w6 cns & pcns

Peripheral Nervous System anatomically consists of ___ pairs of spinal nerves and ___ pairs of cranial nerves.

31 and 12

rovide two-way communication between the…

spinal cord, neck, arms, legs, and

body trunk

Dorsal root contains…

sensory fibers

Ventral root contains…

motor fibers

Spinal nerve

Rami of the spinal nerves (dorsal / ventral /communicating)

Cervical nerves

Thoracic nerves

Lumbar nerves

Sacral nerves

Coccygeal nerves

Cervical plexus C1 – C4

Brachial plexus C5 - T1

Lumbar plexus L1-L4

Sacral plexus L4-S3

Dermatome map -

areas of skin innervated dorsal sensory root except C1 (30 dermatomes)

___pairs of cranial nerves in mammals

12

Somatic nerves

innervate skeletal muscles

nerves innervate skeletal muscles and visceral organs part of…

autonomic nervous system

Cranial nerves emerge from…

the inferior surface of the brain (except vestibulocochlear nerve)

Olfactory

(sensory: olfactory bulb / olfactory tract)

II Optic (sensory: really a tract of the brain / eyeball, optic chiasma)

III Oculomotor (motor: superior / inferior branch / ciliary ganglion)

IV Trochlear (motor: m. superior oblique)

V Trigeminal (mixed: ophthalmic division/ mandibular division /maxillary division)

VI Abducens (motor: m. lateral rectus)

VII Facial (mixed: tears /sublingual gland / submandibular gland/ somatic fibers)

VIII Vestibulocochlear (sensory: vestibular ganglia / cochlear nerve)

IX Glossopharyngeal (mixed: pharyngeal muscles/ salivary gland /carotid body)

X Vagus!!! (mixed: lung / heart/ spleen / liver / stomach / kidney/ s. intestine /colon)!!! (all internal orgrans -Bernstein)

XI Accessory (motor: palate / pharynx / larynx / m. sternocleidomastoid/ m. trapezius)

XII Hypoglossal (mixed: tongue movement / tongue muscles/swallowing)

Function of Olfactory Smell

Function of Optic Vision

Function of Oculomotor Eye movement / Opening of eyelids / Pupil constriction

Function of Trochlear Eye movement

Function of Trigeminal Touch, temperature and pain / Chewing

Function of Abducens Lateral eye movement

Function of Facial Taste / Salivation / Tearing / Facial expression

Function of Vestibulocochlear Hearing / Balance

Function of Glossopharyngeal Taste / Swallowing /Salivation

Function of Vagus!!! Lung / Heart/ Spleen / Liver / Stomach / Kidney/ Intestine/ Colon

Function of Accessory Swallowing / Turning head / Lifting shoulders

Function of Hypoglossal Tongue movements / Speech / Swallowing

The eye is a hallow spherical anatomical structure about ___ cm in diameter

2.5

tough fibrous structure

Sclera

anterior transparent structure

Cornea

Choroid – blood vessels / pigment producing melanocytes to absorb the excess of light

Ciliary Body – produces humor to nourish cornea/lens / maintain intraocular pressure

Iris – smooth muscle diaphragm / regulates amount of light entering the eye

Pupil – opening for the light

Retina – prevents light scatter and contains receptor cells (rods and cones)

Optic Nerve – nerve fibers from retina form the optic nerve

Optic Disc (blind spot) – origin of the optic nerve / no receptor cells (rods and cones)

Fovea Centralis – area of best vision

Anterior Chamber - between cornea and iris

Posterior Chamber – between iris and lens

Vitreous Humor – gelatinous connective tissue maintaining shape of eyeball

Lens – transparent avascular elastic structure

Suspensory Ligaments – regulate curvature of the lens

Scleral venous sinus (canal of Schlemm) – drains humor produced in the ciliary body

Central Artery/Vein

Lacrimal apparatus washes foreign objects from the eye, eliminates bacteria, delivers nutrients and water to cornea and lens

Lacrimal Gland – continuously secretes tears

Ducts of Lacrimal Gland – drain tears into the nasal cavity

Lacrimal Canal

Lacrimal Sac

Nasolacrimal Duct- drains tears into nasal cavity

Extrinsic Eye Muscles (superior/inferior/lateral/medial)

anatomical structure collects and transforms ___ energy in the outer ear into ___ energy in the middle ear, and into ____ _____ in inner ear

acoustic, mechanical, action potentials

Outer ear: collects and funnels sounds

Pinna (Auricle) - (helix / tragus / lobule)

External Auditory Canal (acoustic)

Middle ear: an air-filled cavity in temporal bone amplifies sounds

Tympanic Membrane – receives energy of acoustic waves

Malleus- conducts vibration of tympanic membrane to incus

Incus- conducts vibration to staples

Staples- conducts vibration to cochlea

Eustachian (Auditory) Tube –connects middle ear and mouth cavity/equilibrates pressure

Cochlea – a complex system of interconnected tubes filled with endolymph and perilymph

Scala Vestibuli - interconnected tube filled with perilymph

Scala Tympani- interconnected tube filled with perilymph

Basilar Membrane – directly stimulated by fluid vibration in the Scala Tympani

Organ of Corti (spiral organ) - contains receptors stimulated by fluid vibration

Oval Window- transmits staples vibration to the perilymph in Scala Vestibuli

Round Window – acoustic energy finally dissipates in the middle ear

Cochlear nerve

Organs of Equilibrium: - a complex system of channels in temporal bone

Semicircular Ducts (Canals) – each canal is at 90o to two other / detect rotational acceleration

Utricle – detect linear acceleration in horizontal plane

Saccule– detect linear acceleration in vertical plane

Vestibular nerve