ns test

the fish tank smells like sht

Neurons

cells that carry information through your nervous system

Dendrite

a branchlike structure that picks up the impulses

Axon

the long structure leading away from the cell body

Synapse

* gap between neurons
* transfers a nerve impulse from one neuron to another

Salutatory conduction

process in which electrical signal from sensory neuron moves down axon

Axon tips

where electrical signals change to a chemical form, allowing the message to cross the gap in the synapse

Myelin sheath

* insulating layer or sheath that forms around nerves; allows electrical impulses to transmit quickly along the nerve cells
* like the outside of a wire

Nerve impulses

messages neurons can carry

Stimulus

any change or signal in the environment that an organism can recognize and react to

Response

a reaction to a stimulus

Sensory neuron

picks up a stimulus and converts it into a nerve impulse

Motor neuron

sends an impulse to a muscle or gland, enabling it to respond

Interneuron

carries a nerve impulse to another interneuron or a motor neuron

Neurotransmitters

chemical messengers

Serotonin

regulates sleep, appetite, mood etc.

Melatonin

sleep/tiredness

Dopamine

happiness/reward

Epinephrine (adrenaline)

excitement/fear at work in flight/fight/freeze

Cortisol

stress hormone

Central Nervous System

* directs body activities and interprets stimuli
* brain and spinal cord are part of CNS

Peripheral Nervous System

gathers information & carries out activities

Somatic Nervous System

controls voluntary actions

Autonomic Nervous System

controls involuntary actions

Sympathetic NS

active when in fight/flight/freeze reaction

Parasympathetic NS

at work when your body is at rest/relaxed

Brain

86 billion neurons, central control of nervous system

Cerebrum

“thinking,” problem solving, learning: voluntary actions

Cerebellum

coordinates muscle movement/balance

Spinal Cord

thick bundle of nerves through vertebrae, connects brain to PNS

Brain Stem

controls involuntary body functions; connects brain to spinal cord

Corpus callosum

connects left and right hemispheres of the brain

Frontal Lobe

thinking, reasoning, behavior, judgment, emotions

Parietal Lobe

perception of stimuli

Temporal Lobe

language, hearing

Occipital Lobe

vision & spatial reasoning

Limbic system

is a set of brain structures located at the top of the brain stem involved in emotions, motivation, memory, especially those related to survival

Amygdala

almond shaped structure responsible for autonomic responses associated w/ fears + hormones, determines memory storage

Hippocampus

directs long term memories to appropriate storage areas and retrieves memories

Hypothalamus

connects brain to endocrine system (hormones),what releases/controls hormones

Thalamus

controls sleep/consciousness by relaying sensory perceptions between brain stem + cerebrum

Cornea

clear tissue that covers the front of the eye

Pupil

opening through which light enters the eye

Iris

a circular structure that surrounds the pupil/regulates how much light enters the eye

Lens

is a flexible structure that focuses light

Aqueous Humor

the clear fluid filling the space in the front of the eyeball between the lens and the cornea

Retina

lines the back of the eye and contains light-sensitive cells

Rods (receptor cell)

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

Cones (receptor cell)

work best in bright light and enable you to see colors

Eardrum

* a membrane that vibrates when sound waves strike it
* these vibrations pass to the hammer, anvil, and stirrup

Hammer/Anvil/Stirrup

* small bones named for their shapes
* hammer → anvil → stirrup

Semicircular canal (above cochlea)

helps your Central NS maintain your balance

Ear canal

sound waves travel down (part of outer ear)

Cochlea

a snail-shaped tube lined with sound receptor cells

Auditory nerve

used by sensory neurons to send nerve impulses to the cerebrum 

Taste buds

* sensory receptors on your tongue
* respond to chemicals from anything that have dissolved in your saliva

Touch receptor

enable us to detect the location of the stimulus when an outer force (i.e., touch, pressure) applied and deformed our skin

Myelination

Adding myelin (fat) to the axon of a neuron to speed up signal transfer → learning

Pruning

Getting rid of neural/synapse connection