Nervous System

Question 2

Nervous System

Answer 2

Network of nerves transmitting signals throughout the body.

Question 3

What are the four main functions of the nervous system?

Answer 3

1. Reception of general sensory information (touch, pressure, temperature, pain, vibration)
2. Receiving and perceiving special sensations (taste, smell, vision, sounds)
3. Integration of sensory information from different parts of the body and processing them
4. Response generation

Question 4

Neurons

Answer 4

Specialized cells that gather and transmit information, interpret the information, and react to it.

Question 5

Dendrites

Answer 5

Dendrites receive information from other neurons and pass the signal received via electrical impulses

Question 6

Cell body

Answer 6

Contains the nucleus of the neuron.

Question 7

Axon

Answer 7

Transmit signals on to the other neurons or muscles.

Question 8

Synapses

Answer 8

Small gap between the axon of one neuron and a dendrite of another neuron that allows the transmission of messages between.

Question 9

Neurotransmitters

Answer 9

Chemical messengers that move signals across synapses to neighboring dendrites. At dendrite, the chemical signal converts back into electrical signal.

Question 10

How do neurons communicate with each other?

Answer 10

Electrical Signal: An action potential travels down the axon.
Neurotransmitter Release: At the synaptic terminal, the action potential triggers the release of chemical messengers (neurotransmitters) into the synaptic cleft.
Signal Reception: Neurotransmitters bind to receptors on the receiving neuron’s dendrites, initiating a new electrical signal.
This sequence repeats, transmitting information throughout the nervous system.

Question 11

What is the myelin sheath?

Answer 11

Myelin sheaths insulate nerve cell axons to prevent electrical impulses from leaking and enabling longer-distance communication.

Question 12

What are the nodes of Ranvier

Answer 12

Exposed portion of the axon.

Question 13

How are signals passed?

Answer 13

When neurotransmitters bind to receptors, they open ion channels on the receiving neuron’s membrane. This causes specific ions (like sodium or potassium) to flow in or out, changing the neuron’s voltage. If the voltage change is strong enough, it triggers an action potential, passing the signal along.

Question 14

Types of Neurons

Motor Neurons

Answer 14

Transmit messages from the brain to the muscles to generate movement.

Question 15

Types of Neurons

Sensory neurons

Answer 15

Detect light, sound, odour, taste, pressure, heat, and send messages about the stimulants to the brain.

Question 16

Types of Neurons

Glial Cells

Answer 16

on-neuron cell that supports neutrons to;
* Help support and hold neurons in place
* Protect neurons
* Create insulation called myelin, which helps move nerve impulses
* Repair neurons and help restore neuron function
* Trim out dead neurons
* Regulate neurotransmitters

Question 17

Types of Glial Cells

Satellite Glial Cells

Answer 17

Respond to chemical messengers to optimize them so that vital responses go as smoothly as possible.

In the sensory nervous system, satellite cells regulate potassium levels and the neurons’ response to evoked potentials without the presence of neurotransmitters.

Question 18

Types of Glial Cells

Schwann Cells

Answer 18

Schwann cells (neurolemma) of the PNS mirror the role of oligodendrocytes in the central nervous system; they myelinate the axons of neurons and modulate extracellular fluid.

Question 19

Types of Glial Cells

Microglia

Answer 19

Clear debris and support brain immunity.

Question 20

Types of Glial Cells

Oligodendrocytes

Answer 20

Manufacture, repair, and arrange myelin sheaths around neuron axons. Oligodendrocytes also support the metabolic needs of the nerve cell axon.

Question 21

Types of Glial Cells

Ependymal Cells

Answer 21

Produce cerbrospinal fluid (CFS). The microvilli of ependymal cells can absorb CSF and influence its flow and let certain substances in and out of the brain. Depending on where they are located, ependymal cells also help to distribute neurotransmitters and hormones associated with the central nervous system.

Question 22

Types of Glial Cells

Astrocytes

Answer 22

Maintain the permeability of blood-brain barrier where they sense glucose and ion levels inside the brain and regulate their flow in and out of it.

Question 23

Nervous System Organization

CNS

Answer 23

Includes the brain and spinal cord.

Question 24

Cerebralspinal fluid

Answer 24

cushions the brain and spinal cord from injury, transports chemicals, and removes wastes that are produced in the brain

Question 25

Nervous System Organization

PNS

Answer 25

Connects the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body.

Question 26

Somatic Nervous System

Answer 26

Controls voluntary movement and reflexes.

Question 27

Autonomic Nervous System

Answer 27

Regulates involuntary movement in the body. And carries impulses from the central nervous system to the heart and other internal organs.

Question 28

Sympathetic nervous system

Answer 28

Activates during times of stress or emergency, when the heart rate or breathing rate increases.

Question 29

Parasympathetic Nervous System

Answer 29

Promotes relaxation and digestion processes.

Question 30

The Brain

Answer 30

Called the control center of the entire body
Divided into the cerebrum, the cerebellum, and the brain stem
Functions: thought processes (learning), memory, language, speech, voluntary body movements, and sensory perception.

Question 31

Spinal Cord

Answer 31

Carries nerve signals from the brain to the rest of the body and back.