University:
Biola University
Course:
BIOS 236 | Principles of Human Anatomy and Physiology
Academic year:

2024
Views:

320

Pages:

1
Author:

argatikzu1

PAL Worksheet Week 6 (#1): Neurotransmitters Remember 1. Arrange the events that occur during synaptic transmission (listed below) in the correct sequence: (1) (2) (3) (4) (5) (6) (7) An action potential is propagated along a presynaptic neuron Neurotransmitter binds with receptors on the postsynaptic membrane Neurotransmitter diffuses across the synaptic cleft Neurotransmitter is released from the presynaptic neuron An increase in the permeability of the presynaptic neuron to Ca2+ The postsynaptic membrane permeability to Na+ ions increases Acetylcholinesterase degrades acetylcholine 2. Is the synaptic transmission described above excitatory or inhibitory? How do you know? Understand 3. Neuron A, Neuron B and Neuron C are all presynaptic to Neuron F. If A and B fire, F fires. If A and C fire, nothing happens. Draw this situation below. What can you conclude about the synapse between C and F? Between A and F? What other information might you need? 4. Neuron J, Neuron K, and Neuron L are all presynaptic to Neuron T. J and K both cause EPSPs of +5 on T, whereas L causes an IPSP of -7 on T. Assume that T has a resting potential of -72 and threshold is at -65. A) Describe how temporal summation could result in an action potential on T. B) Describe how spatial summation could result in an action potential on T. Apply 5. The following poisons/toxins affect the synapse between the motor neuron and skeletal muscle, a synapse that is always excitatory, and uses the neurotransmitter acetylcholine (Ach). For each of these poisons/toxins, predict the effect on the "victim" (what symptoms might you observe, could this cause death, and if so, how?) and how this effect develops. A. B. C. D. Black widow spider venom: explosive release of Ach from the presynaptic neuron Clostridium botulinum toxin: blocks release of Ach from presynaptic neuron. Curare: (reversibly) blocks Ach receptor sites on the skeletal muscle membrane. Military nerve gas: irreversibly inhibits acetylcholinesterase