12939 - Cellular Physiology (2)

Learning outcomes

At the end of the course, students will have acquired knowledge of the fundamental functional mechanisms underlying cellular activity in the human body. In particular, students will understand the physiology of the major cellular systems involved in nervous, muscular, epithelial, and endocrine functions.

Course contents

Transcellular and Paracellular Transport Processes

Body fluid compartments. Ionic composition of intracellular and extracellular fluids. Selective permeability of the cell membrane. Transport of water and solutes across the cell membrane. Passive transport mechanisms: simple diffusion and Fick’s law, osmosis, facilitated diffusion (uniporters). Primary active transport: ATP-driven pumps. Secondary active transport: symporters and antiporters. Transport of water and solutes across epithelial tissues. Capillary filtration and fluid exchange according to the Starling-Landis hypothesis.

Resting Membrane Potential and Action Potential

Electrochemical equilibrium potential and the Nernst equation. Membrane potential and the Goldman equation. Excitable membranes and voltage-gated ion channels in nervous tissue, skeletal muscle, smooth muscle, specialized cardiac muscle, and working myocardium. Functional characteristics of different excitable cell types. Generation of the action potential: threshold of excitability and regenerative mechanisms. Ionic conductances and ion fluxes during the different phases of the action potential. Membrane excitability cycle: refractory periods. Propagation of the action potential.

Synaptic Transmission

Electrical synapses. Chemical synapses: synthesis, release, and inactivation of neurotransmitters. Classification of neurotransmitters. Membrane receptors. Effects of neurotransmitter binding to ionotropic and metabotropic receptors: excitatory and inhibitory postsynaptic potentials, modulation of cellular metabolism and gene expression. Spatial and temporal summation of postsynaptic potentials. Presynaptic inhibition and facilitation. Neuromuscular transmission.

Sensory Receptors

Classification of sensory receptors. Adequate stimulus and activation threshold. Signal transduction, receptor potential generation, and propagation of sensory signals along neural pathways. Encoding of stimulus intensity. Receptor adaptation. Receptive fields.

Receptors of General Sensation and Special Senses

Receptors and afferent fibers involved in tactile, proprioceptive, thermal, and nociceptive sensation. Cellular organization of the retina. Phototransduction in the retina. Photopic and scotopic vision. Anatomical and functional organization of the cochlea and vestibular apparatus. Sound transduction and cochlear tonotopy. Auditory thresholds. Responses of vestibular receptors to linear and angular acceleration.

Skeletal, Smooth, and Cardiac Muscle

Skeletal muscle: activation of the contractile mechanism; relationship between electrical and mechanical events; innervation; single twitch and tetanic contraction; grading of contractile force; isometric and isotonic contraction; length–tension relationship. Cardiac muscle: activation of the contractile mechanism; relationship between electrical and mechanical events; length–tension relationship. Smooth muscle: classification; activation of the contractile mechanism; neural and humoral regulation of contraction.

Spinal Reflexes

Spinal reflex arc. Stretch reflex. Muscle tone. Role of the gamma motor system. Inverse stretch reflex. Flexor reflex and crossed extensor reflex.

Fluid Dynamics in the Human Body

Blood flow in vessels and airflow in the respiratory tract: Bernoulli’s principle, laminar flow (Hagen-Poiseuille law), and turbulent flow (Reynolds law). Distribution of flow resistance throughout the vascular system and airways. Blood velocity and pressure in different vascular segments. Rheological properties of blood. Application of fluid dynamics principles to cardiovascular and respiratory physiology.

Readings/Bibliography

Conti F. (a cura di), Fisiologia Medica, Volumi I e II, Edi-Ermes, Milano, 2025. ISBN 978887051867-2/ 978887051868-9

Koeppen B.M., Stanton B.A. (Eds.), Berne & Levy Physiology, Elsevier, Philadelphia, 2023. ISBN 9780323847902.

