Question | Answer |
Central Nervous System | brain and spinal cord |
Peripheral Nervous system | the nerves that enter and leave the brain and spinal cord. consists of autonomic and somatic nervous system |
Grey Matter | brownish-grey nerve tissue (non myelinated) consisting mainly of nerve cell bodies within the brain and spinal cord. in the letter of H. |
white matter | the whitish nerve tissue of the brain and spinal cord. myelinated axons |
Autonomic Nervous System | part of the nervous system that relays info to internal organs that are not under concious control of the individual. made up of sympathetic and parasympathetic nervous systems. |
Somatic Nervous System | part of the nervous system that relays info to and from the skin and skeletal muscles (under the constant control of the individual) |
Sympathetic nervous system
(let me help you) (dad) | network of nerves that control involuntary muscle reactions and organs in time of stress. |
Parasympathetic nervous system
(pshh get over it) | the network of nerves that counteracts the sympathetic nervous system to slow heart rate and breathing rates and relax muscles |
reflex | quick involuntary nerve and muscle reaction to an outside stimulus |
neuron | nerve cell that is the structural and functional unit of the nervous system, consists of a nucleus, cell body, dendrites, axons, and a myelin sheath. |
nerve | message pathway of the nervous system made up of many neurons connected together. |
reflex arc | nerve path leading from a stimulus to a reflex action. |
cell body | main part of a neuron, contains nucleus and other organelles. |
dendrite | primary site on a nerve cell (neuron) for receiving signals from other neurons. |
axon | long cylindrical extension of a neurons cell body, can range from 1mm- to 1m in length. transmits impulses along its length to the next neuron. |
medulla ablongata | attatched to the pinal cord at the base of the brain
has cardiac, vasomotor, respiratory, and vomiting, voughing, hiccuping, and swollowing.
injury to this area usually reults in death |
cerebellum
andrew | part of the brain controlling muscle co-ordination |
thalamus
(thalmore governs gossip in skyrim) | sensory relay centre of the brain that gooverns the flow of info from all other parts of the nervous system. |
hypothalamus
(good thalmore hyperactive for solving missions) | part of the brain acting as the main control center for the autonomic nervous system. re-establishes homeostasis, controls endocrine hormone system |
cerebrum | largest part of the brain.
all info from the senses is sorted and interpreted, voluntary muscles are stimulated, memories stored, decisions made. |
cerebral cortex
tickling | thin layer of grey matter covering each hemisphere of the brain. enables individual to experience sensation, perform voluntary movements, and think |
corpus callosum | layer of white matter made up of axons that joins 2 hemespheres of the cerebral cortex of the brain. |
resting potential | cdifference in charge from the insisde to the outside of a cell at rest. |
neurotransmitters | chemicals sevreted by neurons to stimulate motor neurons and central nervous system neurons. |
action potential | in an axon, the change in charge that ovvurs when the gates of k+ channels close and the gates of Na+ channels open after a wave of depolarization is triggered. |
refractory period | brief time between the triggering of an impulse along an axon and the axons readiness for the next impulse. during this brief time, the axon cannot transmit an impulse. |
myelin sheath | fatty layer around the axon of a nerve cell, composed of schwann cells. |
schwann cells | insulating cells around the axon of a nerve cell |
node of ranvier
randy | the gap between schwann cells around the axon of a nerve cell membrane of the axon is exposed and nerve impulses jump from one node of ranvier to another |
synapse | junction between a neuron and another neuron or muscle cell |
pre-synaptic neuron | the state of a neuron before a synapse- before a neuron carries a wave of polarization to a synapse leading to another cell. |
post synaptic neuron | state of a neuron after a synapse- after the neuron recieves and transmits a stimulus. |
synaptic vesicle | specialized vacuole in the bulb- like ends of the axons of a nerve cell containing neurotransmitters that are released into the synapse when a nerve impulse is recieved. |
excitatory response | when the neurotransmitter reaches the dendrites of a post synaptic neuron and a wave of depolarization is generated by the resultant opening of sodium gates. |
inhibitory response | when the postsynaptic neuron is made more negative on the inside to raise the threshold of stimulas |
cholinesterase | enzyme that breaks down the neurotransmitter acetylcholine |
acetylcholine | primary neurotransmitter of both the somatic and the parasympathetic nervous system |
noradrenaline | primary neurotransmitter of the sympatric nervous system |
glutamate | neurotransmitter in the cerebral cortez that accounts for 75% of all excitatory transmissions to the brain |
GABA | gamma aminobutyric acid, the most common inhibitory transmitter to the brain |
dopamine | neurotransmitter that elevates mood and controls skeletal muscles |
seretonin | organic compound formed from tryptophan, found in tissue throughout the body.
