The Nervous SystemThe Nervous SystemLesson 1:Lesson 1:An OverviewAn Overview

Upon completion of this lesson, students should be able to …

List the functions of the nervous system. Identify and discuss the structures that

make up the central nervous system. Explain how nerve impulses are

transmitted.

State the functions of the peripheral nervous system, the somatic nervous system and the autonomic nervous system, and distinguish the differences between each.

Explain the delicate balance between the sympathetic and parasympathetic nervous systems.

Central Nervous System (CNS)◦Brain◦Spinal Cord

Peripheral Nervous System (PNS)◦Peripheral nerves ◦Cranial nerves

PNS receives sensory information

Information goes to the CNS

The CNS tells the PNS to carry out movement and body functions

Control body’s functions impulse is transmitted from the neural cell

body to muscle or organ Usually have several dendrites and only

one axon.

covered with fatty insulating substance

myelin sheath Myelin increases the speed at which impulses are transmitted along the axon.

Axons may be several feet long Dendrites resemble tree branches and are unsheathed

Lack true dendrites, Sheathedresemble axons

Motor Neuron

Sensory Neuron

Transmit impulses to the CNS. CNS activates motor neurons Respond to sensory information.

located entirely within the CNS Work between sensory and motor neurons

Myelinated sheaths◦inner sheath of myelin◦outer sheath of Schwann cells ◦Schwann cells are needed for

regenerating a damaged nerve

Unmyelinated sheaths

bundled unit of fibers

Group of nerve fibers in CNS The spinal cord

◦Afferent =ascend to the brain◦Efferent = descend from the brain The Brain

largest nerve tract is corpus callosum joins the right and left hemispheres

Solely comprised of the brain and spinal cord.

Parts of the brain

Largest mass of nervous tissueThree meninges: ◦Pia Mater◦Arachnoid◦Dura Mater

Controls body functions and movement

specific areas of the brain Generates thought memory and emotion

REPORT ON REPORTER

Largest part of brain Controls higher thought processes Outer layer is cerebral cortex left and right halves called cerebral

hemispheres

has four lobes

Stores memories and creates emotions

Contains ◦midbrain◦pons◦medulla oblongata (Connects brain [pons] to spinal cord)

Relay information◦visual◦auditory

Located in the back of the skull Second largest portion of the brain Coordinates voluntary and involuntary movement

Adjusts muscles to maintain posture

Label and color the brain

Connects the brain with the peripheral nerves

surrounded by cerebrospinal fluid

encased in the vertebral column (backbone)

four divisions: cervical, thoracic, lumbar, and sacral

Spinal nerves exit through foramina (openings)

1. What do you think is the purpose of cerebrospinal fluid?

Circulates around the brain and spinal cord Provides cushioning and protection Contains nourishment Contains neurotransmitters

http://www.raptorpharma.com/science_neurotrans.html

12 pairs of cranial nerves

Olfactory – provides sense of smell Optic – provides vision Trigeminal –sensory input from the

face Facial – controls the muscles of the

face and scalp

Vestibulocochlear–hearing and equilibrium

Glossopharyngeal – provides general sense of taste

Vagus – controls muscles of the digestive, slowing of heartbeat

Pair up Different stations

Responsible for controlling involuntary bodily functions

divides ◦sympathetic ◦parasympathetic

fight or flight◦increased alertness◦Increase metabolic rate

the adrenal gland releases epinephrine that causes adrenaline rush

conserve energy innervate the digestive systemdecrease in metabolism Decrease in bodily functions

Impulses are transmitted between neurons via chemicals called neurotransmitters

Anesthesiologist Neurologist Neurosurgeon Psychiatrist Psychologist