Skeletal Muscle

Question 1

What are the two main types of muscle?

Answer 1

Striated and non-striated

Question 2

What is the difference between the two different types of muscle?

Answer 2

In striated muscle, the arrangement of the myofibrillar apparatus produces a banding pattern.

Question 3

What are the different types of striated muscle?

Answer 3

Skeletal and cardiac

Question 4

What are the functions of skeletal muscle?

Answer 4

Movement, posture, joint stability and heat generation

Question 5

What are the main groups in which skeletal muscle can be arranged?

Answer 5

Circular , parallel and pennate

Question 6

hat are the most common arrangement of skeletal muscle?

Answer 6

Parallel

Question 7

What are the three main categories of parallel muscle?

Answer 7

Strap, fusiform and fan shaped

Question 8

Describe parallel muscles

Answer 8

Fibres run parallel to force generating axis

Question 9

Describe strap muscles

Answer 9

Shaped like strap or belt. Fibres run longitudinally to contraction direction

Question 10

Describe fusiform muscles

Answer 10

Wider and cylinderically shaped in the centre. Taper off at the end

Question 11

Describe fan shaped muscle

Answer 11

Fibres converge at one end and spread over broad area at other end

Question 12

Give an example for strap muscle

Answer 12

Sartorius

Question 13

Give an example of fusiform muscle

Answer 13

Biceps brachii

Question 14

Give an example of a fan shaped muscle

Answer 14

Pectoralis major

Question 15

Describe circular muscles

Answer 15

Act as sphincters to adjust opening

Concentric fibres

Question 16

What do circular muscle attach to?

Answer 16

Attach to skin, ligament and fascia rather than bone

Question 17

Describe pennate muscle

Answer 17

One or more aponeurosis run through muscle body from tendon

Question 18

What are the different types of pennate muscle?

Answer 18

Unipennate, bipennate, multipennate

Question 19

Describe unipennate muscles

Answer 19

All fascicles on the same tendon

Question 20

Describe bipennate muscles

Answer 20

Fascicles on both sides of central tendon

Question 21

Describe multipennate muscles

Answer 21

Central tendon branches and fascicles run off each branch

Question 22

Example of unipennate muscle

Answer 22

Extensor digitorum longus

Question 23

Example of bipennate

Answer 23

Rectum femoris

Question 24

Example of multipennate

Answer 24

Deltoid

Question 25

What are 'compartments'

Answer 25

Limbs divided into compartments delineated by fascia

Question 26

What can trauma in one compartment cause?

Answer 26

Internal bleeding with exerts pressure on blood vessels and nerves. This can give rise to compartment syndrome

Question 27

What is a muscle agonist?

Answer 27

Primer movers (main muscle responsible for a particular movement)

Question 28

What is a muscle antagonist?

Answer 28

Oppose prime movers

Question 29

What is a muscle synergist?

Answer 29

Assist primer movers (acting alone they can't perform the movement but their angle of pull assist)

Question 30

What are muscle neutralisers?

Answer 30

Prevent the unwanted actions that an agonist can perform

Question 31

What are muscle fixators?

Answer 31

Act to hols a body part immobile whist another body part is moving

Question 32

What are the two main types of contraction?

Answer 32

Isotonic contraction | Isometric contraction

Question 33

What is isometric contraction?

Answer 33

Constant length, variable tension (muscle generates tension but is not shortening) eg hand grip

Question 34

What's isotonic contraction?

Answer 34

Constant tension, variable muscle length - the muscle changes length and moves the loa d

Question 35

What are the different types of isotonic contraction?

Answer 35

Concentric and eccentric

Question 36

What is concentric contraction?

Answer 36

Muscle shortens eg lifting load with the arm

Question 37

What is eccentric contraction?

Answer 37

Muscle exerts a force while being extended eg walking downhill

Question 38

What is a first class lever?

Answer 38

Effort at one end lost at other. | Extension and flexion of the head

Question 39

What is a second class lever?

Answer 39

``` Effort at one end, fulcrum at other. Tip toes (plantar flexion of foot) ```

Question 40

What is a third class lever?

Answer 40

Effort between load and fulcrum. | Flexion of elbow

Question 41

What are the three main muscle fibre types?

Answer 41

Slow type I Fast type II A Fast type II X

Question 42

What are the muscle fibre type based on?

Answer 42

Myosin heavy chain (MHC) expression

Question 43

What are the two ways in which muscles are controlled in the body?

Answer 43

Size principle and rate code

Question 44

What is muscle tone?

Answer 44

Healthy muscles never fully relaxed and retain amount of tension and stiffness (muscle tone)

Question 45

What is the baseline muscles tone due to?

Answer 45

Motor neurone activity and muscle elasticity

Question 46

What is hypotonia?

Answer 46

Lack of skeletal muscle tone | Symptom rather than condition

Question 47

What is myotonia?

Answer 47

Inability to relax muscles at will