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Chapter 37 Nervous System

Chapter 37

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Chapter 37. Nervous System. Nervous System-receives and relays information about activities within the body and monitors and responds to internal and external changes. http://www.biologymad.com/nervoussystem/nervoussystemintro.htm. Three main functions of the nervous system. 1. Sensory Input - PowerPoint PPT Presentation

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Page 1: Chapter 37

Chapter 37

Nervous System

Page 2: Chapter 37

Nervous System-receives and relays information about activities within the body and monitors and

responds to internal and external changes

http://www.biologymad.com/nervoussystem/nervoussystemintro.htm

Page 3: Chapter 37

Three main functions of the nervous system

• 1. Sensory Input

• 2. Integration

• 3. Motor Output

Page 4: Chapter 37

Three main functions of the nervous system

http://cafe.daum.net/beautyskinbody/GY8n/196?docid=16FM2%7CGY8n%7C196%7C20080718134405

Page 5: Chapter 37

Structures of the central Nervous system (CNS)

• 1. brain

• 2. spinal nerve cord

in vertebrates

http://factsabouthumanbodyanditsorgans.blogspot.com/2011/11/central-nervous-system.html

Page 6: Chapter 37

Motor output is the conduction of signals from the CNS to the effector

cells such as muscles

http://mycozynook.com/102RGCh28OH.htm

Page 7: Chapter 37

How are signals conducted

• Signals are conducted by nerves

• Nerves are bundles of neurons which are wrapped in connective tissue

Page 8: Chapter 37

Sensory and motor neurons are collectively called the peripheral

nervous system

http://generalknowledgeupdates.blogspot.com/2012/10/peripheral-nervous-system.html

Page 9: Chapter 37

Neuron-structural and functional unit of the nervous system

http://www.enchantedlearning.com/subjects/anatomy/brain/Neuron.shtml

Page 10: Chapter 37

Four main parts of a neuron

• 1. Cell body

• 2. Dendrites

• 3. Axon (action potential is generated here number 20)

• 4. Axon terminals

Page 11: Chapter 37

Neuron

http://www.enchantedlearning.com/subjects/anatomy/brain/Neuron.shtml

Page 12: Chapter 37

Synapse-The site of contact between a synaptic terminal of a neuron and a target, such as another

neuron, a muscle cell, or a gland, is called a

http://scienceblogs.com/purepedantry/2007/03/06/neuron-to-glia-synapse-on-axon/

Page 13: Chapter 37

Pre-synaptic cell and post-synaptic cells of a synapse

http://www.nature.com/nature/journal/v423/n6943/fig_tab/423931a_F1.html

Page 14: Chapter 37

Reflex arc-the simplest type of nerve circuit

http://www.docstoc.com/docs/115358232/Reflex-Arc-Reflex-Arc

Has to be at least one sensory neuron and one motor neuron

Page 15: Chapter 37

Ganglia and nuclei

• Collections of cell bodies of neurons.

• Ganglia are found in the peripheral nervous system

• Nuclei are found within the brain.

Page 16: Chapter 37

Schwann Cells

• Cells that form the insulating sheaths around axons

• Located outside the Central Nervous System

• It is made of myelin

Page 17: Chapter 37

http://207.204.17.60/schwann-cell-transplants-human-clinical-trials

Page 18: Chapter 37

Membrane potential• All cells have an electrical charge difference

across their plasma membrane called the membrane potential

• It exists because the different concentration of certain ions across the cell membrane

• The membrane potential of an unstimulated neuron is called the resting membrane potential

• These ions move across the membrane either by being pumped by membrane proteins or by simple diffusion through ion channels.

Page 19: Chapter 37

Membrane potential

http://en.wikipedia.org/wiki/Membrane_potential

Page 20: Chapter 37

Resting membrane potential

http://humanbiologylab.pbworks.com/w/page/45302491/Resting%20Cellular%20Membrane%20Potential

Page 21: Chapter 37

• All cells have a membrane potential

• However, only certain cells such as neurons and muscle cells have the ability to generate large changes in their membrane potential

• These cells are called excitable

Page 22: Chapter 37

Action Potential

• If a sufficiently strong stimulus causes depolarization to reach “threshold potential” it triggers a different type of response called an action potential

http://www.answers.com/topic/action-potential

Page 23: Chapter 37

Two factors that affect the speed at which an action potential travels

down an axon • The diameter of the axon, the larger the

diameter the faster the action potential

• The presence of myelin around the axon, myelin insulates the axon and allows the action potential to travel quicker

Page 24: Chapter 37

The “motor division” of the peripheral nervous system is divided into two functional divisions, called the somatic and

autonomic nervous systems

http://ultramindtechniques.blogspot.com/2011/04/know-hardware-iii-nervous-system.html

Page 25: Chapter 37

What do they do?

• The somatic nervous system carries signals to skeletal muscle

• The autonomic nervous system carries signals to cardiac muscle, smooth muscle, and glands

Page 26: Chapter 37

http://www.docstoc.com/docs/105365259/Comparison-of-Somatic-and-Autonomic-Systems

Page 27: Chapter 37

Sympathetic and Parasympathetic of the Autonomic nervous system

• The autonomic nervous system consists of two divisions that act on body organs with opposite affects

• The Sympathetic Division correlates with an activation of the fight or flight response

• The Parasympathetic Division causes a calming effect and a return to an emphasis on self-maintenance functions

Page 28: Chapter 37

http://emsbasics.com/2011/03/31/drug-families-stimulants-and-depressants/sympathetic-parasympathetic/