chapter 2

Question 1

The body is made up of four types of tissues:

Answer 1

connective -
Epithelial - skin
Muscle - muscle
nervous tissue - neurons

Question 2

The cell theory:

Answer 2

Theodor Schwann (1810–1882)

All cells arise from existing cells
The cell is the basic functional unit of all living things
All organism has one or more cells

Not applied to neurons!!!

Question 3

Reticular theory:

Answer 3

Camillo Golgi (1843–1946)

Invented a staining method that permitted researchers to clearly observe all the parts of neurons

The idea that the neurites (axons and dendrites) of neurons fuse with the neurites of other neurons in a neural net

Question 4

Methods to study neurons:

Answer 4

histology
microscopy
microtome

Question 5

Isotropic fractionation:

Answer 5

A method by which the number of cells in a brain area of interest can be estimated

human brain contains, on average, 86.06 billion neurons and 84.61 billion glia

Question 6

neuron types

Answer 6

sensory
motor
interneuron
bipolar and unbipolar
multipolar
pyramidal
stellate
rosehip

Question 7

how do neurons communicate

Answer 7

neurons communicate through electrical impulses called action potentials,

Question 8

neurotrasmitters

Answer 8

Action potentials result in the release of neurotransmitters onto specialized receptors situated on target cells.

Question 9

sections of the brain

Answer 9

coronal plane/frontal - front and back section

horizontal plane - top and bottom

sagittal plane/middle - left and right section

Question 10

brain directions

Answer 10

superior - top of brain
caudal left
rostral - right
inferior - bottom

Question 11

structure of neuron

Answer 11

cell body - soma -

Dendrites -

axon

terminal buttons

Question 12

dentrites

Answer 12

receive info from other neurons and synapses and decide what it is

changes in structure is important for learning and neural develop

Question 13

cell body soma

Answer 13

contains a nucleus and organelles

integrates incoming signals

It has a threshold; if the chemical energy passes it, the soma passes it on to the axon hillock

Protein synthesis is responsible for translating the genetic info stored in the nucleus into proteins

Question 14

axon hillock

Answer 14

when soma decides this signal is enough for me to pass it on, it passes it to axon hillock and axon

site for generation and initiation of action potential

does the convert the chemical impulses to electrical impulses

Question 15

axon

Answer 15

some long and some short

long projection of a neuron that conducts electriacal to

Question 16

action potential - how it is generated

Answer 16

is really the ion movement within a neuron

if the input is strong enough, the neuron becomes less negative,
it needs to reach the activation threshold

then the sodium ion opens, and due to permeablity sodium comes in and the neuron is more positive

the spike that we see on the graph we call ap

Question 17

depolarization and repolarization

Answer 17

possitive ions rushing in like sodium - neuron fires

repolarization - potassium running out - rest begins

Question 18

hyperpolarization

Answer 18

undershoot na and k pump restores - ready again

Question 19

all or nothing principal

Answer 19

the threshold that makes the neuron fire or not fire

Question 20

myelinated & unmyelinated

Answer 20

the one that has it is fast and efficient signalling,

un is slower with continuous signalling

Question 21

axon terminal

Answer 21

electrical signalling is changed back to the chemical

in preparation to be passed on to dendrites

Question 22

presynaptic neuron
post synaptic neuron

Answer 22

pre - the one releasing the neurotransmitter

post- the neuron that receives it,

info crosses the synapse between these neurons, only chemical can be transferred

Question 23

synapses

Answer 23

site of communication

Question 24

explain diffusion

Answer 24

process that molecules move from high concentration to low

when a particular have a high concentration, it diffuses to balance it out

Question 25

Electrostatic pressure

Answer 25

ions from the same charge repel each other and opposites attract

Question 26

Equilibrium potential:

Answer 26

voltage across the membrane where electrostatic pressure and diffusion counteract each other

Question 27

explain the fluids

Answer 27

fluid outside are extracellurar inside is intracellular both are composed of electrically charged molecules refered to as ions

Question 28

what are ions

Answer 28

are postive and negative cation + and anion - are atoms that contain an uneven number protons and electrons negative ions more inside a neuron than outside - resting

Question 29

why is diffusion and important

Answer 29

because they are in charge of the flow of the extra and intracellular fluids of an neuron

Question 30

sodium and potassium and chlorine

Answer 30

more sodium+ outside an ion - moving intera more potassium+ inside - which moves extracellularly to balance it out chloride- more outise than inside

Question 31

neuron at rest (nacl+, k+, cl-)

Answer 31

more sodium+ inwards more potassium+ extra more chloride- outside electrostatic pressure makes the sodium+ go inwards potassium+ go inwards chlorine- outwards

Question 32

selective permeable

Answer 32

selective f what goes in at out when the membrane is at rest example, potassium will go out due to this due to diffusion will go in due to electrostatic will go in

Question 33

neuron at rest

Answer 33

resting potential -70 the holes for potassium is open while for sodium is closed