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.

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.

 

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 endocrine system

Principles of operation of the endocrine glands : synthesis, storage and release of hormones. General principles of the mechanisms of action of hormones. Control mechanisms of hormonal secretion: hypothalamic-pituitary-glands feedback mechanisms.

 

Physiology of the gastrointestinal system

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

Readings/Bibliography

Dee U. Silverthorn: Fisiologia umana. Un approccio integrato

Widmaier, Raff, Srang: Vander, Fisiologia

Teaching methods

Lectures. Simulation exam at the end of the course.

Assessment methods

The knowledge of the course of Neurophysiology will be verified by written examination.

Registration for the examination is made through Almaesami website. Results of the exams will be published on Almaesami web site.

Teaching tools

Overhead projector, PC, video projector

Office hours

See the website of Milena Raffi

See the website of Alessandro Piras