The Nervous System

The nervous system is responsible for controlling many parts of the body and regulating bodily functions.

The central nervous system (CNS) consists of the brain and spinal cord.

The peripheral nervous system (PNS) consists of cranial and spinal nerves.

The somatic nervous system controls voluntary functions and is associated with skeletal muscles.

The autonomic nervous system controls involuntary functions and is associated with smooth muscles, cardiac muscles, and glands.

Nerve block is a procedure to alleviate pain by injecting local anesthetics around the nerves that cause pain.

A neuron or nerve cell is the basic structural unit of the nervous system.

The cell body contains the nucleus and other organelles of the neuron.

Axons transmit stimuli away from the cell body.

Dendrites transmit electrical stimuli toward the cell body.

Terminal boutons connect neurons to other nerve cells and muscle fibers.

Myelin sheath is a protective layer that surrounds the axons of some neurons, made of lipids.

Gaps in the myelin sheath that expose the axon membrane.

The jump of the action potential from one node of Ranvier to the next, increasing the speed of conduction.

Neurons are highly specialized and have limited regeneration abilities.

Neurons are sensitive to oxygen deprivation and require a constant supply of oxygen and glucose.

Membrane potential is the electrical potential difference across the neuron's cell membrane.

The resting potential is the membrane potential of a neuron when it is not actively transmitting a signal (approximately -70mV).

Action potential is a rapid change in the membrane potential of a neuron that occurs when it is stimulated, allowing the neuron to transmit an electrical signal.

Depolarization is the process where the membrane potential becomes less negative, often due to the influx of sodium ions.