Lecture 5: How do we move?

Question 1

What are the three types of muscle?

Answer 1

Cardiac

Smooth

Skeletal

Question 2

What are myocytes?

Answer 2

Muscle fibres

Question 3

What are fascicles?

Answer 3

Bundles of myocytes.

Question 4

What are muscle fibres made from?

Answer 4

Many myofibrils.

Question 5

What are myofibrils made from?

Answer 5

Many actin and myosin filaments.

Question 6

What causes skeletal muscle to be striated?

Answer 6

The overlapping of actin and myosin microfilaments

Question 7

Describe a muscle strain.

Answer 7

When muscle fibres become torn by over exertion.

Question 8

Name the types of skeletal muscle. (5)

Answer 8

• Flat muscle
• Pennate muscle
• Fusiform muscle
• Quadrate muscle
• Circular/sphincter muscle

Question 9

What is the muscle belly?

Answer 9

The collection of contractile muscle fibres.

Question 10

What is the function of tendons?

Answer 10

To attach skeletal muscle to bone.

Question 11

What is an aponeurosis?

Answer 11

A flattened tendon often associated with flat muscles.

Question 12

Where do aponeuroses attach?

Answer 12

From muscle to soft tissue.

Question 13

What is the initial point of attachment to bone of a skeletal muscle called?

Answer 13

The origin

Question 14

What is the secondary point of attachment of a skeletal one to muscle called?

Answer 14

The insertion

Question 15

What happens during contraction of skeletal muscle in terms of muscle fibres and insertions?

Answer 15

• The muscle fibres shorten along the long axis of the muscle.
• The origin and insertion approximate (Move closer together)

Question 16

What are the three functions of the biceps brachii muscle?

Answer 16

• Flexion of the shoulder joint
• Flexion of the elbow joint
• Supination of the forearm

Question 17

What four factors are required to determine the action of a muscle?

Answer 17

• Which joint(s) is/are spanned
• The long axis of the muscle fibres
• The aspects of the joint(s) that are spanned
• The shape of any articular surfaces that may limit movement.

Question 18

What 5 aspects are used to name skeletal muscles?

Answer 18

• Latin greek description of muscle shape (E.g biceps=2 heads)
• The body region the muscle is located in (E.g brachii relates to arm (Brachial) region)
• The muscles relative size (E.g Major. minor, maximus, medius, minimus)
• Principle bony attachment of muscle (E.g tibialis anterior attaches to anterior aspect of the tibia)
• Principle movement produced by the muscle’s contraction. (Extensor digitorum extends the digits of the hand.)

Question 19

Describe the five aspects used in physical examination of skeletal muscles.

Answer 19

• Inspection
• Palpation
• Passive movement to test muscle tone (I.e no resistance)
• Active movement against resistance to test power.
• Deep tendon reflexes with a tendon hammer.

Question 20

What are reflexes?

Answer 20

Rapid, predictable, involuntary reactions to danger as a protective mechanism.

Question 21

What are the two types of reflexes?

Answer 21

• Stretch reflex

- Flexion withdrawal reflex (Think touching something hot)

Question 22

What is hypertrophy?

Answer 22

An enlargement in organ size without an increase in cell numbers.

Question 23

What causes a muscle to become paralysed?

Answer 23

When the motor nerve supply to that muscle stops functioning.

Question 24

What is meant by spasticity and what causes it?

Answer 24

When a muscle over contracts continuously, caused by the descending controls from the brain not functioning properly.

Question 25

What is muscular atrophy and what cause it?

Answer 25

When the individual muscle fibres (myocytes) decrease in bulk reducing the overall muscle bulk, can be cause by immobilisation of that muscle.

Question 26

Where are skeletal muscles located?

Answer 26

Deep to and protected by the deep fascia.

Question 27

What type of muscle carries out protective reflexes such as coughing, sneezing, gagging, swallowing and vomiting?

Answer 27

Skeletal muscles of the respiratory/alimentary tract.

Question 28

What type of muscle is the diaphragm?

Answer 28

Skeletal muscle

Question 29

How many compartments can the thigh muscles be divided into? Name them.

Answer 29

3

Anterior, medial and posterior

Question 30

How many compartments can the leg muscles be divided into? Name them.

Answer 30

3

Anterior, posterior and lateral

Question 31

How many compartments can the arm muscles be divided into? Name them.

Answer 31

2

Anterior and posterior

Question 32

How many compartments can the forearm muscles be divided into? Name them.

Answer 32

2

Anterior and posterior