Biology(2) The Nervous System

The Nervous System

body’s decision and communication center

Central Nervous System (CNS)

consists of the brain and the spinal cord

the Peripheral Nervous System ( PNS )

involves all of the nerves

Central Nervous System (CNS)

• receives and prosses all of the information from all the parts of the body

• controls the entire organ system of the body

• Brain, Spinal Chord

Peripheral Nervous System

• contains all the neveres outside the brain and the spinal cord

• carries impulses from the sensory nerves to the CNS and from the CNS to the motor nerves

• divided into somatic and autonomic

A. Somatic Nervous System (SNS)

• regulates activities that are under conscious control

• specifically receptors

Receptors

eyes, ears, nose, skin and tongue

B. Autonomic Nervous System (ANS)

• regulates all activities that are considered as involuntary

• includes the motor neurons that control the internal organs

• subdivided into sympathetic and parasympathetic

Sympathetic

• known as the “fight or flight” response, controls the internal functions of the body in times of stress

• acceleration of heart rate, constriction of blood vessels, and the rise of blood pressure

Parasympathetic

• “rest and digest” opposite of the sympathetic nervous system

• controls the internal functions at rest

• slows down the heart rate, incrreases intestinal and gland activities