acts as a neurotransmitter.
constricts vessels at injury sites
effects emotional states |
MS | serious progressive disease of the central nervous sytem. the myelin sheath surrounding nerve cells becomes inflamed or damaged, disrupting the nerve impulses that are normally produced |
alzheimers disease | degenerative disorder.
affects the brain causing dementia, an impairment of the brains intelectual functions (memory and orientation) later in life |
parkinsons disease | chronic movement disorder caused by the gradual death of the neurons that produce dopamine. |
meningitis | bacterial or viral infection of the meninges, the 3 membranes that cover and protect the brain and spinal cord |
sclera | thick white outer layer that gives the eye its shape |
cornea | the clear part of the sclera at the front of the eye |
conjunctiva
tear jerker | the thin transparent membrane that covers the cornea.
kept moist by tears |
choroid layer | middle layer of the eye.
absorbs light
prevents internal reflection
the layer forms the iris at the front of the eye |
iris | the muscle that adjusts the pupil to regulate the amount of light enters the eye |
pupil | the aperture in the middle pf the iris of the eye.
size of aperture can be adjusted to control the amount of light |
lens | the clear flexable muscle that adjusts the pupil to regulate the amount of light that enters the eye. |
retina | inner most layer of the eye |
rod | photoreceptors in the eye, more sensitive to light then cones, unable to distinguish colour. |
cones | colour receptors in the eye |
accomodation | adjustment in the eye that the ciliary body makes to the shape of the lens to focus on objects at varying distances |
rhodopsin | a reddish purple light sensitive protein found in the outer segment of rod cells of the retina. the rhodopsin is the pigment that enables the rods to detect light |
fovea centralis | concentrations of cones on the retna lovated directly behind the center of the lens |
cateract | cloudy or opaque are on the lens of the eye that increases in size over time.
can lead to blindness if left un medically treated. |
glaucoma | build up of the aqueus humour in the eye that irreversibly damages nerve fibres responsible for peripheral vision |
myopia | near sightedness or difficulty seeing things far away caused by too strong ciliary muscles or too long eye ball |
hyperopia | far sightedness
difficulty seeing close up
caused by too week ciliary muscles or too short eye ball |
astigmatism | abnormality in the shape of the cornea or lens that results in uneven focus |
outer ear | 1 of 3 separate segments of the ear( outer, inner, middle) consists of pinea and the auditory canal |
middle ear | 1 of 3 separate segments of the ear (inner, middle, outer) begins at the eardrum and ends at 22 small openings called the round window and the oval window |
tympanic membrane | eardrum
membrane of the skin and fiberous tissue that vibrates in response to sound waves, located between the outer ear and the middle ear. |
the 2 small openings at the end of the middle ear | round window and oval window |
the 3 small bones between the ear drum and the oval window of the middle ear that transmit sound waves from the ear drum to the middle ear | malleus, incus, stapes
also known as ossicles |
Eustachian tube
pistachio (2 sides one nut) | bony passage extending from the middle ear to the nasopharynx that plays a role in equilizing air pressure on both sides of the ear drum |
inner ear | 1 of 3 separate segments of the ear (inner, outer, middle)
consists of 3 sections, coclea, vestibule, semicircular canals |
cochlea | 1 of 3 sections of the inner ear (cochlea, vestibule, semicircular canals).
involved in hearing |
vestibule | 1 of 3 sections of the innner ear (cochlea, vestibule, semicircular canals).
involved in balance and equilibrium |
cochlear canal | 1 of 3 canals in the cochlea. |
basilar membrane | 1 of 2 parallel membranes that comprise the organ of corti in the inner ear; forms the lower wall of the cochlear canal |
tectoral membrane | 1 of 2 parallel membranes that comprise the organ of corti in the inner ear.
during transmission of sound waves, the basilar membrane vibrates, causing the sensory hair to flex againt the tectoral membrane |
spiral organ | an organ of corti, the sensory part of the cochlea in the inner ear which responds to sound. |