topic 19: The organization of spinal cord segments and spinal nerves. The general organization and features of the cranial nerves. Flashcards
branches
Muscular Branches
Supply: Muscles in the anterior compartment of the forearm.
Examples: Pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis (partially), and flexor pollicis longus.
Anterior Interosseous Nerve (AIN)
Supply: Deep muscles of the forearm.
Examples: Flexor pollicis longus, pronator quadratus, and part of the flexor digitorum profundus.
Palmar Cutaneous Branch
Supply: Sensory innervation to the skin of the thenar eminence and proximal palm.
Digital Branches
Supply: Sensory innervation to the palm and fingers, excluding the dorsum of the hand and the little finger.
Examples: Common palmar digital nerves and proper palmar digital nerves.
abt median nerve
from brachial plexus,
formed by medial & lateral cords
course:
Course in the Arm:
The median nerve descends through the arm, passing anterior to the axillary artery and running alongside the brachial artery.
It courses through the cubital fossa (anterior elbow region), passing between the biceps brachii muscle and the brachialis muscle.
Course in the Forearm:
In the forearm, the median nerve continues its course along the anterior aspect, traveling between the flexor digitorum superficialis muscle and the flexor digitorum profundus muscle.
As it descends distally, it gives off its anterior interosseous branch (AIN), which innervates deep muscles of the forearm.
Passage through the Wrist:
The median nerve passes through the carpal tunnel at the wrist, along with the tendons of the flexor muscles.
It lies deep to the flexor retinaculum and superficial to the carpal bones.
Compression of the median nerve within the carpal tunnel can lead to a condition known as carpal tunnel syndrome.
Course in the Hand:
After passing through the carpal tunnel, the median nerve enters the palm of the hand.
It gives off its palmar cutaneous branch, which supplies sensory innervation to the skin of the thenar eminence and the proximal palm.
The median nerve further divides into digital branches, which provide sensory innervation to the palmar aspect of the thumb, index finger, middle finger, and half of the ring finger.
Termination:
The median nerve terminates by supplying motor innervation to several muscles of the thumb (thenar muscles) and some of the intrinsic muscles of the hand.
functional loss
1.Carpal tunnel syndrome: compression of median nerve at wrist, causes pain & numbness of lat 3 and a half fingers and thenar muscles are weak
2.Hand of benediction: chronic ulnar neuropathy or ulnar nerve lesion- fracture at supracondylars so inability of making fist flexion
3.Pronator syndrom: median n. is trapped in 2 heads of pronator teres
4.Ape hand deformity: unable to oppose thumb due to damage of distal median nerve
