Lecture test 6 the nervous system

mammillary bodies

- on the ventral side of brain under optic chiasm and pituitary location.

route of impulse transmission

-90 to 100 m/s unmyelinated -faster if myelinated -fat is white axon form white matter dendrite plus cell body is gray matter

hindbrain

-An area of the brain that coordinates information coming into and out of the spinal cord -Area containing the medulla, pons, and cerebellum. -the posterior portion of the brain including cerebellum and brainstem

temporal lobe

-auditory -olfaction "smell" -memory, behavior, emotions, speech

very rapid metabolism

-burns food faster than any other tissue in the body -breaks c-c glucose bonds to get energy to build ATP bonds -utilizes oxygen to do this so much oxygen is needed or cell death in 5 minutes

nerve gas

-causes flaccid paralysis -muscles do not contract -acts by destroying synaptic knobs so no neurotransmitter substance is present

cell action potential

-cell will be conduction an impulse in 2 steps -stimulus alter membrane permeability -sodium moves into cell called depolarization for a split second the charges are = -potassium fluxes out of the cell away from the sodium called repolarization separation of charges again -ATP is required after the impulse to restore the original position of sodium and potassium or no new impulses will occur -done by sodium potassium pump

intensity of sensation

-dose effect how many -relative to the number of neurons firing simultaneously

polarized resting neuron

-due to unequal distribution of charges -no impulse transmission at this time

lobes of cerebrum

-frontal lobe -parietal lobe -temporal lobe -occipital lobe -isle of reil

all or none law of impulse transmission

-if an impulse is initiates down a neuron, it will go all the way or not at all -axon hillock is point of no return

cross pyramidal tracts

-info in these lobes comes in and goes out to the opposite side of the body -90% of people have dominant left cerebrum language side of brain so they are right handed -10% of people have dominant right cerebrum visual, spatial, intuition, emotion, art, and music side

characteristics of the nervous system

-irritability -conductive -limited repair and regeneration of nervous tissue -amitotic tissue -longevity -very rapid metabolism

threshold level stimulus

-liminal level stimulus -minimal level stimulus that will trigger an impulse

tetanus

-lock jaw -bacteria makes a neurotoxin -destroys enzymes that degrade neurotransmitter -keeps muscle in constant contraction -spastic paralysis

stimulation of second neuron

-once neuron number 1 fires its synaptic knobs rupture and drip neurotransmitter substance in the synaptic cleft -neurotransmitter bath, up against the dendrites of neuron number 2 -neuron number 2 fires to stimulate effectors in muscles and glands stimulus is presents of new chemical ACH

limited repair and regeneration of nervous tissue

-only in the peripheral branch -takes up to 2-3 years

duration of a sensation

-pain -the frequency that the neuron continues to fire is how often they fire

irritability

-responsiveness -excitability -ability to respond to a stimulus

conductive

-sends electrical impulses -unique characteristic of all nerve tissue

neuron resting potential

-sodium on the outside of the cell = polarized due to an unequal separation of charges -potassium on the inside of the cell

peripheral nervous system

-somatic voluntary branch -autonomic nervous system -A division of the nervous system consisting of all nerves that are not part of the brain or spinal cord.

to halt an impulse

-stop additional stimulation -eliminate the neurotransmitter substance by recapture it by glial cells the enzyme degrades it example acetyl cholinesterase destroys ACH and sometimes it diffuses out of the synaptic cleft

sub threshold level stimulus

-subliminal level stimulus -stimulus too weak to trigger an impulse

telencephalon

-the end brain -cerebrum

mesencephalon

-the midbrain contains nuclei that processes visual and auditory information and generate responses to these stimuli -Contains centers involved with the maintenance of consciousness

isle of reil

-under lateral fissure -gustation "taste" -Insula

occipital lobe

-visual -interpretation of retinal image

frontal lobe

-voluntary -motor area -contains broca's area for motor ability to formulate speech -A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement

parietal lobe

-voluntary -sensory area made of afferent neurons from receptors -A region of the cerebral cortex whose functions include processing information about touch.

Novocain

-xylocaine -block sodium transport -stops nerve impulse from being transmitted like pain

coccygeal nerves

1 pair, C0

steps of sight

1. light pases through the Cornea 2. cone fires 3. bipolar cells fires 4.ganglion cells fires 5. optic nerve 6. each eye sends info to both sides 7. goes to the thalamus for sensory information 8. cerebrum interpretation of vision

steps of hearing

1. sound strikes tympanic memebrane and it vibrate

thoracic nerves

12 nerves Originates in thoracic spinal cord: these are nerves of muscles of thorax

cranial nerve

12 pairs of nerves that carry messages to and from the brain

spinal nerves

31 pairs of nerves arising from the spinal cord

lumbar nerves

5 pairs, L1 to L5

sacral nerves

5 pairs, S1-S5

cervical nerves

8 nerves Affect the side of the neck and the platyma muscle

color blindness

A complete lack of cones leads -Ishihara's book

farsightedness

A condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina -hyperopia

near sightedness

A condition which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina -myopia

thalamus

A forebrain structure that processes sensory information for all senses, except smell, and relays it to the cerebral cortex.

macular

A gradual loss of acute, central and color vision in the elderly

rhodopsin

A light-sensitive pigment found in the rod cells that is formed by retinal and opsin.

neuron

A nerve cell; the basic building block of the nervous system

action potential

A neural impulse; a brief electrical charge that travels down an axon. The action potential is generated by the movement of positively charged atoms in and out of channels in the axon's membrane.

hypothalamus

A neural structure lying below the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion -birds beck

diencephalon

A region of the forebrain surrounding the third ventricle; includes the thalamus and the hypothalamus.

