Nervous System Intro

Question 1

Define the study of neuroscience

Answer 1

Fields dealing with the structure and function of the nervous system and the brain (ex: neurochem, experimental pysch)

Question 2

Define the study of biopysch

Answer 2

Analyzing how the brain, neurotransmitters, other aspects of biology can influence behaviours, thoughts, feelings

Question 3

List the characteristics of the brain (6)

Answer 3

• Highly complex
• 3lbs (ize of a grapefruit)
• 75% water
• Pink/grey colour
• Grows 4x in size from infancy to adulthood
• Nearly 100B nerve cells

Question 4

Define the body’s two communication systems and how they differ

Answer 4

Nervous system (communicates quickly)
Endocrine system (comms. more slowly)
Biological foundations for thoughts, emotions, behaviours

Question 5

How do the nervous and endocrine systems work together? What happens if one fails?

Answer 5

Help in life situations (ex: stress) to help the body reach homeostasis
Failure can impact brain and mental functions, which can be either temporary or life-altering

Question 6

Explain hypothyroidism

Answer 6

Not enough thyroid to produce hormones in the body. Caused by a failure in the comms. systems, leading to a change in personality. Associated with: lethargy, poor motor coordination, depression, bipolar disorder, confusion, loss of cognitive skills

Question 7

Define neuron + 3 categories

Answer 7

Specialized cells that can receive, carry, and transmit info to other cells
Sensory, motor, inter-

Question 8

Define nerve

Answer 8

Cluster of neuron cells

Question 9

How do neurons operate

Answer 9

1. Electrochemical impulse is received by cell from “feed neuron”
2. Info carried down length of neuron
3. Info passed on to next neuron

Question 10

Define sensory neuron

Answer 10

Info from sensory receptors carried from spinal cord to brain (5 senses) ex: touching something cold

Question 11

Define motor neuron

Answer 11

Sends messages from brain to muscles, organs, glands, allowing them to act. Helps with tasks such as catching or picking up something

Question 12

Define interneurons

Answer 12

Fills gaps between sensory and motor neurons, which cannot directly communicate. Transmit impulses between neurons (ex: reflex arc) in complex pathways

Question 13

List all the parts of a neuron (5) DON’T FORGET TO REVIEW THE IMAGE IN THE NOTES!!

Answer 13

• Dendrite
• Soma
• Axon
• Myelin sheath
• Nodes of Ranvier

Question 14

Define dendrite

Answer 14

Receiver branching off at end of a neuron, accepting (most) incoming messages and sending down to soma

Question 15

Define soma

Answer 15

Cell body, allowing cell to work properly and stay healthy. Analyzes received messages and decides when is the right time to send it to the axon.

Question 16

Define axon

Answer 16

Nerve fibre, long slender projection of nerve cell moving electrical impulses away from soma. Can be very short or long (ex: 1m in sciatic nerve found behind leg)

Question 17

Define myelin sheath

Answer 17

Protective coating surrounding axon to protect electrical signals. Made up of schwann cells (glial cell providing physical/chemical support)

Question 18

Define nodes of Ranvier

Answer 18

Microscopic gaps between myelin cells protecting axon. Help keep action potential going throughout cell by maintaining intensity of charge so that it can reach the end of the cell

Question 19

Define action potential

Answer 19

Neuron firing and impulse travelling down axon, causing neurotransmitters to be released by terminal buttons.

Question 20

Explain how action potential works

Answer 20

Axon energized from ions containing small neg- charges in normal state known as resting potential. When cell is excited, action potential reverses charge to pos+, allowing electrical signal to race down axon. Must then recharge (refractory period) before next action potential

Question 21

How does the “All or nothing” principle apply to action potential?

Answer 21

Depolarization, first movement where impulse passes, must reach a certain threshold or the action potential will not be triggered

Question 22

How do cells communicate?

Answer 22

Synapse (gap between neurons) slowly transfers info between cells

Question 23

Define synaptic transmission

Answer 23

Message transforms from electrical to chemical to flow across synaptic cleft

Question 24

How do cells connect to one another?

Answer 24

Synaptic vesicles (sacs in axon terminals) containing neurotransmitters, ruptured when action potential reaches. Connect to dendrite like lock and key.

Question 25

Define reuptake

Answer 25

Neurotransmitters are reabsorbed once message is sent out

Question 26

Define acetylcholine

Answer 26

Neurotransmitter enabling muscle action, learning, memory. Low levels cause Alzheimer’s

Question 27

Define dopamine

Answer 27

Neurotransmitter influencing movement, learning, attention, emotions. In excess can cause schizophrenia. Decrease can cause Parkinson’s (tremors, loss of mobility).

Question 28

Define serotonin

Answer 28

Neurotransmitter affecting mood, hunger, sleep, arousal. Decrease = depression. Prozac can increase supply.

Question 29

Define norepinephrine

Answer 29

Neurotransmitter (adrenaline) controlling alertness, arousal. Lack of can depress mood.

Question 30

Define GABA (gama-aminobutryicacid)

Answer 30

Inhibitory neurotransmitter. Lack of linked to seizures, tremors, insomnia.

Question 31

Define glutamate

Answer 31

Excitatory neurotransmiter involved in memory. Oversupply linked to migraines, seizures

Question 32

Difference between CNS and PNS?

Answer 32

Central: brain, spinal cord
Peripheral: nerves (sensory, motor neurons) going into brain and spinal cord, connecting with CNS and rest of body