biopsychology

Question 1

how any nerve cells are there

Answer 1

100 billion

80% located in the brain.

Question 2

how are singles transmitted

Answer 2

electrically and chemically

neurons provide the nervous system with its primary means of communication.

Question 3

3 types of neruons

Answer 3

sensory
relay
motor

Question 4

define sensory neurons

Answer 4

carry messages from the PNS to the CNS.

long dendrites and short axons.

located in the PNS in clusters called ganglias.

cell body is out.

Question 5

define relay neurones

Answer 5

connect sensory neurons to motor neurons

short dendrites and short axons.

out of all neurons, 97% are relay neurons and most are in the brain and visual system.

Question 6

define motor neurons

Answer 6

connect the CNS to effectors such as muscles and glands.

short dendrites and long axons.

Cell bodies may be in the CNS but long axons form part of the PNS.

Question 7

define cell body

Answer 7

includes a nucleus which contains the genetic material of the cell.

Question 8

define dendrites

Answer 8

branchlike structures that protrude from the cell body.

carry nerve impulses from neighbouring neurons towards the cell body.

Question 9

define the axon

Answer 9

carries the electrical impulse away from the cell body down the length of the neuron.

covered in a fatty layer of myelin sheath that protects the axon.

Gaps in the axon called nodes of Ranvier: speed up the transmission of the impulse.

Question 10

define the terminal button

Answer 10

end of the axon. They communicate with the next neuron in the chain across a gap called the synapse.

Question 11

what happens when a neuron is in a resting state.

Answer 11

inside of the cell is negatively charged compared to the outside.

Question 12

what happens when a neuron is activated

Answer 12

the inside of the cell becomes positively charged for a split second, causing an action potential to occur.

creates an electrical impulse that travels down the axon towards the end of the neuron.

Question 13

describe the first half of synaptic transmission

Answer 13

Neurons communicate with each other within groups known as neural networks.

neuron is separated by a gap called the synapse

when electrically impulse reaches the end of the neuron ( the presynaptic terminal )

triggers the release of neurotransmitter from tiny sacs called synaptic vesicles.

Question 14

how are singles within a neuron transmitted

Answer 14

electrically,

Question 15

how are singles between a neuron transmitted

Answer 15

chemically across the synapse.

Question 16

describe the second half of synaptic transmission

Answer 16

Once a neurotransmitter crosses the gap, it is taken up by a postsynaptic receptor site on the next neuron, so the impulse only ever travels in one direction.

The chemical message is converted back into an electrical message and the process of electrical transmission begins.

Question 17

what are neurotransmitter

Answer 17

chemicals that diffuse across the synapse to the next neuron in the chain.

Question 18

is adrenerlin inhibitory or excitatory

Answer 18

excitatory, increasing the positive charge of the postsynaptic neuron, making it more likely that the postsynaptic neuron will fire.

Question 19

is seretonin inhibitory or excitatory

Answer 19

inhibitory increasing the negative charge of the postsynaptic neuron, making it less likely that the postsynaptic neuron will fire.