43533 - Physiology of Organs and Apparatuses

Learning outcomes

At the end of the course the student: - knows the basic functional mechanisms of homeostasis of the internal environment, from cellular level to integrated organs, systems and apparatuses, - he is able to describe the basic circulatory, respiratory and renal functions and their dynamic integration for maintaining normal health and survival of the human organism. - He can detect and assess the main functional parameters of cardio-circulatory and respiratory conditions in normal subjects at rest.

Course contents

Cardiovascular Physiology:

Excitation and contraction of the myocardium: Electrophysiology of myocardial cells. Excitation-contraction coupling. Pace-maker and impulse conduction in the heart. Effects of temperature and ion concentrations. Physiological basis of the electrocardiogram.

Mechanical events of the cardiac cycle: Contraction of atria and ventricles. Heart valves and their operating mechanism. Variations in blood pressures and volumes in the cardiac chambers and arteries. Heart sounds. Temporal relationships of the cardiac cycle events. Pressure-volume curves. Frank-Starling law. Stroke volume and its variations.

Functions of blood vessels: General diagram of the circulation. Functions of the arteries. Pulse pressure. Blood pressure. Measurement of blood pressure. Functions of the arterioles. Mechanisms of fluid exchange in capillaries. Functions of lymphatic vessels. Central venous pressure. Venous compliace. Mechanisms of venous return. Blood reservoirs.

Physical principles of blood flow: Hemodynamic variables and their variations in the vascular system. Flow equation. Hydrostatic effect. Laminar flow and blood viscosity. Hagen-Poiseuille law. Vascular resistance.

Control of circulatory system: Autonomic innervation of the heart and blood vessels. Baroreceptor reflexes and their functional importance. Hormonal regulation of blood pressure. Renal control of arterial pressure. Integrated control of cardiac output. Vasomotion and local control of blood flow. Types of hyperemia. Vasoconstrictor and vasodilator substances.

Cardiovascular responses to physical exercise: Changes in heart rate, stroke volume, cardiac output, blood pressure, venous return in relation to the various levels of exercise. Redistribution of flow during exercise. Integration of the cardio-circulatory responses in physical activity.

 

Respiratory Physiology

Respiratory mechanics: Inspiration and expiration. Function of the respiratory muscles. Respiratory pressures and their measurements. Lung volumes and capacities. Respiratory system compliance. Rest position of the chest. Functions of pulmonary surfactant. Airway resistance. Dynamic measurements of expiratory flow. Pulmonary ventilation and alveolar ventilation. Control of bronchial diameter.

Gas Exchanges: Factors affecting gas exchanges. Function of the respiratory membrane. Composition of air environments. Factors affecting gas concentrations. Partial pressures of gases in air and blood. Role of diffusion gradients. Variations of PO2 in the pulmonary capillaries. Variations during hyperventilation. Local variations in ventilation. Pressures in the pulmonary circulation. Effective exchange surface. Ventilation / perfusion ratio.

Energy for exercise: Energy balance and calorimetry. Resting metabolism and metabolic activity. Aerobic and anaerobic mechanisms. VO2 kinetics, respiratory exchange ratio, and maximum oxygen consumption. 

Gas Transport: Hemoglobin as oxygen buffer. Hemoglobin dissociation curve. Factors producing shifts of the curve. Oxygen content of the blood. Chemical forms of CO2 in the blood. Curve of the CO2 content. Haldane effect.

Control of respiration: Location of the respiratory centers. Nervous control of breathing. Central and peripheral chemoreceptors. Effects of O2, CO2 and pH on ventilation.

Respiratory responses to exercise: Ventilatory changes in relation to exercise intensity. Maximal voluntary ventilation and maximal exercise ventilation. Changes in partial pressures of respiratory gases at different levels of exercise. Gas exchange during exercise. Variations of O2 extraction. Physiological integration of ventilatory responses during physical exercise.

 

Renal Physiology

Basic renal processes: Osmolarity and tonicity of body fluids.

Glomerular filtration : properties of the filtration membrane. Forces responsible for glomerular filtration. Magnitude and regulation of glomerular filtration rate. Filtration fraction.

Tubular functions: Transepithelial transport. Na+ reabsorption. Reabsorption of glucose. Tubular maximum. Water reabsorption. Medullary countercurrent mechanism. Urine dilution and concentration. Plasma clearance.

Regulation of fluid balance: Mechanisms of ADH and aldosterone. Feed-back control of ADH and aldosterone secretion. Role of atrial natriuretic peptide.

Acid-base balance. Sources of H+. Buffer systems of the body fluids. Respiratory control of pH. Renal control of pH. Acidosis and alkalosis, and their compensatory mechanisms.

 

Physiology of the reproductive system

Male reproductive functions: Functional anatomy of the male reproductive system. Spermatogenesis. Seminal fluid. Testosterone functions. Hypothalamic control of the testicular function.

Female reproductive functions: Functional anatomy of the female reproductive system. Ovarian cycle. Functions of estrogens and progesterone. Endometrial cycle. Hypothalamic control of ovarian function.

 

Gastrointestinal system

Motor and secretory functions of the gastrointestinal system; nervous and hormonal control mechanisms. Digestion and absorption of nutrients.

Readings/Bibliography

FISIOLOGIA dalle molecole ai sistemi integrati . E. Carbone, G. Aicardi, R. Maggi, EdiSES 2018.

VANDER FISIOLOGIA. Widmaier Eric P., Raff Hershel, Strang Kevin T.; Ambrosiana Editori.

Libri di consultazione:

Fisiologia – un approccio integrato . Silverthorn. Casa Ed Ambrosiana, 2007.

Fisiologia medica . Guyton & Hall, Elsevier-Masson Ed., XI edizione italiana, 2006

Teaching methods

Lectures with audio-visual aids. Practical exercises. Seminars. Out-of-lecture personal support by the teacher.

Assessment methods

written and oral exam

Teaching tools

Physiology laboratory with many facilities for evaluating cardiovascular and respiratory functions in normal conditions

Office hours

See the website of Alessandro Piras