Intro part 1; Neurons & Glial cells

Question 1

a-motor neurons are also known as what?

Answer 1

Lower Motor Neurons

Question 2

Cuteaneous neurons are described as what?

Answer 2

surface level (skin) sensory neurons

Question 3

What are Pyramidal neurons?

Answer 3

major brain neurons that link parts of the brain to other parts.

Question 4

What are the 3 components of the neuron?

Answer 4

1. Soma / body
2. Dendrites
3. Axon

Question 5

what is the function of the dendrites?

Answer 5

they receive incoming signals from other neurons
; communication via chemical and bio electricity

Question 6

What is the function of the Soma?

Answer 6

it is the metabolic centre of the neuron

Question 7

What is the function of the Axons?

Answer 7

they convey information to other neurons and cells; away from soma

Question 8

Dendrites and Axons are referred to as what?

Answer 8

Neurites

Question 9

Which part of the neuron initiates the mode of communication?

Answer 9

Initial Segment

Question 10

What is the function of the Myelin Sheath?

Answer 10

Electrical insulation; confines all electric events to the axon
- increases the speed of AP transmission

Question 11

What is the Schwann cell’s role in a neuron?

Answer 11

It is the cell that produces myelin (not the neuron itself)

Question 12

What is the Collateral Axon?

Answer 12

A major branch that increases innervation to other cells (amount is not constant)

Question 13

What is the Node of Ranvier, and what is its function?

Answer 13

It is the exposed area of the axon between myelin sheaths, increasing the speed of action potential propagation

Question 14

What are presynaptic terminals?

Answer 14

enlargements at the ends of axon branches

Question 15

What characterizes a multipolar neuron?

Answer 15

It has many dendrites and one axon; motor neurons fall into this category, with dendrites receiving approximately 10,000 inputs

Question 16

What characterizes a bipolar neuron, and where is it found?

Answer 16

It has one dendrite and one axon,
found in the retina and olfactory epithelium

Question 17

What is a pseudo-unipolar neuron, and how does it function?

Answer 17

It has no axons or dendrites

functions with one process in the periphery and another transmitting to the CNS, such as in somatosensory neurons

Question 18

What is the function of sensory receptors in pseudo-unipolar neurons?

Answer 18

They generate bioelectrical signals in response to sensory stimuli

Question 19

What is the function of sensory neurons?

Answer 19

Carry info from the periphery to the CNS,
about the external and internal state of life, including motor coordination.

Question 20

How are Interneurons characterized?

Answer 20

relay interneurons: long axons for long-distance communication

local interneurons: short axons connecting nearby neurons

Question 21

What are the most numerous type of neuron?

Answer 21

Interneuron

Question 22

What are the Functional Categories of Neurons?

Answer 22

1. Sensory Neurons
2. Interneurons
3. Motor Neurons

Question 23

What is the function of motor neurons?

Answer 23

They carry information out of the CNS (efferent)

Question 24

What are glial cells, and why are they important?

Answer 24

They are neurons’ supporting cells

Question 25

What are astrocytes, and what is their role?

Answer 25

Star-shaped cells that provide structural support, regulate K+ levels, and maintain homeostasis

Question 26

What is the role of microglial cells?

Answer 26

Protect neurons by absorbing toxic substances and acting as phagocytes to remove bacteria and damaged cells

Question 27

What is the primary function of oligodendrocytes and Schwann cells?

Answer 27

They both produce myelin; oligodendrocytes in the CNS and Schwann cells in the PNS

Question 28

How do astrocytes improve neuron functionality? (3)

Answer 28

1. by separating neurons and synapses 2. by regulating extracellular potassium 3. by absorbing neurotransmitters from synaptic spaces

Question 29

What additional role do astrocytes play in neuron repair?

Answer 29

They release growth factors that trigger the development of new neurons and synapses

Question 30

Where are Schwann cells located, and what is their function?

Answer 30

In the PNS - they produce myelin to insulate axons and prevent AP decay

Question 31

How does myelination by Schwann cells enhance neural communication?

Answer 31

By increasing speed and efficiency of AP propagation and clustering Na+ channels at nodes

Question 32

What is unique about oligodendrocytes compared to Schwann cells? (2)

Answer 32

- Oligodendrocytes are in the CNS (schwann cells are in PNS) - Oligodendrocytes can myelinate multiple axons (up to 30), (schwann cells can only myelinate single axons)

Question 33

What signals oligodendrocytes to increase myelination?

Answer 33

ATP and adenosine release from active neurons (high activity of these indicate importance + need for myelin )

Question 34

What is the initial segment in a neuron responsible for?

Answer 34

initiates the mode of communication

Question 35

What is the role of capillaries in neural function? (2)

Answer 35

1. provides oxygen and nutrients to the brain 2. removes metabolic waste

Question 36

What is the function of ventricles in the brain?

Answer 36

hollow regions where fluid flows, ensuring appropriate fluid balance

Question 37

What is the function of ependymal cells?

Answer 37

Line the ventricles ; help maintain appropriate fluid balance in the brain

Question 38

True or False: glial cells convey bioelectricity.

Answer 38

False: they do not, as they do not have neurites

Question 39

How do microglial cells protect the CNS?

Answer 39

Protect the CNS from oxidative and mild cell-damaging stress - secrete cytokines to modulate the inflammatory response.

Question 40

How does myelination affect axon diameter?

Answer 40

Myelinated axons tend to have larger diameters