Chapter 3 - Biological Psychology

Question 1

Neurons: The Brain’s Communicators

Answer 1

-	Nerve cells that:
o	Communicate with each other
o	Receive signals from sensory organs
o	Carry messages from nervous system to muscles
-	86 billion neurons

Question 2

Glial Cells (the glue)

Answer 2

• Provide nutrition, healing, protection, and support for neurons

Provide protection in 3 ways:

1) Produce cerebral spinal fluid
2) From the blood-brain barrier
3) Contribute to the immune system of the brain

• Also provide structure for neurons forming scar tissue

Question 3

Sleep: Cleaning House?

Answer 3

• We may have a glymphatic system (equivalent to lymphatic system, a network of channels that cleared out toxins from our body)
• Glial cells clear away brain debris (like beta-amyloid, a protein associated with Alzheimer’s disease)
• This happens while we sleep

Question 4

Cell body (soma)

Answer 4

Tiny factory that produces proteins and NT’s

Question 5

Dendrites

Answer 5

Branchlike extension, receives information from other neurons

Question 6

Axons

Answer 6

“Tails” of the neuron that transit information to other neurons

Question 7

Neuronal Components

Answer 7

• Axons: tail-like extensions that stick out of the cell body
• Axon terminal: knob-like structure of the end of the axon, containing synaptic vesicle
• Synaptic Vesicles: contain chemical messengers called neurotransmitters
  o Produced by soma, SV’s travel down the axon until burst and release NT’s at the AT

Question 8

Synapses

Answer 8

• Tiny fluid filled space between neurons including a synaptic cleft
• Synaptic cleft: tiny gap into which neurotransmitters are released
• Dendrites of nearby neurons pick up the neurotransmitters
• Message received!

Question 9

Resting Potentials

Answer 9

When there are no NT’s acting on the neuron (-70 millivolts)

o Neuron of rest – negative charge inside neuron
o Until charge inside neuron reaches threshold and an action potential occurs

Question 10

Action Potentials

Answer 10

electrical impulses travel down axon, triggering the release of NT’s (neuron “fires”)

o Stimulation causes cell membrane to open briefly
o Positively charged particles flow rapidly into the axon, and then quickly back out

Question 11

Absolute Refractory Period

Answer 11

• Neurons fire rapidly (100 to 1000 times/second)
• Each AP is followed by a brief period during which another Ap cannot occur
  o AKA time to “reload”
  o The longer the axon, the more
  limited the maximal firing rate

Question 12

What are neurotransmitters associated with?

Answer 12

Associated with the Synaptic cleft

Synaptic cleft: tiny gap into which neurotransmitters are released.

Question 13

Agonists vs. Antagonists

Answer 13

Agonists: increase receptor site activity, reduce our emotional response to pain by binding to opioid receptors.

Antagonists: decrease receptor site activity, block certain NT’s from binding to receptors.

Question 14

Neural plasticity

Answer 14

Few human behaviours are truly “hardwired”

Nervous system is constantly changing
Development over time & through learning

4 Primary Ways:
Growth of dendrites and axons
Formation of new synapses
Pruning: death of some neurons, remove useless connections
Myelination: insulating axons with myelin sheath

Question 15

Long-term potentiation

Answer 15

Long-term potentiation: repeated synaptic activity leads to a strengthening of the synapse

 - AKA ”Neurons that fire together, wire together”
 - Explains a lot of the learning process.