HUMAN PHYSIOLOGY Anita Ocampo-So, MD, FPSP, DPBA, MHA Professor
GOALS 1.
2. 3.
To understand the important functions of the various organ systems To acquire the ability to problem solving and critical thinking To discern the value of laboratory equipment and procedures as diagnostic aids
GOALS To develop the attitude and habit essential to the practice of medicine and continuing medical education
1.
i. ii. iii. iv.
Sensitivity to colleagues, society, and patient Sensitivity to difference Sensitivity to responsibility to CME Integrity
PHYSIOLOGY Physiology
stated broadly and simply is the study of how living organisms work It
deals with the functions of living beings and the Integration on how the different organ systems work together to accomplish complex tasks
PHYSIOLOGY Claude Bernard “After carrying out an analysis of phenomena, we must always reconstruct our physiological synthesis so as to see the joint action of all the parts we have isolated.”
PHYSIOLOGY and LIFE Physiology
deals with the functions of living things thus it deals with life itself Life
is the interplay of the organism to its environment It explains the physical and chemical factors that are responsible for the origin, development and progression of
ATTRIBUTES OF THE HUMAN BODY 1. 2. 3. 4. 5. 6. 7. 8.
Organization Irritability Contractility Nutrition Respiration Excretion Metabolism and Growth Reproduction
HUMAN BODY 1.
Solid component
2.
Cell Tissues
- master tissues - vegetative tissues
Organs Systems
Liquid component
2 Major fluid compartments
FLUID COMPARTMENTS ECF 7.4-7.45 308 mOsm/L Na+, Ca++ Cl14L 1/3 of TBF ISF – 11L Plasma – 3L Internal Environment
ICF pH Osmolarit y Cations Anions Volume
7.35-7.4 308 mOsm/L K+, Mg++ PO428L 2/3 of TBF
HOMEOSTASIS
The maintenance of the body in a stse of relative constancy in the internal environment CONTROL SYSTEM – works on 1. 2. 3.
Cellular level Organismal level Throughout the entire body
CHARACTERISTICS
Reflex in nature Operates on a feedback mechanism, mostly (-); rarely (+) Amplification or Gain Oscillation – driving, waxing, damped
CELL and its FUNCTIONS
Cells, like the human body has 1. 2. 3. 4.
Division of labor Specialization Mutual interaction Centralized control
Cell – basic living unit of the body
PROTOPLASM The different substances that make up the cell. It is composed of fluid medium – principal 2. Water - Major cations and anions 3. Electrolytes - Next to water, most -Phospholipids and cholesterol abundant 4. Proteins -Triglycerides and natural fats - 2 types 5. Lipids - Little structural a.Structural 6. Carbohydratesfunction
PHYSICAL STRUCTURE of the CELL Contains
highly organized physical structures called Organelles Covered
with a membrane are the nucleus, endoplasmic reticulum, mitochondria, lysosomes, and Golgi apparatus
CELL MEMBRANE
It envelopes the cell It is composed mostly of
Proteins – 55% Lipids – 42% Phospholipids – 25% Cholesterol – 13% Other Lipids – 4%
Carbohydrates – 3%
CELL MEMBRANE Lipid Membrane
1. -
b.
Basic structure is a bilayer Phospholipid part 1.
Hydrophilic part -
2.
Water soluble Consists of the head group Phosphate portion
Hydrophobic part -
Fat soluble Consists of the 2 chain group Fatty acyl portion
CELL MEMBRANE Phospholipid Bilayer Primarily
responsible for the passive permeability properties of the membrane Choline containing lecithin
(phosphatidylcholine) Sphingomyelin Aminophospholipids Phosphatidylserine Phosphatidylethanolamine
CELL MEMBRANE
Others
Phosphatidylglycerol Phosphatidylinositol cardiolipin
Cholesterol
Glycolipids
LIPID BILAYER Features It is fluid and not solid so portions of the membrane can flow literally from one point to another Substances dissolved or floating in the lipid bilayer diffuse to all areas of the cell membrane Lipid soluble substances easily cross the lipid bilayer Water soluble substances do not dissolve in the lipid bilayer; they cross the membrane through water-filled channels, pores, or carriers
2 MEMBRANE PROTEINS
Mostly Glycoproteins Fibronectin – integrins 2 types of Proteins 2. Integral proteins 3. Peripheral proteins
MEMBRANE PROTEINS Functions 2. Anchor 3. Pumps 4. Carriers 5. Ion channels 6. Receptors 7. Enzymes 8. Antibody processing
MEMBRANE CARBOHYDRATES They
are referred to as the cell Glycocalyx In combination with lipids – glycolipids With proteins - glycoproteins
MEMBRANE CARBOHYDRATES Functions Bring (-) charge to the cell Attachment of one cell to the other Act as receptor substances for binding hormones Immune reactions or antigens
CYTOPLASM and its ORGANELLES
Cytosol is the clear fluid of the cytoplasm where the particles are dispersed It contains mainly dissolved proteins, electrolytes and glucose, secretory granules and the organelles 1.
