Nervous system

*The Nervous System

*Nervous System

*The network of nerve cells and fibers that transmits nerve impulses between parts of the body

*Functions (Nervous System)

*Sensory Input*Gathers information from the outside world and from the inside of the body


*Integration*Transmits information to the processing areas in the brain and spinal cord

*Processes information to determine the best response


*Motor Output*A response to integrated stimuli

*The response activates muscles or glands

*Smell of a fried chicken

*Experienced Break up

*Stimuli

*The changes that takes place in an environment

*Neurons (Nerve Cells)*The basic functional

units of structure and functions of the nervous system

*Carry information through the nervous system in the form of nerve impulses

*A Typical Neuron

*Neuron Anatomy

Cell Body• Contains

the nucleus which controls all the activities of the cell

Neuron Anatomy

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Extensions outside the cell body· Dendrites –

conduct impulses toward the cell body

· Axons – conduct impulses away from the cell body

Figure 7.4a

*Types of Neurons

*Sensory (afferent) neurons*Receive initial stimuli from sense organs where most receptors are located

*Types of Neurons

*Interneuron*Also called ‘connector’ neurons or ‘association’ neurons

*“read” impulses received from sensory neurons

*Found in spinal cord and brain

*Passes impulse to motor neurons

*Types of Neurons

*Motor (efferent) neurons*Carry impulses from the central nervous system

*Stimulate effector cells that generates reactions

*Ex. Feel the hot temperature

*Responding to a Stimulus

*Nerve impulse*A wave of chemical and electrical change conducted along the membrane of a neuron

*Responding to a Stimuli

*Synapses*Synaptic Activity

*Action potentials (nerve impulses):

*Are transmitted from presynaptic neuron

*To postsynaptic neuron (or other postsynaptic cell)

*The Structure of a Synapse

*The Structure of

a Synapse

*Synapses

*Neurotransmitters*Are form of chemical messengers

*Reflex*An automatic response to a stimuli

*Divisions of the Nervous System

*Central Nervous System

*Brain and Spinal Cord

*Peripheral Nervous System

*Somatic Nervous System

*Autonomic Nervous System

*Central Nervous System

*Brain*Encased by a bony covering called the ‘skull’

*Divided into 3 main parts

*Cerebrum

*Cerebellum

*Brain stem

*Regions of the Brain

*Cerebrum (Cerebral Hemisphere)

*Largest region of the brain

*Cerebral cortex: surface of the cerebrum

*Area where learning, intelligence and judgement occur

*Controls all the voluntary activities of the body

*Diencephalon

*Located under cerebrum and cerebellum

*Links cerebrum with brain stem

* Three divisions:

*Left thalamus

*Right thalamus

*Hypothalamus

*Diencephalon

*The Brain Stem

*Processes information between:

*Spinal cord and cerebrum or cerebellum

*Includes:

*Midbrain

*Pons

*Medulla oblongata

*Brain Stem*Midbrain:

*Processes sight, sound, and associated reflexes

*Maintains consciousness

*Pons:

*Connects cerebellum to brain stem

*Is involved in somatic and visceral motor control

*Brain Stem

*Medulla oblongata:

*Connects brain to spinal cord

*Relays information

*Regulates autonomic functions:

*heart rate, blood pressure, and digestion

*Cerebellum

*Second largest part of brain

*Coordinates repetitive body movements

*The Brain

Spinal Cord

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Located inside the backbone or the spine

· Relays nerve impulses to and from the brain

· Meninges cover the spinal cord

*Reflexes

*Automatic responses coordinated within spinal cord

*Through interconnected sensory neurons, motor neurons, and interneurons

*Produce simple and complex reflexes


*is the link between the nervous system to the rest of the body

*Made up of network of nerves that extends of the CNS and connects throughout the different organs of the body


*Consist of two types

*Somatic Nervous System

*Stimulates skeletal muscles under our conscious control

*Autonomic Nervous System

*Not under the direct of the conscious mind – involuntary

*Division of the Autonomic Nervous

System

*Parasympathetic

*Most active under normal conditions

*Sympathetic

*Dominates in time of physical or emotional stress

*How Neurons Work Video

Neurons How they work in the Human Brain - YouTube.flv

The Miracle in Human Brain - YouTube.flv

*Body control and response is controlled by ______________

*The functioning unit of the nervous system is ____________

*The Nervous system is divided into two parts, the ________________ and ___________________

*The central nervous system is made up of ______________ and ___________________

*The peripheral nervous system is divided into _______________ and ____________________

*Autonomic nervous system is divided into ________________ and _________________

Nervous system

neurons

Central nervous system Peripheral nervous system

brain Spinal cord

Somatic nervous system Autonomic nervous system

parasympathetic sympathetic

*Quiz

Test I Enumeration

1. Give the three different types of Neurons.

2. Give two functions of the nervous system.

3. Give the 4 important regions of the brain.

4. Give the two main parts of the nervous system.

Test II Essay

5. What is the importance of studying the nervous system?

Nervous system

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