ANATOMY AND PHYSIOLOGY OF THE NERVOUS SYSTEM
The Nervous System is divided into Two Main Divisions: Central Nervous System
(CNS) and the Peripheral Nervous System (PNS)
Functions of the Nervous System:
1. Gathers information from both inside and outside the body - Sensory Function
2. Transmits information to the processing areas of the brain and spine
3. Processes the information in the brain and spine – Integration Function
4. Sends information to the muscles, glands, and organs so they can respond
appropriately – Motor Function
Other branches of the Nervous System
Somatic Nervous System (voluntary)
o It Relays information from skin, sense organs & skeletal muscles to CNS.
, o It Brings responses back to skeletal muscles for voluntary responses.
Autonomic Nervous System (involuntary)
o Regulates the body involuntary responses.
o Relays information to internal organs
o Two divisions
Sympathetic nervous system – in times of stress
- Emergency response.
- Fight or flight.
Parasympathetic nervous system – when body is at rest or with normal functions
- Normal everyday conditions.
Basic Cells of the Nervous System
Neuron
o Basic functional cell of nervous system
o Transmits impulses (up to 250 mph)
Parts of a Neuron
o Dendrite – receive stimulus and carries it impulses towards the cell body.
o Cell Body with nucleus – nucleus & most of cytoplasm.
o Axon – fibers that carries impulses away from cell body.
o Schwann Cells- cells which produce myelin or fat layer in the Peripheral Nervous
System.
o Myelin sheath – It is a dense lipid layer, which insulates the axon – makes the
axon look gray.
o Node of Ranvier – gaps or nodes in the myelin sheath.
o Impulses travel from dendrite to cell body to axon.
Three types of Neurons
o Sensory neurons – bring messages to CNS.
o Motor neurons - carry messages from CNS.
o Interneurons – between sensory & motor neurons in the CNS.
The Nervous System is divided into Two Main Divisions: Central Nervous System
(CNS) and the Peripheral Nervous System (PNS)
Functions of the Nervous System:
1. Gathers information from both inside and outside the body - Sensory Function
2. Transmits information to the processing areas of the brain and spine
3. Processes the information in the brain and spine – Integration Function
4. Sends information to the muscles, glands, and organs so they can respond
appropriately – Motor Function
Other branches of the Nervous System
Somatic Nervous System (voluntary)
o It Relays information from skin, sense organs & skeletal muscles to CNS.
, o It Brings responses back to skeletal muscles for voluntary responses.
Autonomic Nervous System (involuntary)
o Regulates the body involuntary responses.
o Relays information to internal organs
o Two divisions
Sympathetic nervous system – in times of stress
- Emergency response.
- Fight or flight.
Parasympathetic nervous system – when body is at rest or with normal functions
- Normal everyday conditions.
Basic Cells of the Nervous System
Neuron
o Basic functional cell of nervous system
o Transmits impulses (up to 250 mph)
Parts of a Neuron
o Dendrite – receive stimulus and carries it impulses towards the cell body.
o Cell Body with nucleus – nucleus & most of cytoplasm.
o Axon – fibers that carries impulses away from cell body.
o Schwann Cells- cells which produce myelin or fat layer in the Peripheral Nervous
System.
o Myelin sheath – It is a dense lipid layer, which insulates the axon – makes the
axon look gray.
o Node of Ranvier – gaps or nodes in the myelin sheath.
o Impulses travel from dendrite to cell body to axon.
Three types of Neurons
o Sensory neurons – bring messages to CNS.
o Motor neurons - carry messages from CNS.
o Interneurons – between sensory & motor neurons in the CNS.
