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)

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* 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