The Nervous System A REGULATORY SYSTEM The Nervous

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The Nervous System A REGULATORY SYSTEM

The Nervous System A REGULATORY SYSTEM

The Nervous System q The billions of neurons in the body integrate to form

The Nervous System q The billions of neurons in the body integrate to form complex networks that gather sensory input, process information, and execute some type of action. q Nerves – are bundles neurons that appear as fine white threads to the unaided eye.

The Nervous System NEURONS CONDUCT ELECTRICAL SIGNALS p Neurons – cells that transmit nerve

The Nervous System NEURONS CONDUCT ELECTRICAL SIGNALS p Neurons – cells that transmit nerve impulses.

The Nervous System p Dendrites – cytoplasmic extensions of a neuron that receives stimuli.

The Nervous System p Dendrites – cytoplasmic extensions of a neuron that receives stimuli. p Axons – an elongated extension of a neuron that conducts nerve impulses.

The Nervous System q. Cell Body -The portion of a nerve cell that contains

The Nervous System q. Cell Body -The portion of a nerve cell that contains the nucleus but does not incorporate the dendrites or axon. Also called soma. q. Axon hillock - The conical area of origin of the axon from the nerve cell body. Axon Hillock

The Nervous System q. Myelin Sheath - The insulating envelope of myelin that surrounds

The Nervous System q. Myelin Sheath - The insulating envelope of myelin that surrounds the core of a nerve fiber or axon and facilitates the transmission of nerve impulses. q. Node of Ranvier - are gaps between adjacent myelin sheaths in which the axons are not covered by myelin. Myelin allows the fast conduction of nerve impulse.

The Nervous System q Axon Terminal - The somewhat enlarged, often club-shaped endings by

The Nervous System q Axon Terminal - The somewhat enlarged, often club-shaped endings by which axons make synaptic contacts with other nerve cells or with effector cells.

The Nervous System p Membrane Potential – difference in the electrical charge across a

The Nervous System p Membrane Potential – difference in the electrical charge across a cell membrane. p The membrane potential is dependent upon the concentrations of sodium and potassium ions inside and outside the cell. These ions move into and out of the cell by voltage gated ion channels. p The Differences of charges within neurons and the fluid outside them causes a membrane potential, which is measured in volts.

The Nervous System q Resting potential is -70 mv. Sodium channels are closed and

The Nervous System q Resting potential is -70 mv. Sodium channels are closed and potassium channels are open allowing them to leave the cell. Resting Potential – membrane potential of a neuron that is not conducting a nerve impulse.

The Nervous System p Action Potential – sudden reversal of polarity across a neuron

The Nervous System p Action Potential – sudden reversal of polarity across a neuron membrane. p When the nerve is stimulated it reverses its polarity, by becoming more positive inside the nerve cell +40 mv.

The Nervous System p Sodium channels open causes Sodium ions to move into the

The Nervous System p Sodium channels open causes Sodium ions to move into the cell. An action potential moves down the neuron from the cell body to the axon terminal.

The Nervous System q The myelin sheath around the axon allows the nerves impulse

The Nervous System q The myelin sheath around the axon allows the nerves impulse to move much quicker than if it were not mylelinated. The nerves impulse skips to the nodes of Ranvier.

The Nervous System NEURONS USE NEUROTRANSMITTERS TO COMMUNICATE A nerve impulse will travel down

The Nervous System NEURONS USE NEUROTRANSMITTERS TO COMMUNICATE A nerve impulse will travel down the axon to the axon terminal. p Synapse – junction at which a neuron meets another cell. p Neurotransmitters – signal molecule that transmits nerve impulses across synapse.

The Nervous System p There is a space between neurons called a synapse. In

The Nervous System p There is a space between neurons called a synapse. In order to relay a message to the next neuron the electrical impulse is converted into a chemical signal that can move across the synaptic cleft. p The nerve cells make chemicals called neurotransmitters that serve this purpose. p Neurotransmitters are stored in vesicles and are released into the synapse when a nerve impulse reaches the axon terminal.

The Nervous System p Neurotransmitters are very specific and will only bind to one

The Nervous System p Neurotransmitters are very specific and will only bind to one kind of receptor and not others.

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY p The Central Nervous

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY p The Central Nervous System consists of the brain and spinal cord. It is most developed part of the nervous system. p The peripheral nervous system is all the other neurons that run throughout the body. They can be sensory neurons or motor neurons. p Somatic is the part of the peripheral nervous system you can control. Ex. Messages from brain to muscles that allow you to move your arms and legs while walking.

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY Autonomic is part of

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY Autonomic is part of the peripheral nervous system that you do not consciously control. Has two parts: q Parasympathetic controls “Rest and Digest” q Sympathetic controls “Fight or Flight”

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY q Receptors are groups

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY q Receptors are groups of specialized cells which can detect energy changes in the environment and turn them into electrical impulses. q Receptors are often located in the sense organs - ear, eye, skin etc with each organ having receptors sensitive to particular kinds of stimulus.

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY p Sensory Neurons –

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY p Sensory Neurons – neurons that send information from the sense organs to the central nervous system. p Motor Neurons - neuron that sends motor responses from the central nervous system to muscles, gland, and other organs. p Interneuron – neurons that link neurons to each other.

The Nervous System Reflexes p p p Receive stimulus (receptor) Sensory neuron Spinal cord

The Nervous System Reflexes p p p Receive stimulus (receptor) Sensory neuron Spinal cord (interneuron) Motor neuron Effector- muscle gland.

