Nervous System and Action Potentials

These flashcards cover key concepts related to the nervous system, action potentials, neurotransmitters, and examples like the knee-jerk reflex.

What are the two methods of communication in the nervous system?

Fast and slow methods of communication.

What is the role of synapses in the nervous system?

Synapses are connections where information flows between interconnected neurons.

How many neurons does the human brain contain approximately?

The human brain contains about 86 billion neurons.

What are the two types of neurotransmitters mentioned?

Stimulatory neurotransmitters (sNT) promote depolarization and inhibitory neurotransmitters (iNT) inhibit depolarization.

What determines if an action potential will be fired?

An action potential is fired if the membrane potential at the axon hillock reaches threshold.

What is the function of voltage-gated Na+ channels?

Voltage-gated Na+ channels open in response to changes in membrane potential, facilitating action potentials.

What occurs during exocytosis at the synapse?

Synaptic vesicles fuse with the presynaptic membrane to release neurotransmitters into the synaptic cleft.

What type of neuron receives input and integrates signals?

The postsynaptic neuron receives input and integrates signals based on the net membrane potential.

What is the basic mechanism behind the knee-jerk reflex?

A strike against the patellar ligament causes sensory input that leads to a reflexive upward movement of the leg.

What happens to the muscle spindle during stretching?

Stretching leads to the opening of stretch-gated channels in sensory neurons, potentially generating an action potential.

What effect do the toxins from Clostridium botulinum have on synaptic function?

They prevent synaptic vesicle exocytosis at neuromuscular junctions, impairing acetylcholine release.

What is an action potential?

A rapid rise and fall in voltage across a neuron's membrane, leading to signal propagation.

How does the postsynaptic cell react to neurotransmitter binding?

Binding of neurotransmitters can cause depolarization or hyperpolarization of the postsynaptic cell membrane.

What is the role of interneurons in reflex actions?

Interneurons relay information between sensory and motor neurons and can inhibit motor neuron activity.

What is the result when stimulatory neurotransmitters are released at synapses?

They increase the likelihood of reaching threshold and firing an action potential.