Lecture 2 - Muscles, Nerves Of Upper Limb Flashcards
What are skeletal muscles made of?
- fibres
- endomysium, perimysium, and tendon (all together)
What are the different forms of skeletal muscles?
Parallel
Oblique
Circular
What is meant by a parallel muscle?
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
What’s an oblique muscle fibre type
Running oblique to muscle pull
Produces forceful contractions
Ie. deltoid muscle
What is a circular muscle fibre type
Circular (sphincter) muscle fibres surrounds a body opening
Eg. Eye, anus
Single muscle activity (shutting eyes shut)
Discuss the terms related to muscle attachment
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)
Explain the difference between muscle action and function
Muscle action is movement produce when it shortens (concentric)
Muscle function is the role played (eg. Resist movement, provide stability, maintain posture)
Describe the types of muscle contractions
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.
Explain the naming of muscles
Size, shape, no. Of heads, location, action
Name the muscle groups helping move the shoulder joint
Rotator cuff muscles
Huneroscapular muscles
Thoracohumeral muscles
Identify and what’s the function of the muscles of the rotator cuff
stabilise movement of shoulder joint, and are the primary muscles holding the humeral head in glenoid fossa
Subscapularis
Supraspinatus
Infraspinatus
Teres minor
Identify the thoracohumeral muscles
Muscles attach the arm to the thorax
Anterior group: pec. Maj. , serratus anterior
Posterior group: latissimus dorsi, trapezius
Identify and name the function of the muscles of the scapulohumeral muscles
Control the shoulder joint, but attach to scapula
Teres major (deep) Deltoid (superficial)
Identify the muscles around the arm
2 components divided by intermuscular septa
Anterior (flexor);
Brachialis
Biceps brachii
Coracobrachialis
Posterior (extensor);
Triceps brachii
What nerves innervate the muscles around the arm?k
Anterior = musculocutaneous nerve
Posterior = radial nerve
Identify and determine the function of the muscles around the forearm
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
What nerves innervate the muscles around the forearm?
Anterior = median nerve
- FCU and half of FDP = ulnar nerve
- supinator = radial nerve
Posterior = radial nerve
Identify and determine the functions of the muscles of the hand
Control fine movements of thumb, little finger and other digits
4 compartments
Thenar muscles
Hypothenar muscles
Adductor pollicis
Central intrinsics (lumbricals, dorsal, palmar)
Explain the actions carried out by the muscles of the shoulder region
Flexsion = pectoralis major, deltoid (ant), biceps
Extension = lat. dorsi, deltoid (post), triceps
Adduction = pectoralis major, lattisumus dorsi, teres major
Abduction = deltoid (mid)
Explain the actions carried out by the muscles of the elbow region
Flexsion= biceps, brachialis, brachioradialis
Extension = Triceps, ECRL,ECU,ED,
Adduction = FCU, ECU
What nerves innervate the muscles of the hand?
All innervated by ulnar nerve,
except thenar and 2 lumbricals = median nerve
Explain the actions carried out by the muscles of the wrist region
Flexsion= FCU, FCR, FDS
Extension = ECRL, ECRB, ED
Abduction = FCR, ECRL, ECRB
Adduction = FCU, ECU
Explain the anatomy of the spinal cord
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
What is the main function of the brachial plexus and its network of nerves?
Provide sensory/cutaneous (skin) and motor (muscle) functions
Spinal nerves branching from C5-T1
This supplies the whole upper limb