reflex

A simple, automatic, inborn response to a sensory stimulus, such as the knee-jerk response.

utricle

A small, fluid-filled sac in the vestibular system above the saccule that responds to static positions of the head.

saccule

A small, fluid-filled sac under the utricle in the vestibular system that responds to static positions of the head.

infundibulum

A stalk that attaches the pituitary gland to the hypothalamus.

metencephalon

A subdivision of the hindbrain that includes the cerebellum and the pons.

somatic nervous system

A subdivision of the peripheral nervous system. Enables voluntary actions to be undertaken due to its control of skeletal muscles

autonomic nervous system

A subsystem of the peripheral nervous system that carries messages between the central nervous system and the heart, lungs, and other organs and glands.

myopia

A visual defect like nearsightedness

glaucoma

An eye disease in which the intraocular pressure is high enough to cause damage to the optic nerve, resulting in visual loss; caused by impaired drainage of the aqueous fluid out of the eye

tensor tympani

Arises from the wall of the auditory tube-inserts to malleus

inferior colliculi

Auditory reflex center

central nervous system

Brain and spinal cord

organ of corti

Center part of the cochlea, containing hair cells, canals, and membranes

blind spot test

Closing eye and focusing on X and moving figure closely toward face and the dot on the other side will disappear

cataract

Clouding of the eye's lens; often congenital or age-related.

cones in eye

Colors are determined by this

somatic reflex

Involve the somatic nervous system which controls the contraction of all skeletal muscles. Innate responses designed to protect the body, and enable posture maintenance and balance when standing and moving. Patellar and Achilles reflex are stretch reflexes used to demonstrate somatic reflexes.

path of tears

Lacrimal glands, lacrimal canaliculli, lacrimal sac, nasolacrimal duct, nasal cavity

basal ganglia

Large clusters of neurons, located above the thalamus and under the cerebral cortex, that work with the cerebellum and the cerebral cortex to control and coordinate voluntary movements.

refraction in the eye

Light passing through the center of the cornea is not bent; light striking off-center is bent towards the center. Aqueous humor and lens do not greatly alter the path of light. Cornea refracts light more than lens does. Lens merely fine-tunes the image; lens becomes rounder to increase refraction for near vision.

stapedius muscle

Prevents very large vibrations of stapes from loud noise

visceral reflex

Reactions of glands, cardiac muscle, and smooth muscle, controlled by the autonomic nervous system

astigmatism chart

Test for Astigmatism -10 Feet

Division of nervous system

The nervous system is divided into the central nervous system and the peripheral nervous system

hypophysis

The pituitary gland.

scala vestibuli

The superior chamber of the cochlea. Receives sounds and is filled with Perilymph.

superior colliculi

Visual reflex centers

stimulus

a change in the environment of a neuron large enough to cause a impulse

axons

a part of a neuron that carries impulses away from the cell body

impulse

a wave of ion permeability that moves across a neuron's membranes from dendrite to cell body to axon -unidirectional flow -salutatory propagation faster node to node transmission due to thickness of myelin sheath -thicker sheath with faster transmission rates

amitotic tissue

absence of continued mitosis

sympathetic branch

activated in emergency or stressful situations like fight, flight, fright -emergency, excitement, exertion, emotion, eyes dilate, epinephrine, and extra energy by fat catabolism -speeds up respiratory, blood pressure, and blood to skeleton muscle

cerebral aquaduct

canal like; runs through the midbrain; connects 3rd and 4th ventricles

cerebrum

controls somatic voluntary branch of peripheral nerve system organization of cerebrum left and right cerebral hemisphers

function of middle ear

convert acoustic energy of sound pressure wave into mechanical vibrations

cerumen gland

ear wax

conduction of a nerve impulse

electrical impulse causes a charge in permeability of membrane. This causes sodium that is on the outside to move in and Potassium to move out. Electrical impulse travels along outside of the cell

3rd ventricle

found in the diencephalon and communicates with lateral ventricles via intraventricular foramen

refracted

light deflected from a straight path

tegumentum

movement and arousal

emmetropic eye

normal eye with light focused properly

dorsal mesencephalon

origin and course of trochlear nerve

branches of autonomic nervous system

parasympathetic = rest and digest sympathetic = emergency

bleaching of the pigment

process of breaking down the retinal-opsin combinations that form the rhodopsin found in the rods and cones

longevity

should live throughout a human's lifetime if uninjured and no circulatory blockage

homunculus theory

sites of outgoing and incoming information in these two lobes is organized medially to latterly around the hemispheres

ampullae

special sensing organs called electroreceptors, forming a network of jelly-filled canals; these organs help sharks sense electric fields in the water

optic chiasma

the crossing of the optic nerves from the two eyes at the base of the brain

parasympathetic branch

the division of the autonomic nervous system that restores the body's normal resting state and conserves energy -digest "gland secretion", duplicate, defecate, kidney active

pros encephalon

the forebrain

equilibrium organs

vestibule and semicircular canals

rhodopson

visual pigment in rods, in membrane of stacked disks in each rod, absorption of light changes its shape: inactive to active

rod cells

work best in dim light and enable you to see black, white, and shades of gray

forebrain

-Covers the brain's central core. It includes the cerebral cortex, the cerebrum, and the limbic system, which consists of the hypothalamus, thalamus, amygdala, and hippocampus.

hyperopia

-Farsightedness

diplopia

Double vision.

outer ear

Funnel-shaped to collect sound

division of peripheral nervous system

Somatic Nervous System and Autonomic Nervous System

voluntary neuron

Somatic motor neuron

middle ear

The chamber between the eardrum and cochlea containing three tiny bones the hammer, anvil, and stirrup that concentrate the vibrations of the eardrum on the cochlea's oval window

scala tympani

The duct below the scala media that is filled with perilymph