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Transcript of Human Nervous System Most Remarkable Communication Center Regulates the actions of organs ...
Human Nervous System
Most Remarkable Communication Center Regulates the actions of organs Monitors the senses Controls one’s thinking, learning & memory capacity Specialized nerve receptors in sensory organs of
eyes, ears, nose Constantly send data to brain at 300 mph
February 2, 2010
New Notebooks… Get ‘er done!!
Please turn to 36.1 page 973
Draw a neuron on the left side… Label it please…
Notes 36.1
Nervous System!!Chapter 36
Neurons – nerve cells which conduct impulses thru/out body - can be 1 m long in humans
Composed of 3 parts: 1. Cell body – contains the nucleus, interprets 2. Axon – carries impulses away from the cell
body 3. Dendrite – receive stimuli and conduct
towards the cell body Synapse – space that separates neurons from
each other, a chemical neurotransmitter is released that bridges the gap and is unidirectional
1. The basic unit of the nervous system = neuron?
Dendrites receive stimuli
Nerve cell body@ nucleus transmits the stimuli
Axon transmits the impulse to another dendrite
Resting neuron has a polarized membrane “– “ inside the cell, “+”outside the cell,
that can transmit an electrical charge or impulse Depolarization - increase in Na+ inside
cell give it a positive charge (wave) moves at speeds > 130m/sec
myelin - covers the axon (white matter) allows impulse to “jump”
gray matter - found in CNS brain, spinal cord
Axon ending: terminal bud
Transfers the electrical nerve impulse
By chemical neuron-transmitters
From one neuron to the next
Nerve depolarization is all or none principle
What is the function of the nervous system?
To receive information from a sensory neuronTo process info by the brain & spinal cordTo respond by an effectors
(muscle/gland)
The Central Nervous System:1) Spinal Cord
2) Brainmedulla for
breathingcerebellum for
balancecerebrum for higher thinking bw
Central Nervous System (CNS) Central Nervous System (CNS) - brain and
spinal cord, receives and processes info and makes appropriate response
1. Cerebrum - 2 hemispheres, intelligence, memory, verbal, language, senses, “bridge connection”
2. Cerebellum - controls balance, posture, coordination
3. Medulla Oblongata – involuntary responses like heartbeat, breathing
Right versus left Cerebrum
Peripheral Nervous System Peripheral Nervous
System (PNS) - all nerve pathways from the CNS to rest of body
1. Somatic Nervous System – voluntary system, connection between spinal cord cranial & spinal nerves, skinReflex - automatic
response to a stimulus, sensory neurons, spinal cord, motor neurons
R-SIM Reflex arc pathway . . . R
receptor neuron receives the stimuli S
sensory neuron passes the impulse on I
interneuron at the spinal cord processes M
motor neuron acts
Autonomic Nervous System 2. Autonomic Nervous System - carries
impulses from the CNS to internal organs, involuntary controlled by the hypothalamus (BP, stomach movements, body temp, homeostasis)
a. Sympathetic Nervous System -
fight or flight b. Parasympathetic Nervous System –
rest/relaxing
The Autonomic Nervous System
Sensory neurons or“receptors” receive a stimulus from:
eyes - sight ears - hearing nose - smell skin - touch mouth - taste