Physio Exam Ch.2

Front 1

Dualism

Back 1

Mind/soul & body are not the same.

the body is physical, mind/soul is not

Front 2

Sensory Neuron

Back 2

Neuron that detects changes in the external or internal env. and sends info about these changes to the CNS.

Front 3

Motor Neuron

Back 3

neuron located w/in the CNS that controls the contraction of muscle or the secretion of a gland

Front 4

Interneuron

Back 4

neuron located entirely w/in the CNS

Front 5

Soma

Back 5

Cell body of a neuron, contains the nuclues

Front 6

Synapse

Back 6

the junction btwn the terminal button of an axon and the membrane or another

Front 7

Multipolar Neuron

Back 7

most common type of neuron in the CNS; has one axon and many dendrites attached to its soma.

Front 8

Bipolar Neuron

Back 8

primarily found in special sensory systems (ex vision, audition, taste)

Soma in the MIDDLE
1 (single) sensitive dendrite/ receptor attached to its soma w/ 1 axon, leading to the brain (terminal buttons)

Front 9

Unipolar Neuron

Back 9

neuron found in the
Somatosensory System (ex touch, pain)
1 axon divides from the soma; one branch RECEIVES sensory info from many dendriteS and the other SENDS info to the CNS.

Front 10

Neurotransmitter

Back 10

a chemical "produced from w/in" a cell that is released by the terminal buttons-->sends signals to another cell; packaged in Synaptic Vessicles

Release follows Action Potential

Excitatory or inhibitory effect on another neuron

Front 11

Membrane

Back 11

structure consisting principally of lipid molecules that defines the outer boundaries of a cell and also constitutes many of the cell organelles

Front 12

Nucleus

Back 12

structure in the central region of a cell, containing the nucleolus and chromosomes.

Front 13

Nucleolus

Back 13

structure w/in the nucleus of a cell

produces ribosomes

Front 14

Ribosomes

Back 14

cytoplasmic structure made by Nucleolus

site where mRNA attaches and causes the production of protein

Front 15

Chromosome

Back 15

strand of DNA, w/ associated protein, found in the nucleus

carries genetic info

Front 16

Gene

Back 16

the functional unit of the chromosome

directs synthesis of one or more proteins

Front 17

mRNA

Back 17

a macromolecule that delivers genetic info concerning the synthesis of a protein from a portion of a chromosome to a ribosome

Front 18

Enzyme

Back 18

protein that catalyze chemical reaction
molecule that controls a chemical reaction, COMBINING 2 substances OR BREAKING a substance into 2 parts

Front 19

Genome

Back 19

the sequence of nucleotide bases on the chromosomes that provide the info needed to synthesize all the proteins that can be produced by a particular organism

Front 20

Cytoplasm

Back 20

viscous, semiliquid substance contained in the interior of a cell

Front 21

Mitochondrion

Back 21

"power house"
organelle that is responsible for extracting energy from nutrients

Front 22

Adenosine Triphosphate (ATP)

Back 22

molecule of prime importance to cellular energy metabolism; its breakdown liberates energy

Front 23

Endoplasmic Reticulum

Back 23

2 parts

Rough ER: contains ribosomes and is involved w/ production of PROTEIN that are secreted by the cell.

Smooth ER: is the site of synthesis of LIPIDS and provides channels for the segregation of molecules involved in various cellular processes.

Front 24

Golgi Apparatus

Back 24

"packaging plant"
complex of parallel membranes, wraps the products of a secretory cell

Front 25

Exocytosis

Back 25

secretion of a substance by a cell through means of vesicles the process by which neurotransmitters are secreted.

Front 26

Lysosome

Back 26

an organelle surrounded by membrane; contains enzymes that BREAK DOWN waste products

Front 27

Cytoskeleton

Back 27

formed of microtubules and other protein fibers; linked together forming a cohesive mass that gives the cell its shape

Front 28

Microtubule

Back 28

a long strand of bundles of protein filiments arranges around a hollow core; part of the cytoskeleton and involved in transporting substances from place to place within the cell

Front 29

Axoplasmic transport

Back 29

an active process by which substances are propelled along microtubules that run the length of the axon

Front 30

Anterograde

Back 30

start (anterior) moving down an axon, from the cell body ---> terminal buttons

FAST!!

