Gross Anatomy Tutorial 1 Flashcards
A lesion of the nerve that supplies the supraspinatus muscle results in what deficit?
problems with abduction and external rotation of the humerus, and wasting away of supraspinatus and infraspinatus.
Age-related changes in or an injury to what bony prominence may compromise the integrity of the tendon of the supraspinatus muscle?
Scapula
The nerve that supplies the deltoid muscle is a branch of what cord of the brachial plexus?
Posterior cord (Axillary nerve: upper trunk, posterior division, posterior cord)
What are three actions of the deltoid muscle?
Rotates arm medially and laterally Adducts Abducts Flexes Extends
What is the origin and course of the posterior humoral circumflex artery?
Origin
It is a branch of the axillary artery (subclavian before clavicle, axillary after, then becomes brachial artery at teres major muscle)
Course
The posterior humoral circumflex artery runs with the axillary nerve through the quadrangular space bounded by the teres minor and teres major muscles, the long head of the triceps brachii and the humerus.
It anastomoses with the anterior humoral circumflex artery and an ascending branch of the profunda brachii artery.
It sends a branch to the acromial rete.
What muscles does the posterior humoral circumflex artery supply?
Teres minor
Deltoid
What is the course and origin of the suprascapular artery?
The suprascapular artery is a branch of the thyrocervical trunk. It passes over the superior transverse scapular ligament (whereas the suprascapular nerve passes under the ligament).
Name an important anastamotic connection in which the suprascapular artery participates.
The suprascapular artery anastamoses with the deep branch of the transverse cervical artery (aka dorsal scapular artery) and the circumflex scapular artery around the scapula, providing a collateral circulation.
A lesion to the nerve supplying the triceps brachii muscle group would result in what major functional deficit?
The triceps brachii is innervated by the radial nerve. A lesion would result in the inability to extend the elbow against resistance.
What nerve supplies the rhomboid major muscle?
Dorsal scapular nerve (C5)
Name 2 actions of this muscle.
Retracts scapula
Rotates scapula to rest position
A lesion of the accessory nerve as it enters the trapezius muscle would produce which functional deficits?
Cranial nerve XI, the spinal accessory nerve (SAN), is vulnerable to injury, owing to its long and superficial course in the posterior cervical neck.[1] An important landmark in the neck, the SAN is considered to contribute most motor innervation to the trapezius muscle. Injury to the SAN results in varying degrees of shoulder dysfunction.
Lesion = “shoulder quadrilateral space syndrome” - lose motor fx to teres minor and deltoid muscles, lose sensory to the skin on the upper lateral arm and the capsule of the shoulder joint
What is the nerve supply to biceps brachii?
Musculocutaneous nerve
A lesion of the long thoracic nerve produces what classical syndrome?
“Winging scapula”
Inability to comb hair bc of inability to upwardly rotate scapula, inability to do pushing movements
What muscles does the median nerve supply in the forearm?
The median nerve supplies every muscle in the ANTERIOR forearm BUT: the flexor carpi ulnaris, and half of the flexor digitorum profundis. The median nerve supplies: Protonator teres Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor pollicis longus Pronator quadratus 1/2 of flexor digitorum profundus
The median nerve may become compressed between the two heads of what muscle?
The median nerve can become compressed as it passes into the forearm between the median and ulnar heads of the pronator teres muscle, which it innervates.
What functional deficits would most likely occur as the result of a lesion of the lower subscapular nerve?
Lower subscapular nerve supplies the lower part of the subscapularis muscle, and also supplies the teres major muscle.
A lesion would yield the inability to adduct and rotate the arm medially, which are both functions of both muscles.
Name the other branches of the posterior cord of the brachial plexus besides the lower subscapular nerve, list the muscles that they supply and describe the actions of these muscles
Besides the lower subscapular nerve, the branches of the posterior cord are: upper subscapular nerve, thoracodorsal nerve and axillary nerve.
Innervation:
Upper subscapular nerve –> upper part of subscapularis muscle
Thoracodorsal nerve –> Lattisimus dorsi
Axillary nerve –> deltoid, teres minor muscles, and branches to become the lateral brachial cutaneous nerve
Functions:
Subscapularis –> Adduct and rotate the arm medially
Lattisimus dorsi –> adduct, extend, and rotate the arm medially
Deltoid –> Abducts, adducts, flexes, extends and rotates the arm medially and laterally
Teres minor –> adduct and rotate the arm medially
The suprascapular nerve is a branch of which trunk of the brachial plexus?
Upper trunk
The branches of the upper trunk are suprascapular nerve and the nerve to the subclavius