Neurons

Question 1

What are neurons?

Answer 1

Are cells which carry action potential around the body

Question 2

What are neurons involved with?

Answer 2

Cell signalling and cell communication

Question 3

Adaptation One of Neurons

Answer 3

Many dendrites/axon terminals to connect with many other neurons

Question 4

Adaptation Two of Neurons

Answer 4

Many have a mylein sheath which protects and insulates the axon/dendron and speeds up transmission of the action potential

Question 5

Adaptation Three of Neurons

Answer 5

Are long so action potential can be transmitted over long distances quickly

Question 6

Adaptation Four of Neurons

Answer 6

Have many sodium-potassium pumps so neurons have many mitochondria for ATP

Question 7

Adaptation Five of Neurons

Answer 7

Have many sodium, calcium and potassium channels

Question 8

How do some neurons end up paralysed?

Answer 8

Many neurons are amitotic so if damaged, can’t do mitosis so end up paralysed

Question 9

What are the 3 types of neuron?

Answer 9

-Sensory
-Relay
-Motor

Question 10

Sensory Neuron

Answer 10

-Afferent Neuron
-From PNS to CNS

Question 11

Relay Neuron

Answer 11

-In CNS (brain and spinal chord)

Question 12

Motor Neuron

Answer 12

-Efferent Neuron
-From CNS to PNS

Question 13

What can an effector be?

Answer 13

-Muscle
-Gland

Question 14

Structure of Sensory Neuron

Answer 14

-Dendrites
-Long Dendron
-Schwan Cells
-Short Axon
-Axon Terminals
-Cell Body just outside of CNS
-Action Potential along from PNS to just outside CNS

Question 15

Structure of Relay Neuron

Answer 15

-Many Dendrites
-Short/No Dendron
-No Schwan Cells
-Short Axon
-Axon Terminals
-Cell Body
-Action Potential from top of CNS/Spinal Chord working way down

Question 16

Structure of Motor Neuron

Answer 16

-Dendrites connect straight to cell body
-No Dendron
-Schwan Cells
-Long Axon
-Axon Terminals leading to effector
-Cell Body in CNS
-Action Potential from CNS out into PNS

Question 17

Draw a Sensory Neuron

Answer 17

See Notes

Question 18

Draw a Relay Neuron

Answer 18

See Notes

Question 19

Draw a Motor Neuron

Answer 19

See Notes

Question 20

What does it mean if neurons are myelinated?

Answer 20

They have schwan cells that produce mylein

Question 21

How many peripheral neurons (PNS) are myelinated?

Answer 21

1/3

Question 22

What neurons are usually myleinated? And why?

Answer 22

-Neurons that are involved taking action potentials to/from CNS
-Have to transmit action potential quickly

Question 23

What does a Schwan cell look like that produce mylein?

Answer 23

See Notes

Question 24

Schwan cell look like that produce mylein properties

Answer 24

-Axon/Dendron
-Nuclues
-Schwan cell membrane which secretes mylein but don’t have any Na+ of K+ channels where Schwan Cells are

Question 25

What does a Schwan cell look like that doesn’t produce mylein?

Answer 25

See Notes

Question 26

Schwan cell look like that don’t produce mylein properties

Answer 26

-Nucleus
-Houses several axons/dendrons and provides some protection
-There’s a gap around axons/dendrons so NA+ and K+ channels are found along the whole length of axon/dendron