Anatomy exam 2
The musculocutaneous nerve innervates the following muscles:
Coracobrachialis Biceps brachii Brachialis
The divisions merge to form three
Cords (Lateral, Posterior and Medial)
Each of the three trunks divides laterally to form 3 Anterior and 3 Posterior ______________
Divisions.
examples of brachial plexus innervations
the Axillary nerve which innervates Deltoid and Teres Minor muscles.
Median Nerve
The Median Nerve is derived from the medial and lateral roots of the brachial plexus which converge together. Branches of the median nerve supply the majority of the muscles in the ANTERIOR FOREARM and give CUTANEOUS INNERVATION to portions of the hand.
The Lumbosacral Plexus
The Plexus is formed from the Ventral rami of spinal nerves L1-S4. The lumbosacral plexus is divided into the Lumbar Plexus! and Sacral Plexus! based on the location of the plexuses and the anatomical areas that they supply
The Ulnar Nerve
is a continuation of the medial cord of the brachial plexus
The Peripheral nervous system is composed of:
31 pairs of spinal nerves 12 pairs of cranial nerves
The Ulnar nerve innervates the following muscles:
Flexor Digitorum Profundus (medial half) Flexor Carpi Ulnaris The majority of hand muscles.
Innervation to the muscles of the arm, forearm and hand is derived from the terminal branches of the brachial plexus. These terminal branches are:
Musculocutaneous Nerve Radial Nerve Median Nerve Ulnar Nerve
The Median Nerve innervates the following muscles:
Pronator Teres Flexor Carpi Radialis Palmaris Longus Flexor Digitorum Superficialis Flexor Digitorum Profundus (lateral half) Flexor Pollicis Longus Pronator Quadratus What's missing? FLEXOR CARPI ULNARIS Cutaneous branches of the median nerve innervate the lateral surface of the palm and the distal ends of digits 1, 2, 3 and the lateral half of digit 4.
The Radial nerve innervates all posterior arm and forearm muscles including:
Triceps Brachii Brachioradialis Extensor Carpi Radialis Longus Extensor Carpi Radialis Brevis Extensor Digitorum Extensor Digiti Minimi Extensor Carpi Ulnaris Anconeus Supinator Abductor Pollicis Longus Extensor Pollicis Brevis Extensor Pollicis Longus Extensor Indicis The superficial branch of the radial nerve innervates the skin on the lateral dorsal surface of the hand and lateral palmar surface of the thenar area. (the area shaded in purple
The five roots combine together to form three
Trunks (Superior, Middle and Inferior).
The brachial plexus is comprised of the __________________
Ventral Rami of cervical and thoracic spinal nerves C5, C6, C7, C8 and T1.
The Ulnar Nerve lies posterior to the medial epicondyle of the humerus,
along the groove for the ulnar nerve! and continues distally along the medial surface of the forearm
Ventral Rami
are large branches off of spinal nerves that supply the flank of the body and anterior aspects of the thorax, abdomen and pelvic regions.
Ulnar Nerve
innervates the skin on the medial surface of the palm and dorsum of the hand. It also innervates the distal end of digit 5 and the medial half of digit 4. (the area shaded in blue)
The Radial Nerve
is a continuation of the posterior cord of the brachial plexus after the axillary nerve is given off
The musculocutaneous nerve is derived from the
lateral cord of the brachial plexus.
The brachial plexus supplies the
musculature of the entire upper limb with the exception of the trapezius muscle (CN XI) and levator scapulae (C3 and C4 spinal nerves). The brachial plexus also gives cutaneous innervation to the majority of the upper limb except for the skin over the upper medial portion of the arm and part of the upper shoulder.
Ventral rami also give rise to the ______ _______________
nerve plexuses that innervate the upper and lower limbs
The brachial plexus forms a network arrangement of nerves starting with the VENTRAL RAMI, OR
roots
There are four major plexus systems that supply separate regions of the body. These include:
•cervical plexus •brachial plexus •lumbar plexus •sacral plexus
