Introductions Biology 235 Questions Human Physiology Roots Fall Semester, 2009 Physiology Foundations Integrated Physiology

Physiology – It’s Roots Physiology – It’s Roots

• One of the oldest branches of science • Next big influence was Galen • Starting around 420 B.C. – 129-200 (ish) A.D. – Hippocrates – – Became father of modern medicine, studied • moved it from theology and religion into its own field anatomy* extensively – Argued that disease was not a handout from angry Gods, but rather from poor diet, environment, and habits • His drawings of mammalian structure were used • Called the “father of medicine” until 1500’s! • Founded Hippocratic School of Medicine • Developed the concept that the brain controls the • His sons, and son-in-law studied under him muscles and that there where cranial and – Polybus (son-in-law) and Thessalus founded the Dogmatic peripheral nervous systems School of Medicine

*of monkeys – human dissection not allowed

1 Physiology – It’s Roots Physiology – It’s Roots

• Not much happened until… • William Harvey (1578 – 1657) – Vesalius (1514 - 1564) was an anatomist and – Correctly figured out systemic circulation and the physician properties of blood and its pumping • Did extensive human dissection • Fixed a century old belief that blood only circulated – Published the premier book on human anatomy De continuously in the lungs humani corporis fabrica – Figured out the function of venous valves – Corrected the error of Galens circulation pattern – First to use quantitative analysis in study of human • However held onto the misconception that arteries and veins function carry different types of blood • Measured how much blood the heart pumped in a day (540 – Fame led him to become the physician to the Holy pounds) which then made Galen look silly. . . the liver would have to manufacture 540 pounds of blood each day! Roman Emperor Charles V – Was the personal physician to James I & Charles I

Physiology – It’s Roots Physiology – It’s Roots

• (1813 – 1878) • Walter Bradford Cannon (1871 – 1945) – The first to establish scientific methodology in – Chaired the Department of Physiology at medicine – Introduced experimental medicine and specifically “blind studies” to ensure objectivity – Coined the term “fight or flight” – Introduced “Milieu interieur” which was the initial – Did work with x-rays and different metals to concept of improve x-ray quality of bowels (today’s • “The constancy of the is the condition barium meal is a direct result) for a free and independent life” • Furthered in the next century by William Bradford Canon – Given credit for concept of homeostasis, published it in 1932

2 Physiology Foundations Organizational Hierarchy in Biology

• Organization biosphere ecology ecosystem • Homeostasis & Controls community • Biological Energy population • Structure Function Relationships organisms organ systems • Communication physiology organs

tissues cell biology molecular cells biology molecules chemistry atoms

Homeostasis Homeostasis • Components • The maintenance of physiological – Receptor parameters within the body/cell • Monitors the controlled condition – “homeo” = similar or like • Creates input signal – “stasis” = condition or state – Control center • Processes input signal • Provides a teleological answer to questions • Makes decision • Creates output signal • Acts in a mechanistic way – Effector – Components • Returns controlled condition to normal state in one of two ways –Process

–Types output signal receptor input signal control effector center

3 Homeostasis Functional unit in Homeostasis Process: homeostasis • Types of homeostasis maintenance pathways external internal – Negative Feedback Loop Mechanisms change change • Common – Reverse the change in the regulated variable back to normal change results in disruption • May be local or long distance of homeostasis – Require reflex pathways – Positive Feedback Loop Mechanisms compensation for change is •Rare attempted (feedback processes) – Enhances the stressor in a cascading effect until stressor is removed, causing regulated variable to return to normal

compensation fails compensation succeeds – Controls • Aid in homeostatic processes by “anticipating” events, rather than waiting for them to happen and then responding

illness/disease Wellness/health

Homeostasis Homeostasis • Negative Feedback Control Example: blood Ca2+ levels • Other Negative Feedback Examples? regulated variable blood levels of calcium receptors in plasma normal value 8.5 – 10.5 mg/dl body temperature membrane maintenance drop in blood rise in blood levels of Ca2+ change causes levels of Ca2+ blood glucose levels ventilation rates blood pressure regulation PTH secretion is PTH secretion is Urine concentration/ stimulated inhibited thyroid hormone levels dilution pH controls ↑Vit D ↑Ca2+ release ↑Ca2+ uptake ↓Vit D ↑Ca2+ ↑Ca2+ CO levels synthesis from bone by bone synthesis 2 reabsorption secretion by cell cycle GI motility & secretion in kidney kidney blood Ca2+ levels normalize ↑Ca2+ uptake ↓Ca2+ uptake in GI tract in GI tract

4 Homeostasis Homeostasis • positive feed back control example: childbirth (parturition)

regulated variable • Other examples of positive feedback loops? female reproductive tract

change lactation

End of term fetus, uterus contracts, some enzyme production increases pressure on the cervix

pressure causes release of oxytocin hemostasis (blood clotting)

Oxytocin causes increased contraction of the uterus & relaxation of cervix

Process continues until the cervix is dilated enough and the uterus contractions expel the fetus

Homeostasis Biological Energy

• Feedforward loops? • What is the Biological Energy Currency? – Adenosine Triphosphate (ATP)

•Why?

• How is it made?

5 Structure v Function Communication

• How are the two related? • Major theme in physiology –Forms • Electrical • Can they be separated? • Chemical –Between • Cell/cells • Tissues • Organs… • Communication allows for the integration of physiology!

Integrated Physiology Integrated Physiology Illustrations

Integumentary System • What is it? Respiratory system Nervous system

Circulatory system

• How can we grasp it? Endocrine system

Digestive system • Examples of a integrated physiology illustrations

Musculoskeletal system Urinary system

Reproductive system

6 Integrated Physiology Illustrations Biology 235 Biology Biology 235 Biology Graphic Syllabus Graphic Syllabus

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