ANIMAL PHYSIOLOGY Dr. Sam Rhodes Office Hours: T – 9-10, W 9-10, R 10-12, F 1:30-3:30 Tel:

Syllabus Class Organization Course Website The Importance of the Textbook

1. What is Physiology? Mechanistic approach Evolutionary approach 2. The Importance of the Hypothetico-Deductive Method

Interstitial fluid Plasma Blood Vessel Extracellular fluid Intracelluar fluid Cell Issues of Being Multicellular A. each cell has requirements B. interstitial fluid C. circulatory system D. cells form tissues and organs that perform specialized functions for the whole organism oxygen nutrients Carbon dioxide wastes

Organs are made of two or more types of of tissue (epithelium, connective tissue muscle or nerve) Organ systems consist of two or more organs functioning together to serve the body (exchange gases, obtain nutrients, void wastes All organ systems function together to provide the requirements of each cell in the body

Issues of Size and Scale SA / V = 6 SA / V = 3 Obtaining nutrients Voiding wastes Heat loss / gain Gas exchange

Homeostasis: maintaining a relatively constant internal environment Regulators (expend metabolic energy to maintain homeostasis) Conformers (do not expend metabolic energy to maintain homeostasis)

Maintain Homeostasis Is essential For survival of Cells Make up Body systems Fig. 1-6, p.11

Major Components of a Homeostatic Control System Set point Sensor (receptor) Integrator Effector Feedback

Sensor Integrator Effector(s) Compensatory response Controlled variable restored to normal Negative feedback to shut off the system responsible for the response Deviation in controlled variable Set Point (leads to) (results in) (brings about) (sends instructions to) (informs) *Relieves (detected by) Fig. 1-8a, p.13

Fig. 1-8c, p.13 Increase in fluid concentration Detected by the hypothalamus – which signals the pituitary Pituitary releases Antidiuretic Hormone which acts on the kidney Kidney produces a low volume of very concentrated urine. This helps retain more water in body Helps dilute body fluids and counteract affects of dehydration Provides Negative Feedback

Controlled variable Sensor Integrator Effector Set point Higher regulator (a) Reset control of negative feedback by a higher system or clock Fig. 1-10a, p.17

Integrator or regulatory process Deviation in controlled variable (May use a Sensor) Output (may use an effector) (b) Positive feedback Accentuates the change Fig. 1-10b, p.17

Uterus begins contractions Stretch sensors Mother’s hypothalamus Pituitary gland Contractions enhanced (c) Example of positive feedback: birth of a mammal Oxytocin secreted Signal from mature fetus Fig. 1-10c, p.17

Importance of Mathematical Modeling (Curve Fitting) Describe and communicate information effectively Make predictions about the function of a system Help to formulate and select from alternative hypotheses