Lecture 9

Question 1

Whats makes up the CNS

Answer 1

• Brain
• Spinal cord

Question 2

Whats part of the PNS

Answer 2

• Somatic nervous system (conscious actions)
• Autonomic nervous system (unconscious actions)

Question 3

What makes up the CCN

Answer 3

• CNS
• PNS
• Endocrine system
• Local support and defence system

Question 4

Explain Alzheimers in comparison to the nervous system

Answer 4

• Lots of neurons going to the brain are lost
• Acetylcholine can be reduced by up to 90%
• Changing in signalling molecules have serious impact on health

Question 5

What is the input and output of the CNS

Answer 5

Sensory input and motar output

Question 6

Explain sensory input

Answer 6

Response to external stimuli

Question 7

Explain the 2 types of sensory input

Answer 7

1) Inputs from internal organs (signalling that you’re feeling full)

2) Input from sensory receptors on skin and joints

Question 8

Explain motor output

Answer 8

Actions signalled by the CNS

Question 9

What type(s) of motor output does the SNS direct

Answer 9

Directs voluntary movements

Question 10

What type(s) of motor output does the ANS direct

Answer 10

Regulates bodily activities such as HR and BR

Question 11

What are the roles of parasynthetic vs synthetic nervous system on motor output

Answer 11

Parasympathetic nervous system: Governs bodily activities during restful states

Sympathetic nervous system: Prepares body for emergencies

Question 12

What are the 5 major cell types in adult CNS

Answer 12

1) Neurons
2) Oligodendrocytes (CNS) and Schwann cells (PNS)
3) Astrocytes
4) Microglia
5) Ependymal Cells

Question 13

What is the role of neurons

Answer 13

Transmit electrical signals

Question 14

Can neurons be be excitatory or inhibitory

Answer 14

Yes

Question 15

Explain dendrites, cell body, axon, and axon endings of neurons

Answer 15

• Dendrites: receive info from other neuron or environment
• Cell body: controls cells metabolic activity, generates input from other neurons
• Axon: Conducts nerve impulse away from cell body
• Axon ending: release chemicals called neurotransmitters that affect of the nearby neuron and effector

Question 16

Where is action potential regenerated in neurons

Answer 16

Action potential regenerated in dendrite vessels

Question 17

Characteristics of unmyelinated neurons

Answer 17

• Unmyelinated neurons do not have myelin sheath

— Neurons travel 0.5 to 2m/sec
— Very few of these

Question 18

Characteristics of myelinated neurons

Answer 18

• Myelinated have myelin sheath

— Neurons travel 6m to 120m/sec
— Quicker nerves signaling

Question 19

MS connection to myelin sheeth

Answer 19

In Multiple sclerosis, there is a disturbance of the myelin sheath, due to an autoimmune disease

Question 20

Do all neurotransmitters share a general site?

Answer 20

No, there’s very specific sites for neurotransmitters in neurons

Neurons release one type of neurotransmitter at given pre-synaptic neuron

Question 21

What is net response of neurons based on

Answer 21

Net response based on overall (summation) effect on all imputes

Question 22

What is needed for generation of action potential

Answer 22

1) More excitatory than inhibitory neurons
2) Action potential threshold met

Question 23

How does the body maintain homeostasis with neurons

Answer 23

Body will release excitatory or inhibitory neurons to maintain homeostasis

Question 24

Examples of the body maintain homeostasis with neurons

Answer 24

Acetylcholine in excitatory - increase HR

Epinephrine in inhibitory - decrease HR

If HR is too high, epinephrine will be release to lower heart rate

Question 25

How does the body remodel neural networks at 10

Answer 25

• New neural synapses - can enhance memory and ability to learn
• Pruning away unused synapsis

Question 26

What causes bad behaviour in toddlers

Answer 26

Turnover in neural networks

Question 27

What is the role of Oligodendrocytes (CNS) and Schwann cells (PNS)

Answer 27

Responsible for producing myelin

Question 28

Compare Oligodendrocytes (CNS) and Schwann cells (PNS)

Answer 28

Oligodendrocytes span multiple axons having an affect on multiple neurons

Schwann cells do not span multiple axons, only support one axon

Question 29

Shape of astrocytes

Answer 29

Stellate (Starlike) cells

Question 30

What are astrocytes used for

Answer 30

Important for communication

Question 31

What are astrocytes abundant in

Answer 31

Very abundant in neurons

Question 32

5 functions of astrocytes

Answer 32

1) Cordinae overall function of blood brian barrier (BBB) and provide nutrients to feed neurons

2) Coordinate function of the ventrice epithelium (brain network)

3) Coordinate function at nodes of Ranvier

4) Participate in.form tripartite synapse with neurons

5) Serves as “superhubs” for neutral networks via syncytium formation and calcium signaling ( astrocyte cells)

Question 33

Define microglia

Answer 33

Macrophage-like immune cells

Question 34

Role of ependymal cells

Answer 34

Lines ventricles to form a barrier, produces cerebrospinal fluid

Question 35

What is the Brain blood barrier (BBB)

Answer 35

Has very tight control over what gets through the brain - neurons are meant to be long lived and typically do not regenerate

Good protection against most bacteria and toxins

Question 36

What gets through the BBB

Answer 36

Small lipid soluble compounds (essential fatty acids)

Caffeine and alcohol

Glucose gets through with specific glucose transporter GLUT1 (not insulin sensitive)

Issue with small molecules traveling brain molecule is for drugs in the pharmaceutical industry to be able to make drugs small enough to cross to brain