FISIOLOGIA I - channel 2

13 CFU - 1° and 2° Semester

Teaching Staff

LUCIA CIRANNA - Module Physiology and Biophysics - BIO/09 - 4 CFU
ROSARIO GIUFFRIDA - Module PHYSIOLOGY - Part I - BIO/09 - 9 CFU
ROSALBA PARENTI - Module PHYSIOLOGY - Part I

Learning Objectives

Physiology and Biophysics
Knowledge of the biophysical laws involved in body function regulation

Knowledge of the basic neurophysiology, particularly related to the mechanisms underlying cell excitability

Knowledge of the theoretical basis aimed at understanding the translation of such laws to clinical practice
PHYSIOLOGY - Part I
Physiology studies the vital functions of animals and humans, also in a comparative manner. It analyzes how the living organism maintains the homeostasis of its internal medium at the molecular, cellular and tissue levels, in the context of the surrounding environment. It studies biophysics, electrophysiological and functional mechanisms of transport and communication systems in biological membranes, cell motility and the specialized functions of single cells. It verifies the validity of functional laws in the Man and in the other primates. It evaluates the nutritional characteristics of foods, the state of nutrition, the expenditure and energy needs, the physiological use of nutrients in the diet. He studies the neurobiological and psychophysiological foundations related to the behavior and cognitive and emotional interactions between the subject and the environment. It also analyzes the integrated functioning of the various organs and systems in the course of motor activities and in extreme environmental conditions. Finally, he studies the potential applications of this knowledge in the environmental, biotechnological and sports fields.

The course also aims to develop students' interest in the experimental approach; in fact, the physiology preserves the character of a dynamic science in great evolution and provides a connection between the other basic sciences.

Course Structure

Physiology and Biophysics
Lectures.
PHYSIOLOGY - Part I
Lectures and theoretical-practical exercises.

Detailed Course Content

Physiology and Biophysics

Detailed Program	THE CELL AS AN INTEGRATED SYSTEM Dynamic balance, cell functions, the cell as a thermodynamic system, energy and entropy, the cell as a chemical system. Gas and solute exchanges through cell membranes (Fick's law, passive diffusion, facilitated diffusion, controlled diffusion, primary and secondary active transport). Homeostasis, steady state, regulation of cellular functions. GAS LAWS AND THEIR APPLICATIONS Ideal gas law, Boyle's law, Charles and Gay-Lussac’s law, second law of Gay-Lussac, Avogadro's law, Dalton's law, Graham's Law, Henry's Law, Laplace’s law. Applications in physiology and diseases. FLUID COMPARTEMENTS AND HOMEOSTASIS Human body fluid compartments: intracellular and extracellular compartments, compartments volumes and methods for their measurements. Sources and removal of body fluids. Water and salts balance. Exchanges of water and electrolytes through biological membranes. Concentration and electrochemical gradients. Saline, isotonic and iso-osmotic solutions, and their use. Osmotic pressure: definition, units of measurements, plasma values. Van't Hoff’s law, Gibbs-Donnan equilibrium. Hydrostatic pressure. Colloid osmotic and oncotic pressure: plasmas value and fluctuations. Consequences of oncotic pressure modifications. Starling's law and capillary exchanges. Edema. PRINCIPLES OF HEMODYNAMICS AND HEMORHEOLOGY Systemic circulation: generalities. Blood volume and velocity in different areas of the vascular system. Morphological and physiological characteristics of vessels: arteries, capillaries and veins. Blood flow: physical factors affecting blood flow. Bernoulli’s principle. Pressure, flow and resistance: Hagen-Poiseuille Law. Blood viscosity: relationship between viscosity and hematocrit. Turbulent blood flow. Laplace's law applied to vessels. Vascular tone: nervous, hormonal and humoral control. ION CHANNELS AND MEMBRANE POTENTIAL Cell excitability: cell membrane polarization (ion distribution across the membrane and its genesis, polarization measurement, conductance). Ion channels: voltage-gated ion channels for sodium, potassium, calcium, chloride (characteristics, functions, main agonist and antagonists), patch clamp, canalopathies. Electric potentials: membrane potential, electrochemical potential, Nernst equation, Goldman equation. Genesis and characteristics of an action potential. All-or-none law. Refractory period. Membrane repolarization. Graded potentials. Excitability conduction along cell membranes. Propagation velocity. Saltatory or continuous conduction, myelin sheath. SYNAPTIC TRANSMISSION Excitable cells communication. Electric and chemical synapses. Synaptic types. Neurotransmitters and neuropeptides: synthesis, transport, release and secretion, neurotransmitter release cycle, vesicle cycle (trafficking). Neuromuscular junction. Endplate potential, miniature potential, quantal neurotransmitter release. Synaptic integration and transmission in CNS (EPSP, IPSP, spatial and temporal summation). Ionotropic and metabotropic receptors. Synaptic plasticity, Hebbian theory, long-term and short-term plasticity (long-term potentiation e long-term depression). NEUROTRANSMITTERS AND RECEPTORS Acetylcholine, nicotinic receptors, muscarinic receptors, cholinergic synapses, main agonists and antagonists, notes on related diseases (Miastenia gravis). Glutamate glutamine cycle, NMDA, AMPA and Kainate receptors, metabotropic receptors, involvement in synaptic plasticity (LTP), main agonists and antagonists, glutamate excitotoxicity, notes on related diseases (Alzheimer’s disease, glutamate hypothesis of schizophrenia). GABA, Ionotropic and metabotropic receptors, , Notes on benzodiazepine, barbiturate and alcohol mechanism of action.. Catecholamine and their receptors, Role in SNA, Notes on stress and catecholamine Dopamine and its receptors, Notes on related diseases (addiction, Parkinson’s disease Schizophrenia) Serotonin and its receptors, Drugs acting on serotonin receptors Endocannabinoids and opioids, notes on drug abuse (cocaine, amphetamine, heroine, hallucinogens, etc.) Nitric oxide pathway and retrograde transmission MUSCLE CONTRACTION Skeletal muscles: structure, myofibrils, sarcomere and mechanisms of contraction, Sliding filament theory of muscle contraction, Neuromuscular junction, Excitation-Contraction Coupling, single muscle twitch and tetanus, isometric and isotonic contraction, length-tension curve, force-velocity curve, muscle energetics, oxygen consumption, muscle work, performance, and fatigue. Muscle fibers. Skeletal muscle innervation. Electromyogram. Smooth muscle: generalities, unitary and multiunit muscles, sctructure, contraction mechanisms, contraction regulation (arteriolar tone), biomechanics. Cardiac muscle: generalities, structure, contraction mechanisms, contraction regulation, biomechanics. NERVOUS SYSTEM: GENERALITIES Neuron: morphologic, functional, biochemical and trophic unit of the nervous system Glia: macroglia and microglia. Myelin synthesis at central and peripheric level.

