PNS

Abducens Nerve (VI)

Motor cranial nerve controlling lateral eye movement

Abducens Nerve (VI)

Accessory Nerve (XI)

Motor cranial nerve controlling neck muscles like trapezius and sternocleidomastoid

Accessory Nerve (XI)

Anterior Ramus

Branch of spinal nerve that supplies muscles and skin of limbs and front/side of trunk

Anterior Root

Structure containing motor axons that carry information OUT OF the spinal cord, with no ganglion present

Autonomic Nervous System

Division of PNS that controls involuntary functions like heart rate and digestion

Axillary Nerve

Brachial plexus branch that supplies deltoid muscle for shoulder abduction

Axillary Nerve

Brachial Plexus

Network formed by spinal nerves C5-T1 that supplies the upper limb with five major branches

Brachial Plexus

Brachial Plexus

Cervical Plexus

Network formed by spinal nerves C1-C4, giving rise to the phrenic nerve

Cervical Plexus

Cervical Plexus

Common Fibular Nerve

Portion of sciatic nerve that supplies leg muscles and provides sensation to top of foot

Cranial Nerves

12 pairs of nerves connected to brain and brainstem, numbered I-XII with mixed functions

Dermatome

Area of skin innervated by a specific spinal nerve, important for clinical diagnosis

Dorsal Ramus

Endoneurium

Thin connective tissue layer that surrounds individual axons within a nerve, providing support and insulation for each nerve fiber

Endoneurium

Epineurium

Tough, fibrous outer covering that surrounds the entire nerve, providing protection and structural support

Epineurium

Facial Nerve (VII)

Mixed cranial nerve controlling facial expression and taste sensation

Facial Nerve (VII)

Fascicle

Bundle of axons grouped together within a nerve, with multiple fascicles making up a complete nerve

Fascicle

Femoral Nerve

Lumbar plexus branch that supplies quadriceps muscles for thigh extension and provides sensation to anterior thigh

Femoral Nerve

Femoral Nerve

Ganglion

Cluster of neuron cell bodies located outside the CNS

Glossopharyngeal Nerve (IX)

Mixed cranial nerve involved in swallowing, taste, and salivation

Glossopharyngeal Nerve (IX)

Hypoglossal Nerve (XII)

Motor cranial nerve controlling tongue muscles

Hypoglossal Nerve (XII)

Intercostal Nerves

Spinal nerves T1-T11 that do not form plexuses and supply intercostal muscles

Lumbar Plexus

Network formed by spinal nerves L1-L4, giving rise to femoral and obturator nerves

Lumbar Plexus

Median Nerve

Brachial plexus branch that supplies forearm flexors and thumb muscles, provides sensation to palm and lateral fingers

Median Nerve

Median Nerve

Median Nerve

Mixed Nerve

Nerve containing both sensory and motor axons in the same bundle, allowing bidirectional information flow (most spinal nerves are mixed)

Motor Nerve

Nerve containing only motor axons that carry signals from the CNS to muscles and glands

Motor Neuron Ending

Musculocutaneous Nerve

Brachial plexus branch that supplies arm flexors like biceps and brachialis

Musculocutaneous Nerve

Musculocutaneous Nerve

Musculocutaneous Nerve

Myotome

Group of muscles innervated by a specific spinal nerve

Nerve Plexus

Network of interweaving anterior rami of spinal nerves that redistributes fibers to create named nerve branches

Nerve

Cable-like bundle of parallel axons in the PNS wrapped in connective tissue that carries signals between the CNS and peripheral structures

Obturator Nerve

Lumbar plexus branch that supplies adductor muscles for thigh adduction and provides sensation to medial thigh

Obturator Nerve

Oculomotor Nerve (III)

Motor cranial nerve controlling eye movement and pupil constriction

Oculomotor Nerve (III)

Olfactory Nerve (I)

Sensory cranial nerve responsible for smell

Olfactory Nerve (I)

Optic Nerve (II)

Sensory cranial nerve responsible for vision

Optic Nerve (II)

Perineurium

Connective tissue layer that wraps around each fascicle (bundle of axons), acting as a barrier to maintain the internal environment of nerve fibers

Perineurium

Phrenic Nerve

Nerve from cervical plexus that controls diaphragm function, essential for breathing

Phrenic Nerve

Posterior Ramus

Branch of spinal nerve that supplies muscles and skin of the back region

Posterior Root Ganglion

Cluster of sensory neuron cell bodies located on the posterior root outside the spinal cord

Posterior Root

Structure containing sensory axons that carry information INTO the spinal cord, associated with a ganglion

Radial Nerve

Brachial plexus branch that supplies extensors of arm, forearm, and hand

Radial Nerve

Radial Nerve

Radial Nerve

Rami Communicantes

Connections between spinal nerves and sympathetic trunk ganglion for autonomic functions

Rami Communicantes

Sacral Plexus

Network formed by spinal nerves L4-S4, giving rise to the sciatic nerve

Sacral Plexus

Sciatic Nerve

Largest nerve in the body from sacral plexus, consists of tibial and common fibular portions

Sciatic Nerve

Sciatic Nerve

Sciatica

Pain along the distribution of the sciatic nerve, often caused by nerve compression

Sensory Nerve

Nerve containing only sensory axons that carry information from sensory receptors to the CNS

Spinal Nerve

One of 31 pairs of nerves connected to the spinal cord, almost all of which are mixed nerves

Sympathetic Trunk

Chain of ganglia that runs alongside the spinal cord for sympathetic nervous system functions

Tibial Nerve

Portion of sciatic nerve that supplies calf muscles and provides sensation to sole of foot

Tibial Nerve

Trigeminal Nerve (V)

Mixed cranial nerve providing facial sensation and controlling chewing muscles

Trigeminal Nerve (V)

Trochlear Nerve (IV)

Motor cranial nerve controlling superior oblique eye muscle

Trochlear Nerve (IV)

Ulnar Nerve

Brachial plexus branch that supplies hand intrinsic muscles and provides sensation to medial hand

Ulnar Nerve

Ulnar Nerve

Ulnar Nerve

Vagus Nerve (X)

Mixed cranial nerve providing parasympathetic control of thoracic and abdominal organs

Vagus Nerve (X)

Ventral Ramus

Vestibulocochlear Nerve (VIII)

Sensory cranial nerve responsible for hearing and balance

Vestibulocochlear Nerve (VIII)

Common Fibular Nerve

Obturator Nerve

Radial Nerve