Anatomy for Human Body fixed resources session

Notes for anatomy

1. 1.03 Anatomy Fixed Resource Session 1 Answers Connie V. Bartolome MD

2. ANSWERS: Superior angle Superior border Coracoid process Acromion Supraspinous fossa Glenoid fossa Infraspinous fossa Spine of scapula Medial border Lateral border Inferior angle A B C D E F G H I J K

3. A- greater tubercle B – head C – lesser tubercle D - anatomical neck E – surgical neck F – intertubercular sulcus G – shaft H – radial groove I- lateral supracondylar ridge J- medial supracondylar ridge K – radial fossa L- coronoid fossa M- olecranon fossa N- medial epicondyle O- capitulum P- trochlea Q- lateral epicondyle 2. Axillary nerve 3. Deltoid and teres minor muscle

4. ROTATOR CUFF MUSCLES 1 – Supraspinatus 2 – Infraspinatus 3 – Teres minor 4 – Subscapularis Dorsal view Ventral view

5. Serratus anterior Nerve supply: Long thoracic nerve Neurovascular lesion: Winging of scapula

6. DELTOID MUSCLE Origin: -lateral anterior 1/3 of distal clavicle -lateral border of the acromion -scapular spine Insertion: deltoid tuberosity of humerus Action: -abducts arm flexion and medial rotation (anterior portion) Extension and lateral rotation (posterior portion) Blood supply: - posterior humeral circumflex artery deltoid branch of thoracoacromial artery Nerve supply: - Axillary nerve, C5, C6

7. A. Biceps brachii Origin: One head from the coracoid process of the scapula; the other from a tubercle above the glenoid cavity Insertion: Tuberosity of radius Action: Flexion at elbow and shoulder; Supination B. Triceps brachii Origin: One head from the superior, lateral margin of humerus , one from the posterior surface of the humerus , and one from the scapula Insertion: Olecranon of ulna Action: Extension of elbow, plus extension and adduction at the Shoulder C. Brachialis Origin: Anterior, distal surface of humerus Insertion: Tuberosity of ulna Action: Flexion at elbow A B C

8. The trapezius is a broad, flat and triangular muscle. The muscles on each side form a trapezoid shape. It is the most superficial of all the back muscles. Attachments : Originates from the skull, ligamentum nuchae and the spinous processes of C7-T12. The fibres attach to the clavicle, acromion and the scapula spine. Innervation : Motor innervation is from the accessory nerve. It also receives proprioceptor fibres from C3 and C4 spinal nerves. Actions : The upper fibres of the trapezius elevates the scapula and rotates it during abduction of the arm. The middle fibres retract the scapula and the lower fibres pull the scapula inferiorly.

9. Axillary artery Superior thoracic artery Thoracoacromial artery Lateral thoracic artery Anterior circumflex humeral artery Posterior circumflex humeral artery Subscapular artery Circumflex scapular artery Thoracodorsal artery Pectoralis minor muscle

10. 1. A- Brachial plexus B – Axillary nerve C – Musculocutaneous nerve D - Radial nerve E – Median nerve 2. Erb’s palsy; waiter’s tip 3. Klumpke’s palsy; clawed hand A B C D E

11. Brachial plexus

12. Excessive traction or even tearing of C5 and 6 roots of the brachial plexus. It occurs in infants during a difficult delivery or in adults after a blow to or fall on the shoulder. Suprascapular nerve, the nerve to the subclavius , and the musculocutaneous and axillary nerves all possess nerve fibers derived from C5 and 6 roots and will therefore be functionless. The position of the upper limb in this condition has been likened to that of a porter or waiter hinting for a tip. supraspinatus (abductor of the shoulder) and infraspinatus (lateral rotator of the shoulder); the subclavius (depresses the clavicle); the biceps brachii (supinator of the forearm, flexor of the elbow, weak flexor of the shoulder) and the greater part of the brachialis (flexor of the elbow) and the coracobrachialis (flexes the shoulder); and the deltoid (abductor of the shoulder) and the teres minor (lateral rotator of the shoulder). There will be a loss of sensation down the lateral side of the arm. Erb-Duchenne palsy (Upper lesions of brachial plexus)

13. Lower Lesions of the Brachial Plexus ( Klumpke Palsy) Lower lesions of the brachial plexus are usually traction injuries caused by excessive abduction of the arm, as occurs in the case of a person falling from a height clutching at an object to save himself or herself. The 1st thoracic nerve is usually torn. The nerve fibers from this segment run in the ulnar and median nerves to supply all the small muscles of the hand. The hand has a clawed appearance caused by hyperextension of the metacarpophalangeal joints and flexion of the interphalangeal joints. The extensor digitorum is unopposed by the lumbricals and interossei and extends the metacarpophalangeal joints; the flexor digitorum superficialis and profundus are unopposed by the lumbricals and interossei and flex the middle and terminal phalanges. In addition, loss of sensation will occur along the medial side of the arm. If the 8th cervical nerve is also damaged, the extent of anesthesia will be greater and will involve the medial side of the forearm, hand, and medial two fingers. Lower lesions of the brachial plexus can also be produced by the presence of a cervical rib or malignant metastases from the lungs in the lower deep cervical lymph nodes

14. Musculocutaneous nerve injury causes loss of sensation over the lateral side of the forearm

15. Loss of sensation over the inferior deltoid and inability to abduct the affected limb beyond 15 degrees is caused by axillary nerve injury