Front 31

Retrograde

Back 31

"backwards" movement along axon from the terminal buttons ----> back up to the cell body

Front 32

Glia

Back 32

supporting cells of the CNS

3 important types: Astrocyte, Oligodendrocytes, Microglia

Front 33

Astrocyte

Back 33

a glial cell that provides support for neurons of the CNS

provides nutrients and other substances, and regulates the chemical composition of the extracellular fluid.

Front 34

Phagocytosis

Back 34

process when a cell engulfs and digests another dying cell/debris

done by astrocytes and microglia

Front 35

Oligodendrocyte

Back 35

a type of glial cell in the CNS

forms myelin sheath for many adjacent axons

Front 36

Myelin Sheath

Back 36

80% lipid, 20% protein

coating (series of segments) that surrounds and insulates axons, preventing messages from spreading between adjacent axons.

produced by Oligodendrocyte

Front 37

Node of Ranvier

Back 37

the "naked" portion of an axon between the segments of myelin sheath

Front 38

Microglia

Back 38

smallest of the glial cells

act as phagocytes and protect the brain from invading microorganisms

Front 39

Shwann Cell

Back 39

cell in the PNS, produce myelin

provides one segment of myelin along an axon

Front 40

Blood Brain Barrier (BBB)

Back 40

"selectively permeable" barrier btwn the blood and the brain;

occurs because the cells in the walls of the brain's capillaries fit tightly together

prevents chemicals from reaching the brain that might disturb the deleicate environment needed to work efficiently

Front 41

Area Postrema

Back 41

region of the medulla where the BBB is weak

here poison can be detected and induce vomiting

Front 42

Electrode

Back 42

conductive medium that can be used to apply electrical stimulation or to record electrical potentials

Front 43

Microelectrode

Back 43

very fine electrode, generally used to record activity of individual neurons

Front 44

Withdrawal Reflex

Back 44

Dendrites of (unipolar) sensory neuron detect painful stimulus &
sends message down axon to terminal buttons (located at the spinal cord)

Buttons release a neurotransmitter excites the interneuron

The message is sent to the terminal buttons of the Interneuron, which release a neurotransmitter & excites the Motor neuron

The axon of the motor neuron joins a nerve and travels to a muscle

Terminal B. of the motor neuron release NeuroTM, the muscle cells contract (hand moves)

Front 45

Membrane Potential

Back 45

electrical charge across a cell membrane; the difference in electrical potential inside and outside the cell

Front 46

Oscilloscope

Back 46

lab instrument capable of displaying a graph of voltage as a function of time on the face of a cathode ray tube

Front 47

Resting Potential

Back 47

membrane potential of a neuron when it is not being altered by excitatory or inhibitory postsynaptic potentials

approx -70mV

Front 48

Depolarization

Back 48

reduction (towards 0) of the membrane potential of a cell from its normal resting potential (-70)

Front 49

Hyperpolarization

Back 49

an increase in the membrane potential of a cell, relative to the normal resting potential

Front 50

Action Potential

Back 50

the brief electrical impulse that provides the basis for conduction of info along an axon

Front 51

Threshold of excitation

Back 51

the value of the membrane potential that must be reached to produce an action potential

Front 52

Diffusion

Back 52

movement of molecules from regions of high concentration to low concentration

Front 53

Electolyte

Back 53

aqueous solution of a material that ionizes a soluble acid, base, or salt.

