Task 2

Question 1

neurons

Answer 1

cells that are specialized for the reception, conduction and transmission of electrochemical signals

Question 2

unipolar neuron

Answer 2

a neuron with one process extending from its cell body

Question 3

multipolar neuron

Answer 3

a neuron with more than two processes extending form its cell body

Question 4

bipolar neuron

Answer 4

a neuron with two processes extending from its cell body

Question 5

interneurons (schakelneuronen)

Answer 5

neurons with a short or no axon. Function is to integrate the neural activity within a single brain structure.

Question 6

nuclei

Answer 6

Clusters of cell bodies in the central nervous system

Question 7

ganglia

Answer 7

Clusters of cell bodies in the peripheral nervous syste,

Question 8

nucleus has two different meanings

Answer 8

1. it is a structure in the neuron cell body

2. it is a cluster of cell bodies in the CNS

Question 9

tracts

Answer 9

bundles of axons in the CNS

Question 10

nerves

Answer 10

bundles of axons in the peripheral nervous system

Question 11

Kinds of glial cells

Answer 11

1. Oligodendrocytes
2. Schwann Cells
3. Microglia
4. Astrocytes

Question 12

Schwann cells function

Answer 12

• increase speed and efficiency of axonal conduction.

- guide axonal regeneration (regrowth) after damage

Question 13

4 neuroanatomical techniques

Answer 13

1. Golgi Stain - using nitrate and dichromate to view the silhouettes of a few neurons.
2. Nissl Stain - using cresol violet to estimate the number of cellbodies in an area
3. Electron Microscopy - provides information about the details of neuronal structures
4. neuroanatomical tracing techniques- to trace the paths of axons by injecting chemicals in a specific brain area.

Question 14

membrane potential

Answer 14

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

Question 15

resting potential

Answer 15

steadily membrane potential (inside the cell) of -70 mV

Question 16

sodium-potassium pumps

Answer 16

natrium-kalium pumps: Transport / exchange 3 Na ions inside the neuron for 2 Ka ions outside the neuron

Question 17

neurotransmitter may depolarize the receptive membrane

Answer 17

from -70 to -67mV

Question 18

neurotransmitters may hyperpolarize the receptive membrane

Answer 18

from -70 to -72 mV

Question 19

Excitatory Postsynaptic Potentials –> EPSPs

Answer 19

are postsynaptic depolarizations, who increase the likelihood that the neuron will fire

Question 20

Both EPSPs and IPSPs are graded responses

Answer 20

amplitude of the potentials are proportional to the intensity of the signals that elicit them (weak signals–> small postsynaptic potentials)

Question 21

Two characteristics of the transmission of the Postsynaptic potentials

Answer 21

• rapid

- the transmission is decremental ( the potential decreases in amplitude as they travel trough a neuron)

Question 22

action potentials are generated:

Answer 22

in the adjacent (aangrenzend) section of the axon

Question 23

threshold of excitation

Answer 23

the action potential is elicited when the depolarization of the neuron reaches -65mV

Question 24

All-or-none responses

Answer 24

action potentials occur to their full extend or don’t occur at all. ( EPSPs and IPSPs on the other hand, have different levels of responding)

Question 25

Neurons integrate postsynaptic potentials in 2 ways:

Answer 25

1. spatial summation: 2 EPSPs tegelijkertijd versterken elkaar, 1 EPSPs en 1 EPSPs tegelijkertijd cancel each other out. 2. temporal summation: postsynaptic potentials produced in rapid succession at the same synaps increase/decrease the signal

Question 26

voltage-activated channels

Answer 26

ion channels that open or close in response to changes in the level of the membrane potential

Question 27

absolute refractory period

Answer 27

a brief period after the initiation of an action potential during which it is impossible to elicit another one

Question 28

relative refractory period

Answer 28

the period during which it is possible to fire the neuron again, but only applying higher-than-normal levels of the stimulation. ( Not possible to create a second separate stimulation in this period)

Question 29

conduction of an AP along an axon differs from the conduction of EPSPs/IPSPs in 2 ways:

Answer 29

1. conduction of Aps along an axon is non decremental, and IPSPs and EPSPs are decremental. 2. APs are conducted more slowly than postsynaptic potentials

Question 30

orthodromic conduction

Answer 30

axonal conduction in the natural direction: from the cell body to the terminal buttons

Question 31

antidromic conduction

Answer 31

Action potential that travels from the terminal end of an axon along the axon to the cell body

Question 32

nodes of Ranvier

Answer 32

the gaps between adjacent myelin segments

Question 33

quality of myelination

Answer 33

it increases the speed of axonal conduction

Question 34

saltatory conduction

Answer 34

the transmission of APs in myelinated axons

Question 35

Conduction in interneurons is typically

Answer 35

passive and decremental (different than cells with long axons)

Question 36

neuron doctrine

Answer 36

the hypothesis that the brain is composed of separate cells that are distinct structurally, metabolically and functionally

Question 37

mitochondrion

Answer 37

a cellular organelle that provides metabolic energy for the cell's processes

Question 38

cell nucleus

Answer 38

(Cell kern) the spherical central structure of a cell that contains the chromosomes

Question 39

ribosomes

Answer 39

structures in the cell body where genetic information is translated to produce proteins

Question 40

dendrite

Answer 40

receptive surfaces of the neuron

Question 41

axon

Answer 41

carries action potentials from the cell body to other neurons

Question 42

cell body

Answer 42

soma

Question 43

axon collateral

Answer 43

a branch of an axon from a single neuron

Question 44

axon terminal

Answer 44

synaptic bouton, end of an axon which forms a synapse on a neuron

Question 45

motor neuron

Answer 45

A nerve cell that transmits motor messages, stimulating a muscle or gland

Question 46

sensory neuron

Answer 46

A neuron that is directly affected by changes in the environment (light, odor, touch)

Question 47

interneuron

Answer 47

A neuron that is neither a sensory or motor neuron. It receives input from and sends output to other neurons

Question 48

arborization

Answer 48

the elaborate branching of the dendrites in some neurons