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.

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 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.

Readings/Bibliography

- Fisiologia dell'Uomo (a cura di E. Di Prampero e A. Veicsteinas) Edi Ermes 2002

- Sherwood L. Fisiologia Umana. Dalle cellule ai sistemi. Zanichelli, 2008

Teaching methods

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

Assessment methods

The knowledge of the Course of “Physiology of the organs and apparatuses" will be verified by written and oral examination. The written test consists of 50 multiple response questions, to be completed in two hours. The score will be so assigned: +1 point for each correct answer, 0 points for each question not answered -1 point for each incorrect answer. The test will be passed with a score equivalent to half the maximum achievable (100/200). Passing the written test is required for admission to oral examination. Upon passing this, a score (in thirtieths) will be assigned. If the oral exam is not passed, the written test will need to be repeated. The final grade of this course will contribute, together with that of Neurophysiology, to the evaluation of the integrated course of Human Physiology. The completion of the two examinations will assign the 12 CFUs of the integrated Course, while no credits are awarded for passing individual partial examinations.

 Exam registration:
Enrollment for the examination, both written and oral tests, must be made by web site AlmaEsami (https://almaesami.unibo.it/almaesami/welcome.htm) starting one month before the opening of each call. The closure of the lists is done at 00 hours the day before the call (eg if the call is on June 10, the list will close at midnight between 8 and 9 June). Since the correction of the tests will be done by optical reading of personalized forms produced on the basis of the subscription list, one can not take the test if has not subscribed to the list. Please consider that for every student in the list a form and a bundle of questions are printed. Therefore, students who give up to take the examination are urged to cancel before the expiration of the list. In case of technical problems with AlmaEsami please contact the webmaster. If (exceptionally) the problem can not be solved, please send an e-mail to the teacher, before the closure of the lists, reporting name, identification number and the exam that one wish to attend.

Publication of the results and test scrutiny:
The outcomes of each partial examination are published on the web site AlmaEsami. Publication is purely for information and is not eligible for credits. The written assignments can be consulted and discussed with the teacher during its office hours.

Limitations
Students will not be allowed to take a test in case he/she have failed the last three tests in a row.

Teaching tools

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

Office hours

See the website of Salvatore Squatrito

See the website of Milena Raffi