Nervous system

Neurons and nervous systems

Communication around the body Neurons - the basic building blocks of the nervous system, soecialised to communicate info around the body
Three different types of neurons sensory neurons (afferent) : transfer info from the body to the brain
Motor neurons (efferent) : transmit info from brain to the body
Interneurins : communication b/w sensory and motor neurons Structure communication with a neuron
Communication within neurons is an electrochemical process
An electrical impulse known as an action potential (or neural impulse) is initiated by the soma and travels along the axon towards the axon terminals
An action potential is an all or nothing process

Peripheral nervous system
The complete network of neurons located outside the central nervous system, comprising of muscles, organs and glands
Carries info from sensory organs and internal organs to the CNS
Conveys info from the CNS to the muscles, organs, glands
It is broken into two sub-divisions

Somatic nervous system
Network of neuron within the body that transmits info from the receptor sites on the sense organs to the CNS and carries info from the CNS to the muscles that control movement.
It controls all voluntary movement

Autonomic nervous system
A network of neurons that carries neural messages b/w the CNS and the heart, lungs and other organs and glands.
Autonomic nervous system regulates the functioning of internal organs and glands autonomically - without you being consciously aware of it.
It is possible to exert some conscious control over ANS responses through a process of biofeedback
It has two sub-divisions; sympathetic and parasympathetic nervous systems.

Sympathetic Nervous Sysytem
A division of the ANS that activates the interna muscles, organs and glands to prepare the body for vigorous activity, or to deal with a stressful or threatening situation
The sympathetic nervous Sysytem releases adrenalin, increases HR and respiration