Lecture 12 - Axilla, arm and elbow Flashcards
What is the axilla?
It is a pyramid shaped region
What creates the four walls, the base and apex of the axilla?
Four walls
- Anterior: Pectoralis major & minor
- Posterior: Scapula, Teres major, Latissimus dorsi
- Medial: Lateral thoracic wall, Serratus anterior
- Lateral: Humerus, muscle attachments
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Base: Skin of the armpit, Fascia
- Apex: Entrance from base of neck to axilla (1st rib, superior edge of subscapularis)
Label this
Label this E12 slice
Describe the arterial path from the aortic arch until the brachial artery on the right side
Right side of body
- Subclavian artery branches off brachiocephalic trunk on right side
- Subclavian artery becomes axillary artery, once it passes first rib
- The axillary artery becomes the brachial artery, once it passes the lower border of teres major
Describe the arterial path from the aoritc arch to the brachial artery on the left side of the body
- Left subclavian artery branches from the aorta
- Subclavian artery becomes the axillary artery once is passes the first rib
- The axillary artery then becomes the brachial artery once it passes the inferior border of teres major
Label these key regions through which essential nerves and arteries pass through
Which nerve and artery pass through the Quadrangular space?
Axillary nerve
Posterior circumflex
Which artery passes through the Triangular space?
Circumflex scapulae artery
Which nerve and artery pass through the Triangular interval?
Radial nerve
Profunda brachii artery
Which levels of the spine do the roots of the brachial plexus originate?
C5-C8, T1
Describe how peripheral nerves are formed from the roots of the spine in the brachial plexus (talk about how they divide and recombine etc)
The roots combine to form trunks
The trunks divide into anterior and posterior divisions
The divisions divide and combine to from cords
The cords divide and combine to form peripheral nerves
Which main peripheral nerves are formed by the brachial plexus? (5)
Axillary nerve
Radial nerve
Musculocutaneous nerve
Median nerve
Ulnar nerve
Which nerve provides motor supply to the biceps brachii?
Musculocutaneous nerve
What levels of the brachial plexus do the following peripheral nerves originate from?
Axillary nerve
Radial nerve
Musculocutaneous nerve
Median nerve
Ulnar nerve
- C5, C6: Axillary
- C5-Th1: Radial
- C5-C7: Musculocutaneous
- C5-Th1: Median
- C8-Th1: Ulnar
What are the two synovial hinge joints of the elbow?
- Humeroulnar joint: Trochlea of humerus and trochlear notch of the ulna
- Humeroradial joint: Capitulum and head of radius
What are the two movements of the elbow joint?
Flexion & extension
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Label these ligaments of the elbow
What are the flexors of the eblow?
Flexors in arm
- Biceps brachii (insertion at radial tuberosity)
- Brachialis (insertion at coronoid process)
Flexors in forearm
- Brachioradialis
- Pronator teres
- Flexor carpi radialis
What are the extensors of the elbow?
Triceps brachii (Insertion at olecranon)
Anconeus (weak extension movement)
Label this
What function does the interosseus membrane have?
Stabilises both the ulnar and the radius, and allows for muscle attachment
What does the oblique cord prevent?
Over supination and pronation
What way does the palm face in pronation, and supination?
Supination = palm facing up
Pronation = palm facing down
What are the supinator muscles?
Supinator
Biceps brachii (stronger supinator)
What are the pronator muscles?
Pronator teres
Pronator quadratus
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