78450 - Neurophysiology

Learning outcomes

Knowledge and skills to be achieved
At the end of the module the student has the knowledge and the ability to understand the biophysical principles related to nerve cells; he knows and understands the physiology of sensory receptors, in particular of the auditory and vestibular systems.

Course contents

Introduction

Concept of homeostasis and regulation of the internal environment. Body water compartments and their composition. Concept of acid, base and pH. Diffusion through non permeable membranes. Concept of osmolarity, osmotic and oncotic pressure. Concept of tone.

Physiology of cell membranes and ion channels

Structure and permeability of the cell membrane. Passive ion channels of potassium and sodium and their properties (selectivity filter and halo hydration). Introduction to variable access channels. Voltage-dependent sodium and potassium channels and their properties. Transporters (carriers) and their properties. The Sodium-Potassium pump. Concept of cotransport, uniport, antiport. Endocytosis and exocytosis.

Physiology of excitable cells

Ionic equilibria and equilibrium potentials. Genesis of the membrane potential at rest. The action potential: genesis and properties. Conduction of point-to-point and jumpy nerve impulse. Functional classification of nerve fibers. Synaptic transmission, neurotransmitters and receptors.

Physiology of synapses

Electrical synapses: description and properties. Chemical synapses: description and classification. Synthesis, liberation and destiny of the neurotransmitter. Postsynaptic receptors. Excitatory and inhibitory post-synaptic potential. Concept of decreasing electrotonic propagation. Signal integration: spatial and temporal summation. Neuronal networks: concept of convergence and divergence, series and parallel processing.

Physiology of the nervous system

Functional anatomy and histology of the brain and spinal cord. Functional aspects and organization of the nervous system. Reflex arch. Receptors and transduction mechanisms. Receptive fields. Tactile and dolorific sensitivity, sensitive pathways and their central integration. Neuromuscular spindles, motor neurons and motor pathways. Autonomic nervous system: orthosympathetic and parasympathetic.

Physiology of the muscle

Functional classification of muscle fibers (skeletal, cardiac and smooth). Contractile mechanism: excitation-contraction coupling. Neuromuscular junction. Contraction mechanics: simple muscle shock, summation, tetanus. Tension-length curve. Motor unit and gradation of contraction. Smooth muscle functional characteristics and differences with striated muscle.



Physiology of the auditory system

Structure and functions of the external ear (amplification and spatial localization of a sound). Middle ear: functions of the Eustachian tube, tympanum and ossicular chain (amplification and impedance adaptation). Concept of air and bone conduction. Structure and functions of the inner ear. Pascal principle, oval window and round window. Organ of the Courts and sensory transduction in the cochlea. Cochlear tonotopia. Organization of acoustic pathways and processing of acoustic information in higher centers.

Physiology of the vestibular system

Structure and functions of labyrinth. Vestibular receptors of semicircular channels (ampullar ridges) and of Utriculo and Sacculo (macule). Sensory transduction of adequate stimuli (angular and linear accelerations). Vestibular pathways and transmission of information to nerve centers. Hints on vestibular reflections.

Acoustics, Psychoacoustics and Audiometry

Notes on wave physics (definition of transverse, longitudinal, interference, harmonic motion, resonance); notes on the physics of sound waves (definition of sound pressure, period, harmonic motion, frequency, wavelength, amplitude, waveform Fourier theorem). Psychoacoustics: psychological characteristics of sound (pitch, intensity, timbre): examples and considerations. Auditory perception: concept of absolute and differential threshold. Notes on the Laws of Weber, Weber-Fechner, Stevens. Auditory field: concept of Bel and Decibel. Auditory thresholds and audiogram: how an audiometric examination is carried out. Concept of transmission, neurosensory and mixed hearing loss: examples.

Language

Definition of language. Lateralization of language and dominant hemisphere. Wada test. Broca area, language production and the case of Monsieur "Tan". Wernicke area and reception of language. Arcuate paper and connection of language areas. Concept of Brodman’s cytoarchitectural area. Notes on aphasia (receptive, expressive, conductive and global). Functional activation in Magnetic Resonance and demonstration of the areas of language and hemispherical dominance with these new advanced techniques of Magnetic Resonance.

Readings/Bibliography

It is possible to use any recently published Physiology text, together with lessons.

Suggested texts:

Zocchi. Principles of physiology. Publishing house EDISES.

Battaglia. Human Physiology. Publishing House Mc Graw Hill.

Monticelli. Physiology. Ambrosiana Publishing House.

Teaching methods

Lectures with practical examples of clinical applications.

Assessment methods

Written test with 11 closed questions, each with 4 possible answers, of which only one is required (false). It is enough to correctly answer 6 questions to pass the exam. If the written test is sufficient, it is possible to take an additional oral test; in any case, the vote of the written test will be questioned.

The partial grade obtained for each module will be mediated (weighted average by number of credits) with the partial marks obtained in the other modules of the integrated course.

Teaching tools

PowerPoint presentations with added audiovisual tools (movies, animations, etc.). All PowerPoint presentations shown during lectures are provided personally to students in pdf format from the first day of class.

Office hours

See the website of Daniela Cevolani