Nervous System Overview

What is the nervous system?

• It is a complex network of cells that transmit information throughout the body.
• The communication happens via electrical and chemical signals.

Central Nervous System (CNS)

• Made up of the brain and spinal cord.
• Processes and integrates sensory information.
• Initiates and controls motor functions.

Peripheral Nervous System (PNS)

• All parts of the nervous system that are not part of the CNS.
• Relays information between the body and the CNS.
• Contains the Autonomic and the Somatic nervous systems.

Autonomic Nervous System (ANS)

• Controls involuntary bodily functions (breathing, heart rate, digestion)
• Broken down further into Sympathetic and Parasympathetic branches.
• Sympathetic nervous system: responsible for the "fight or flight" response.
• Parasympathetic nervous system: responsible for the "rest and digest" response.

Somatic Nervous System

• Controls voluntary movements.
• Broken down further into Sensory and Motor neurons.
• Sensory neurons carry information from the body to the CNS.
• Motor neurons carry information from the CNS to the body.

Nervous Tissue

• Comprised of neurons and neuroglia (glia).

Neurons

• The main cells of the nervous system for communication.
• Excitable and transmit electrical signals.
• Consist of a cell body (soma), dendrites, and an axon.

Neuroglia (Glia)

• Supporting cells of the nervous system.
• Provide neurons with oxygen, insulation, and protection.
• Examples are Schwann cells and astrocytes.

Neuron anatomy

• Soma: Contains the nucleus and organelles for cell maintenance.
• Dendrites: Receive information from connecting neurons.
• Axon: Also called nerve fiber, where the nerve impulse is generated and transmitted.
• Myelin Sheath: Made of fatty protein and acts as an insulator preventing loss of charged ions.
• Nodes of Ranvier: Gaps between sections of the myelin sheath that allow information to jump from section to section, speeding up transmission.

Efferent and Afferent

• Efferent neurons carry information away from the CNS.
• Afferent neurons carry information towards the CNS.

Explore the intricate structure and function of the nervous system, including its two main divisions: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). Delve into the roles of the Autonomic and Somatic nervous systems and understand how they impact bodily functions and responses.