Peripheral Nervous System Flashcards
Nerve
White matter of the PNS, contains bundles of axons enclosed in connective tissue wrappings
Endoniurium
Surrounds individual axons
Perinurium
Surrounds bundles of axons called fascicles
Epinerinum
Surrounds entire nerve
Olfactory Nerve I (CNI)
Sensory- Carries the sense of smell (olfaction)
Optic II (CNII)
Sensory- carries the sense of vision
Oculomotor III (CNIII)
Motor- excited most extraocular muscles, excites levator palpebrae superioris, carries parasympathetic efferent fibers that stimulate intraocular muscles
Trochlear Nerve IV (CNIV)
Motor, excites the superior oblique extraocular muscles
Trigeminal (CNV)
Both sensory and motor- carries the sense of touch from the face and excites the muscles of mastication including the masseter and temporalis
Ophthalmic Branch of Trigeminal Nerve
Sensory from superior facial region including orbits
Maxillary Branch of Trigeminal Nerve
Sensory from middle facial skin including superior oral region
Mandibular Branch of Trigeminal Nerve
Motor to masseter and temporalis
Abductens (CNVI)
Motor-lateral reclusive extraocular muscles
Facial Nerve (CNVII)
Both sensory and motor- carries the sense of taste from the anterior 2/3 of the tongue and excites the muscles of facial expression including frontalis, orbicularis oris, orbicularis oculi, depressor anguli oris, depressor labii inferioris, carries parasympathetic efferent fibers that stimulate the lacrimal gland, sublingual salivary gland and submandibular salivary gland
Vestibulocochlear (CNVIII)
Sensory-carries the sense of hearing (audition)
Glossopharyngeal (CN IX)
Both sensory and motor- carries the sense of taste from the posterior 1/3 of the tongue, sense of touch from the posterior tongue and pharynx, sense of blood pressure and sense of blood gas concentration from arterial baroreceptors and chemoreceptors located in the carotid sinus, and excited muscles of the pharynx important for swallowing, and carries parasympathetic efferent fibers that stimulate the parotid salivary glands
Vagus Nerve (CNX)
Both sensory and motor- sensory information from visceral organs, sense of BP, and gas concentrations from arterial baroreceptors and chemoreceptors in the aortic arch, carries the majority of parasympathetic efferent fibers that regulate visceral organs.
Accessory (CNXI)
Motor- Excites the trapezius and deltoids
Dorsal Root Ganglia
Bulge on dorsal root, contains soma of pseudounipolar sensory neurons
Trunk of a spinal nerve
Forms by the fusion of ventral and dorsal nerve roots
Dorsal Ramus
Small branch that curves posteriorly and inner ages the skin and muscles of the posterior regions of the body
Ventral Ramus
Large branch that curves anteriorly and inner ages the anterior trunk and the limbs
Nerve Plexus
Interlacing nerve network formed by several ventral rami that join together three branch again
Cervical Plexus
Forms from C1-C5, innervates skin and muscles of the neck and shoulder
Phrenic Nerve
Forms from ventral rami of C3-C5, excites the diaphragm
Brachial Plexus
Forms from C5-T1, innervates pectoral girdle and arm
What are the 3 trunks of the brachial plexus
Superior (C5-C6)
Middle (C7)
Inferior (C8-T1)
Lateral Cord
Formed from anterior divisions of superior & middle trunks
Medial Cord
Formed by anterior division of inferior trunk
Posterior Cord
Formed by union of all 3 posterior divisions
Ulnar Nerve
Travels down the medial brachial and antebrachial regions
Innervates: Flexors of medial forearm and hand; flexor carpi ulnar is, flexor digital rum profundus
>Forms from C8-T1 by way of the medial cord
Medial Nerve
Travels down the anterior brachial and antebrachial regions just lateral to the ulnar nerve
Innervates: Flexors of lateral forearm, and hand; flexor carpi radialis, flexor digitorum superficalis
>Forms from C6-T1 by way of the lateral and medial cords
Musculocutaneous nerve
Travels down the anterior of the brachial region deep to biceps brachii and superficial to brachialis
Innervates: Flexor arm muscles; biceps brachii & brachialis
>Forms from C5-C7 by way of the lateral cord
Radial Nerve
Travels down the posterior lateral brachial and antebrachial regions
Innervates: Arm and forearm extensor muscles; extensor carpi or digitorum
>Forms from C5-T1 by way of the posterior cord
Axillary Nerve
Travels through axillary region
Innervates: Deltoid, Teres Minor
>Forms from C5-C6 by way of the posterior cord
Lumbar Plexus
T12-L4
Innervates: Lower abdomen, medial and anterior portions of the thigh
Femoral Nerve
Travels down anterior formoral region
Innervates: Quadriceps femoris
>Forms from L2-L4
Obturator Nerve
Travels down medial femoral region
Innervates: Adductor Magnus, Adductor Longus
>Forms from L2-L4
Sacral Plexus
L4-S4
Innervates: Lateral and posterior portions of femoral and aural regions
Sciatic Nerve
Largest Nerve in the body, travels down the posterior femoral region; Excites hamstrings
>Forms from L4-S3
Sacral Nerve
Innervates posterior compartment of lower leg; gastrocnemius & Soleus
Superficial Fibular Nerve
Innervates lateral compartment of leg
Fibularis longus and fibularis brevis muscles
Deep Fibular Nerve
Innervates anterior compartment of lower leg, dorsi flexors and toe extensors; tibialis anterior, extensor digitorum longus
Somatic Nervous System
Controls Skeletal Muscles, voluntary
Autonomic Nervous System
Regulates glands, smooth and cardiac muscles, involuntary
Sympathetic Autonomic Division
Fight or flight, enables body to cope rapidly when excited, frightened, or during exercise and emergency situations
Parasympathetic autonomic division
Rest and Digest, dominant in non stressful situations, conserves energy and directs maintenance activities such as digestion and excretion
Thoracolumbar Origin
Preganglionic fibers emerge from thoracic and lumbar spinal nerve roots (T1-L2)
Paravertebral Ganglia
Lateral to bodies of thoracic and lumbar vertebrae contains soma of “postganglionic” sympathetic motor neurons that are postsynaptic to the preganglionic sympathetic motor neurons
Collateral Ganglia
Anterior to the vertebral column
Adrenal Medulla
Endocrine gland directly stimulated by preganglionic sympathetic fibers
Camiosacral Origin
Preganglionic fibers emerge from brain stem and sacral regions (through cranial nerves and sacral spinal nerves)