PHYSIOLOGY - Part I
PHYSIOLOGY - Part I

Urinary system

- The functional unit of the kidney: the nephron. Differences between cortical and juxtamidollar nephrons. Glomerular ultrafiltration, filtration pressure, characteristics of the ultrafiltered liquid. Measurement of the volume of ultrafiltered liquid: inulin and urea clearance. The resorption process at proximal tubule level. Active and passive transport. The concept of renal threshold and maximum transport threshold. The reabsorption of glucose and glycosuria. Reabsorption at the distal tubule level.

Action of aldosterone. The concentration of urine by means of the countercurrent multiplication mechanism: function of the Henle loop. Function of the vasa recta. Vasopressin action.

- Tubular secretion: secretion of hydrogenions, potassium and ammonium ion. Acidification of urine.

- Renal circulation: extrinsic control of renal circulation. Renal autoregulation of blood flow in relation to systemic blood pressure.

Renal factors affecting systemic blood pressure. Endocrine functions of the kidney.

- Renal function tests: the concept of renal clearance and its application to the control of glomerular, tubular and vascular functions. Osmotic diuresis and water diuresis. The role of the kidney in the regulation of the volume and composition of organic liquids. Dehydration and general consequences of dehydration. Excess of liquids: water intoxication, edema. Renal contributions to the regulation of acid-base balance; alkalosis and acidosis. - Physiology of the urinary bladder: filling and emptying. Action of the nervous system. The cystogram.

Blood and lymph

- Blood composition: corpuscular part and liquid part. Hematocrit. Erythropoiesis and iron metabolism. Life and destruction of erythrocytes. Globular resistance and hemolysis. Respiratory functions of red blood cells. Functions of leukocytes: their distribution and leukocyte formula. Platelet functions. Blood as a factor in the regulation of body temperature. The lymphatic system: the lymphatic stations, composition and function of the lymph. The hemato-tissue barrier.

Cardiovascular system

- Structure and function of arterial vessels. Nervous and endocrine regulation of arterioles. The capillary bed. General information on the capillary bed; types of capillary endothelium. Transcapillary exchange: diffusion, filtration, absorption and micropinocytosis. Microcirculation. The venous bed. Distensibility of the veins. Posture and veins. Venous return to the heart. Phlebogram and its characteristics. Venous pressure and its variations, the jugular pulse.

