The Muscular system

Question 1

What are the features of skeletal muscle?

Answer 1

-voluntary
-striated
-multinucleated

Question 2

What are the features of cardiac muscle?

Answer 2

-involuntary
-striated
-single nucleus

Question 3

What are the purpose of intercalated discs in cardiac muscle?

Answer 3

They help to boost nerve impulses so that it can contract efficiently.

Question 4

What are the features of smooth muscle?

Answer 4

-involuntary
-non-striated
-single nucleus

Question 5

What are the functions of muscle?

Answer 5

-movement
-position
-regulating organ volume
-moving substances into the body
-heat production (shivering, muscle contractions produce heat).

Question 6

What are the characteristics of muscle?

Answer 6

-excitability
-contractility
-extensibility
-elasticity

Question 7

What is the meaning of excitability?

Answer 7

The ability to respond to a stimulus.

Question 8

What is the meaning of contractility?

Answer 8

The ability to contract when stimulated.

Question 9

What is the meaning of extensibility?

Answer 9

The ability to be stretched or extended.

Question 10

What is the meaning of elasticity?

Answer 10

The ability to return to the original length after stretching.

Question 11

During muscle contraction, what is the origin of the muscle?

Answer 11

This is the end of muscle attached to a structure (usually bone) that remains stationary.

Question 12

During muscle contraction, what is the insertion part of the muscle?

Answer 12

This is the opposite end to the origin and it is moved by the contraction.

Question 13

What is a tendon?

Answer 13

Attached muscle to bone.

Question 14

What is the gaster/belly of muscle?

Answer 14

This is the fleshy/ meaty portion of the muscle that contracts.

Question 15

What are antagonistic pairs of muscles?

Answer 15

Opposing pairs of muscles working together to create movement.

Question 16

What is the agonist muscle?

Answer 16

(prime mover) contracts to cause an action.

Question 17

What is the antagonist muscle?

Answer 17

This stretches and yields to the action go the agonist.

Question 18

What is the synergist?

Answer 18

This contracts to stabilise intermediate joints (against dislocation).

Question 19

What is the fixator?

Answer 19

This stabilises the origin of the agonist.

Question 20

What is the order of structures that make up a muscle?

Answer 20

Myofibrils-> muscle fibres-> fascicles-> muscle

Question 21

What is a fascicle?

Answer 21

This is a bundle of muscle fibres.

Question 22

What does the epimysium surround?

Answer 22

The whole muscle.

Question 23

What does the perimysium surround?

Answer 23

The fascicle (bundle of fibres).

Question 24

What does the endomysium surround?

Answer 24

The individual muscle fibres.

Question 25

What are myofibrils made up of?

Answer 25

These are made of contractile proteins actin and myosin (myofilaments).

Question 26

What gives the muscle a striated appearance?

Answer 26

The overlapping of thin (actin) and thick (myosin) filaments.

Question 27

What is a sarcomere?

Answer 27

One section of myofibril- made of actin strands and myosin strands.
These sections are separated by a z- line.

Question 28

What happens to sarcomere when muscle contracts?

Answer 28

These contracts and squash together, essentially bringing the z-lines closer together.

Question 29

Why do muscles always pull (not push)?

Answer 29

The insertion is always brought towards the origin so always pulling.

Question 30

What is a motor unit?

Answer 30

A group of muscle fibres that all get their signals from the same, single motor neuron (therefore, act together).