12939 - Cellular Physiology (AK-A)

Course Unit Page

SDGs

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.

Good health and well-being Quality education Life on land

Academic Year 2022/2023

Learning outcomes

At the end of the course, the student will know the basic functional mechanisms of nervous, muscular, epithelial, endocrine cells of the human body

Course contents

1) Transcellular and paracellular exchange processes

Fluid compartments of the body. Ionic composition of the intracellular and extracellular fluids. Selective permeability of the cell membrane. Transport of water and solutes across the cell membrane. Passive transport: simple diffusion and Fick's law; osmosis, facilitated diffusion (uniporters). Primary active transport: ATP-driven pumps. Secondary active transport: symporters; antiporters. Transport of water and solutes across epithelia. Capillary fltration according to the Starling-Landis hypothesis.

2) Resting membrane potential and action potential

Electrochemical equilibrium and Nernst equation. Membrane potential and Goldman equation. Voltage-dependent channels and excitability in cells of the nervous system, skeletal muscle, smooth muscle and heart. Genesis of the action potential: threshold membrane potential and self-regenerating mechanisms. Ionic conductances in the various phases of the action potential. Cycle of membrane excitability: refractory periods. Propagation of the action potential.

3) Synaptic transmission

Electrical synapses. Chemical synapses: synthesis, release and inactivation of neurotransmitters. Classification of neurotransmitters. Membrane receptors. Effects of binding of neurotransmitters to ionotropic and metabotropic receptors: excitatory and inhibitory postsynaptic potentials, changes in cellular metabolism and gene expression. Spatial and temporal summation of postsynaptic potentials. Presynaptic inhibition and facilitation. Synaptic transmission at the neuromuscular junction.

4) Sensory receptors

Classification of sensory receptors. Adequate stimulus and stimulation threshold. Signal transduction: generator potential and action potential propagation in nerve fibers. Encoding the intensity of sensory stimulation. Adaptation in sensory receptors. Receptive field of sensory receptors.

5) General somatic and special senses receptors

Receptors and afferent fibers of the tactile, kinesthetic, thermal and pain sensibility. Cellular organization of the retina and mechanism of phototransduction. Photopic and scotopic vision. Functional anatomy of the cochlea and vestibular apparatus. Transduction of sound and cochlear tonotopy Auditory thresholds. Responses of vestibular receptors to linear and angular acceleration.

6) Skeletal, smooth and cardiac muscle

Skeletal muscle: activation of the contractile mechanism; excitation-contraction coupling; innervation of fibers; muscle twitch and tetanic contraction; gradation of contractile force; isometric and isotonic contraction; length-tension relationship. Cardiac muscle: activation of the contractile mechanism; excitation-contraction coupling; length-tension relationship. Smooth muscle: classification; activation of the contractile mechanism; nervous and humoral regulation of contraction.

7) Spinal reflexes

Spinal reflex arc components. Myotatic (stretch) reflex. Muscle tone. Function of the gamma circuit. Inverse myotatic (stretch) reflex. Flexor withdrawal, crossed extensor reflex.

8) Dynamics of body fluids

Blood and air flow in circulatory and respiratory systems: Bernoulli's principle, laminar flow (Hagen-Poiseuille formula); turbulent flow (Reynolds formula). Distribution of resistance in the vascular bed and tracheobronchial tree. Changes of blood flow velocity and pressure in the different vessels of systemic circulation. Rheological properties of blood.

Readings/Bibliography

Berne & Levy PHYSIOLOGY, (B.M. Koeppen and B.A. Stanton, Editors) 7th revised edition, Philadelphia, Mosby Year Book, 2018 (ISBN: 9780323393942).

Teaching methods

Lectures, covering the whole Course Program. The Course consists of 6 CFU, corresponding to 48 hours of teaching. The Course is held by Prof. Zoccoli (3 CFU, sections 2,3,4,5) and Prof. Bastianini (3 CFU, sections 1,6,7,8). Slides shown during lectures are mostly taken from suggested readings. If not, the reference is indicated.

Assessment methods

The whole Course in Physiology covers both the First term (Cellular Physiology) and the Second term (Apparatus-Applied Physiology) of the Academic Year. Students will take a final oral examination at the end of the Second term, but may also undergo a written single choice test (true or false ) at the end of the Cellular Physiology Course. The mid-term exam includes 44 questions. The final score of the test is given by the algebraic sum of the score of the correct answers (1 point), of the wrong answers (-0.6 points) and of those not given (0 points), converted into thirtieths. The intermediate test is considered sufficient with a score of 18/30. Students that accept the score of the written test on Cellular Physiology will take the oral exam on the topics of Apparatus-Applied Physiology, while students that either refuse the score of the written test or have not taken it will take the oral exam in both Cellular and Apparatus-Applied Physiology.

In the oral exams students will be questioned on topics selected with a weighted random procedure (two topics of Apparatus-Applied Physiology and/or, according to the specifications outlined above, one of Cellular Physiology) by a different examiner for each topic. If the answers are considered sufficient, each question is evaluated with a variable score between 18 and 30 with points. The achievement by the student of an organic vision of the topics discussed during the exam combined with their critical use, and the use specific language are evaluated with marks of excellence. The mostly mechanical and / or mnemonic knowledge of the subjects, not articulated ability to synthesize and analysis and / or a correct but not always appropriate language lead to discrete evaluations; partially incomplete knowledge and / or inappropriate language - albeit in a context of minimal knowledge of the exam material - lead to marks that reaches sufficiency. Incomplete knowledge, inappropriate language, lack of orientation within the teaching materials offered during the course are negatively evaluated. Each of the three questions weighs one third in the calculation of the final grade. Insufficient evaluation of the answer to even one of the three questions makes the exam insufficient.

Teaching tools

Teaching tools used for lectures: 2 digital Video projectors, PC, Overhead digital projector and camera.

Slides From Lectures: Separate set of slides concerning each topic of the Course Program can be downloaded from the website https://virtuale.unibo.it/ by students enrolled at the University of Bologna (University institutional username and password required) .

Office hours

See the website of Giovanna Zoccoli