One evening a grandfather told his grandson about a battle that goes on inside people. He said, “My son, the battle is between two wolves inside us all. “One is Evil – It is anger, envy, jealousy, sorrow, regret, greed, arrogance, self-pity, guilt, resentment, inferiority. “The other is Good – It is joy, peace, love, hope, serenity, humility, kindness, benevolence, empathy, generosity, truth, compassion and faith.” The grandson thought about it for a minute and then asked his grandfather: “Which wolf wins?” The grandfather simply replied, “The one you feed”
Mission Hills High School The Nervous System Mission Hills High School
Myelin in PNS and CNS Axons in large peripheral nerves contain a fatty, supportive sheath called myelin sheath Presence of myelin makes nerve tissue appear white (white matter) In CNS spinal cord, unmyelinated nerve tissue appear gray (grey matter)
What makes up the brain, the spinal cord or your peripheral nerves? Neurons are “the cell” Cell body Nucleus Axon Dendrite What do you think surrounds the cell? What other organelles would be needed?
A nervous impulse is an electrochemical wave How might it be similar to a wave in the ocean?
Check it out! http://www.youtube.com/watch?v=9euDb4TN3b0
In Summary… A nervous impulse is called an action potential. Depolarization occurs when sodium ions enter the neuron. Repolarization occurs when potassium ions exit the neuron. Sodium Potassium Pumps restore the concentrations during the refractory period.
How are neurons connected? Synapses!!
Why are neurons connected?
More neuron connections!
Close up look at your synapse (The Gray Matter) AXON What is this in the membrane? The synapse - where the action happens Transport protein The next cell’s plasma membrane
How does the Synapse carry the signal? 1. impulse travels down the axon (The White Matter) Vesicles with neurotransmitters move toward the membrane Neurotransmitters are released and diffuse toward the next cell’s plasma membrane 4. The chemicals open up the transport proteins and allow the signal to pass to the next cell
The synapse carries a signal from cell to cell 1 3 4 2
The Reflex Arc
Action of peptide hormones 15.1 Endocrine glands Action of peptide hormones
Action of steroid hormones 15.1 Endocrine glands Action of steroid hormones
Visualizing the vital capacity 9.4 Mechanism of breathing Visualizing the vital capacity
9.6 Gas exchanges in the body External respiration Exchange of gases between the lung alveoli and the blood capillaries PCO2 is higher in the lung capillaries than the air thus CO2 diffuses out of the plasma into the lungs The partial pressure pattern for O2 is just the opposite so O2 diffuses the red blood cells in the lungs Carbon dioxide transport: carbonic H+ + HCO3- H2CO3 anhydrase H2O + CO2 Oxygen transport: Hb + O2 HbO2