Physiology of Behavior: Structure and Function of Cells of the Nervous System

A collection of 50 flashcards based on key concepts from the lecture on the physiology of behavior, focusing on the structure and function of cells of the nervous system.

What are the two basic divisions of the nervous system?

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

What does the Central Nervous System consist of?

The brain and spinal cord.

How do the CNS and the rest of the body communicate?

Via nerves.

What are cranial nerves?

12 pairs of nerves that originate from the brain.

What are spinal nerves?

31 pairs of nerves that originate from the spinal cord.

What are the three types of neurons?

Sensory neurons, Motor neurons, and Interneurons.

What do sensory neurons do?

They carry sensory information from the PNS to the CNS.

What do motor neurons do?

They send outputs from the CNS to the PNS, primarily to muscles.

What role do interneurons play?

They relay information within the CNS.

What is the primary function of neurons?

To communicate with each other and the body.

What do glial cells do?

Support and protect neurons.

What is the function of astrocytes?

Supply nutrients to neurons and form the blood-brain barrier.

What do oligodendrocytes form?

Myelin sheath around axons in the CNS.

What is the role of microglia?

They protect the brain from invasive agents by engaging in phagocytosis.

Define action potentials.

A wave of changed polarity from negative to positive inside the axon.

Where do action potentials begin?

At the axon hillock.

What is the resting membrane potential in neurons?

Approximately -70mV.

What must the neuron reach to fire?

Firing threshold, which is about -55mV.

What happens during an action potential?

The inside of the axon becomes positive, reaching +40mV.

How do sodium channels behave during action potential?

They open to allow Na+ to enter the axon rapidly.

What happens to potassium channels during action potentials?

They open after Na+ channels, allowing K+ to exit the neuron.

What is the refractory period?

The time before the neuron can generate another action potential.

What is the sodium-potassium pump's role?

It pumps 3 Na+ ions out and 2 K+ ions into the cell to help restore resting potential.

What is the All or None Law in action potentials?

Neurons either fire fully or not at all; there are no partial action potentials.

What does the Rate Law state?

The strength of a stimulus is reflected in the frequency of axon firing.

What facilitates conductivity in myelinated axons?

Nodes of Ranvier, where ion channels are located.

What is neurotransmission?

Communication between neurons through chemical signaling.

What occurs when an action potential reaches a nerve terminal?

Neurotransmitters are released into the synapse.

What is the lock and key analogy in neurotransmission?

Neurotransmitter molecules fit into receptors like keys fit into locks.

What are the three locations of synapses?

Axodendritic, Axosomatic, and Axoaxonal.

What triggers the release of neurotransmitters?

The arrival of an action potential at the nerve terminal.

What mechanism does reuptake refer to?

The removal of neurotransmitters from the synaptic cleft back into the presynaptic neuron.

What does enzymatic deactivation involve?

An enzyme degrading the neurotransmitter in the synaptic cleft.

Define ionotropic receptors.

Receptors that are coupled to ion channels and have immediate effects.

Define metabotropic receptors.

Receptors that activate a G protein and lead to longer-lasting changes.

What are autoreceptors?

Receptors located on presynaptic neurons that respond to their own neurotransmitter.

What is the main effect of autoreceptors?

They mainly regulate internal processes such as neurotransmitter synthesis.

What do astrocytes do in relation to blood-brain barrier?

They strengthen and help regulate the blood-brain barrier.

What do the nodes of Ranvier facilitate?

Saltatory conduction, increasing the speed of action potentials.

What happens during the depolarization phase of an action potential?

Na+ channels open, allowing Na+ to rush into the neuron.

What does the term 'EPSP' stand for?

Excitatory Post-Synaptic Potential.

What does the term 'IPSP' stand for?

Inhibitory Post-Synaptic Potential.

What are glial cells responsible for besides nutrition and support?

They help keep the brain healthy by cleaning debris and attacking viruses.

What do neurotransmitters influence in the postsynaptic neuron?

They can cause depolarizing (EPSPs) or hyperpolarizing effects (IPSPs).

What type of channels open during the repolarization phase of an action potential?

Potassium (K+) channels.

When K+ exits the neuron, what happens to the membrane potential?

It returns to a negative state.

What is the main chemical that requires an enzyme for deactivation?

Acetylcholine (ACh).

What do synaptic vesicles store?

Neurotransmitters.

What occurs during the 'kiss and run' mechanism of synaptic vesicle recycling?

Vesicles fuse with the membrane, release neurotransmitters, then recycle.

What is the significance of phagocytosis by microglia?

It protects the brain by removing debris and harmful agents.

What kind of cellular changes can metabotropic receptors induce?

Activation of genes and changes in intracellular processes.