BCMB 230 Exam 2

sensory input

the information we take in about the world around us.

integrative functions

the way our body figures out what we take in, it recognizes what the sensory input means.

motor output

the physical response to the sensory input

the central nervous system (CNS) is comprised of...

the brain and the spinal cord.

the peripheral nervous system (PNS) contains...

nerves that branch off the spinal cord and sensory receptors.

autonomic nervous system

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs; TWO long neurons in communication.

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles; ONE long neuron.

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy.

neurons

a nerve cell; their function is to take in information and share it with other cells.

glial cells

cells in the nervous system that support, nourish, and protect neurons.

flows ONLY from dendrite to axon.

what is the method in which a neuron sends a signal?

dendrites

receive messages from other cells.

if there is a chemical signal...

the signal will go to the cell body, make a protein, then go down the axon.

if there is an electrical signal...

the signal goes to the cell body then the axon.

axon terminals

branches at the end of an axon where information is released.

multipolar neuron

a nerve cell that has many dendrites and a single axon.

bipolar neuron

looks like it has two axon terminals.

unipolar neuron

a neuron in which the cell body is pushed off to the side.

convergence

allows one neuron to receive input from many different neurons.

divergence

allows one neuron to communicate with many different neurons.

afferent neurons

bring sensory input from the body to the central nervous system (CNS); from the body to the brain OR peripheral to CNS.

interneurons

decipher the sensory information and "plan" a response; they code the information.

efferent neurons

bring the motor output from the central nervous system (CNS) to the body; from the brain to the body OR CNS to peripheral.

Schwann cells

type of glial cells in the PNS; responsible for the formation of myelin sheaths at regular intervals along some axons.

Nodes of Ranvier

gaps in the myelin sheath that help to propagate the signal down the axon.

saltatory conduction

when action potentionals jump from one node to the next.

the Na +/K+ pump helps to regulate...

the resting membrane potential for neurons which is between -40 and -90 mV (closer to -90mV).

action potentials

large alterations in the membrane potential; generally rapid and may repeat at frequencies.

the ability to generate action potentials is known as...

excitability.

depolarization occurs when...

sodium rushes in, causing a voltage increase.

repolarization occurs when...

potassium leaves, causing a voltage decrease.

threshold

the level of stimulation required to trigger a neural impulse, if the membrane potential doesn't reach threshold then an action potential will not be formed.

refractory period

a period of inactivity after a neuron has fired.

synapse

the gap between the axon terminals of one neuron and the dendrites of another neuron.

presynaptic neuron

releases neurotransmitters (signals).

postsynaptic neuron

receives neurotransmitters (signals).

gap junctions

in electrical signals, pre and postsynaptic cells are connected by...

excitatory post synaptic potential (EPSP)

brings the next neuron closer to an action potential; decreases in magnitude as it gets farther from the presynaptic cell.

inhibitory post synaptic potential (IPSP)

prevents an action potential from occurring in the post synaptic cell.

Selective Serotonin Reuptake Inhibitors (SSRIs)

these prevent serotonin from being taken back up in the presynaptic neuron, so it can't go to the post synaptic neuron and cause an action potential.

dynein and kinesin...

are the two proteins responsible for transporting other proteins or vesicle down the axon.

neurotransmitters

the chemical messengers of the nervous system.

neuromodulators

changing how the postsynaptic cell responds to neurotransmitters.

NMDA receptors

voltage dependent magnesium block (nothing can happen even if the ligan binds to receptor); involves LONG TERM CHANGES.

AMPA receptors

no magnesium block; involves SHORT TERM CHANGES.

atrocytes

aid in the metabolic exchange between the neurons and blood; neurons personal assistant.

microglia

plays an immune roles; can become phagocytic and digest pathogens.

ependymal cells

a type of epithelial cell that lines the ventricles of the brain and keep cerebrospinal fluid flowing.

during a spinal injury, a problem is apoptosis of what cell?

oligodendrocytes (the cells that make the myelin sheath).

what is a reflex arc?

when an interneuron in the spinal cord makes the decision for us; this acts as a way to protect ourselves without taking the time to send signals to the brain.

brain plasticity

when our brain can adjust its structure and function in response to stimulation or injury.

synaptic pruning

when neurons and synapses are eliminated during infancy to increase the efficiency of neurotransmission and to eliminate overstimulation.

cerebellum

responsible for movement, balance, and posture.

frontal lobe

planning and decision making, social appropriateness, empathy, personality, creating language (speech).

parietal lobe

organizes your senses to help you figure out where you are in the world

temporal lobe

understanding speech, controls automatic reactions like hunger and thirst.

occipital lobe

vision processing; takes what we want to see and it helps us understand what it means.

spinal cord

carries messages from the body to the brain and from the brain to the body.

corpus callosum

connects the two hemispheres so they can communication to one another.

pituitary gland

produces hormones that control everything in the body.

hypothalamus

manages bodily functions like blood pressure, sleep, mood, and hunger.

thalamus

carries sensory information from the body to the brain.

brain stem

eye movements, breathing, swallowing, heart rhythms.

hippocampus

"saves" memory; protein synthesis happens in the _______.

amygdala

emotional memories

Parkinson's Disease

the neurons that make dopamine are dying.

Alzheimer's Disease

abnormal buildup of toxic proteins that result in dementia.

epilepsy

neuron activity is irregular so they fire randomly and cause seizures.

stroke

part of the brain dies because it did not receive blood.

aneurism

one of the blood vessels in the brian is distended and weakened.

coding

the conversion of stimulus energy into a signal that conveys the relevant sensory information t o the central nervous system.

what is another term for stimulus type?

stimulus modality

sensory receptors

at the peripheral ends of afferent neurons and they pick up a signal, create an electrical signal, and then send it to the CNS.

receptor potentials

initiate action potentials, which travels into the central nervous system.

what are the five major classes of sensory receptors?

mechanoreceptors, thermoreceptors, photoreceptors, chemoreceptors, and nociceptors.

exteroceptors

receive stimuli from outside the body.

interceptors

chemical stimuli and deep pressure; inside the body.

sensory adaptation

the tendency of some sensory receptors to become less sensitive when they are stimulated repeatedly.

lateral inhibition

enables the localization of a stimulus site for some sensory systems; allows us to determine exactly where a stimulus is and helps us pinpoint important information.

the cerebral cortex.

where is sensory information sent to be decoded?

modality

type of stimulus: chemical, light pressure, mechanical, and temperature.

duration

how long does the stimuli last.

intensity

how strong the signal is.

sensation and perception

integrating emotions and past experiences.

free neuron ending

slowly adapting, including nocicepters, itch receptors, thermoreceptors, and mechanoreceptors.

referred pain

the sensation of pain that is experienced at a site other than the injured or diseased tissue.

hyperalgesia

an increased sensitivity to painful stimuli; feel pain more intensely than the average person.

analgesia

the selective suppression of pain without effects on consciousness or other sensations.

the eyes are composed of...

an optical and a neural component.

sclera

the white of the eye.

pupil

the hole in the iris where light passes through.

iris

the colored part of the eye that contracts and expands to change the pupil's size.

lens

marble-like structure that focuses light.

cornea

clear covering over the eye.

ciliary muscles

change the shape of the lens to focus light different; controls movement of eye.

lacrimal gland

on the skin around the eye, creates tears to keep the eye lubricated.

retina

receives light signals, converts them into neural signals, and sends the information to the brain.

rods

contains the visual pigment rhodopsin which absorbs dim light; helps us see shades of gray.

cones

contain the visual pigment photopsin which absorbs bright-colored light; helps us see color in bright-light.