Test 1: Neurons

Question 1

Neuron: cell membrane

Answer 1

boundary between cell and external environment

Question 2

Neuron: mitochondrion - what does it do

Answer 2

gives energy to the cell by converting sugar and oxygen into energy-providing molecules

Question 3

Neuron: microtubules

Answer 3

“skeleton” of cell

avenues of transport that substances can travel on from soma to axon/dendrites or vice versa

Question 4

Neuron: rough endoplasmic reticulum

Answer 4

contains ribosomes which produce neurotransmitters

Question 5

Neuron: smooth endoplasmic reticulum

Answer 5

packages neurotransmitters into synaptic vesicles

Question 6

Neuron: nucleus

Answer 6

contains genetic info of the cell

Question 7

Neuron: axon

Answer 7

main protruding element

sends info to other neurons

Question 8

two types of axons

Answer 8

collateral axons: branch wildly

recurrent collaterals: loop back to near original cell

Question 9

Neuron: dendrites

Answer 9

protrude from the cell body; receive info from other neurons

Question 10

soma

Answer 10

cell body

Question 11

What do axons lack and how do they make up for it?

Answer 11

rough endoplasmic reticulum and ribosomes

rely on soma for proteins needed to function

Question 12

Neuron: synaptic vesicles

Answer 12

synthesize, store, and release neurotransmitters

Question 13

What two ways can a neuronal circuit be linked?

Answer 13

convergently: many come together to affect one cell
divergently: single cell affects many neurons

Question 14

Synapses

Answer 14

neuronal linking sites

Question 15

synaptic transmission

Answer 15

neurotransmitters carry messages across synaptic gap

Question 16

polarization

Answer 16

difference of electrical charge on two sides of membrane

Question 17

Ions outside of membrane

Answer 17

Na+ sodium

Cl- chloride

Question 18

Ions inside of membrane

Answer 18

A- anions (large negative protein ions)

K+ potassium

Question 19

Positive charge on outside of membrane due primarily to _____; negative charge inside due to _______

Answer 19

Na+

A-

Question 20

What does it mean to say a neuron is negatively polarized?

What causes this negative polarization?

Answer 20

its inside has a negative electrical potential as compared to the outside of the plasma membrane (at resting potential)

Caused by the difference in concentration of negatively charged proteins inside the cell

Question 21

Describe the semi-permeability of the plasma membrane

Answer 21

Although positively charged ions outside of neuron are attracted to the negative ions in the cell, they can’t get in

Membrane has channels designated for potassium (K), sodium (Na), chloride (CL), and calcium ions

These only open when they are signaled to

Question 22

Ion pumps

Answer 22

embedded in the plasma membrane

maintain the negative polarization

pump Na out and bring K in to maintain its negative potential

Question 23

3 steps of an action potential

Answer 23

1. Neuron becomes slightly positive from receiving certain chemicals at the synapse
2. This slight change in potential opens sodium and calcium gates which causes those ions to rush in
3. The inside of the axon becomes briefly positively charged, which causes the next set of channels to open, and so on and so on

Question 24

Polarizations of an action potential

Answer 24

1. Depolarization - Na+ begins to rushes becomes more (+) on the inside
2. Reverse polarization - because of the increase in sodium with the K+, inside is (+) and outside is (-)
3. Repolarization - fixes itself back to resting potential via ion pumps; (-) inside and (+) outside

Question 25

How do neurons communicate?

Answer 25

Via synaptic neurotransmitters that flow across synapses presynaptic neurons send postsynaptic neurons receive

Question 26

How are excess neurotransmitters removed in communication process?

Answer 26

enzymatic degredation (also called reuptake)

Question 27

Describe enzymatic degredation

Answer 27

An enzyme affects a neurotransmitter leaving an inactive produce

Question 28

autoreceptors where are they and what do they do

Answer 28

on presynaptic neuron monitor and help regulate the amount of neurotransmitter there is in the synapse

Question 29

Types of synaptic messages

Answer 29

1. Excitatory postsynaptic potential (EPSP) 2. Inhibitory postsynaptic potential (IPSP)

Question 30

What causes a postsynaptic neuron to fire?

Answer 30

It reaches a neural threshold potential which is determined by the amount of neurotransmitter that is released

Question 31

What two ways can impulses build up?

Answer 31

1. Across time (one neuron firing many times) 2. Across space (many axons firing at once)

Question 32

What occurs at an excitatory synapse?

Answer 32

Na+ rushes in Depolarization in the membrane - makes it more positively charged

Question 33

What occurs at an inhibitory synapse?

Answer 33

Channels open Cl- flows into membrane - makes potential more negative Hyperpolarization (-90 mv)

Question 34

Most "common" type of neurotransmitter

Answer 34

amino acid neurotransmitters

Question 35

Major excitatory neurotransmitters (amino acids)

Answer 35

glutamate aspartate

Question 36

Major inhibitory neurotransmitters (amino acids)

Answer 36

gamma-aminobutyric acid (GABA) glycine

Question 37

Acetylcholine (ACh)

Answer 37

first neurotransmitter identified (by Otto Loewi) causes muscles to contract

Question 38

Monoamine neurotransmitters

Answer 38

Catecholamines Indoleamines

Question 39

3 Catecholamines

Answer 39

Dopamine (DA) Norepinephrine (NE) Epinephrine (E)

Question 40

Type of Indoleamine

Answer 40

Serotonin (5-HT)

Question 41

What are peptide neurotransmitters Frequency Example

Answer 41

chains of amino acids link together and form peptides lower presentation than amino acid and monoamine neurotransmitters Ex: opiod peptides

Question 42

1 opiod peptide

Answer 42

endorphins

Question 43

Endorphins What is it referred as and why? What are its effects similar to? What are its effects?

Answer 43

opiod peptide called endogenous morphine ("from within") uses same receptors as morphine similar effects to opiate derivative drugs analgesia & euphoria (pain killing and mood elevating)

Question 44

Two major receptor types for a given neurotransmitter

Answer 44

1. Ionotropic receptors 2. Metabotropic receptors

Question 45

Ionotropic receptors How does it work? Identify two outcomes

Answer 45

Neurotransmitter binds to an associated ion channel that either opens or closes, causing a postsynaptic potential (PSP) If Na+ channels are opened - EPSP occurs If Cl- channels are opened - IPSP occurs

Question 46

Metabotropic receptors Where are they located? What is it associated with and where is it found? What happens?

Answer 46

Attached to a portion of a signal protein _outside_ of the neuron A G-protein is attached to a part of the signal protein _inside_ of the neuron A subunit of the g-protein breaks off into the neuron: either binding to an ion channel or stimulating the synthesis of a 2nd messenger

Question 47

2 types of glial cells

Answer 47

glial - in central nervous system (CNS) Astrocyte Oligodendrocyte

Question 48

Astrocyte

Answer 48

glial - in CNS Cleans up excess neurotransmitter provides support and nutrients

Question 49

Oligodendrocyte

Answer 49

Glial - in CNS provides myelin (cellular insulation) which increases the speed of impulse

Question 50

Schwann cells

Answer 50

in peripheral nervous system (PNS) provides cellular insulation (myelin) that increases the speed of impulse aids in regeneration of nerve fibers