Structure of Cells in the Nervous System

Study Notes

Structure of Cells in the Nervous System

Neurons are the fundamental units of the nervous system, specialized for transmitting information.
Neurons exhibit a wide range of shapes and sizes, but generally contain a cell body (soma), dendrites, and an axon.
The cell body contains the nucleus and other organelles necessary for cell function.
Dendrites are branched extensions of the cell body that receive signals from other neurons.
The axon is a long, slender projection that transmits signals away from the cell body to other neurons, muscles, or glands.
Myelin sheaths, composed of glial cells (oligodendrocytes in the CNS and Schwann cells in the PNS), insulate axons, increasing the speed of signal transmission.
Nodes of Ranvier are gaps in the myelin sheath where the axon membrane is exposed, allowing for saltatory conduction (rapid signal transmission).
Glial cells are non-neuronal cells that support and protect neurons. They are crucial for maintaining the integrity of the nervous system.

Function of Cells in the Nervous System

Neurons communicate with each other via electrical and chemical signals.
Action potentials are rapid, transient changes in membrane potential that propagate along the axon.
Neurotransmitters are chemical messengers that transmit signals across synapses (the junctions between neurons).
Synapses facilitate communication between neurons, enabling complex interactions and processing of information.
Neurotransmitters bind to specific receptors on the receiving neuron, triggering a response.
Various neurotransmitters exist, each with specific roles in neural function.
Synaptic transmission involves the release, diffusion, and binding of neurotransmitters, which trigger postsynaptic potentials. These potentials summate to produce a response in the receiving neuron.

Sodium-Potassium Pump

The sodium-potassium pump (Na+/K+ ATPase) is a crucial membrane protein found in the plasma membrane of all animal cells.
This is an active transport mechanism.
It actively maintains the concentration gradients of sodium (Na+) and potassium (K+) ions across the cell membrane.
High intracellular potassium, low intracellular sodium, while extracellular sodium is high and potassium is low.
This gradient is essential for various cellular processes, including nerve signal transmission, muscle contraction, and nutrient uptake.
The pump transports 3 sodium ions out of the cell and 2 potassium ions into the cell for each ATP molecule hydrolyzed.
This pumping action establishes and maintains the electrochemical gradients for sodium and potassium.
The pump is essential for maintaining the resting membrane potential of neurons.
The resting membrane potential is the difference in electrical charge across the neuronal membrane when the neuron is at rest.
The sodium-potassium pump is crucial for the generation and propagation of action potentials.
The pump maintains the sodium and potassium gradients required for generating the large electrical potential changes that are the basis for signal transmission in nerve cells.
Dysfunction of the Na+/K+ pump can lead to various neurological and physiological disorders.

Description

This quiz covers the fundamental components of neurons in the nervous system, including their structure and functions. You'll learn about cell bodies, dendrites, axons, myelin sheaths, and glial cells. Test your knowledge of how these elements work together to facilitate communication within the nervous system.