BILD 2 Midterm 2

eplilepsy

condition where people often get seizures + neurons being in a hyperexcitable state

aura

the first symptom of a seizure + is considered to be apart of the seizure

middle of a seizure (itchal phase)

period of time from the first symptoms to end of the seizure activity

ending (postictal phase)

recovery period after a seizure

endocrine system

uses hormones to transmit signals -> secretes hormones into surrounding fluid

signals

chemicals that are released into the blood or other parts of the body by glands

nervous system

uses nerve cells (neurons) to pass signals

neurons

cells with long skinny parts that stretch long distances within the body

nervous system uses

electrical signaling to pass signals within themselves and chemical signaling to transmit signals between different neurons

central nervous system (CNS)

brain + spinal cord, astrocytes, microglia, and oligodendrocytes

blood-brain barrier

blocks many substances from entering the CNS

peripheral nervous system (PNS)

all the other neurons of the body except brain + spinal cord

PNS function

carry information to and from the CNS

glia

supports the function of the nervous system

What is the primary function of neurons?

Responsible for the electrical signals that communicate information.

What do neurons produce in response to stimuli?

Movements.

hormone

signaling molecule

hormones are produced in _______ by one part of an organism's body

low concentrations

glia in the CNS

oligodendrocytes, astrocytes, microglia

glia in the PNS

schwann cells

oligodendrocytes

insulate neurons with myelin

astrocytes

main supports for the brain

astrocytes function

transports nutrients from the blood to neurons + balance ionic and chemical environment

microglia

white blood cells of the brain -> fight micro-organisms + clean up debris

schwann cells

insulate cells of PNS with myeline (1 schwann cell myelinates 1 axon)

synapses

where neurons send signals to each other

neurons collect input at

dendrites

neurons send output targets at

axon terminals

action potential (AP)

allow cells in the body to communicate over long distances, consistently, and quickly (spikes/firing)

AP starts at

the beginning of axon as a result of input

AP ends at

axon terminals -> initiates a process to send signals to the next neuron

membrane potential

voltage inside a cell

mechanism

each complicated process is made up of smaller components that are relatively simple

casual

certain inputs have certain effects

Na+/K+ pump

slowly pumps Na+ out of the cell and K+ inside the cell

what triggers the Na+/K+ pump to work/open

works all the time (slowly)

Voltage-gated Na+ channel

opens immediately, allows fast flow of Na+ and then inactivates (shuts off)

what triggers the voltage-gated Na+ channel to work/open

high voltage (above the threshold)

Voltage-gated K+ channel

short delay then opens + allows fast flow of K+

what triggers the voltage-gated K+ channel to work/open

high voltage → above threshold

ion pumps

moves substances through the membrane + selective for certain ions

ion pumps require

ATP for active transport

ion pumps are

slow

ion pumps create

concentration gradients by transporting molecules against gradients

ion channels

moves substances through the membrane and are selective

ion channels do

not require ATP -> passive transport

ion channels are

fast

ion channels allow

ions to diffuse down concentration gradients

tumor suppressors

represses growth

tumor suppressors when inactivated

promote cancer

proto-oncogenes

encourage growth

proto-oncogenes when over-activated

promote cancer

genes that promote differentiation

turn off growth

genes that promote differentiation when inactivated

promote growth + spread of cancer

DNA repair genes

fix errors in DNA

DNA repair genes when inactivated

promote mutations + cancer

genes that promote angiogenesis

promote growth of blood vessels

genes that promote angiogenesis when over-activated

promote tumor growth + spread of cancer

radiation/chemotherapy

kill dividing cells

surgery

cut the tumor out

immunotherapy

enhance immune system to kill cancerous cells