PHYSIOLOGY

Vertebrate Physiology Dr. Kristin Hager 334 Jordan Life Sciences Khager1@nd.edu Office Hours Tuesdays 11:00 AM-1:00 PM Sign-up sheet outside of Jordan 232

How to do well... Reading in the textbook ‘Human Physiology’ (D.U. Silverthorn) is required. Do it BEFORE the lecture. Use CourseWare (webfile) for Syllabus, Lectures, Movies: CourseWare: CourseWare (sp.11): /afs/nd.edu/courses/bios/bios30344.01 Lecture PowerPoints for the week will be uploaded every Monday Hesburgh reserve readings available for extra help.

Suggested Supplementary Reading Material Textbook of medical physiology / Arthur C. Guyton, John E. Hall. 2011. Essentials of human anatomy & physiology / Elaine N. Marieb. 2009. Human physiology and mechanisms of disease / Arthur C. Guyton and John E. Hall. 1997. Human physiology: from cells to systems / Lauralee Sherwood. 2010. Review of medical physiology/ William F. Ganong. 2010.

EXAMS Four exams Each exam will contribute 25% of grade. Feb 10 March 10 April 14 Finals week (May 9-13) Each exam will contribute 25% of grade. Material will come from text and lecture.

Levels of organization and the related fields of study Copyright © 2009 Pearson Education, Inc.

System Organ Tissue Cell Cardiovascular Heart Myocardium Muscle Cell

Integration between systems of the body

Homeostasis

Homeostasis Claude Bernard (1880’s) ‘constancy of the internal environment’ Walter B. Cannon (1929) Regulation of a ‘relatively constant internal environment’

Physiology is an Integrative Science

Homeostasis Summary

Physiological control systems keep regulated variables within a desired range during homeostasis

Factors under homeostatic control nutrients gases waste products pH salt and other electrolytes temperature volume and pressure

Normal Ranges for Some Blood Values Arterial pH 7.35-7.45 Bicarbonate 24-28 mEq/L Sodium 135-145 mEq/L Calcium 4.5-5.5 mEq/L Oxygen content 17.2-22 ml/100ml Urea 12-35 mg/100 ml Amino acids 3.3-5.1 mg/100ml Protein 6.5-8 g/100ml Total lipids 400-800 mg/100ml Glucose 75-110 mg/100ml

Homeostatic Mechanisms Compensating regulatory responses that correct deviations from a stable condition. Intracellular level e.g. allosteric modification of enzymes Local or Intrinsic level autoregulation within a tissue usually nervous or endocrine systems not required e.g. dilation of blood vessels in response to CO2 Reflex control or Extrinsic level control system is outside the organ or tissue being influenced nervous or endocrine systems involved

Antagonistic homeostatic control of heart rate

Tonic control of blood vessel diameter

Local vs. Reflex Control

Variable to Control Sensor Receptor Effector Integrating Center

Functions of the Integrator Possess a “set point” Look for error signals Respond by controlling the effector

Positive Feedback Systems Reproductive hormone cycles in females Action potentials in nerve cells Uterine contractions during childbirth NOT always homeostatic

Set-points can be modified e.g. thermostat in brain hypothalamus (integrator) Increase in set-point for core body temperature during fever e.g. acclimatization to environmental temperature, altitude (increase red blood cells) e.g. circadian rhythms

Loop efficiency can be altered Frequency Speed Sensitivity Anticipation (Feed-Forward Control) continual observation prediction from other information e.g. salivation in response to smell of food

Arterial blood pressure decrease Heart and blood vessels Baroreceptor Variable Heart and blood vessels Baroreceptor decreases firing Effector Receptor Integrator Afferent Pathway Efferent Pathway Brainstem

Homeostatic control of blood sugar (glucose)

Blood glucose negative feedback loop

Glucose Pancreas Body cells islet beta cells liver, muscle, fat Variable Pancreas islet beta cells Body cells liver, muscle, fat Receptor Effector Integrator Pancreas islet beta cells Insulin none

Antagonistic homeostatic control of blood sugar

Antagonistic homeostatic control of blood sugar Insulin vs. glucagon