Week 2

Question 1

What are the CNS, PNS, and Nerves

Answer 1

Central Nervous System- contains the brain and spinal cord
Peripheral Nervous System- contains the nerves and most sensory organs
Nerves- Bundles of individual neurons contained within a protective membrane

Question 2

what are the three types of neurons

Answer 2

sensory neurons; a neuron that detect changes in the external or internal environment and sends information about these changes to the CNS.
Motor neurons; a neuron that controls the contraction of a muscle or the secretion of a gland.
Interneurons; a neuron located entirely within the CNS and have a communicative role

Question 3

List the 4 key parts of a Neuron

Answer 3

1, Soma
2, Dendrites
3, Axon
4, Terminal Buttons

Question 4

Explain the Soma

Answer 4

The Soma is the brain of the cell. It contains membrane cytoplasm nucleus and mitochondria

Question 5

explain membrane cytoplasm nucleus and mitochondria

Answer 5

membrane is a double layer of lipid molecules within protein molecules in bedded that is substance detectors, security guards and transport is.
Cytoplasm fills the space surrounded by the membrane and contains organelles
nucleus contains the chromosomes – jeans – protein production – important for structure and function
Mitochondria is the energy extraction and ATP

Question 6

explain dendrites and the synapse

Answer 6

Dendrites help individual neurons talk with one another

Synapse is neural messages that are transmitted from neuron to neuron across the small gap

Question 7

Explain the Axon and the myelin sheath

Answer 7

an axon is a long tube that carries information from the Soma of a neuron to its terminal buttons called the action potential. The myelin sheath is a fatty substance that works as an insulator of the action potential

Question 8

Describe axoplasmic transport, anterograde transport, retrograde transport, and microtubules

Answer 8

Axoplasmic transport: Active processes by which substances are propelled along the inside of the length of an axon.

anterograde transport: movement from cell body to terminal buttons

Retrograde transport: movement from the terminal buttons to the cell body

Microtubules: bundles of protein filaments arranged in a hollow core the act as a train tracks to propel substances along the axon. Also provide structural support to a neuron

Question 9

What are terminal buttons

Answer 9

Located at the end of an axon

They secrete a chemical into the synapse = neurotransmitter

Question 10

List the 4 types of Glial Cells + brief explanation

Answer 10

Astrocytes (CNS): provide nutrients to neurons
Oligodendrocytes (CNS): provide support to axons and produce the myelin sheath
Microglia (CNS): a very small glial cells involved in phagocytosis
Schwann Cells (PNS): similar to oligedendrocytes, produce a myelin sheath covering pns

Question 11

Explain the Blood Brain Barrier

Answer 11

The blood brain barrier is a barrier that exists between the blood and the fluid that surrounds the cells of the brain that is selectively permeable. BBB is thinner in some areas (area postrema - vomiting)

Question 12

what are inhibitory synapses and inhibitory into neurons responsible for

Answer 12

they are the reason why you do not drop a coffee cup when it is too hot for your hand. You are able to stop the motor neuron action and reflex of dropping the cup

Question 13

What is an action potential

Answer 13

The communication of information within a neuron

Question 14

what is an membrane potential

Answer 14

The electrical charge across the cell membrane is called the membrane potential. It is the difference in electrical potential inside versus outside of the neuron

Question 15

What is a resting potential

Answer 15

axons at rest have a negative electrical charge called the resting potential (inside of the axon is more negatively charged compare to the outside)

Question 16

Explain hyper polarisation and depolarisation

Answer 16

hyper polarisation is when the electrical charge of an axon goes from resting potential – more negative

depolarisation is when the electrical charge of an axon goes from resting potential – more positive

Question 17

when is In action potential more likely to be sent

Answer 17

when the neuron is D polarised it is more likely to send an action potential. Hyper polarisation is less likely to send an action potential

Question 18

how is membrane potential established

Answer 18

The electrical charge within the neuron is the result of to opposing forces, diffusion and electrostatic pressure

Question 19

Explain diffusion and Electro static pressure

Answer 19

diffusion is the movement of molecules from regions of high concentration to regions of low concentration.

Electrostatic pressure is the attractive force between atomic particles charged with opposite signs, or repulsive force between atomic particles charge with the same sign

Question 20

what are ions, cations, anions

Answer 20

ions are charged particles

cations are positive

anions are negative

Question 21

what are the ions related to membrane potential

Answer 21

organic ions which are negatively charged and remain inside the cell

chloride ions which are negatively charged and are mostly outside the cell

potassium ions which are positively charged inside the cell

sodium ions which are positively charged outside the cell

Question 22

what is the sodium potassium pump

Answer 22

The sodium potassium pump contributes to the negative membrane potential by constantly pushing sodium ions outside of the cell and pushing potassium ions in.
Specifically three sodium ions are pumped out and 2 potassium ions are pumped in.

Question 23

what are ion channels

Answer 23

Ion channels are protein molecules in the neuron membrane to open and close to allow ions to rush in and out of a neuron

Question 24

what is action potential propagation

Answer 24

the all or none law and the rate law (rate law means the principle that variations in the intensity of a stimulus or other info being transmitted in an axon are represented by variations in the rate at which an axon fires; how often an action potential is triggered)

Question 25

What are the two types of postsynaptic receptors

Answer 25

Ionotropic receptors - directly open with NT binding

Metabotropic receptors - indirectly opens ion channels

Question 26

what are the two mechanisms which end postsynaptic potentials

Answer 26

Reuptake: neurotransmitter removed from the Psynapse via special transport of molecules that work like a vacuum sucking the neurotransmitter back up directly into the cytoplasm of the presynaptic cell.

Enzymatic deactivation: destruction of a neurotransmitter by an enzyme after it has been released

Question 27

What are auto receptors

Answer 27

auto receptors are receptor molecules located on a neuron that respond to the neurotransmitter released by the neuron. They play a regulatory role in the release of neurotransmitters

Question 28

what are axoaxonic synapses 

Answer 28

Synapses found in the axon that influence the overall amount of neurotransmitter being released into the axodendritic synapse

Question 29

What are neuromodulators

Answer 29

They are a naturally secreted substance that acts like a neurotransmitter, except that it is not restricted to the synaptic cleft. They modulate activity of neurons in particular brain areas and are involved with vigilance

Question 30

What are hormones

Answer 30

they are a chemical substance released by Endo Crine glands. Cells with hormone receptors are called target cells.