Electrochemical communication Flashcards
(18 cards)
Which type of glial cell is responsible for myelination in the central nervous system?
a. Astrocytes
b. Oligodendrocytes
c. Microglia
d. Schwann cells
Oligodendrocytes
What was the key contribution of Hodgkin and Huxley to neuroscience?
a. Discovery of neurotransmitter release mechanisms
b. Demonstrating electrical conduction in squid giant axons
c. Proposing the synapse as the site of communication between neurons
d. Identifying the resting membrane potential
Demonstrating electrical conduction in squid giant axons
The “all-or-none” rule of action potentials means:
a. Action potentials occur at varying intensities based on the stimulus.
b. Action potentials either occur fully or not at all.
c. Only inhibitory signals can prevent action potentials.
d. The rate law governs the amplitude of action potentials.
Action potentials either occur fully or not at all
What is the primary benefit of myelin sheaths for axonal transmission?
a. Increased resistance to electrical signals
b. Slower but more accurate conduction
c. Economical and faster saltatory conduction
d. Complete prevention of synaptic transmission
Economical and faster saltatory conduction
Which neurotransmitter is the primary excitatory neurotransmitter in the brain?
a. GABA
b. Dopamine
c. Glutamate
d. Serotonin
Glutamate
What triggers the release of neurotransmitters from the presynaptic terminal?
a. Potassium ion influx
b. Sodium ion influx
c. Calcium ion influx
d. Chloride ion influx
Calcium ion influx
Ionotropic receptors differ from metabotropic receptors in that they:
a. Use second messengers for signal transmission.
b. Are slower but longer-lasting in their effects.
c. Directly open ion channels upon ligand binding.
d. Always inhibit neuronal activity.
Directly open ion channels upon ligand binding.
Acetylcholinesterase inhibitors can help treat:
a. Parkinson’s disease
b. Myasthenia gravis
c. Epilepsy
d. Depression
Myasthenia gravis
Which of the following is NOT a function of astrocytes?
a. Nourishing neurons
b. Phagocytosis of debris
c. Forming myelin in the central nervous system
d. Supporting the blood-brain barrier
Forming myelin in the central nervous system
What was the primary scientific disagreement between Santiago Ramón y Cajal and Camillo Golgi?
a. Whether the brain used electrical or chemical signals
b. Whether neurons were individual units or formed a syncytium
c. The role of neurotransmitters in neural communication
d. The existence of the synapse
Whether neurons were individual units or formed a syncytium
The resting potential of a neuron is maintained by:
a. The diffusion of sodium ions into the cell
b. Ion pumps that actively move potassium and sodium ions
c. The absence of ion channels in the membrane
d. Voltage-gated calcium channels
Ion pumps that actively move potassium and sodium ions
Which of these statements about action potentials is FALSE?
a. They follow the “all-or-none” rule.
b. Depolarization precedes hyperpolarization.
c. Their amplitude decreases as they travel along the axon.
d. They rely on voltage-sensitive ion channels.
Their amplitude decreases as they travel along the axon.
Myelin sheaths increase the speed of action potential transmission through:
a. Increasing the number of voltage-gated sodium channels
b. Enabling saltatory conduction between nodes of Ranvier
c. Blocking potassium ion channels
d. Eliminating passive transmission
Enabling saltatory conduction between nodes of Ranvier
Tetrodotoxin (TTX), a toxin found in pufferfish, blocks action potentials by:
a. Preventing the release of neurotransmitters
b. Inhibiting voltage-gated sodium channels
c. Blocking voltage-gated calcium channels
d. Destroying the myelin sheath
Inhibiting voltage-gated sodium channels
Synaptic communication begins when:
a. Sodium ions enter the postsynaptic neuron
b. Neurotransmitters bind to receptors on the presynaptic neuron
c. Calcium ions trigger neurotransmitter release from the presynaptic neuron
d. The postsynaptic neuron generates an action potential
Calcium ions trigger neurotransmitter release from the presynaptic neuron
Which of these neurotransmitters is the brain’s major inhibitory neurotransmitter?
a. Glutamate
b. Dopamine
c. GABA
d. Serotonin
GABA
Ionotropic receptors differ from metabotropic receptors in that they:
a. Directly control ion channels
b. Use G-proteins for signal transduction
c. Have slower but longer-lasting effects
d. Can only be inhibitory
Directly control ion channels
Acetylcholinesterase inhibitors can be used to:
a. Treat myasthenia gravis by increasing acetylcholine levels
b. Reduce excitatory neurotransmitter activity
c. Enhance serotonin signaling in depression
d. Block calcium channels in neurons
Treat myasthenia gravis by increasing acetylcholine levels