Endoplasmic Reticulum (ER) a. b.
2.
Granular ER Agranular ER
Golgi Apparatus
ORGANELLES 1. 2.
Peroxisomes Mitochondria Other structures include: b. Filaments • •
c.
Tubules ∀ • •
d.
13 tubulin protofilaments Myosin I, II, MTOCs α,β,δ tubulins Kinesia Dynein
nucleus
INTERCELLULAR CONNECTIONS 1.
Tight Junctions
2.
Tight Leaky
Gap Junctions
CELLULAR TRANSPORT SYSTEM
Transport across but NOT through Membranes 1.
Endocytosis
2.
Energy requiring Receptor-ligand complex Sample:cholesterol & LDL receptors V-SNARES and T-SNARES 2 forms: pinocytosis phagocytosis
Exocytosis
CELLULAR TRANSPORT SYSTEM A.
Cellular Transport through Membranes 1.
Diffusion
No energy needed Downhill 2 pathways
Through intermolecular intertices Through channels or transport proteins
RATE OF DIFFUSION Determined by: 2. Amount of substance available 3. Velocity of kinetic motion 4. Range of diffusion – distance and time 5. Member of openings in the membrane
DIFFUSION COEFFICIENT Diffusion Coefficient = D Proportional to the speed with which the diffusing molecule can move in the surrounding medium Size
of molecule
Small
molecule 1/(MW1/2) Larger molecule 1/(MW1/3) Spherical molecule Viscosity
of the medium
Stokes – Einstein Equation D= KT / 6πrη Fick’s Law of Diffusion J = (-) DA (∆c/ ∆x)
DIFFUSION PERMEABILITY of the C ELLULAR MEMBRANE Permeable to lipid-soluble molecules Impermeable to water-soluble molecule
Ions are also relatively insoluble in lipid solvents; diffusion is through protein channels: a. b. c.
Ion specific Allows small ions only Others – diameter, shape, charge
Ion channels are controlled by: a.
Voltage difference
CELLULAR TRANSPORT THROUGH MEMBRANE Osmosis Semi-permeable
membrane Osmotic pressure Van’t Hoff’s Law of O.P. π = RT (φic) Isoosmotic Solutions Hypoosmotic Hyperosmotic
PREDICTORS OF VOLUME CHANGES
The steady-state volume of the cell is determined only by the concentration of impermeant solutes in the ECF Permeant solutes cause only transient changes in cell volume The greater the permeabilty of the membranes to the permeant solute, the more rapid the time course
TRANSPORT THROUGH MEMBRANES Protein-Mediated Transport Properties More rapid transport Shows saturation kinetics Mediating protein has chemical specificity Structurally related molecules may compete for transport Transport may be inhibited by compounds that are not structurally related
In the form of carrier proteins or
TRANSPORT THROUGH MEMBRANES Facilitated Transport System Movement of solutes from an area of higher concentration to an area of lower concentration with the use of transporters No energy required Can’t move substances against a concentration gradient They act to equalize concentrations of the transported substance on the 2 sides of the membrane Show saturation kinetics Phloretin inhibits sugar uptake while insulin stimulates it
ACTIVE TRANSPORT
With the use of Transporters With the use of channels a. b.
Voltage Ligand-gated
Types: 1. 2.
Primary Secondary
Cotransport – symport Countertransport - antiport
OTHER MEMBRANE TRANSPORT PROCESSES 1.
Ion-transporting ATPases 3 Major classes 1. 2. 3.
P-type V-type F-type
Ca++ transport Ca++ ATPase Calmodulin
Na+-Ca++ exchanger
OTHER MEMBRANE TRANSPORT PROCESSES
Na+-H+ exchanger Anion exchanger Na+,K+,Cl- cotransport Facilitated Transport of Glucose Amino Acid Transport ABC (ATP-binding cassette) transporters
Cystic Fibrosis Transmembrane Regulator (CFTR) Multiple Drug Resistance (MDR) Transporter
TRANSPORT ACROSS EPITHELIA
Epithelia are polarized Transport properties differ from one side to the other side of membrane With tight and leaky junctions 2 types of pathways 1. 2.
Transcellular Paracellular
Thank You And Good Morning!