I have no humor

aqueous humor on deez biologically nonexistent nuts

Sense Organs

Sense Organs

body structures that gather info from surroundings

Stimuli

change/signal in environment organism can react to

Nervous System

receives info of what’s happening in and outside the body; directs how body reacts to this; maintains homeostasis

Divisions of Nervous System

Central NS

• Brain

• Spinal Cord

Peripheral NS

• Somatic NS

• Automatic NS

• Sympathetic NS

• Parasympathetic NS

Peripheral Nervous System

gathers info and carries out activity; like workers in a corporate company;

Somatic Nervous System

controls voluntary actions

Automatic Nervous System

control involuntary actions

Sympathetic Nervous System

at work when body is at rest/relaxed (homeostasis)

Parasympathetic Nervous System

active when in flight/fight/freeze reaction

Central Nervous System

directs body activities and interprets stimuli; the a-hole boss you gotta listen to.

Spinal Cord

thick bundle of nerves through vertebrae; connects brain to PNS

Brain

86 billion interneurons and neurons, central control of Nervous System.

Brain Stem

Control involuntary functions, connects the brain to the spinal cord

Cerebrum

“Thinking”, problem-solving, learning, voluntary actions,

4 lobes split into left and right hemisphere connected by the corpus callosum

Cerebelium

coordinates muscle movement/balance

Frontal lobe

thinking, reasoning, behaviors, judgement

Parietal lobe

perception of stimuli

Temporal lobe

language, learning

Occipital lobe

vision and spacial reasoning

Limbic system

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

Amygdala

almond shaped structure; responsible for automatic responses associated with fear and hormones; determines memory storage

Hippocampus

directs long-term memories to appropriate storage areas and retrieves memories

Hypothalamus

connects brain to endocrine system; what releases hormones

Thalamus

controls sleep/ consciousness by relaying sensory receptors between the brain stem and cerebral

Nerve Impulse

message neurons can carry

Neurons

Cells that carry info through the nervous system

Types of Neurons

Sensory Neurons

Interneurons

Motor Neurons

Sensory Neurons

pick up stimuli; converts in to nerve impulse; impulse travels with other sensory neurons til it reaches interneurons; usually in brain or spinal cord

Interneurons

carry nerve impulse to another interneuron or motor neuron

Motor Neurons

send impulse to a muscle or gland enabling it to respond

Neuron Vocabulary

Dendrite

Axon tips

Axon

Synapse

Salutatory conduction

Myelin sheath

Dendrites

thread-like extensions of a neuron that picks up nerve impulses

Axon

Long structure leading away from cell body; cells only have one axon

Synapse

liquid in between neurons where neurons transfer impulses; impulses are changed from electrical to chemical to cross gap of synapse.

Saltatory conduction

Process of which an impulse skips down the axon.

Axon tips

branch-like structure at end of an axon that transfers nerve impulses to other neurons.

Myelin sheath

a layer around axons that allow nerve impulses to travel faster; myelination, the process where a neuron due to a change or maturing develops a myelin sheath. Pruning; the removal of the myelin sheath.

Neurotransmitters

Serotonin

Apetite

Melatonin

Dopamine

Epinephrine (Adrenaline)

Cortisol

Serotonin

sleep, mood,

Apetite

mood, etc

Melatonin

sleep/tiredness

dopamine

happiness/reward

epinephrine(adrenaline)

excitement/fear/flight/fight/freeze

cortisol

stress hormones

How nerve impulse travels

Sensory neurons gather stimuli/ info and create electrical signal that moves from dendrites to axon →

Electrical signal move down axon by saltatory conduction →

Axon tips convert signals to chemical neurotransmitters so signals can cross synapse (goo) to interneurons →

Interneurons interpret info/signals →

message/reactions get sent back to motor neurons to carry out reactions

Eye

Respond to stimuli of light; convert to impulse the brain can interprets.

Eye Vocab

Cornea

Pupil

Iris

Lens

Aqueous Humor

Retina

Rods

Cones

Optic Nerve

Optic Nerve

carry light sensory info from retina to the cerebrum

Cornea

where light strikes first; clear tissue covers front of the eye

Aqueous Humor

clear jelly-like fluid between cornea and lens

Pupil

opening which light enters through

Iris

Circular structure; muscles in iris adjust how much light enters pupil; gives color to eye

Lens

Flexible structure that focuses light; flips image upside down

Retina

lines the back of eye; contains light sensitive cells

Rods

work best in dim light; detects black, white, shades of gray

Cones

work best in bright light; detects colors

Farsightedness

blurry nearby; clear far; short eyeballs; fixed by convex lens

Nearsightedness

blurry far; clear nearby; long eyeballs; fixed by concave lens

Ear

Sense organ that responds to the stimuli of sound; converts sound to impulses the brain can interpret

Ear Vocab

Outer

• Ear Canal

Middle

• Eardrum

• Hammer/Anvil/Stirrup

Inner

• Cochlea

• Semicircular canal

• Auditory nerve

Ear Canal

Funnel shaped; gather sound waves; waves travel down ear canal

Eardrum

membrane that vibrates when sound waves hit it

Hammer/Anvil/Stirrup

small bones pass vibrations to each other

Cochlea

snail shaped tube lined w/ sound receptor cells; receive vibrations from stirrup that travels via liquid in the cochlea; Vibrations stimulate receptors which send nerve impulse through the auditory nerve

Semicircular Canal

above cochlea; help maintain balance; Semicircular canal and two sacs behind it are filled with fluid and lined with tiny cells with hair-like extensions. When the head moves, the fluid moves causing the extensions to bend stimulating the receptors and creating nerve impulses containing info about the body’s motion and position.

Auditory Nerve

carry auditory sensory info from cochlea to the cerebrum

Taste bud

sensory receptors on tongue; respond to chemicals dissolved by saliva; main taste sensations: sweet, sour, salty, bitter, unami

Touch receptors

• First type responds to delicate/light touch; senses textures; located in upper part of dermis

• Second type responds to heavy pressure; located deeper in the dermis

• Other types respond to temperature and pain

Olfactory Bulb

two, one above each nasal cavity, picks up info about smell and sends it to brain.