nervous system lab

Pre-central gyrus and primary somatomotor cortex 

function is to control all voluntary skeletal muscle movement

Post-central gyrus and primary somatosensory cortex

function is to receive all somatic sensory information

Occipital lobe

vision

Temporal lobe

hearing and olfaction

Insula

 taste and visceral sensory perception

Olfactory nerve (CNI)

olfaction; passes through cribriform foramina

Olfactory bulb

contains fibers of olfactory nerve (CNI)

Optic nerve (CN II)

function is vision; passes through optic canal

Optic chiasm(a)

function: some fibers of the optic nerve (CNII) contralaterally cross over here

Infundibulum

function is to connect the hypothalamus to the pituitary gland

Mamillary bodies

it is a part of the limbic system whose function is to regulate emotions

Cerebral peduncles

carry motor information from the cerebral hemispheres to the brain stem and spinal cord

Oculomotor nerve (CN III)

function is motor to four extrinsic eye muscles and carries parasympathetic innervation to the iris; passes through the superior orbital fissure

Middle cerebellar peduncles

connect the pons and the cerebellum

Trigeminal nerve (CN V)

sensory from the face; motor to muscles of mastication; passes through superior orbital fissure, foramen rotundum, foramen ovale

Abducens nerve (CN VI) 

function: motor to lateral rectus eye muscle; passes through superior orbital fissure

Pyramids

motor information from the cerebral hemispheres to the brain stem and spinal cord

Decussation of the pyramids

motor tracts cross contralaterally

Subarachnoid space

contains cerebrospinal fluid

Arachnoid villi 

transfer wastes from the subarachnoid space to dural venous sinuses (such as the superior sagittal sinus)

Superior sagittal sinus

contains venous blood

Cingulate gyrus

it is a part of the limbic system whose function is to regulate emotions

Corpus callosum

contralateral connection between the right and left cerebral hemispheres

Thalamus

all incoming sensory information is relayed to the thalamus first (except for olfaction); filters sensory information going to cortex

Interthalamic adhesion (intermediate mass)

connects the right and left thalami

Pineal gland

secretes a hormone called melatonin which functions in day/night cycle

Superior colliculus

visual reflexes

Inferior colliculi

auditory reflexes

Ventricles

contain cerebrospinal fluid

Septum pellucidum

separates two lateral ventricles

Interventricular foramen

allows CSF to flow from the lateral ventricles into the third ventricle

Choroid plexus 

produces cerebrospinal fluid

Conus medullaris

found at L1 or L2

Cauda equina

made up of spinal roots

Filum terminale

formed by the pia mater

Subarachnoid space

contains cerebrospinal fluid

Spinal nerve

carries sensory and motor information

Posterior rootlets & posterior root

carry sensory information

Anterior rootlets & anterior root

carry motor information

Posterior ramus

carries sensory and motor information

Anterior ramus

carries sensory and motor information

Posterior root ganglion

contains cell bodies of sensory unipolar neurons

Gray matter

contains cell bodies, dendrites, and interneurons

White matter

contains myelinated axons

Central canal

contains cerebrospinal fluid coming from the fourth ventricle

Phrenic nerve (C3-C5) Motor innervation

diaphragm

Median nerve (C5-T1) Motor innervation

anterior forearm compartment muscles, except for the medial muscles (see ulnar nerve)

Median nerve (C5-T1) Sensory innervation

lateral 2/3 of hand on ventral side; dorsum of fingers 2 & 3

Ulnar nerve (C8-T1) Motor innervation

flexor carpi ulnaris; medial half of flexor digitorum profundus

Ulnar nerve (C8-T1) Sensory innervation

medial third of hand; anterior and posterior

Musculocutaneous nerve (C5-C7) Motor innervation

anterior compartment of the arm

Musculocutaneous nerve (C5-C7) Sensory innervation

lateral forearm

Axillary nerve (C5-C6) Motor innervation

deltoid, teres minor

Axillary nerve (C5-C6)Sensory innervation

shoulder joint; skin over part of the deltoid

Radial nerve (C5-T1) Motor innervation

posterior arm and forearm compartments

Radial nerve (C5-T1)Sensory innervation

posterolateral arm and hand, except dorsum of fingers 2 & 3

Femoral nerve (L2-L4) Motor innervation

anterior thigh muscles

Femoral nerve (L2-L4)Sensory innervation

anterior and medial thigh; hip and knee joints; skin of medial leg and foot

Obturator nerve (L2-L4) Motor innervation

medial thigh muscles

Obturator nerve (L2-L4)Sensory innervation

medial thigh; skin over hip and knee joints

Tibial nerve (L4-S3) Motor innervation

posterior thigh and posterior leg muscles

Tibial nerve (L4-S3)Sensory innervation

posterior leg and sole of foot

Common fibular (peroneal) nerve (L4-S3)Motor innervation

short head of biceps femoris; lateral and anterior leg muscles

Common fibular (peroneal) nerve (L4-S3) Sensory innervation

skin of anterior and lateral surface of leg; dorsum of foot

Vagus nerve (CN X)

contains parasympathetic innervation to 80% of the body; sensory for taste from epiglottis and pharynx and general sensation in the oral cavity; motor to larynx

Superior rectus function

Pulls eye up and in (superior and medial)

Superior rectus innervation

Oculomotor (CN III)

Inferior rectus function

Pulls eye down and in (inferior and medial)

Inferior rectus innervation

Oculomotor (CN III)

Medial rectus function

Pulls eye medially (adducts)

Medial rectus innervation

Oculomotor (CN III)

Lateral rectus function

Pulls eye laterally (abducts)

Lateral rectus innervation

Abducens (CN VI)

Superior oblique function

Pulls eye down and out (inferior and lateral)

Superior oblique innervation

Trochlear nerve (CN IV)

Inferior oblique function

Pulls eye up and out (superior and lateral)

Inferior oblique innervation

 Oculomotor (CN III)

Ciliary body/ muscle

changes the shape of the lens to focus objects on the retina

Iris

contains muscles that regulate the amount of light reaching the retina by controlling the size of the pupil

Sphincter pupillae muscle

constricts the pupil to allow less light into the eye; innervated by parasympathetic fibers from oculomotor nerve (CNIII)

Dilator pupillae muscle

dilates the pupil to allow more light into the eye; innervated by sympathetic fibers

Rods

more sensitive to light and permit vision in dim light

Cones

 responsible for high-acuity color vision

Bipolar cells

receive signals from photoreceptors and send them to ganglion cells

Ganglion cells

receive signals from bipolar cells and send them towards the brain

Optic nerve (II)

 formed of axons of ganglion cells

Optic disc

called the blind spot because it lacks photoreceptors

Macula lutea

contains mostly cones

Fovea centralis

contains only cones, providing maximal visual acuity

Anterior segment

contains aqueous humor

Posterior segment

 contains the vitreous body

Pinna (auricle)

funnels sound into the ear; composed of elastic cartilage

Auditory tube (Eustachian tube)

connects middle ear to nasopharynx to equilibrate pressure in the middle ear

Semicircular canals

detect rotational, acceleration and deceleration

Vestibule

detects changes in head position and linear acceleration and deceleration