Muscles & Movements

Question 1

What are the 3 types of muscle found in the body?

Answer 1

1. Cardiac 2. Smooth 3. Skeletal

Question 2

Out of the 3 types of muscle stated, which one is voluntary? Which type is non- striated, while the others are striated?

Answer 2

Skeletal

Smooth muscle

Question 3

Skeletal msucles contain many muscle _, which are further divided into _ , which contain _ and _

Answer 3

Fibres

Myofibrils

Actin & Myosin

Question 4

What happens to the muscle fibres when a seletal muscle is strained?

Answer 4

They are torn.

The more fibres torn, the worse the strain

Question 5

What are the types of skeletal muscle? (5) Give an example of each type.

Answer 5

1. Circular- orbicularis oculi
2. Pennate- deltoid
3. Quadrate- rectus abdominus (abs)
4. Flat with aponeurosis- external oblique
5. Fusiform- biceps brachii

Question 6

Skeletal muscles have to cross the joint and attach to bones on the other side in order to move it. T/F?

Answer 6

True

Question 7

Muscles extend during contraction. T/F?

Answer 7

False- shorten

Question 8

Muscles attach to bone via _ .

Answer 8

Tendons

Question 9

Tendons have contractile properties. T/F?

Answer 9

False- non contractile

Question 10

Define an aponeurosis.

Answer 10

Flattened tendon- commonly associated with flat muscles.

They attach muscle to soft tissue rather than bone.

Question 11

What are the two attachments of a skeletal muscle called?

Answer 11

1. Origin
2. Insertion

Only thing skeletal muscle can do is shorten during contraction, shortening the long axis between the origina and the insertion

Question 12

Direction of movement of a muscle depends on what?

Answer 12

Side of the joint the muscle spans.

Eg bicep brachii- spans over anterior surface of shoulder joint- flexes shoulder joint

Also spans anterior elbow joint- flexes elbow joint.

Question 13

Where are the 3 origins of the deltoid found?

Answer 13

1. Spine of scapula
2. Acromion process of scapula
3. Lateral 1/3rd of clavicle

Question 14

At which point is the insertion of the deltoid found?

Answer 14

Deltoid tuberosity of humerus

Question 15

What are the movements produced by the posterior, middle and anterior fibres of the deltoid?

Answer 15

Posterior- Extension of shoulder

Middle- Abduction of shoulder

Anterior- Flexion of shoulder

The deltoid muscle only crosses one joint – the shoulder joint, however it can cause different movements at that joint as it has muscle fibres in different orientations.

Question 16

The _ of the articular surface determines the extent of possible movement.

Answer 16

Shape

Eg Shallow socket- cicrumduction movement

Trochlea of the distal humerus- only flexion/extension

Question 17

Reflexes are rapid, involuntary responses that serve a _ function

Answer 17

Protective

Question 18

What are the two main reflexes involving skeletal muscles?

Answer 18

1. Stretch reflex
2. Flexion withdrawal reflex- when we touch something potentially dangerous, a sudden Flexion to withdraw from the danger (eg hot plate)

Question 19

The brain is involved in reflexes. T/F?

Answer 19

False- Nerve connections at spinal cord level

Question 20

Stretch reflex is also known as deep _ reflex. Describe this reflex.

Answer 20

Tendon- eg Patellar tendon

A brief sudden stretch is applied to the muscle via its tendon. This causes a contraction of the muscle- resulting in a brief twitch of the muscle belly or a movement in the normal direciton.

Reflexes are protective against over-stretching

Question 21

Describe the communications between the spinal cord and the deep tendon during reflex action.

Answer 21

•Sensory nerve from muscle detects the stretch & tells the spinal cord

•

•Synapse (communication) in the spinal cord between the sensory & motor nerves

•

•Motor nerve from spinal cord passes message to muscle to contract

Whole route taken by the AP’s is called the reflec arc

Question 22

Define muscle paralysis.

Answer 22

Muscle wihtout a functioning motor nerve supply

Question 23

Define muscle spasticity.

Answer 23

Muscle has functioning motor nerve, but descending controls from the brain are not working

Question 24

What are the examinational differences in muscle tone between muscle paralysis and spasticity?

Answer 24

Paralysis- reduced tone

Spasticity- increased tone

Question 25

Define atrophy.

Answer 25

Wasting of muscle- develops as a result of inactivity

Myocytes become smaller

Question 26

The opposite to muscle atrophy is _

Answer 26

Hypertrophy - each individual myocyte enlarges

Question 27

Skeletal muscle are usally found in deep fascia, which have a tough fibrous _ _ covering

Answer 27

Connective tissue

Question 28

Lower limb muscle have _ muscle compartments.

Answer 28

3- Anterior, middle, posterior

Question 29

The thigh and the leg are _ and _ compartments of the lower limb

Answer 29

Middle and lateral

Question 30

The arm and forearm both have_ number of muscle compartments.

Answer 30

2- Anterior & posterior

Question 31

What is compartment syndrome?

Answer 31

Fascia creates enclosed space. Increased pressure due to swelling of tissue or increased fluid- Affects the muscle and nerves of that compartment.

Fasciotomy is needed in an acute presentation to relieve pressure