bio 156 chapter 10 powerpoint

8/14/2019 BIO 156 Chapter 10 Powerpoint

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BIO 156

Chapter 10


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The Nervous System


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The nervous system controls

body functions, but also

allows for higher functionssuch as thinking.

The nervous system consists

of two parts, the central and

peripheral nervous systems.

The central nervous

system (CNS) is made up

of the brain and spinalcord

The peripheral nervous

system (PNS) consists ofthe spinal and cranial


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In the CNS:

Receptors transmit sensory input to the CNS via sensory

neurons.The CNS integrates all sensory input and generates

appropriate responses.Motor output leaves the CNS in motor neurons.

In the PNS:

The peripheral consists of the somatic and the autonomic

subdivisions.The autonomic division controls involuntary actions.The somatic division largely controls voluntary actions.


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Structure and Function of the Neuron


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The fundamental unit of the nervous system is the neuron.

This highly specialized cell generates and transmits

bioelectric impulses.


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Nerve impulses result from the flow of ions across

their plasma membranes.

The electrical potential across the membrane is known as

the membrane potential or resting potential.

When a nerve cell is stimulated, its plasma membrane

increases its permeability to sodium ions.

Sodium ions rush in, causing depolarization down the

membrane.

Depolarization is followed by repolarization.

The depolarization and repolarization of the neurons

plasma membrane constitute a bioelectric impulse or action

potential.


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Action Potential


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Nerve impulses travel

from one neuron toanother across

synapses.

When an impulse

reaches the terminalbouton, it stimulates

the release of

neurotransmitters.

Neurotransmittersmay excite or inhibit

the postsynaptic

membrane.


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The spinal cord transmits information to and from the brainand houses many reflexes.

The nerves attached to the spinal cord carry motor andsensory impulses.

Two types of nerves emanate from the CNS: spinal andcranial.

Spinal nerves arise from the spinal cord and may besensory, motor, or mixed.

Cranial nerves attach to the brain and supply thestructures of the head and several key body parts.


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The Reflex Arc


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The Brain


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Hypothalamus


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The Reticular Activating System


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Cerebrospinal fluid

cushions the CNS.


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End of Chapter 10

bio 156 chapter 10 powerpoint

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