- Functions of the heart. Electrophysiology of the heart muscle. Excitability of the myocardium. Cardiac automation. Effects of innervation of the heart on the properties of the myocardium. The chemical mediators of the heart. Mechanical events of the cardiac cycle. Valve movements and pressure changes in the atria and ventricles during the cardiac cycle phases. Duration of the phases of the cardiac cycle. Cardiac output. Starling's Heart Law. Cardiac metabolism and oxygen consumption. Laplace law applied to the heart. Heart rate and its regulation. Flutter, fibrillation and extrasystole. Nervous control of the cardiovascular system. Bulbar centers. Hypothalamic centers. Reflex regulation of the cardiovascular system. Cardiac, vascular and extravascular mechanoceptors. Systemic arterial chemoreceptors. Cortico-hypothalamic influences on the cardiovascular system. Humoral control of the cardiovascular system. Renin-angiotensin aldosterone system. Catecholamines and dopamine. Serotonin.

- Special vascular circuits. District division of cardiac output. Coronary, cerebral, cutaneous, muscular, hepatosplancnic, pulmonary, renal, splenic, fetal circulation.

- Cardiorespiratory functiional tests. Determination of systemic arterial pressure. Cardiac tones: auscultation sites and features of cardiac tones. Determination of cardiac output and most commonly used methods. Electrocardiography: Einthoven's triangle, mono- and bipolar derivations, precordial derivations. Analysis of the most common patterns, determination of the heart axis and its functional significance. Echocardiogram.

Respiratory System

- Respiratory mechanics. General consideration. Upper airway functions. Mechanical respiratory processes in eupnea: costal and diaphragmatic components. Intrapleural pressure. Pneumothorax. Pulmonary surfactant. The pulmonary and thoracic compliance.

- Respiratory activity and its nervous regulation. Respiratory centers and their functional significance. Respiratory reflexes: slow and rapid adapting tensioceptors. Lung Volumes and capacities. Alveolar ventilation. Pulmonary gaseous exchanges.

- Transport of oxygen and carbon dioxide in the blood. Hemoglobin and its combination with oxygen or carbon dioxide. Transport of O2 and CO2 in the organism. Myoglobin. The normal reaction of the blood: buffer actions, the relationship between CO2 and pH, functional significance of the Henderson-Hasselbach equation, O2 and blood CO2 dissociation curves.

- Chemical regulation of respiration. Hydrogenionic concentration and respiration. Aortic and carotid chemoreceptors. Anoxia. Respiratory changes during physical activity.

- Lung metabolism. Biotransformations of circulating or inhaled substances. Biotransformations of hormones and mediators. Pulmonary metabolism of proteins, lipids and carbohydrates.

- Respiratory function tests. Spirometry. Determination of dead space. Techniques for artificial respiration. Respiratory quotient. Basal metabolism. Notions of physiopathology of the respiratory system. Dyspnea and its characteristics.

Digestive system, metabolism and nutrition

- Chewing. Salivary secretion. Composition and function of saliva. Conditioned reflexes. Swallowing. Gastric movements and secretion. Nervous and humoral regulation of gastric secretion. Pancreatic secretion. Secretin and pancreozimine. Pancreatic juice. Intrinsic innervation of the intestine. Myogenic and neurogenic mechanisms of intestinal movements. Extrinsic innervation of the intestine. Visceral reflexes. Motility of the colon. Defecation.

- Liver. The functional unit of the liver. Arterial and portal hepatic circulation. Oxygen consumption. Overview of the main functions of the liver. Liver intervention in hematopoiesis and blood coagulation. Biliary excretion. Hepatic bile and cystic bile. The entero-hepatobiliary circulation. Process of degradation of hemoglobin: Jaundice and its various forms. Detoxifying and protective action of the liver.

- Metabolism. Mechanisms of biological oxidation. Carbohydrate metabolism. Lipid metabolism. Protein metabolism. Nitrogenous equilibrium.

-Nutrition. Principles of dietetics. Energy requirements. Composition of the normal diet. Food requirements in particular conditions (pregnancy, lactation, infancy, senescence, etc.). Mechanisms of hunger and satiety. Basic metabolism.

PH regulation. PH control in intracellular and extracellular fluids, buffer systems, alterations in acid-base balance and compensation mechanisms.

Regulation of body temperature in humans. Physiological and pathological changes in body temperature. Thermal balance, thermogenesis, heat dispersion. Heat and cold response mechanisms.

- Adaptations to physical exercise (cardiovascular, respiratory, plasmatic, muscular responses). Body responses to altitude.

Textbook Information

Physiology and Biophysics
Testi consigliati: Fiorenzo Conti – Fisiologia Medica, Edi-Ermes
PHYSIOLOGY - Part I
Various authors - Fisiologia medica - a cura di F. Conti - Edi-ermes, Milano

Guyton & Hall - Fisiologia medica - Edises, Napoli.

Open in PDF format Versione in italiano