Cells of the Nervous System

Afferent & Efferent Divisons

1. Afferent- oncoming sensory pathway 2. Efferent- outgoing motor pathways

Central & Peripheral Nervous Systems

1. CNS- brain and spinal cord 2. PNS- all the remaining nerves

Somatic & Autonomic Nervous System

1. SNS- afferent & efferent pathway to skeletal muscles. 2.ANS- afferent & efferent pathway to smooth muscle, cardiac muscle, and glands a. sympathetic division b. parasympathetic division

Organization of the Nervous System

Central & Peripheral Nervous System, Afferent & Efferent Division, Somatic & Autonomic, Systems.

The Neuron

the human brain is estimated to contain about 100 billion neurons, 10% of the total number of NS cells in the brain. neuron have cellular components. ex the nucleus, golgi apparatus, mitochondria, etc,

Structural Classification

Multipolar neurons, Bipolar neurons, Unipolar neurons.

two principal cell types compose the Nervous System (NS)

Neurons and Glia ( Glial cell or Neuroglia)

Glia

do not readily conduct information. instead they support the function of neurons in a myriad of ways

Sympathetic Division

fight or flight response

Multipolar Neurons

have one axon and multiple dendrites. this configuration represent the typical neuron shape in the public mind and is in the brain.

Bipolar neurons

have one axon and only one branched dendrite. this the common type found in the retina, inner ear and olfactory pathway.

Unipolar neurons

have only one process extending from the cell body which branches into peripheral ( away from CNS) and central ( toward CNS) processes. these are always sensory neurons in function.

Neurons

highly excitable cells capable of conducting electrochemical impulses that enable the NS's function.

Parasympathetic Division

rest and repair