The Nervous System p Simple Reflex - a rapid unconscious response to a specific

The Nervous System p Simple Reflex - a rapid unconscious response to a specific stimulus. p Conditioned Reflex - response that is conscious and learned.

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY An effector organ is

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY An effector organ is any organ which has an effect. For example: n A muscle contracting to move your arm, a muscle squeezing saliva out of your salivary gland. n Could be an endocrine gland squirting a hormone into your blood.

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY Cerebrum Thalamus Cerebellum Corpus

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY Cerebrum Thalamus Cerebellum Corpus collasum hypothalamus Pituitary gland Brain Stem

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY Meninges 3 tough membranes

The Nervous System THE CENTRAL NERVOUS SYSTEM CONTROLS THE BODY Meninges 3 tough membranes that cover the brain and spinal cord. Cerebrum The largest part of the brain. Where memory, thinking, reasoning and motor control occur. Cerebellum Balance and coordination. Voluntary movement and muscle tone. Medulla Nerves that control involuntary actions: breathing, heart rate, blood pressure and digestion Spinal cord Links brain to the peripheral nervous system. White myelin sheath of neuron. Thalamus Relay center, sensory processor. Hypothalamus Controls temperature, emotions, sleep. Corpus collasum Connects the right and lefts sides of the cerebrum

The Nervous System p Malfunctions of the Nervous System p Meningitis - Inflammation of

The Nervous System p Malfunctions of the Nervous System p Meningitis - Inflammation of the membrane around the spinal cord and brain. Caused by bacteria fungi, and viruses. p Cerebral Palsy - is a term used to describe a group of chronic disorders impairing control of movement that appear in the first few years of life and generally do not worsen over time. The disorders are caused by faulty development of or damage to motor areas in the brain that disrupts the brain's ability to control movement and posture. p Stroke - blood clot between the brain and the heart. Results in damage brain when it is deprived of oxygen and nutrients in the blood.

The Nervous System p Malfunctions of the Nervous System p Parkinson's Disease (PD) -

The Nervous System p Malfunctions of the Nervous System p Parkinson's Disease (PD) - for reasons that are not fully understood, nerve cells in the part of the brain that produces dopamine, called the substantia nigra, begin to decrease in number. This causes a decrease in the amount of the available dopamine. p Dopamine is an important neurotransmitter that triggers neurons that will ultimately control skeletal muscles.

The Nervous System p Malfunctions of the Nervous System p Polio - caused by

The Nervous System p Malfunctions of the Nervous System p Polio - caused by a virus that damages grey matter, symptoms include weakness in muscles. Jonas Salk and colleagues created a vaccine in 1955. p Alzheimer's - disease is the most common cause of dementia. Dementia is a collective name for progressive degenerative brain syndromes which affect memory, thinking, behavior and emotion. Symptoms may include: loss of memory, difficulty in finding the right words or understanding what people are saying, difficulty in performing previously routine tasks, And personality and mood changes. p Multiple Sclerosis (MS) - is an inflammatory disease of the Central Nervous System (CNS) - that's the brain and spinal cord. Predominantly, it is a disease of the "white matter" tissue. The white matter is made up of nerve fibers, which are responsible for transmitting communication signals both internally within the CNS and between the CNS and the nerves supplying rest of the body.

The Nervous System p Drug addiction- dependence on drug, an uncontrolled habit. n Stimulants

The Nervous System p Drug addiction- dependence on drug, an uncontrolled habit. n Stimulants - Increased alertness, reduce, fatigue, increased blood pressure, and increased breathing. n Depressants - relieves anxiety, nervousness, tension, and slows the CNS.

The Nervous System ANIMATIONS Nerve Muscle Connection http: //www. innerbody. com/anim/arm. html Action Potential

The Nervous System ANIMATIONS Nerve Muscle Connection http: //www. innerbody. com/anim/arm. html Action Potential p http: //www. wisc-online. com/objects/index_tj. asp? objid=AP 1201 p http: //www. blackwellpublishing. com/matthews/channel. html p http: //www. blackwellpublishing. com/matthews/actionp. html p Synapse http: //www. blackwellpublishing. com/matthews/nmj. html Various nerve animations http: //highered. mcgrawhill. com/sites/0072437316/student_view 0/chapter 45/animations. html# Cranial Nerves http: //www. wisc-online. com/objects/index_tj. asp? objid=AP 11504 Upper and lower motor neurons http: //www. wisc-online. com/objects/index_tj. asp? objid=AP 21204 p http: //outreach. mcb. harvard. edu/animations/actionpotential. swf p p p

The Nervous System ANIMATIONS Sense Organs Ear p p p http: //www. wisc-online. com/objects/index_tj.

The Nervous System ANIMATIONS Sense Organs Ear p p p http: //www. wisc-online. com/objects/index_tj. asp? objid=AP 1502 http: //www. wisc-online. com/objects/index_tj. asp? objid=AP 14204 http: //highered. mcgraw-hill. com/sites/0072437316/student_view 0/chapter 46/animations. html Eye p http: //www. wisc-online. com/objects/index_tj. asp? objid=AP 14304 p http: //www. innerbody. com/anim/ear. html http: //www. innerbody. com/anim/vision. html p Taste p http: //www. bbc. co. uk/science/humanbody/factfiles/taste_ani_f 5. swf p http: //www. wisc-online. com/objects/index_tj. asp? objid=AP 14104 Smell p http: //www. bbc. co. uk/science/humanbody/factfiles/smell_ani_f 5. swf