Nervous System Central Nervous System CNS Peripheral Nervous
- Slides: 20
Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS)
Organization of the nervous system
Organization of the nervous system
The Nervous System: Consists of all the nerve cells. **It is the body’s speedy, electrochemical communication system. Central Nervous System (CNS): the brain and spinal cord. Peripheral Nervous System (PNS): the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.
Organization of the nervous system
4 The central nervous system Brain Spinal cord A collection of neurons and supportive tissue running from the base of the brain down the center of the back Protected by spinal column
Central Nervous System – The Spinal Cord and Reflexes
Organization of the nervous system
The Nerves • Nerves consist of neural “cables” containing many axons. • They are part of the peripheral nervous system and connect muscles, glands, and sense organs to the central nervous system.
Divisions of the Peripheral Nervous System • There are two divisions of the peripheral nervous system: – the somatic, or voluntary portion – the autonomic, or involuntary portion § Somatic Nervous System: The division of the peripheral nervous system that controls the body’s skeletal muscles (voluntary). § Autonomic Nervous System: Part of the PNS that controls the glands and other muscles (involuntary).
Organization of the nervous system
Autonomic Nervous System (ANS) • The autonomic portion of the peripheral nervous system governs involuntary, visceral functions…such as heart and breathing rate, blood pressure, etc. • It is divided into two systems: – Sympathetic Nervous System: Division of the ANS that arouses the body, mobilizing its energy in stressful situations. – Parasympathetic Nervous System: Division of the ANS that calms the body, conserving its energy.
Organization of the nervous system
The Sympathetic Nervous System • Mobilizes the body’s resources for emergencies and creates the fight-orflight response. • “Arouses”
Organization of the nervous system
The Parasympathetic Nervous System • Activates processes that conserve bodily resources… slowing heart rate, reducing blood pressure, etc. • “Calms” (rest and digest)
Recap
See “Fight or Flight” in action in this short cartoon: http: //cmhc. utexas. edu/stressreces s/Level_One/fof. html
Review • In everyday situations the sympathetic and parasympathetic nervous system work together to keep you in a steady internal rate. • What happens if these are out of wack? –.
Journal • How does information flow through your nervous system as you pick up a fork? Summarize this process.