Chapter 2: Nerve cells

Question 1

What are the two types of cells that nervous cells contain

Answer 1

Neurons
glia cells

Question 2

number of neurons the human brain contains

Answer 2

approximately 100 billion individual neurons

Question 3

How many neurons do we have

Answer 3

billions of them

Question 4

the structure of animal cells

Answer 4

1. Membrane
2. Nucleus
3. Mitochondria
4. Ribosomes
5. Endoplasmic reticulum

Question 5

membrane

Answer 5

a structure that separates the inside of the cell from the
outside environmens

Question 6

Nucleus

Answer 6

the structure that contains the chromosomes

Question 7

Mitochondria

Answer 7

the structure that performs metabolic activities, providing the energy that the cell uses for all activities

Question 8

Ribosomes

Answer 8

the sites within a cell that synthesize new protein molecules. Proteins provide building materials for the cell and facilitate chemical reactions

Question 9

Endoplasmic reticulum

Answer 9

a network of thin tubes that transport newly synthesized proteins to other locations

Question 10

structure of a neuron diagram

Answer 10

Question 11

what is the difference between motor and sensory neurons

Answer 11

motor neuron Has its soma in the spinal cord, Conducts impulses along its axon to a muscle
sensory neurons specialized at one end to be highly sensitive to a particular type of stimulation (touch, light, sound, etc.)

Question 12

motor neuron diagram

Answer 12

Question 13

sensory neuron diagram

Answer 13

Question 14

components of all neurons

Answer 14

1. Dendrites
2. Soma/cell body
3. Axon
4. Presynaptic terminals

Question 15

Dendrites

Answer 15

Branching fibers with a surface lined with synaptic receptors
responsible for bringing information into the neuron

The greater the surface area of the dendrite, the more the information it can receive

Question 16

Soma/cell body

Answer 16

Contains the nucleus, mitochondria, and ribosomes

Question 17

Axon

Answer 17

The thin fiber of a neuron is responsible for transmitting nerve impulses toward other neurons, organs, or muscles

Maybe have a myelin sheath, an insulating material that
contains interruptions in the sheath known as nodes of Ranvier

Question 18

Nods of renvier

Answer 18

the interruptions in the myelin sheet, play an important role in action potential of
neuron.

Question 19

Presynaptic terminals

Answer 19

they are at the endpoints of an axon and they release
chemicals to communicate with other neurons

Question 20

Myelin Sheaths

Answer 20

act as a protective film for the axons.

Question 21

how many axons neurons have

Answer 21

Neurons have only one axon, but the axon may have branches.
The end of each branch has a swelling, called a presynaptic
Terminals

Question 22

Afferent axon

Answer 22

refers to ADMITTING information into a structure: sensory

Question 23

Efferent axon

Answer 23

refers to EXITING with information away from a structure: Motor

Question 24

Interneurons or intrinsic neurons

Answer 24

whose dendrites and axons are completely contained within a single structure

interneurons are the ones in between - they connect the spinal motor and sensory neurons.

Question 25

Do neurons vary in size and shape and why

Answer 25

Neurons vary in size, shape, and function,The function is closely related to the shape of a neuron Example: Purkinje cells of the cerebellum branch are extremely widely within a single plane

Question 26

Types of glial cells

Answer 26

Astrocytes Microglia Oligodendrocytes Radial glia

Question 27

Astrocytes

Answer 27

astrocytes are star-shaped glial cells with many functions which include providing nutrients and support to neurons helping repair damaged nervous system tissue regulating communication between neurons and maintaining the blood-brain barrier which keeps potentially toxic substances in the blood from entering the brain

Question 28

Microglia

Answer 28

Remove waste material, viruses, and fungi from the brain

Question 29

Oligodendrocytes

Answer 29

is responsible for the myelination of neurons in the CNS

Question 30

Schwann cells

Answer 30

are responsible for the myelination of neurons in PNS

Question 31

Radial glia

Answer 31

are involved in neurogenesis and neural development they can give birth to new neurons and also serve as a scaffold along which new neurons can travel from their site of origin to their final destination in the brain

Question 32

What is BBB and what its function

Answer 32

It’s a mechanism that protects the brain and surrounds it protecting it from harmful stuff getting into the brain, when neurons get affected by bacteria or virus etc. the immune system destroys he neuron and remove it, and because the neurons in the brain don’t regenerate it's very vital that that is protected and that's wat BBB does.

Question 33

How does BBB work

Answer 33

Doesn’t let in large molecules or non-fat soluble, oxygen and co2 can travel easily for larger molecules it needs a special mechanism: Active transport Sugar or glucose is one of the few nutrients that can pass through the blood-brain barrier and it’s the only one that crosses it in large quantities Glucose and oxygen are essential for the neurons and the body needs thiamin to use the glucose, its deficiency can cause the death of neurons

Question 34

Active transport

Answer 34

The protein-mediated process that expends energy to pump chemicals from the blood into the brain Glucose, certain hormones, amino acids, and a few vitamins are brought into the brain via active transport

Question 35

what neurons depend for their nutrition

Answer 35

Vertebrate neurons depend almost entirely on glucose A sugar that is one of the few nutrients that can pass through the blood-brain barrier

Question 36

what is the only thing that can cross the BBB in large molecules

Answer 36

Glucose is the only nutrient that crosses the blood–brain barrier in large quantities.

Question 37

what does the body need to use glucose

Answer 37

The body needs a vitamin, thiamine, to use glucose

Question 38

what does the deficiency of thiamin cause

Answer 38

Prolonged thiamine deficiency leads to the death of neurons as seen in Korsakoff’s syndrome, a result of chronic alcoholism Korsakoff’s syndrome is marked by severe memory impairment

Question 39

Nerve impulse

Answer 39

is the electrical message that is transmitted down the axon of a neuron Does not travel directly down the axon, but is regenerated at points along the axon so that it is not weakened

Question 40

what is the speed of the nerve impulse

Answer 40

The speed of nerve impulses ranges from less than 1 meter/second to 100 meters/second A touch on the shoulder reaches the brain more quickly than a touch on the foot