Ch3-P61-65

Question 1

Neurons information

Answer 1

Cell specialised to receive, process, and/or transmit information to other cells in body.

200 different types of neurons that vary in shape, size, chemical composition and function but all have same basic structure.

At least 100 billion neurons in typical adult brain.

Question 2

Neuron picture

Question 3

Neuron in words

Answer 3

Dendrite takes signal, through nucleus, along axon which is covered in myelin sheath which is made of cells call Schwann cells and each sheath is separated by Node of Ranvier, then this goes to Axon Terminal to go to next cell

Question 4

Neuron cell body is called what and what does it contain?

Answer 4

Soma and it contains nucleus and cytoplasm

Question 5

Length of axon

Answer 5

In brain less than a millimetre but in the spinal cord it can be several feet long

Question 6

Neuroscience defined

Answer 6

the scientific study of the brain and of the links between brain activity and behaviour

Question 7

Dendrites are?

Answer 7

The branched fibres of neurons that receive incoming signals

Question 8

Soma is?

Answer 8

The cell body of a neuron, containing the nucleus and cytoplasm

Question 9

Axon is?

Answer 9

The extended fibre of a neuron through which nerve impulses travel from the soma to the terminal buttons

Question 10

Terminal buttons are?

Answer 10

The bulb like structures at the branched endings of axons that contain vesicles filled with neurotransmitters

Question 11

Sensory neurons are?

Answer 11

The neurons that carry messages from the sense receptors towards the central nervous system

Question 12

Motor Neurons are?

Answer 12

The neurons that carry messages away from the central nervous system towards the muscles and glands

Question 13

Interneurons are?

Answer 13

Brain neurons that relay messages from sensory neurons to other interneurons or to motor neurons

Question 14

Glia is? (textbook answer)

Answer 14

The cells that hold neurons together and facilitate neural transmission, remove damaged and dead neurons and prevent poisonous substances in the blood from reaching the brain

Question 15

Glia cells wikipedia

Answer 15

Glial cells, sometimes called neuroglia or simply glia are non-neuronal cells that maintain homeostasis, form myelin, and provide support and protection for neurons in the brain, and for neurons in other parts of the nervous system such as in the autonomic nervous system.
Glia are commonly known as the glue of the nervous system; however, this is not fully accurate. Neuroscience currently identifies four main functions of glial cells: to surround neurons and hold them in place, to supply nutrients and oxygen to neurons, to insulate one neuron from another, and to destroy pathogens and remove dead neurons. They modulate neurotransmission, although the mechanisms are not yet well understood.

Question 16

Glia cells what they do? textbook

Answer 16

Glia is Greek for glue. Provide scaffolding and structure to hold neurons in place. During development glial cells guide newborn neurons to appropriate locations in the brain. Glial cells housekeep and clean up dead and damaged neurons. Also take up excess neurotransmitters and other substances at the gaps between neurons. Glial cells also form myelin sheath around some types of axons.

Question 17

Myelin sheath is?

Answer 17

insulating material that surrounds axons and increases the speed of neural transmission

Question 18

Excitatory inputs are?

Answer 18

information entering a neuron that signals it to fire

Question 19

Inhibitory inputs are?

Answer 19

Information entering a neuron that signals it not to fire

Question 20

Action potential is?

Answer 20

the nerve impulse activated in a neuron that travels down the axon and causes neurotransmitters to be released into a synapse

The right balance of excitatory and inhibitory inputs will lead to the production of an action potential: the neuron fires

Question 21

Resting potential is? (textbook)

Answer 21

The polarisation of cellular fluid within a neuron, which provides the capability to produce an action potential

Question 22

Action Potential (wikipedia) is?

Answer 22

a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and endocrine cells, as well as in some plant cells.

Question 23

Action Potential diagram

Question 24

action potential steps in words

Answer 24

1. Resting state. Fluid inside axon is polarised with respect to exterior fluid providing restng potential
2. Stimulus received. Na+ channels open. Na+ ions flow into axon causing depolarisation. Nerve impulse moves down the axon as each successive segment becomes depolarised
3. Once nerve impulse has passed Na+ flows back out of axon to restore resting potential
4. Ready to transmit another impulse

Question 25

All or none rule

Answer 25

The rule that the size of the action potential is unaffected by increases in the intensity of stimulation beyond the threshold level.

Question 26

Refractory period is?

Answer 26

the period of rest during which a new nerve impulse cannot be activated in a segment of an axon

Question 27

Refractory period diagram

Question 28

Synapse is?

Answer 28

The gap between one neuron and another

Question 29

Synaptic transmission is?

Answer 29

The relaying of information from one neuron to another across the synaptic gap.

Question 30

Neurotransmitters are?

Answer 30

The chemical messengers released from neurons that cross the synapse from one neuron to another, stimulating the postsynaptic neuron.