Berne R.M., Levy M.N., Koeppen B.M., Stanton B.A. (a cura di), Fisiologia di Berne e Levy, Casa Editrice Ambrosiana, Milano, 2018. ISBN 978-8808480040.

Teaching methods

The Integrated Course (C.I.) of Physiology is divided into three parts: Cellular Physiology (first semester of the second year) and Apparatuses Physiology and Applied Physiology (second semester of the second year). The teaching activities of the Physiology course aim to provide students with the fundamental principles of cellular physiology and the general mechanisms governing the functioning of the human body. The Cellular Physiology course consists of 6 CFU, corresponding to 51 hours of in-person lectures and 24 hours of distance/supplementary teaching, with mandatory attendance for both. These requirements must be met according to the modalities defined by the Degree Program and approved by the Department of Medicine and Surgery. The course is taught jointly by Prof. Amici (3 CFU) and Prof. Ciani (3 CFU), who cover the syllabus topics in a coordinated and integrated manner. The lectures are structured to encourage connections between the different topics and promote an integrated understanding of physiological processes. In-person teaching consists of classroom lectures, while distance/supplementary teaching consists of audiovisual and multimedia material with faculty commentary, which is made available to students through the University's Virtuale Platform (https://virtuale.unibo.it/ ). The visual material presented in class is mainly taken from the recommended textbooks; when other sources are used, they are appropriately cited.

Assessment methods

The Integrated Course (C.I.) of Physiology is divided into three parts: Cellular Physiology (first semester of the 2nd year), and Apparatuses Physiology and Applied Physiology (second semester of the 2nd year). The final exam is a single assessment held at the end of the second semester. Upon completion of the Cellular Physiology course, students can take a mid-term exam consisting of a 44- question true/false test. The score is calculated by awarding 1 point for each correct answer, (-0.6) points for each incorrect answer, and 0 points for unanswered questions. The score obtained is converted to a scale of 30. The test is considered passed with a grade of (18\30) or higher. Students who accept the grade obtained in the mid-term exam will take the final oral exam exclusively on the Apparatuses Physiology and Applied Physiology topics. The oral exam is based on a balanced topic drawing procedure and involves different professors for the various parts of the syllabus. Students who have passed the midterm exam answer two questions concerning Systems Physiology and Applied Physiology. Students who have not taken the midterm exam must also answer a third question relating to Cellular Physiology. Each question is graded on a scale from 18/30 to 30 cum laude. The final grade corresponds to the average of the scores obtained in the individual questions. Failing even a single question means failing the exam. The evaluation takes into account: the accuracy and completeness of the acquired knowledge; the ability to integrate the different topics of the discipline; the capacity for physiological reasoning and making connections between different biological systems; the appropriate use of scientific terminology; and the clarity and precision of the presentation. A broad and in-depth preparation, combined with the ability to make independent connections between various topics and a full mastery of scientific language, is awarded the highest scores. A predominantly rote-learned preparation, with limited analytical and integration skills, leads to intermediate grades. Gaps in knowledge, difficulty in using specific terminology, and a limited ability to navigate the covered topics will result in barely passing or failing grades. The use of generative Artificial Intelligence during assessments is strictly prohibited, and any such use constitutes a violation of academic integrity. Students with specific learning disabilities (SLD/DSA) or temporary or permanent disabilities are encouraged to contact the University's dedicated support service ( https://site.unibo.it/studenti-con-disabilita-e-dsa/it ) in a timely manner to arrange any necessary accommodations, while ensuring that the learning objectives of the course are maintained.

Teaching tools

Lectures are supported and supplemented by multimedia presentations and appropriately annotated digital teaching materials, which together form the distance/supplementary teaching. The iconographic and textual materials used during the course are made available to students through the University of Bologna Virtual Platform [https://virtuale.unibo.it/] (https://virtuale.unibo.it/ ), which serves as a tool to support individual study and further exploration of the topics covered in class. Access to the materials is restricted to students enrolled in the course via authentication with their institutional University credentials.

Office hours

See the website of Elisabetta Ciani