2.2 Subdivisions of the Nervous System

Neruon

Neurons are cells that specialise in the reception and transmission of information throughout the nervous system.

Neuron structure (7)

dendrites, nucleus, soma, axon, myelin sheath, axon terminal, terminal buttons

Nervous system

The nervous system is the network of neurons/nerves throughout the body that receives information, process information and coordinates a response to information

Subdivisions of the NS

Central NS

Carries messages to and from the PNS. Brain and spinal cord.

Brain

Responsible for everything one thinks, feels, and does. Many functions involve the activation of neural pathways that link different brain areas and structures.

Spinal cord

Bundle of nerve fibers that extend from the base of the brain to the lower back. Connects the brain and the PNS, and initiates spinal reflexes.

Neural pathway

Comprises one or more circuts of interconnected neurons that form a communication network.

Peripheral NS

Carries messages to and from the CNS. Autonomic and Somatic

Somatic NS

Carries sensory info to CNS and motor instructions from CNS to muscles. SAME

Autonomic NS

Connects CNS to internal organs and glands. Self regulating. Sympathetic, parasympathetic and enteric

Sympathetic

Prepares for action and controls stress response

Parasympathetic

Calms body after action and maintains homeostasis

Enteric

Neurons imbedded within the walls of the gastrointestinal track.

Parts of the ENS (6)

Oesophagus, stomach, duodenum, large intestine, small intestine, rectum