PHYSIOLOGY

Department of Physiology and Patophysiology

Course Description The course will offer basic physiological knowledge

necessary to understand the essential facts and concepts of human physiology, in order for you to be able to make clinical judgments on a rational scientific basis.

Course duration- 40 weeks,

Total course hours – 220,

– Lecture - 60 hours

– experiment - 160 hours

BOOKS YOU MUST HAVE

THE TEXTBOOK OF PHYSIOLOGY BY GUYTON & HALL, TENTH EDITION (2000)- REQUIRED!!!

REVIEW OF PHYSIOLOGY BY GANONG. TWENTYTH EDITION (2000)- HIGHLY RECOMMENDED!

About Exam

Assessment by final examination – General

Modul - (80 points)

Assessment by experimental practice

(120 points)

Chapter 1

Introduction to Physiology

Conception of Physiology What is Physiology ?

Simply put, physiology is the scientific discipline that seeks to understand the function of living organisms and their constituent parts.

The word itself is composed of two Greek roots: physis (meaning nature) and logos (meaning study or science).

Division of Physiology

Plant Physiology Bacterial Physiology Animal Physiology Human Physiology

Studying Physiology (Why?) Exploring the living mass by questioning

observations

– Teleological Question - "Why does the XYZ exist?"

– Mechanistic Question - "What does XYZ do?“

For example: Why dose a neuron has dendrites and axon? What does dendrite or axon do during a neuron excitation?

Solving Physiological Questions

The laboratory Component

– Scientific Method (How)

a. Develop a hypothesis

b. Plan and implement an experimental

design

Define the variables of the hypothesis

c. Analysis of experimental results

d. Interpretation of results

Obviously Development of physiology relies

on the development of other

discipline, such as anatomy,

histology, biochemistry, physics,

chemistry, molecular

biochemistry and so on.

Physiology and Medicine

Def. of medicine:-The science of diagnosing, treating, or preventing disease and other damage to the body or mind.

A definition of physiology requires a definition of life, at the point of life, there is a tight link between physiology and medicine.

Physiology is important foundation of medical practice.

The purposes of study for medical students are as follows:

To get basic sense of normal functions and its regulation of living organisms

To know how to update medical

knowledge via research

GeneralGeneral concept of Physiologyconcept of Physiology Function is a form of living structure.

Functional unit is a smallest group of cells, united to perform a specific function (nephron, motor unit).

Physiological system is a union of the organs for a specified function (blood system, circulatory system, the system of external respiration)

Operating system is a temporary union of the organs and physiological systems for biologically useful effect to the body (gas transportation system - combining the systems of blood, circulatory, respiratory)

Functional state is a state of biological structures and functions of the organism as a whole at a particular time (state of calm, state of activity, state of rest)

Basic functional properties of the bodyBasic functional properties of the body

1. Metabolism2. Regulation

3. Homeostasis4. Adaptation

5. Growth, development, reproduction6. Irritability

Metabolism: the sum of all the chemical reactions in the body.

Metabolism is divided into two inter-related processes:

– Catabolism: breaking down relatively complex molecules into simpler ones .

• Yields energy

– Anabolism: building larger, more complex molecules from smaller, simpler ones.

• Requires energy

energy coupling between catabolism and anabolism allows life to exist.

Metabolism

assimilation anabolism

Intake

Composition Consume energy

Decomposition Release energy

Excretory

Regulation : the body's ability to carry out the regulation of physiological functions.

There are two mechanisms of regulation of

functions:

• nerve (by means of the nervous system);

• humoral (by means of chemicals dissolved in body fluids).

Homeostasis

Maintenance of relatively constant internal conditions despite large fluctuations in the environment.

The concept of homeostasis was first articulated by the French scientist Claude Bernard (1813-1878) in his studies of the maintenance of stability in the milieu interior. The term itself was coined by American physiologist Walter Cannon, author of The Wisdom of the Body (1932).

Claude Bernard, a father of experimental physiology in France, said: “constancy of the internal environment is the condition for free life”.

Homeostatically maintained variables Temperature Ion concentrations pH Nutrient levels in body fluids and in storage Gases

Adaptation

The purpose of adaptation - maintaining homeostasis of the organism in an environment that is constantly changing.

By the mechanism are distinguished:

• immediate adaptation;

• long-term adaptation.

Growth, development, reproduction

This physiological property provides self-healing and self-reproduction of organisms.

Irritability - the ability of biological structures to move from a state of calm in the active state under the influence of various factors (irritants)

Classification of the irritants1 By the nature of power:• Physical;• Chemical;• Biological;• Social.

