ANATOMY - Muscle

Question 1

What is skeletal muscle composed of?

Answer 1

Mainly muscle tissue
Also
- connective tissue
- blood vessels
- nerves

Question 2

What is the cell membrane of a muscle cell called?

Answer 2

Sarcolemma

Question 3

What binds muscle fibres together?

Answer 3

Connective tissue sheaths

Question 4

What is the name of the layer which surrounds the entire muscle?

Answer 4

Epimysium

Question 5

What is the name of the layer which surrounds each fascicle of muscle fibres?

Answer 5

Perimysium

Question 6

What is the name of the layer which surrounds each individual muscle fiber?

Answer 6

Endomysium

Question 7

What is a fascicle?

Answer 7

Group of muscle fibres

Question 8

What separates muscles groups?

Answer 8

Fascia

Question 9

Is the origin or insertion of a muscle more moveable?

Answer 9

The insertion

Question 10

What are the two types of muscle attachments ?

Answer 10

1. Fleshy attachments
2. Indirect attachments

Question 11

Describe a fleshy muscle attachment

Answer 11

The connective tissue fibres which join muscle to bone are SHORT

Question 12

Describe an indirect attachment of a muscle to bone?

Answer 12

The connective tissue fibres form a tendon or an aponeurosis

Question 13

What does the organisation of muscle fibres affect?

Answer 13

• power of contraction
• range of contraction

Question 14

Are fibres in a fascicle parallel to each other?

Answer 14

Yes

Question 15

How can the arrangements of fascicles vary?

Answer 15

• parallel
• circular
• pennate
• convergent

Question 16

Describe arrangement of fascicles in parallel muscles.

Answer 16

The fascicles run parallel to the long axis of the muscle

Question 17

What happens when a parallel muscle contracts?

Answer 17

The muscle gets shorter and the diameter of the muscle body increases

Question 18

What are the two types of parallel muscles?

Answer 18

Strap like eg SCM
Fusiform eg biceps brachii (thicker in centre than ends)

Question 19

Describe arrangement of a convergent muscle

Answer 19

The origin is broad and the fascicles converge towards the insertion

Question 20

Give example of convergent muscle

Answer 20

Pec major

Question 21

Describe pennate muscle structure

Answer 21

• Large amount of short fibres in a small space
• can have 1 or more tendons
• the fascicles are oblique to the tendon

Question 22

What are the three types of pennate muscle?

Answer 22

• unipennatee
• bipennate
• multi pennate

Question 23

Describe unipennate muscle

Answer 23

Fibres insert into one side of tendon

Question 24

Describe bipennate muscle

Answer 24

Fibres attach to both sides of tendon

Question 25

Describe multipennate muscle

Answer 25

Fascicels insert onto one large tendon from all sides e.g recuts femoris

Question 26

Describe the structure of a circular muscle

Answer 26

Question 27

What happens when a circular muscle contracts

Answer 27

The cavity closes

Question 28

Give example of a circular muscle

Answer 28

Sphincters e.g orbicularis oris

Question 29

How can muscle bellies be organised

Answer 29

- 1 belly with tendon at either end - 2 bellies which attach to a single tendon at one end - many heads in series e.g digastric muscle

Question 30

What are tendons made of?

Answer 30

Collagen fibres surrounded by connective tissue

Question 31

Are tnedons innervated ?

Answer 31

Yes but only with sensory nerves.

Question 32

What is a sesamoid bone?

Answer 32

A bone located within a tendon

Question 33

What is a sesamoid fibrocartilage?

Answer 33

Cartilage in a tendon

Question 34

What is a bursa?

Answer 34

A sac containing synovial fluid

Question 35

What is the function of a bursa?

Answer 35

Distribute pressure and prevent friction

Question 36

What can happen if you have an infected bursa?/

Answer 36

Swelling

Question 37

What is a synovial sheath?

Answer 37

A sac containing synovial fluid which surrounds a tendon e.g synovial sheaths surrounding tendons in fingers

Question 38

Function of synovial sheath?

Answer 38

Protect against friction

Question 39

What can happen if a synovial sheath becomes infected?

Answer 39

There can be damage to the tendon which can immobilise the limb

Question 40

What is a prime mover/agonist

Answer 40

The main muscle for a movement

Question 41

What is an antagonistic muscle

Answer 41

Opposes / reverses a movement

Question 42

What is a synergist?

Answer 42

Helps the prime mover by ; - adding extra force - reducing undesirable movement

Question 43

What is a fixator?

Answer 43

A type of synergist which holds a bone firmly in place

Question 44

What is a motor unit?

Answer 44

A somatic motor nerve and all the muscle fibres innervated by it