Neurobiology unit 1

dendrite

neurites convey information toward cell body (receives information)

soma

sell body of neuron (contains nucleus) integrates info, is also the metabolic center

axon

neurites convey info away from soma, sometimes over long distances (sending info)

synaptic terminal

ouput of neuron, passed along to target

convergence

number of inputs to a single neuron; reflects ability to integrate signals

divergence

number of targets innervated by one neuron

glia

non-neuronal cells, have no active electrical response, small, and have symmetrical branches;

They provide physical support, regulate extracellular env, and produce myelin

astrocytes

most numerous and diverse macroglia, surround blood vessels, migrate to site of neural injury and proliferate to aid in repairing damaged neural tissue

oligodendrocytes

predominate in white matter, extend multiple arms to myelinate multiple axons within the CNS, insulate cells in the CNS

microglia

survey the CNS to combat infection, infiltrate ones and scavenge for damage and infeciton

somatic nervous system

controls voluntary muscles and transmits info

sympathetic nervous system

arouses body to expend energy (fight or flight)

parasympathetic nervous system

calms body to conserve and maintain energy

PET scan

measures radioactive glucose in brain; acquires signals more slowly and approaches spacial resolution of fMRI

fMRI

measures neuronal activity in the brain by measuring rate of oxygenated to deoxygenated blood in brain; allows for good balance between spacial and temporal resolution

myotatic reflex cycle

hammer tap —> sensory neuron —> motor neuron (extensor) —> interneuron —> motor neuron (flexor) —> leg extends

anterograde tracer

maps connections from source to termination (soma —> down axon)

retrograde tracer

maps connections from termination to origin (up axon—> to soma)

tract tracing

brain mapping with high spacial resolution, produces lots of data and hypothesis, but is very invasive and time sensitive

DTI (diffusion tensor imaging)

brain mapping thatmeasures magnetic fields to calculate the diffusion of water molecules

maps the trajectory of axons

can be conducted in living humans and animals

amphipathic

the phospholipid structure is ______ (hydrophilic and phobic region)

hydrophilic head

part of phospholipid that contains the phosphate and charged group

hydrophobic head

part of phospholipid that contains the fatty acids

hydrophobic and small polar molecules

molecules that can passively move across the plasma membrane

diffusion

movement of a solute from an area of high concentration to an area of low concentration until equilibrium is reached

fluid mosaic

term to model the plasma membrane made of bilayer, proteins, and carbohydrates

integral membrane proteins

proteins that span the entire membrane

peripheral membrane proteins

proteins that do not span the entire membrane and are usually temporary

large polar molecules and ions

molecules that cannot pass through the membrane passively

facilitated diffusion

ion channels facilitate ions through the channel, or transport/carrier proteins

ion channels

allow ions to diffuse down the concentration gradient; can be selective or gated

transport/carrier proteins

allows large molecules to diffuse through membrane from area of high to low concentration

active transport

moves ions against their concentration gradient; require energy

Na+/K+ pump

makes a decrease in electrical charge inside the cell; for every 2 K+ pumped into the cell, 3 Na+ are pumped out

-70 mV

resting membrane potential is about _____

electrical potential

uneven distribution of charge forms basis for __________

electrochemical gradient

ion transporters moving ions across the plasma membrane create an ________; a reparation of charge across the membrane

ATPases

_____ create an ion concentration gradient and separation of charge, creating an electrical and chemical gradient which mediates ion movement

electrochemical gradient

the aggregate force of the chemical gradient and electrical potential which mediate ion movement; the net effect of the chemical and electrical gradient

resting potential

the result of ion concentration gradients and selective permeability

nernst equation

the voltage across a membrane that exactly counteracts the movement of ions from the side with high to the side with low concentration