch glycolytic fibres ?

Answer 13

They produce very fast contractions and primarily use anaerobic respiration
Fatigue more quickly than others
(Oxidative fibres contain more mitochondria )

Question 14

What are SO fibres good for and why?

Answer 14

As they can function for a long time without fatiguing, they are good for maintaining posture,
Producing isometric contractions
Stabilising bones and joints
Making small movements that happen often but don’t require lots of energy

Question 15

What are FO fibres good for ?

Answer 15

They produce ATP relatively quickly (can produce high amounts of tension) have lots of mitochondria
Don’t fatigue quickly
Don’t have myoglobin so they have a lighter red
Useful for walking (as they produce more tension that SO fibres but are more fatigue resistant than FG fibres)

Question 16

What are FG fibres used for?

Answer 16

(They have lots of glycogen used in glycolysis to generate ATP)
Don’t have mitochondria or myoglobin so their white
Produce rapid contractions for quick movements (only for short time ) running

Question 17

How is a muscle attached to a bone?

Answer 17

Via a tendon

Question 18

Where is cardiac muscle found?

Answer 18

In the heart

Question 19

Where is smooth muscle found ?

Answer 19

Blood vessels and hollow organs (stomach, bowels)

Question 20

How is smooth muscle and cardiac muscle controlled ?

Answer 20

Automatically/involuntary

Question 21

How is skeletal muscle controlled?

Answer 21

It’s voluntary

Question 22

Which muscles are slow and which muscles are fast?

Answer 22

The smooth muscle is the slowest and the skeletal muscle is the fastest

Question 23

What’s the structure of smooth muscle ?

Answer 23

It’s spindle shaped (like an eye/almond)

It has one nuclei in the middle

Question 24

What’s the structure of a cardiac cell?

Answer 24

-it’s quite branched
-1 or 2 nuclei
-

Question 25

What’s the structure of the skeletal cell?

Answer 25

-have LOTS of nuclei (on the edges)
-straight (not branched)
-

Question 26

Which muscles have stripes/striated?

Answer 26

Cardiac and skeletal

Question 27

The main site of regulation of contraction in smooth muscle is?

Answer 27

Myosin. In smooth muscle as myosin heads need to be phosphorylated, the main site of regulation of this type of muscle is myosin.

Question 28

In skeletal muscle what is the main site of regulation of contraction?

Answer 28

Actin.

Question 29

The main parasympathetic neurotransmitter associated with smooth muscle function is ?

Answer 29

Noradrenaline

Question 30

When does maximum force production occur ?

Answer 30

The force velocity relationship demonstrates that max force production occurs when velocity of shortening is 0 (isometric contraction)

As power is = force x velocity , max power occurs at 1 third of velocity of shortening.