Module 2, Lecture 3: Organismal Neurophysiology

Question 1

Do all animals have neurons?

Answer 1

• No
• Sponges, porifera, and others don’t have neurons

Question 2

What are neurons?

Answer 2

Nerve cells that transmit electrical and chemical signals in the nervous system

Question 3

Pufferfish - Tetrodotoxin

Answer 3

-Toxin that blocks Na channels, preventing transmission of action potentials

Question 4

Poisonous Hemlock - Piperidine alkaloids

Answer 4

• Blocks acetylcholine receptors
• Paralyzes motor nerve endings, leading to respiratory failure

Question 5

Clostridium botulinum - Botulinum toxin

Answer 5

• Blocks release of acetylcholine at neuromuscular junctions
• Paralyzes muscles, leading to respiratory failure
• Most poisonous known substance

Question 6

5 normal functions of a neuron

Answer 6

1. Makes and stores neurotransmitters
2. Sends an electrical signal (nerve impulse)
3. Signal opens calcium channels
4. Neurotransmitters are released
5. Neurotransmitters bind to the next neuron, openeing chanels and continung message

Question 7

Normal function - Voltage-gated Na+ channels, Closed

Answer 7

At the resting potential the channel is closed

Question 8

Normal function - Voltage-gated Na+ channels, Open

Answer 8

In response to a nerve impulse, the gate opens and Na+ enters the cell

Question 9

Normal function - Voltage-gated Na+ channels, Inactivated

Answer 9

For a brief period following activation, the channel doesn’t open in response to a new signal

Question 10

Cognitive abilities

Answer 10

brain function associated with focus, processing of info, use of logic and reason, memory, planning, communication, and comprehension

Question 11

Proximate hypothesis

Answer 11

explains how a trait or behavior occurs, focusing on mechanisms like genetics, physiology, and environmental influences

Question 12

Ultimate hypothesis

Answer 12

explains why a trait or behavior exists, focusing on evolutionary advantages and survival benefits