Nervous System-Intro

Nervous System-Intro

By Aguado Angelica

Central Nervous System-CNS

​3 Parts to know

​Brain

1. Forebrain

2. Midbrain

3. hindbrain​

Friday's quiz will cover new material​

​Brainstem

1. Midbrain

2. pons

3. medulla oblongata​

​Spinal cord

1. cervical

2. thoracic

3. lumbar

4. sacral

5. coccygeal levels​

Peripheral nervous system-PNS

Cranial Nerves and Ganglia

• 12 pairs of cranial nerves exit the skull through the foramina​

​Spinal Nerves and Ganglia/Plexuses

• 31 pairs of spinal nerves exits the vertebral column through the intervertebral foramina​.

  • 8Cervical, 12Thoracic, 5Lumbar, 1coccygeal​

Prepares the body for emergency response; norepinephrine neurotransmitter; generally a stimulating response.

Sympathetic Division

​Conserving and restoring energy; acetylcholine neurotransmitter; general an inhibitory response.

​​Parasympatheic division

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​Autonomic Nervous System (ANS)

Nervous tissue contains two types of cells:

• neuron (accept and conduct signals)

• glia-neuroglia (support and protect neurons)

• there are more glial cells than neurons

NEURONS

consists three parts (cell body, dendrite, axon)

Neuron

• body (contains most of cell organelles and nucleus)

• dendrite (short projection of neuron, it receives the nerve signal (information) and transfers it TO the body, one neuron usually has many denrites)

• axon ( long projection, it send information AWAY from the body, a neuron has only one axon)

Functionally neurons can be divided into 3 groups

• Sensory neurons ( receive signals from sensory organs and carry it to the nervous system)

• Interneurons (they are in the brain and spinal cord, they receive signals from sensory neurons and give them to motor neurons)

• Motor neurons (take signals from interneurons and send them to effector cells(mostly muscle cells)

2 types of axon

• Myelinated axons are covered by myelin protein. they conduct information faster

• Unmyelinated axons are not covered by myelin protein. they conduct information slowly

synapse

connection between two neurons

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permits a neuron  to pass a signal to another neuron

neurotransmitters

information passes from one neuron to another through special molecules

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AXON produces neurotransmitters

Functions of the Nervous System

• Feeling

• Thinking

• Moving

• Awareness

• Coordination of body functions

• Homeostasis

• Responsiveness to changes