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Module 6: The nervous system and the endocrine
system
Identify and describe the functions of the parts of a neuron
Explain the process of neural transmission Explain the roles of neurotransmitters in the
neural transmission Identify and describe the divisions of the
nervous system Discuss the nature and the function of the
endocrine system communication
Learning goals:
Neurons: the building blocks of the nervous system(biology review) Nervous system is electrochemical
communication system Neurons-a nerve cell; basic building block of
the nervous system Example:brain, spinal cord, and nerves Neuron used for 3 tasks1. Receive information(form of electrochemical
impulses2. Carry information down its length3. Pass information on to the next neuron in line
Behavior thought and emotion you’ve experienced is dependent on the ability of the neuron to process information(ability to do 3 steps)
Fire or not fire Dendrites- branching extensions of a
neuron that receive information and conduct impulses toward the cell body
Soma-the cell body of a neuron which contains the nucleus and other parts that keep the cell healthy
Axon-the extension of a neuron through which neural impulses are sent
length of axon is dependent upon location Example brain VS leg Longer axons covered by myelin sheath that
protects the axon and speeds up the transmission of information
axon terminals-the endpoint of a neuron where neurotransmitters are stored
Neuron firesAction potential-a neural impulse;a brief
electrical charge that travels down the axon of a neuron
Refractory period-the “recharging phase” during which a neuron after firing can not generate another action potential
Example camera flash resting potential-the state of a neuron when
it is at rest and capable of generating an action potential
How do neurons communicate
All-or-none-principle that states that if a neuron fires it always fires at the same intensity;all action potentials have the same strength
Example toilet http://www.funnypicturefunnyphoto.com/
funny-picture-photo-toilet-mural-dark-mephi.jpg
Doesn’t necessarily need 2 neurons to meet Synapse-the tiny, fluid filled gap between
the axon terminal of one neuron and the dendrite of another
Neurotransmitter-a chemical messenger that travels across the synapse from one neuron to the next and influences whether a neuron will generate an action potential
When action potential works towards end of neuron it causes the release of neurotransmitters from the axon terminals
Communication between neurons
Neurotransmitters have unique shapes and rapidly cross the synapse and fit into receptor sites on the dendrite
Neurotransmitters can come to rest only in receptor sites designed to fit the their shape. Once in side can serve as 2 functions:
1. excitatory factor-a neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential or fire
2. inhibitory factor-a neurotransmitter effect that makes it less likely that a receiving neuron will generate an action potential or fire
Example just do it or red light
Think of a radio station? What is the steps to hearing a song on the radio
Receptor cells-(antenna) specialized cells in every sensory system of the body that can turn other kinds of energy into action potentials(neural impulses) that the brain can process
Examples light and sound sensory nerves- carry information from the
sense receptors to the spianal cord and brain Interneurons- nerve cells in the brain and spinal
cord responsible for processing information
Neural chain
Senosry information enters the body through receptor cells
Brain processes the sensory info and decides what to do
Motor nerves receive commands from the brain and react
Brain determines when action is necessary to deal with incoming information
Brain determines course of action To trigger actions the brain must get word
to the body’s muscle Motor nerves-nerves that catrrty
information away from the brain and spinal cord to the muscles and glands
2 major components:1. Central nervous system(CNS)-brain
and spinal cord2. Peripheral nervous system(PNS)-
contains all sensory nerves and motor nerves that connect the brain and the spinal cord to the rest of the body
CNS is encased in bone for protectionInterneurons are responsible for processing
information
Structure of the nervous system
PNS divides into 2 systems:1. Somatic nervous system- division of the
peripheral nervous system that controls the body’s skeletal muscle
Example-develop idea to walk across the classroom, CNS commands -> somatic nervous system commands legs to move
2. Autonomic nervous system-division of the peripheral nervous system that controls the glands and muscles of the internal organs.
PNS
sympathetic nervous system- the part of the autonomic nervous system that arouses the body to deal with perceived threats
Fight or flight responseParasympathetic nervous system-calms
the body down
Subdivisions of autonomic nervous system
Besides nervous system, endocrine system is another way for communicating
Slower communicating system Endocrine system-one of the body’s 2
communicating systems; a set of glands that produce hormones, chemical messengers that circulate in the blood
Hormone-chemical messengers that circulate throughout the body in the blood
Endocrine system
Hormones and neural transmitters are similar
Carry and communicate messages to receptor sites
Pituitary gland- “master gland” controls endocrine glands
Connected to hypothalamus Work together to monitor levels of glucoseand insulinThyroid, adrenal glands examples
cont
http://parsonsdc.com/faq.aspx
http://www.rmcybernetics.com/science/cybernetics/ai_vision_perception_brain.htm