Front 54

Ion

Back 54

a charged (+/-) molecule

Cations +
Anions -

Front 55

Cations

Back 55

+ charged ion

Front 56

Anions

Back 56

- charged ion

Front 57

Electrostatic Pressure

Back 57

attractive force btwn atomic particles charged with opposite signs
OR
repulsive force btwn atomic particles w/ the same sign

Front 58

Intracellular Fluid

Back 58

fluid contained w/in the cell

Front 59

Extracellular

Back 59

body fluids located outside of cells

Front 60

Potassium

Back 60

K+

concentration INside the axon

forces of...
-Diffusion: push it outside the cell

(low) outside <--- (K+ ^ inside)

-Electrostatic Pressure: push it inside the cell (b/c outside is + and same charges repell)

(+ outside) <---> (K+ inside)

Front 61

Chloride

Back 61

Cl-

concentration OUTside the axon

forces of...
-Diffusion: push it inside the cell

(Cl- high outside) --> (low in)

-Electrostatic Pressure: push it outside the cell (b/c inside is - and same charges repell)

(Cl- outside) <---> (- inside)

Front 62

Sodium

Back 62

Na+

concentration OUTside the axon

forces of...
-Diffusion: push it inside the cell

(Na+ high outside)--->(low in)

-Electrostatic Pressure: is NOT prevented from entering

(Na+ outside) ---> (- inside)

Front 63

Sodium Potassium Pump

Back 63

force that pushes 3 Na+ ions out of the axon for every 2 K+ they push inside.

Not permeable to Na+, very effectively keeps intracellular concentration of Na+ low

Pump consists of a large # of protein molecules embeded in the membrane, driven by energy provided by ATP (made by mitochondria)

Front 64

Ion Channel

Back 64

Specialized protein molecule that permits specific ions to enter or leave cells

Front 65

Voltage-Dependent Ion Channel

Back 65

An ion channel that opensor closes according to the value of the membrane potential

Front 66

All or None Law

Back 66

principle that once an action potential is triggered in an axon it remains constant in size traveling down the axon

Front 67

Ion Movement during Action Potential

Back 67

1. Threshold of excitation is reached (above -70); Na+ channels open & Na+ enters the cell
2. K+ channels open & K+ begins to leave the cell
3. Na+ channels become refractory/blocked, no more can enter the cell until the membrane potential reaches (-70)
4. K+ continues to leave, membrane potential returns to resting level
5. K+ start to close, when -70 is reached Na+ channels reset
6. Membrane Potential overshoots resting value, K+ channels totally close, gradually returns to -70

Front 68

Rate Law

Back 68

Priciple that variations in the intensity of a stimulus or other info being transmitted in an axon are represented by variations in the rate at which that axon fires

Front 69

Cable Properties

Back 69

passive conduction of electrical current, in a decremental fashion, down the length of an axon.
When subthreshold depolarization is applied to the axon the disturbance in the membrane potential is largest near the stimulating electrode and gets progressively smaller at distances farther along the axon

Front 70

Saltatory Conduction

Back 70

Conduction of action potentials by myelinated axons. The action potential appears to jump from one node of Ranvier to the next

Front 71

Postsynaptic Potential

Back 71

Alterations in the membrane potential of a postsynaptic neuron, produced by liberation of neurotransmitter at the synapse

Front 72

Binding site

Back 72

location on a receptor protein to which a ligand binds

Front 73

Ligand

Back 73

chemical that binds w/ the binding site of a receptor

Front 74

Dendritic Spine

Back 74

a small bud on the surface of a dendrite, w/ which a terminal button of another neuron forns a synapse.

Front 75

Presynaptic Membrane

Back 75

membrane of a terminal buton that lies adjacent to the postsynaptic membrane and through which the neurotransmitter is released

Front 76

Postsynaptic Membrane

Back 76

cell membrane opposite the terminal button in a synapse; the membrane of a cell that recieves the message

Front 77

Synaptic Cleft

Back 77

Space btwn the Pre- & Postsynaptic membranes

Front 78

Types of Synapses:
Axodendritic
Axosomatic
Axoaxonic

Back 78

-can occur on the smooth surface of a dendrite or dendritic spines

-occur on somatic membrane

-occurs btwn 2 terminal buttons

Front 79

Synaptic Vessicle

Back 79

small, hollow, beadlike structure found in terminal buttons; containsmolecules of a neurotransmitter

