Lecture 13

Question 1

What is the function of the Nervous System?

Answer 1

Homeostasis
- Everything the body does
- The Nervous System is innervating every major organ in your body to regulate different things

Question 2

List the main nervous system cell types

Answer 2

• Nerves
• Neurons
• Glia

Question 3

What are the cell types within Neurons?

Answer 3

• Dendrites
• Cell body
• Axon
• Axon Terminals

Question 4

What is the function of Neurons?

Answer 4

• Make decisions
• Send out signals
• Controls the functions of the body

Question 5

What is the function of the Dendrites?

Answer 5

Input Zone
- Receives chemical signals from other neurons

Question 6

What is the function of the Cell Body?

Answer 6

Summation Zone
- Contains the nucleus
- Summation of inputs

Question 7

What is the function of the Axon?

Answer 7

Conduction Zone
- Carries electrical signals between neurons or from neuron to effector
- Conducting action potentials

Question 8

What is the function of the Axon Terminal?

Answer 8

Output Zone
- Contact with other neurons (In the CNS) or effectors (organs)
- Release neurotransmitter to conduct the signal onwards

Question 9

What are the cells within the Glia cells?

Answer 9

• Astrocytes
• Ependymal cells
• Oligodendrocytes
• Schwann cells
• Microglia

Question 10

What is the function of Astrocytes?

Answer 10

• Supply nutrients
• Ensheath capillaries within the brain

Question 11

What is the function of Ependymal cells?

Answer 11

• Line fluid-filled spaces in brain and spinal cord
• Have cilia on the ends that help move CSF around the brain

Question 12

What is the function of Microglia

Answer 12

• Immune cells of the CNS
• Important in many different stages of development for the protection of the brain

Question 13

Which cell forms Myelin in the CNS?

Answer 13

Oligodendrocytes

Question 14

Which cell forms Myelin in the PNS?

Answer 14

Schwann cells

Question 15

List the major components of the CNS

Answer 15

• Brain
• Brain stem
• Spinal cord

Question 16

List the major components of the PNS

Answer 16

• Peripheral nerves & ganglia
• Afferent Division
• Efferent Division

Question 17

What makes up the Afferent Division?

Answer 17

• Somatic sensory
• Visceral sensory
• Special sensory

Question 18

What makes up the Efferent Division?

Answer 18

Somatic
Autonomic nervous system (ANS)

Question 19

What is the ANS?

Answer 19

Controls organs of the body to maintain homeostasis

Question 20

What are the 3 divisions of the ANS?

Answer 20

1) Sympathetic
2) Parasympathetic
3) Enteric

Question 21

What are the 2 receptors associated with the Parasympathetic division?

Answer 21

1) Nicotinic Receptors (ion channel)
2) Muscarinic Receptors (g-protein coupled)

Question 22

What is a “homunculus” in neuroscience?

Answer 22

A spatial map representing the body layout in the motor and somatosensory cortices

Question 23

What determines the size of the region in the cortex dedicated to a body part?

Answer 23

The density of sensory receptors (somatosensory cortex) or the degree of fine motor control required (motor cortex)

Question 24

How is information encoded in neurons?

Answer 24

Through changes in membrane potential (graded potentials and action potentials)

Question 25

What is the function of myelin in action potential conduction?

Answer 25

Increases conduction speed via saltatory conduction

Question 26

What is the refractory period?

Answer 26

The time after an action potential during which a neuron is less excitable and cannot fire another AP immediately

Question 27

What is the main difference between electrical and chemical synapses?

Answer 27

- Electrical synapses use direct ion flow through gap junctions - Chemical synapses use neurotransmitters across a synaptic cleft

Question 28

What types of summation occur in neurons?

Answer 28

- Spatial summation (inputs from multiple neurons) - Temporal summation (rapid successive inputs from one neuron)

Question 29

What are the major functions of the CNS?

Answer 29

Integration and processing of sensory information and motor commands

Question 30

How is the body “mapped” in the brain?

Answer 30

Through somatotopic maps in the primary motor and somatosensory cortex ("homunculus")

Question 31

What is convergence in neural networks?

Answer 31

Multiple inputs to a single neuron

Question 32

What is divergence in neural networks?

Answer 32

One neuron sending output to many targets

Question 33

What neurotransmitters are used by the autonomic nervous system?

Answer 33

Acetylcholine (ACh) and noradrenaline (NA)

Question 34

What are the three major fiber tracts in the CNS?

Answer 34

1) Commissural tracts (connect two hemispheres) 2) Association tracts (connect regions on the same side) 3) Projection tracts (connect cerebrum with other CNS areas)

Question 35

What does the afferent division of the PNS do?

Answer 35

Carries sensory information from receptors to the CNS

Question 36

What does the efferent division of the PNS do?

Answer 36

Carries motor commands from the CNS to muscles and glands