Anatomy and Physiology Sam Rhodes, Ph.D. Professor of Biology What is it?
Post on 25-Dec-2015
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Anatomy:
Physiology:
Structure and Nomenclature of the Body Parts
Function, Chemistry and Physics of the Body Systems
So what do we expect you to learn in this class (and all college classes)?
1. Learn/memorize specific facts
2. Communicate effectively in writing and orally
3. Use the information you learned to solve problems.
Anatomy and Physiology Are Sciences
• Science relies on empirical evidence. If you can’t measure something then it is out of the realm of science.
• Scientists accept uncertainty. We never know something as “absolutely true.”
• Scientists use controlled experiments and repetitions to reduce uncertainty and increase confidence.
The Scientific Method
Hypothesis: Should attempt to explain what is observed. “Why did the observation happen?”
The Experiment: Produces new empirical evidence that may support or refute the hypothesis.
The hypothesis may have to be refined or completely changed.
The Scientific Method is Comparable to a Court of Law
A crime is committed (observation of fact)
The prosecutor states that the defendant is guilty (hypothesis)
Both lawyers present new evidence (experiments)
The jury examines the evidence and draws a conclusion (the hypothesis is accepted or rejected).
Important Note: just because the jury draws a conclusion doesn’t mean it is correct.
The Scientific Community
• Relies on many repetitions to build confidence• Uses controlled experiments
Experimental Condition: the individuals are treated with variable stated in the hypothesis
Control Condition: the individuals are treated exactly like the experimental EXCEPT for the variable in the hypothesis.
• Publishes and distributes results for peer review
What is a theory?• A hypothesis that is supported by
a great deal of experimental evidence from a variety of different sources.
• A hypothesis that has been examined by a large number of different scientists and is accepted as the best explanation for the existing data.
• Only subject to change if new data or a substantially different, and equally valid, explanation is given.
Homeostasis: Central Theme of Physiology
• How do we define homeostasis?• “Maintaining a relatively constant internal
environment, despite changes in the external environment.”
• How does the body maintain homeostasis?• Receptors, Integrator/Controller, Effector,
Feedback.
Receptor: cells that detect a change in a specific physiological parameter
Integrator/Controller: receives input from the receptor and compares the input to an ideal setpoint. If input differs from setpoint, then an efferent signal is sent to an effector.
Effector: tissue or organ that can directly change (increase or decrease) the specific physiological parameter. It directly EFFECTS the parameter.
Feedback: A change in the the specific parameter that is detected by the receptor. “Tells the receptor” that the parameter has changed.
Goal of Glucose Homeostasis
• Glucose is an essential nutrient needed by all tissues.
• Maintain blood glucose close to 100 mg/100 mL
• When glucose levels are low, release glucose from body stores.
• When glucose is high, take glucose out of blood and store in the liver and muscle.
Homeostasis of Resting Blood Pressure
• Large blood vessels contain nerve endings that detect when blood pressure is low
• The nerve endings send signals to the “cardiac center” in the brain that compares the information to the normal set-point of blood pressure.
• If blood pressure is too low, the cardiac center will signal the heart to beat at a faster rate.
• The increased heart rate will cause blood pressure to increase.
• The increased blood pressure is detected by the nerve endings in the large arteries.
1. Nerve endings detect thatblood pressure is low.
2. Signal sent to the cardiaccenter in the brain
3. Cardiac center comparesblood pressure to the setpoint.
4. Cardiac center sends signal to increase heart rate.
5. Increased heart ratecauses blood pressure toreturn toward set point.
6. The increased blood pressure provides negative feedback to the nerve endings.
Analysis
• What is the Receptor in the cardiac control system?
• What is the Controller?• What is the Effector?• What is the Negative Feedback?
Understanding the Organization of the Body
Cells: fundamental units of all living organisms. Cells are specialized to specific functions in the body. There is a division of labor. Some cells produce mineral for bone, some cells produce protein for muscle contraction, etc.
Tissues: Tissues are groups of similar cells that function together. There are four major categories of tissues - epithelium (coverings and linings), connective tissue (strength, support), muscle (contraction), and nerve (control and communication).
Organs: Combinations of two or more tissues. The skin is an organ because it is composed of epithelium, connective tissue and small amounts of nerve and muscle.
Organ Systems: Combinations of organs that together serve a general function for the body. For example, the circulatory system pumps blood and carries nutrients, wastes and gases to cells throughout the body.
Introduction to ChemistryThe Study of Changes in Matter.
Gain & Release of Energy
Changes in Physical State (solid, liquid, gas)
Changes in Physical Properties: Elasticity, Density, Color, Smell
The world is made up of 92 naturally occurring substances which can not be reduced to a simpler state by chemical reactions. These substances are called elements.
Important biological elements include:
Carbon: CHydrogen: HOxygen: ONitrogen: NSodium: NaPotassium: KChloride: ClPhosphorous: PSulfur: SCalcium: CaMagnesium: Mg
Each Element Has Unique Physical and Chemical Properties
Carbon: a crumbly, black solid
Magnesium: a shiny, highly reactive metal
Chlorine: A green corrosive gas
When Two Elements React, They Form Compounds That May Have Completely Different Properties
Magnesium Metal
Chlorine Gas
Magnesium ChlorideA white Powder ThatDissolves in Water
Radioactive DecaySpontaneous Decomposition of an
Unstable Atom
Alpha Particle = two protons and two neutrons
Beta Particle = electron
Chemical Reactions Involve an Exchange of Energy and a Rearrangement of Chemical Bonds.
2 H2 + O2 2 H2 O
H-H H-H O-O O O H H H H
Two hydrogen molecules and one oxygen molecule react to form two water molecules
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