CH 3 Neurology (QUESTIONS)

Question 1

Every psychological experience is simultaneously a…?

Answer 1

Biological experience

Question 2

Approximately, how many neurons are in the brain? How many neurons can the activity of one neuron influence?

Answer 2

• 86 billion
• 15,000

Question 3

Neurons Summary (6)

Answer 3

Neurons a specialized cells that send, process and receive information.

Neurons are either firing an AP or not

After travelling down an axon and entering the terminal buttons, an AP causes chemical messengers (Neurotransmitters) to spill their contents into a small gap called a synapse.

Neurotransmitters then bind with receptor sites found on the dendrites of post-synaptic neurons.

These neurotransmitters can unlock ion channels, allowing excitatory or inhibitory messages to enter the neuron.

These neurotransmitters and then released for re-uptake.

Question 4

Action potential: Electrical Charge (4)

Answer 4

1. Resting state: -70 mv
2. +50 mv
3. -75 mv
4. Homoeostasis -70 mv

Question 5

Action Potential (AP) Events: Sodium Ions (2,1)

Answer 5

• Cause of AP; Allows the transmission of signals

1. Resting potential: (-70 mv) When the neuron is at rest, the inside of the cell is more negative compared to the outside.
   
   • There is a high concentration of sodium ions (Na⁺) outside the neuron
2. Neuron Stimulation: When the neuron is stimulated, sodium channels open, allowing Na⁺ ions to rush into the cell (electrical charge becomes +50 mv)

Question 6

Action Potential (AP) Events:
Potassium Ions (3,1)

Answer 6

• Returns the electrical charge to the resting potential (-70 mV), preparing the neuron for the next AP

1.Potassium Channels Open & K⁺ Rushes Out: After Na⁺ enters the cell and makes the neuron positive (+50 mV), potassium (K⁺) channels open, allowing K⁺ to leave the cell, causing the neuron to be negative again

2. Hyper-polarization: (-75 to -80 mV) The neuron briefly becomes too negative, dropping below its normal resting potential (-70 mV) to around -75 to -80 mV. This makes it harder for the neuron to fire again immediately.
3. Sodium-Potassium Pump Restores Balance: Pumps Na⁺ out, Brings K⁺ back in; Electrical charge returns to resting potential

Question 7

Process of Synaptic Transmission (6,2)

Answer 7

1. Action potential travels to the terminal button
2. Stimulates synaptic vesicles (containing neurotransmitters) to migrate to cell membrane
3. Vesicles open and release neurotransmitters
4. Neurotransmitters travel across synaptic cleft and bind to the appropriate receptor
5. Ion channels on post-synaptic membrane open
   - Excitatory post-synaptic potential: Na+ ions ions into cell
   - Inhibitory post-synaptic potential: Cl- ions into cell
6. Neurotransmitters released for re-uptake or inactivation by enzymes

Question 8

Parts of Neuron (6)

Answer 8

1. Dendrites
2. Cell body - Nucleus
3. Axon Hillock
4. Axon
5. Myelin sheath
6. Terminal buttons