exam 1 chapter 1

Question 1

two types of cells in nervous system

Answer 1

neurons and glia

Question 2

neuron

Answer 2

cells that receive and transmit information to other cells

Question 3

membrane

Answer 3

animal cell
composed of two layers of fat molecules, allowing small uncharged chemicals to flow both into and out of a cell

Question 4

nucleus

Answer 4

animal cell
structure that contains chromosomes

Question 5

mitochondria

Answer 5

animal cell
provides cell with energy, requires fuel and oxygen to function

Question 6

ribosomes

Answer 6

animal cell
site of protein synthesis

Question 7

endoplasmic reticulum

Answer 7

animal cell
network of thin tubes that transport newly synthesized proteins to other locations

Question 8

motor neuron

Answer 8

receives excitation from other neurons and conducts impulses along its axon to a muscle

soma in the spinal chord

Question 9

sensory neuron

Answer 9

(receptor neuron)
specialized at one end to be highly sensitive to a particular type of stimulation (light, temp, touch, etc.)

Question 10

four components of a neuron

Answer 10

dendrites, cell body, axon, presynaptic terminal

Question 11

dendrite

Answer 11

neuron
branching fibers that extend from the cell body and get narrower at their end

Question 12

dendritic spines

Answer 12

short outgrowths found on some dendritic branches

Question 13

cell body

Answer 13

(soma)
neuron
contains nucleus, ribosomes, mitochondria, and other structures found in most cells

Question 14

axon

Answer 14

nueron
long, thin fiber which is the information-sending part of the neuron, sending an electrical impulse toward other neurons/glands/muscles

Question 15

presynaptic terminal

Answer 15

(end buld)
nueron
swelling at the tip of the axon, the part of the nueron that releases chemicals that cross the junction between one nueron and the next

Question 16

myelin sheath

Answer 16

neuron
insulating covering found on some vertebrae axons

Question 17

nodes of ranvier

Answer 17

nueron
interruptions along the myelin sheath

Question 18

afferent

Answer 18

bringing information into a structure

Question 19

efferent

Answer 19

carrying information away from a structure

Question 20

interneurons/intrisic neurons

Answer 20

dendrites and axons are completely contained within a structure

Question 21

types of glia

Answer 21

astrocytes, microglia, ogliodendrocytes, shwann cells, radial glia

Question 22

astrocytes

Answer 22

regulation of synapse function
regulation of blood flow
brings blood into brain for nutrients

Question 23

microglia

Answer 23

remove waste material
remove virus, fungi, etc.
remove dead, dying, damaged nuerons

Question 24

ogliodendrocytes

Answer 24

builds myelin sheath around neurons in brain and spinal cord (central nervous system)

Question 25

schwann cells

Answer 25

builds myelin sheath around neurons in periphery of body (peripheral nervous system)

Question 26

radial glia

Answer 26

guides migration of nuerons and growth of axons and dendrites during embryonic development

Question 27

blood brain barrier (BBB)

Answer 27

surrounds brain and blocks most chemicals from entering

Question 28

why do we need BBB

Answer 28

brain nuerons dont regenerate so they must be protected

Question 29

endothelial cells

Answer 29

form walls of the capillaries, blocks most molecules from passing

Question 30

molecules that cross BBB passively

Answer 30

small uncharged molecules
fat-soluble molecules (oxygen, co2)

Question 31

active transport system

Answer 31

protein mediated process that uses energy to pump necessary chemicals through the BBB
(glucose, amino acids, vitamins, hormones)

Question 32

nerve impulse

Answer 32

electrical message that is transmitted down the axon of a neuron

Question 33

resting potential

Answer 33

state of neuron prior to the sending of a nerve impulse
( -70 millivolts)

Question 34

ion channels

Answer 34

ion selectivity along concentration gradient

Question 35

ion pumps

Answer 35

against concentration gradient, requires energy

Question 36

concentraiton gradient

Answer 36

difference in distribution of ions between the inside and outside of the membrane

Question 37

electrical gradient

Answer 37

difference in electrical charge between the inside and outside of the cell

Question 38

depolarization

Answer 38

reduced polarization towards 0, more positive

Question 39

hyperpolarization

Answer 39

increased polarization, more negative

Question 40

threshold of excitation

Answer 40

the level that a depolarization must reach for action potential to occur
(all or nothing)

Question 41

action potential

Answer 41

messages sent by axons
rapid depolarization and slight reversal of the usual membrane polarization

Question 42

voltage gated channels

Answer 42

regulating channels of sodium and potassium

Question 43

propagation of the action potential

Answer 43

transmission of the action potential down the axon

Question 44

refractory period

Answer 44

prevent action potentials from moving in the opposite direction towards axon hillock

Question 45

absolute refractory period

Answer 45

sodium gates are incapable of opening
(regardless of amount of stimulation)

Question 46

relative refractory period

Answer 46

sodium gates are capable of opening but potassium channels remain open
(stronger than normal stimulus will initiate action potential)

Question 47

saltatory conduction

Answer 47

jumping of action potential from node to node

Question 48

graded potentials

Answer 48

membrane potentials that vary in magnitude in proportion to the intensity of the stimulus
(get smaller as they travel)