Front 80

Release Zone

Back 80

region of the interior of the presynaptic membrane of a synapse to which synaptic vesicles attach and release their neurotransmitter into the synaptic cleft

Front 81

Release of a Neurotransmitter

Back 81

Action Potential opens calcium channels. Calcium ions enter and bind w/ the protein embedded in the membrane of synaptic vesicles docked at the release zone. The fusion pores open, and the neurotransmitter is released into the synaptic cleft

Front 82

Postsynaptic Receptor

Back 82

receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter

Front 83

Neurotransmitter Dependent Ion Channel

Back 83

Ion channel that opens when a molecule of a neurotransmitter binds w/ a post synaptic receptor

Front 84

Ionotropic Receptor

Back 84

receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of the neurotransmitter attaches to the binding site

Front 85

Metabotropic Receptor

Back 85

receptor that contains a binding site for a neurotransmitter; activates an enzyme that begins a series of events that opens an ion channel elsewhere in the membrane of the cell when a moleculeof the neurotransmitter attaches to the binding site

Front 86

G Protein

Back 86

protein coupled to a metabotropic receptor; conveys messages to other molecules when a ligand binds w/ an activates the receptor

Front 87

Second Messenger

Back 87

chemical produced when a G protein activates an enzyme; carries a signal that results in the opening of the ion channel or causes other events to occur in the cell

Front 88

Excitatory Postsynaptic Potential (EPSP)

Back 88

an excitatory depolarization of the postsynaptic membrane of a synapsecaused by the liberation of a neurotransmitter by the terminal button

Front 89

Inhibitory Postsynaptic Potential (IPSP)

Back 89

inhibitory hyperpolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button

Front 90

Reuptake

Back 90

reentry of a neurotransmitter just liberated by a terminal button back through its membrane, thus terminating the postsynaptic potential

Front 91

Enzymatic Deactivation

Back 91

the destruction of neurotransmitter by an enzyme after its release

Front 92

Acetylcholine (ACh)

Back 92

neurotransmitter found in the brain, spinal cord, and parts of the peripheral nervous system

responsible for muscle contraction

Front 93

Acetylcholineserase (AChE)

Back 93

the enzyme that destroys acytelcholine soon after it is liberated by the terminal buttons, thus terminating the postsynaptic poternial

Front 94

Neural Integration

Back 94

Process by which inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron

Front 95

Autoreceptor

Back 95

receptor molecule located on a neuron that responds to the neurotransmitter released by that same neuron

Front 96

Presynaptic Inhibition

Back 96

action of a presynaptic terminal button in an axoaxonic synapse; reduces the amount of neurotransmitter released by the postsynaptic terminal button

Front 97

Presynaptic Facilitation

Back 97

action of the presynaptic terminal button in an axoaxonic synapse; increases the maount of neurotransmitter released by the postsynaptic terminal button

Front 98

Gap Junction

Back 98

special junction btwn cells that permits direct communication by means of electrical coupling

Front 99

Neuromodulator

Back 99

naturally secreted substance that acts like a neurotransmitter BUT it is NOT restricted to the synaptic cleft- diffuses through the extracellular fluid

dopamine, serotonin, acetylcholine, histamine

Front 100

Peptide

Back 100

chain of amino acids joined together by peptide bonds. Most neuromodulators, and some hormones, consist of peptide molecules

Front 101

Hormone

Back 101

chemical substanc that is released by an endocrine gland that effects on target cells in the other organs

Front 102

Endocrine Gand

Back 102

GLAND THAT LIBERATES ITS SECRETIONS INTO THE EXTRACELLULAR FLUID around capillaries and hence into the bloodstream

Front 103

Target Cells

Back 103

gland that is directly affected by hormone or other chemical signal

Front 104

Steroid Hormone

Back 104

chemical of low molecular weight, derived from cholesterol by the gonads and adrenal gland. Steroid hormones affect their target cells by attaching to receptors found w/ in the nucleus.

Lipid base-diffuse fairly freely from the blood through the cell membrane, into the cytoplasm of target cells (binds to DNA)