The Nervous System

The nervous system

nerve cells communicate with each other they communicate with other parts of the body in the role of coordination and regulation

structure of the nervous system

the nervous system is composed of the brain the spinal cord all the nerve cells connecting the nervous system has two sections the CNS (central nervous system) and PNS (peripheral nervous system)

The Peripheral Nervous System

composed of two parts sensory division  and motor division find a photo

sensory division

also known as the afferent division transmits information about the external and internal environments to the CNS the sensory neurons is divided again into two sections somatic sensory neurons carry information to the CNS from the external environment via nerves visceral sensory neurons carry information to the CNS from the internal environment; for example, from organs such as the heart and etc

motor division

also known as the efferent division transmits information away from the CNS to muscles and glands the muscles and glands are referred to as effector organs. somatic nervous systems transmits messages to skeletal muscles. also known as voluntary nervous system. voluntary: under your conscious control the automatic system transmits messages to the smooth muscle, heart muscle and glands. involuntary: when you are not conscious of the movement occurring.

two parts to the automatic system?!

yes there is!!!sympathetic and parasympathetic.the automatic system plays an important role in controlling many essential functions in the body without consciousness and voluntary movement.

sympatheticcauses heart to contract faster and metabolic rate to rise.major role in flight or fight responseparasympathetic:directs body system when relaxed overall the automatic nervous system allows the body to to react smoothly and quickly change by coordinating the action of a muscles and glands.

                                                    nerve cells/neurons consist of

cell body

dendrites

nucleus 

axon

myelin sheath

axon terminals

DID YOU KNOW?!

THAT A GROUP AXONS BOUND TOGETHER MAKE A NERVE

CELL BODY: that part of a neuron that contains the nucleus 

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