Electricity

Question 1

what is the function of neurons?

Answer 1

to receve, modify and transmit signals quickly

Question 2

how does the nervous system transport signals?

Answer 2

as rapidly changing voltages

Question 3

what is charge

Answer 3

fundamental buidling block of electricity

all matter contains charged particles

Question 4

what are the two components of charge?

Answer 4

protons and electrons

Question 5

what are the biological charge carriers?

Answer 5

ions

Question 6

what is an anion and cation

Answer 6

anion = negative charge (more electrons)
cation = more positive (more protons)

Question 7

what are the four main cations and the main anion

Answer 7

na, k, mg, ca

cl

Question 8

what is current

Answer 8

net flow of charge

Question 9

what is current in a nerve

Answer 9

the flow of ions

Question 10

what are three factors which make ions flow

Answer 10

voltage and a conducting path
metabolic pump
chemical gradient/permeable membrane

Question 11

what is the potential difference

Answer 11

the difference in field strength between 2 charged points in space

Question 12

how do we generate a voltage

Answer 12

charge seperation generates the electric field and voltage is measure of field strnegth between these two points

Question 13

what is the equation for electrical field force?

Answer 13

F=Qxe

Question 14

what are the conditions for many ions flowing and not many ions flowing?

Answer 14

many = low resistance / high conductance
low = high resistance/ low conductance

Question 15

what is the equation for resistance and conductance

Answer 15

R=1/g

Question 16

what is the ohms law equation

Answer 16

V=IR or V=Ig

Question 17

describe current if we have a large resistance

Answer 17

smaller current flow

Question 18

what are two key points about the conservation of charge and current

Answer 18

you cannot creat nor destroy net charge

the sum of currents ar a point in a circuit is zero

Question 19

what are three things which capacitors do

Answer 19

store charge
slow down changes in voltage
introduce time into the electrical circuits

Question 20

what is a conductor i neuron

Answer 20

cytoplasm and blood separated by lipid membrane (insulator)

Question 21

what is the process of applying voltage to a capcacitor

Answer 21

charge flows into capacitor causing voltage to develop across it
charge flows until the voltage on capacitor= applied voltage
capacitor is now full so flow stops
amount of charge stored for a given V depends on the capacitance of capacitor

Question 22

what is the equation for voltage, charge, and capacitance

Answer 22

Q=VC or C=e x A/d

Question 23

what are two descriptors of passive conduction

Answer 23

response amplitude is proportional to different stimulus strengths
attenuates with distance

Question 24

what are four descriptors of active conductio

Answer 24

response amplitude is constant with stimulus strength
response frequency is proportional to different stimulus strengths
no attentuation
finite conduction velocity

Question 25

whats two advantages of active conduction

Answer 25

noise resistant

quite fast

Question 26

whats two disadvantages of active conduction

Answer 26

indirect coding

limited dynamic range

Question 27

what are two disadvantages of passive conduction

Answer 27

attenuation

noise

Question 28

what are two advantages of passive conduction

Answer 28

direct coding

signals can be summated

Question 29

what are the two types of summation?

Answer 29

spatial (inputs from seperate branches)

temporal(consequetive)

Question 30

what are two modes of summation

Answer 30

excitatory (depolarise)

inhibitory(hyperpolarise)