2 By the biological features: •adequate ; •inadequate

3 By the power, the intensity of the action: •sub-threshold; •threshold; •suprathreshold.

The laws of the irritation  I The law of power relations

(the law of power)

The greater power of the stimulus, the greater (up to certain limits) biological response

Biologicalreaction

Power of the stimulusThreshold of stimulation

Maximum power

ІІ The law "all or nothing"On the effect of subthreshold stimulus biological structure does not answer ("nothing"). On the effect of stimulus of the threshold power occurs once the maximum response ("all"). Further increase in stimulus force did not cause increased biological response.

Biologycal reaction

Power of the stimulusthreshold of stimulation

ІІІ The law of duration of the stimulation

(the law «Power of time") The greater power of the stimulus, the less time is neededso

that there was a biological reaction.

Structure of the cell membrane

Proteins - 55 %;Phospholipids - 25 %; cholesterol - 13 %;other lipids - 4 %; carbohydrates - 3 %.

The basic lipid bilayer is composed of phospholipidmolecules. One end of each phospholipid molecule is

soluble in water; that is, it is hydrophilic. The other endis soluble only in fats; that is, it is hydrophobic. The

phosphate end of the phospholipid is hydrophilic, andthe fatty acid portion is hydrophobic.

The cholesterol molecules in the membrane are alsolipid in nature because their steroid nucleus is highlyfat soluble. These molecules, in a sense, are dissolved

in the bilayer of the membrane. They mainly helpdetermine the degree of permeability (or impermeability)

of the bilayer to water-soluble constituents ofbody fluids. Cholesterol controls much of the fluidity

of the membrane as well.

Two types of proteins occur: integral proteins that protrudeall the way through the membrane, and peripheral proteins

that are attached only to one surface of the membraneand do not penetrate all the way through.

Many of the integral proteins provide structuralchannels (or pores) through which water moleculesand water-soluble substances, especially ions, candiffuse between the extracellular and intracellular

fluids.These protein channels also have selective propertiesthat allow preferential diffusion of some substances

over others. Other integral proteins act as carrier proteins fortransporting substances that otherwise could not penetrate

the lipid bilayer. Sometimes these even transportsubstances in the direction opposite to their

natural direction of diffusion, which is called “activetransport.” Still others act as enzymes.

Integral membrane proteins can also serve as receptorsfor water-soluble chemicals, such as peptide hormones,

that do not easily penetrate the cell membrane.Interaction of cell membrane receptors with specific

ligands that bind to the receptor causes conformationalchanges in the receptor protein. This, in turn,

enzymatically activates the intracellular part of theprotein or induces interactions between the receptor

and proteins in the cytoplasm that act as second messengers,thereby relaying the signal from the extracellularpart of the receptor to the interior of the cell. In

this way, integral proteins spanning the cell membraneprovide a means of conveying information about the

environment to the cell interior. Peripheral protein molecules are often attached to the integral proteins. These peripheral proteins

function almost entirely as enzymes or as controllers oftransport of substances through the cell membrane

“pores.”

Membrane carbohydrates occur almost invariably incombination with proteins or lipids in the form of

glycoproteins or glycolipids. The carbohydrate moieties attached to the outer surface of the cell have several

important functions: (1) Many of them have a negative electrical charge, which gives most cells an overall negative

surface charge that repels other negative objects. (2) The glycocalyx of some cells attaches to the glycocalyx of

other cells, thus attaching cells to one another. (3)Many of the carbohydrates act as receptor substancesfor binding hormones, such as insulin; when bound,this combination activates attached internal proteins

that, in turn, activate a cascade of intracellularenzymes. (4)

Chemical compositions of extracellular and intracellular fluids

Metabolism between the cell and its microenvironmentTransmembrane

transportVesiculartransport

Passive Active Endocytosis Ectocytosis

Mechanism of pinocytosis

Mechanism of phagocytosis

OsmosisOsmosis

Osmosis is the net diffusion of water (the solvent) across the membrane. For osmosis to occur, the membrane must be selectively permeable.

FiltrationFiltration

Simple diffusionSimple diffusion

Simple diffusion means that kinetic movement of molecules or ions occurs through a membrane opening or throughintermolecular spaces without any interaction with carrier Proteins in the membrane.

Facilitated diffusion

Facilitated diffusion, like simple diffusion, is powered by the thermal energy of the diffusing molecules and involves net transport from the side of higher to the side of lower concentration. ATP is not required for either facilitated or simple diffusion.

Primary active transport Primary active transport Postulated mechanism of the sodium-potassium pumpPostulated mechanism of the sodium-potassium pump

A transport process, that pumps sodium ions outward through the cell membrane of all cells and at the same time pumps potassium ions from the outside to the inside. The ATPase function of the protein becomes activated.

Co-transport

Secondary active transport Secondary active transport

Secondary active transport Secondary active transport

Counter transport