regulation: nervous system. a world without pain perry goldberger, 15, can't distinguish...
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NERVOUS SYSTEM NERVE REGULATON STIMULUS: Example – heat From a stove IMPULSE: Example – neurons Send a message to CNS to tell the hand To move RESPONSE: Example – removing Hand off the stoveTRANSCRIPT
Regulation:Nervous System
A World Without Pain
Perry Goldberger, 15, can't distinguish between hot and cold and cannot feel pain
Four-year-old Roberto Salazar does not feel pain because of a rare genetic disorder.
NERVOUS SYSTEM
NERVE REGULATON
STIMULUS:Example – heat
From a stove
IMPULSE:Example – neurons Send a message to CNS to tell the hand
To move
RESPONSE:Example – removing
Hand off the stove
HUMANNERVOUSSYSTEM
Central Nervous System (CNS) –brain and spinal
cord
Peripheral Nervous System (PNS) –
nerves outside the CNS
Nerve Cells
• Nerve cells = neurons• Receive impulses and send the
messages to various parts of the body via Cellular Communication
• Nerve cells make up:– Nerves– Brain– Spinal cord – Receptors
????
• You accidentally place your hand on a hot iron and quickly move it away.– What is the stimulus?– What is the impulse?– What is the response?
• What is the difference between the CNS and PNS?
• What is the function of a neuron?
Neuron Structure
• 1. Cyton- cell body• 2. Cell nucleus• 3. Dendrites –
receive impulses
Neuron Structure Cont…• 7. Axon – carries
impulses away from the dendrites
• 6. Myelin Sheath – fatty covering of the axon which speeds up impulses
• 5. Schwann Cells (make myelin)
Neuron Structure Cont…• 9. Terminal Branches• Synapse – gap where
impulses travel from the axon of one neuron to the dendrites of another neuron.
• Neurotransmitters – chemical messengers that cross the synapse
Types of Neurons
– Sensory: carry impulses to the CNS– Motor: carry impulses from the CNS to
other parts of the body such as muscles– Mixed: contain both
Receptors• Receive messages• Found on the cell membrane and are
VERY SPECIFIC!!!
CNS
The Brain• Cerebrum – thinking,
memory, voluntary actions, emotions
• Cerebellum – coordination and balance
• Medulla (brain stem) – involuntary actions like breathing and heartbeat
Spinal Cord
• Mass of nerve cells • Vertebrae – protect it• Function –
– relays impulses to and from the brain– center for some reflex actions
Autonomic Nervous System• Part of the peripheral nervous system• Controls involuntary behavior (automatic)• Examples:
– Breathing– Heart rate– Blinking, dilation of pupil– Production of saliva– Increases and decreases the rate of these
involuntary behaviors to help maintain homeostasis
Reflexes- Reflex arc• Involuntary behavior• Reflex:
– Receptor (nerve endings in the knee) receive a message
– Sensory neuron sends to message to the spinal cord (CNS)
– The interneuron connects the sensory neuron to the motor neurons
– The motor neuron sends the message to the muscle in the leg (EFFECTOR)
– Effector then reacts such as a knee jerk
Somatic Nervous System
• Part of the peripheral nervous system• voluntary behavior• Examples: movement of skeletal
muscles
Disorders of the Nervous System
Cerebral Palsy
• Birth disorder that affects motor function.
Polio
• a viral pathogen that weakens muscles and leads to paralysis
Stroke
• When a free-floating blood clot reaches the brain
• Blood vessel ruptures in the head/neck
Meningitis
• Inflammation of the meninges (membrane surrounding the brain and spinal cord)
• Can be viral (not severe) or bacterial (VERY severe)
• Symptoms come quickly– Fever and chills, nausea and vomiting,
sensitivity to light, severe headaches
The meningococcal vaccination is recommended for:
• Adolescents ages 11 - 12 and adolescents entering high school (about age 15) who have not already received the vaccination.
• All college freshmen who have not been vaccinated and are living in dorms.
• Those traveling to countries where diseases caused by meningococcus are very common