Brachial Plexus Nervous System Flashcards
Spinal nerves
8 pairs = cervical spinal nerves
13 pairs= thoracic spinal nerves
7 pairs= lumbar spinal nerves
3 pairs= sacral spinal nerves
5 pairs = caudal spinal nerves
Intumescentiae
Segments of the spinal cord that give origin to the nerves supplying thoracic and pelvic limbs (cervical and lumbar)
Functional regions of spinal cord
Cervical =c1-5 (neck)
Cervical intumescence = c6-T2 (thoracic limb)
Thoracolumbar = T3-L3 (trunk)
Lumbosacral intumescence = L4-S3 (pelvic limbs and pelvic viscera)
Caudal segment =Cd1-5 (tail)
Spinal roots - unidirectional
Dorsal root = afferent fibers (sensory and proprioceptive fibers)
Ventral root = efferent fibers (motor neurons to muscles and glands)
Spinal nerves bidirectional
Dorsal branch = Carries fibers innervates structures dorsal to the transverse processes (afferent and efferent)
Ventral branch = Carries nerve fibers that innervates structures ventral to transverse process (afferent and efferent)
Brachial plexus
Network of nerves
Formed by ventral branches of spinal nerves C6 C7 C8 T1 and T2
Nerve supply to thoracic limb (motor skeletal muscles, sensory to skin and proprioception to thoracic limb)
Phrenic nerve
Motor nerve of diaphragm related with brachial plexus
Areas and zones of nerves
Cutaneous area = area on skin to test nerve
Overlap zone = more than one nerves have innervation to some areas of skin
Autonomous zone= only one nerves innervates here
Nerves must have what area in order to have what two zones
Nerves must have a cutaneous area in order to have a overlap zone or autonomous zone
Nerves of brachial plexus (B, double C, T, double L, double S, M, A, R, M, U)
Brachiocephalic nerve
Cranial pectoral nerves
Caudal pectoral nerves
Thoracodorsal nerve
Long thoracic nerve
Lateral thoracic nerve
Suprascapular nerve
Subscapular nerve
Musculocutaneous nerve
Axillary nerve
Radial nerve
Median nerve
Ulnar nerve
Brachiocephalic nerve innervates
Cleidobrachialis muscle
Cranial pectoral nerves innervates
Superficial pectoral muscle
Caudal pectoral nerves innervates
Deep pectoral muscle
Thoracodorsal nerve innervates
Latissimus dorsi muscle
Long thoracic nerve innervates
Serratus ventralis muscle
Lateral thoracic nerve innervates
Cutaneous trunci muscle
Suprascapular nerve
Motor to suprasoinatus muscle and infraspinatus muscle
No sensory innervation
Subscapular nerve
Motor to subscapularis muscle
No sensory innervation
Musculocutaneous nerve
Motor to biceps brachii, brachialis muscle and coracobrachialis muscle
Sensory to medial aspects of antebrachium and palmar aspect of manus
Axillary nerve
Motor to teres major, teres minor, deltoideus muscle, and caudal part of subscapularis muscle
Sensory to craniolateral shoulder area, cranial aspect of antebrachium
Radial nerve motor to
Triceps brachii
Tensor fasciae antebrachii
Anconeus muscle
Brachioradialis muscle
Extensor carpi radialis muscle
Common digital extensor muscle
Lateral digital extensor muscle
Extensor carpi ulnaris muscle
Supinator muscle
Abductor pollicis longus muscle
Deep branch of radial nerve
Motor to extensors and supinators of antebrachium
Superficial Radial branch sensory to
Cranial and lateral aspect of antebrachium
Medial and dorsal aspect of manus
Median nerve motor to
pronator teres
flexor carpi radialis muscle
superficial digital flexor muscle
deep digital flexor
pronator quadratus muscle
Median nerve sensory to
Palmar aspect of manus
Has communicating branch to Musculocutaneous nerve and median nerve
Ulnar nerve
Motor to: flexor carpi ulnaris muscle, deep digital flexor muscle, and interossei muscles
Sensory to:
Caudal aspect of antebrachium
Palmar aspect of manus
