The parietal cells of the stomach lining contain membrane “pumps” that transport hydrogen ions from the cytosol (pH 7.0) into the stomach, contributing to the acidity of gastric juice (pH 1.0). Calculate the free energy required to transport 1 mol of hydrogen ions through these pumps.  Assume a temperature of 37 °C.

#Question id: 11205

#Unit 7. System Physiology – Animal

What would probably happen if a long neuron had one continuous myelin sheath down the length of the axon with no nodes of Ranvier?

#Question id: 11206

#Unit 7. System Physiology – Animal

Tetrodotoxin blocks voltage-gated sodium channels, and ouabain blocks sodium-potassium pumps. If you added both tetrodotoxin and ouabain to a solution containing neural tissue, what responses would you expect?

#Question id: 11207

#Unit 7. System Physiology – Animal

In multiple sclerosis, the myelin sheaths around the axons of the brain and spinal cord are damaged and demyelination results. How does this disease manifest at the level of the action potential?

 I) Action potentials move in the opposite direction on the axon.

 II) Action potentials move more slowly along the axon.

 III) No action potentials are transmitted.

#Question id: 11208

#Unit 7. System Physiology – Animal

Neurotransmitters are released from axon terminals via ________.

#Question id: 11209

#Unit 7. System Physiology – Animal

Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium/potassium channel and opens it. This is an example of ________.

#Question id: 11210

#Unit 7. System Physiology – Animal

An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more permeable to ________.