Lecture 2 - Muscles, Nerves Of Upper Limb

Question 1

What are skeletal muscles made of?

Answer 1

• fibres

- endomysium, perimysium, and tendon (all together)

Question 2

What are the different forms of skeletal muscles?

Answer 2

Parallel
Oblique
Circular

Question 3

What is meant by a parallel muscle?

Answer 3

Runs parallel to to line of muscle pull(large range of movement )
Ie. biceps brachii

Different directions of fibres pull in different ways, hence, might not be balanced, so to have good range of movement, parallel is best

Question 4

What’s an oblique muscle fibre type

Answer 4

Running oblique to muscle pull

Produces forceful contractions
Ie. deltoid muscle

Question 5

What is a circular muscle fibre type

Answer 5

Circular (sphincter) muscle fibres surrounds a body opening
Eg. Eye, anus

Single muscle activity (shutting eyes shut)

Question 6

Discuss the terms related to muscle attachment

Answer 6

Origin = fixed end
Insertion = moving end 

Attachment can be

• tendon (indirect ie. biceps)
• fleshy (direct eg. Facial muscles. Muscle to bone)
• aponeurotic (indirect ie. rectus sheath of abdomen)

Question 7

Explain the difference between muscle action and function

Answer 7

Muscle action is movement produce when it shortens (concentric)

Muscle function is the role played (eg. Resist movement, provide stability, maintain posture)

Question 8

Describe the types of muscle contractions

Answer 8

Static/isometric = contracts but length remains, therefore no action produced (happens all over body and we don’t even notice)

Dynamic/isometric = cocentric (shortens), eccentric (lengthens). Works against gravity to keep you in one position.

Question 9

Explain the naming of muscles

Answer 9

Size, shape, no. Of heads, location, action

Question 10

Name the muscle groups helping move the shoulder joint

Answer 10

Rotator cuff muscles
Huneroscapular muscles
Thoracohumeral muscles

Question 11

Identify and what’s the function of the muscles of the rotator cuff

Answer 11

stabilise movement of shoulder joint, and are the primary muscles holding the humeral head in glenoid fossa

Subscapularis
Supraspinatus
Infraspinatus
Teres minor

Question 12

Identify the thoracohumeral muscles

Answer 12

Muscles attach the arm to the thorax

Anterior group: pec. Maj. , serratus anterior

Posterior group: latissimus dorsi, trapezius

Question 13

Identify and name the function of the muscles of the scapulohumeral muscles

Answer 13

Control the shoulder joint, but attach to scapula

Teres major (deep)
Deltoid (superficial)

Question 14

Identify the muscles around the arm

Answer 14

2 components divided by intermuscular septa

Anterior (flexor);
Brachialis
Biceps brachii
Coracobrachialis

Posterior (extensor);
Triceps brachii

Question 15

What nerves innervate the muscles around the arm?k

Answer 15

Anterior = musculocutaneous nerve

Posterior = radial nerve

Question 16

Identify and determine the function of the muscles around the forearm

Answer 16

Divided into ant and post by interosseous membrane
Origin of common flexor tendons begins at medial epicondyle

Anterior: flexsion and pronation of forearm

• superficial; pronator teres, FCR, FCU, palmaris longus, FDS
• deep; FDP, pronator quadratus, supinator

Posterior: extension of wrist and digits, supination of forearm, but brachioradialis flexes forearm

• brachioradialis
• ECRB, ECRL, ECU, ED
• extensor indicis
• extensor digiti minimi

Question 17

What nerves innervate the muscles around the forearm?

Answer 17

Anterior = median nerve

• FCU and half of FDP = ulnar nerve
• supinator = radial nerve

Posterior = radial nerve

Question 18

Identify and determine the functions of the muscles of the hand

Answer 18

Control fine movements of thumb, little finger and other digits
4 compartments

Thenar muscles
Hypothenar muscles
Adductor pollicis
Central intrinsics (lumbricals, dorsal, palmar)

Question 19

Explain the actions carried out by the muscles of the shoulder region

Answer 19

Flexsion = pectoralis major, deltoid (ant), biceps

Extension = lat. dorsi, deltoid (post), triceps

Adduction = pectoralis major, lattisumus dorsi, teres major

Abduction = deltoid (mid)

Question 20

Explain the actions carried out by the muscles of the elbow region

Answer 20

Flexsion= biceps, brachialis, brachioradialis

Extension = Triceps, ECRL,ECU,ED,

Adduction = FCU, ECU

Question 21

What nerves innervate the muscles of the hand?

Answer 21

All innervated by ulnar nerve,

except thenar and 2 lumbricals = median nerve

Question 22

Explain the actions carried out by the muscles of the wrist region

Answer 22

Flexsion= FCU, FCR, FDS

Extension = ECRL, ECRB, ED

Abduction = FCR, ECRL, ECRB

Adduction = FCU, ECU

Question 23

Explain the anatomy of the spinal cord

Answer 23

Around 45 cm long, 14 mm wide

Ends at L1-2 vertebrae

2 enlargements;

• cervical (nerves of shoulder and UL)
• lumbar (nerves of pelvis and LL)

Each 31 spinal

Question 24

What is the main function of the brachial plexus and its network of nerves?

Answer 24

Provide sensory/cutaneous (skin) and motor (muscle) functions

Spinal nerves branching from C5-T1

This supplies the whole upper limb

Question 25

What regions are innervated by the axillary nerve?

Answer 25

Deltoid, triceps (long head), latissimus dorsi, teres minor

Very short nerve

Question 26

In what order do the arteries supply blood to the upper limb?

Answer 26

Subclavia 
Axillary 
Brachial
Radial + ulnar
Superficial +deep palmar arches 
Digita aa

Question 27

Explain the components of the venous drainage

Answer 27

Deep veins =
run beside arteries,
contain valves
Paired (venae comitantes)

Superficial veins (in skin)=
Fewer valves
Communicate frequently with deep veins

Question 28

List the other in which superficial veins travel in venous drainage

Answer 28

Digital veins
Superficial and deep Palmer arches + Palmer Venus plexus
Cephalic vein + basilica vein

Question 29

List the order in which deep veins travel in venous drainage

Answer 29

Radial veins and ulnar veins
Brachial veins
Axillary vein