Nervous System Overview

The nervous system receives information from the body's internal and external environments, processes it, and generates appropriate responses.

The brain and spinal cord form the Central Nervous System (CNS), the control center of the nervous system.

The peripheral nervous system (PNS) includes the nerves that connect the brain and spinal cord to the rest of the body.

The PNS relays information to and from the CNS, acting as a communication network.

The Somatic Nervous System controls voluntary movements by sending signals to skeletal muscles.

The Autonomic Nervous System controls involuntary functions such as heart rate, digestion, and breathing.

The Sympathetic division of the ANS prepares the body for 'fight or flight' responses, increasing heart rate, blood pressure, and alertness.

The Parasympathetic division of the ANS promotes 'rest and digest' functions, slowing heart rate, lowering blood pressure, and promoting digestion.

The "fight or flight" response, prepares the body for stressful situations. It increases heart rate, blood pressure, and alertness, diverting blood to muscles and organs needed for action.

The "rest and digest" response, promotes calming and restorative processes. It slows heart rate, lowers blood pressure, and facilitates digestion.

Maintaining a stable internal environment, despite external changes. It ensures optimal conditions for body functions.

The main functional units of the nervous system, responsible for transmitting information as electrical impulses.

Supporting cells in the nervous system, providing structural and metabolic support for neurons. They also contribute to the function of nervous tissue.

The largest and most numerous type of glial cells, found in the CNS. They transfer nutrients, support the blood-brain barrier, and may have limited information transmission roles.

Immune cells of the CNS, removing cellular debris and foreign material through phagocytosis. They're not directly related to other nervous cells.

Glial cells that line fluid-filled cavities of the CNS, creating barriers and producing cerebrospinal fluid (CSF), which helps circulate nutrients and remove waste.

Glial cells in the CNS that wrap around nerve fibers, forming the myelin sheath, which insulates and speeds up nerve impulse transmission.

Glial cells in the PNS that form the myelin sheath around nerve fibers, also contributing to nerve regeneration. They form the neurolemma.

The main body of a neuron containing the nucleus and most organelles, responsible for the neuron's metabolic processes.

Branch-like extensions of the cell body that receive incoming signals from other neurons, leading towards the cell body. They're responsible for receiving information.

A fatty sheath that wraps around nerve fibers, providing insulation and speeding up the transmission of nerve impulses. It's formed by Schwann cells (PNS) or oligodendrocytes (CNS).

A covering over the myelin sheath, formed by the nuclei and cytoplasm of Schwann cells, found only in the PNS. It plays a vital role in nerve regeneration.

Neurons that carry sensory information from receptors to the CNS, providing information about the internal and external environments.

Neurons that carry motor commands from the CNS to effectors (muscles and glands), initiating action and movement.