BPS-121: INTRODUCTION TO HUMAN PHYSIOLOGY AND PATHOPHYSIOLOGY

Physiology

• the scientific discipline that deals with the processes or functions of living things.

• Types: cellular physiology or systemic physiology.

Cellular physiology

processes inside the cells

Systematic

processes or functions of organ systems.

Pathophysiology

• medical science whose subject is the change in regulatory mechanisms related to the onset, development, and outcomes of diseases

• When there is a disease in the body, the normal processes will be altered.

Chemical level

Cellular level

Tissue level

Organ level

Organ system level

Organism level

Structural and Functional Organization of the Human Body

Chemical level

chemical make-up; how atoms such as hydrogen and carbon interact and combine into molecules

Cellular level

basic structural and functional units of organisms

Tissue level

similar cells and surrounding materials

Organ level

combination of different tissues

Organ system level

composed of different organs

Organism level

any living thing considered as a whole, whether composed of one cell; network of organ systems that are mutually dependent upon one another.

Organization

specific interrelationships among the individual parts of an organism and how the parts interact specific functions.

Metabolism

The capability of living organisms to use energy to perform other vital functions such as grow, movement, and reproduction

Responsiveness

the ability to sense changes in external and internal environment, and to adjust to those changes.

Growth

simply increase in size or number of cells living to the enlargement of all

Development

changes in organisms through time, eg. fertilization to death

Reproduction

formation of the new cells or organisms

Differentiation

involves changes in cell’s structure and functions from being immature to mature specialized state.

Homeostasis

• Maintenance of a relatively constant environment within the body.

• Usually achieved by actively regulating body conditions that are constantly changing.

Homeostatic mechanism

__________ to maintain body temp--> sweating or shivering to maintain body temperature near an ideal normal value or set point.

Nervous system (faster)

Endocrine system (slower)

2 systems of Homeostasis

Negative feedback

• To decrease

• When any deviation from the set point is made smaller or is resisted.

Receptor

Control

Effector

Three components of Negative and Positive feedback mechanism

Receptor

Monitors the value of variable, it detects the stimuli

Control

The part of a brain that determines the set point for the variable

Effector

the one that’s adjusting the variable

Positive feedback

• Occurs when a response to the original stimulus results in the deviation from the set point becoming even greater.

• Required to return to homeostasis

• “To increase”

• applied in childbirth

• Mostly mas nakakasama

Example of Positive feedback

When blood lost happen, the thrombin will increase so there will be an increase in clot formation, which disrupts the homeostasis.

Plasma membrane and lipid bilayer

• protect the cell’s interior from the changing conditions of the extracellular environment.

Plasma membrane

hydrophobic molecule

Hydrophillic

________ can post through plasma membrane as long as it is assisted by water-filled channels or specific carrier proteins.

Diffusion

Osmosis

Endocytosis

Exocytosis

Protein-mediated transport

Types of Membrane Transport

Diffusion

• Not carrier-mediated or uninterrupted

• Does not require the expenditure of chemical energy directly produced by the cell but depends on the electrochemical gradients at adjacent points.

• Governed by Fick’s law of diffusion

J = P x A x (C1 - C2)

Fick’s Law of diffusion formula

Net rate of diffusion

Where J is the _________ of solute from compartment 1 to C2.

Surface area

Where A is the _______

Permeability coefficient of barrier

Where P is the ___________. Which is inversely proportional to the molecular size of solute that passing through and thickness of the membrane and viscosity of the medium, but directly proportional to the mobility of the solute molecules in the medium.

concentration

Where C is the ______

Osmosis

• Diffusion of water across a semi-permeable membrane from a solution of low solute concentration to one of higher solute concentration.

• Does not require energy expenditure by cells.

Endocytosis

• Transport of substances too large for diffusion or passage through protein channels from the outside of the cell to the cell interior .

• Passage without passing through the lipid bilayer .

• Makes use of vesicle; energy dependent process

Phagocytosis

Pinocytosis

Receptor Mediated Endocytosis

Type of Endocytosis

Phagocytosis

Type of endocytosis that the subtance are particle matters

Pinocytosis

Type of endocytosis that the substance are soluble small molecule (fluid)

Receptor Mediated cytosis

Type of endocytosis that the substance are extracellular molecules that converted into integral proteins

Extocytosis

• Intracellular materials in a vesicle is expelled from the cell when the vesicle fuses with the plasma membrane.

• Requires energy

Endocytosis & Exocytosis

They allow the shuffling of receptors or transporters from the plasma membrane to intracellular compartment for the purpose of regulating the insertion or removal of receptor, channel, or transporter in plasma membrane in appropriate manner. Or also called as Aided transport system.

Facilitated Diffusion

• Movement of substance that cannot freely cross the membrane down an electrochemical gradient.

• Does not require metabolic energy

• requires transporter (katulong)

1. Insulin dependent glucose transporter

2. Ion specific channel (Na, K, Cl)

Examples of Facilitated Diffusion

Ligand Gated Ion Channel

Type of Ion specific channel that opens in response to an extracellular hormone.

Voltage Gated Ion Channel

Type of Ion specific channel that changes in electric potential in plasma membrane.

Active transport

• Requires energy

• Primary or secondary

Adenosine Triphosphate

Primary active transporters requires __________.

Na - K - ATPase

Example of Primary active transport that transports Na and K

Ca - ATPase

Example of Primary active transport that can be found in sarcoplasmic reticulum, renal tubules, intestines, and cardiac muscle.

H - K - ATPase

Example of Primary active transport that can be found in gastric-parietal cells (produces Hydrogen and forms gastric acid)

Uniporter

• Carry one solute across the membrane

• Requires no added energy if the movement is down the electrochemical gradient but if against the gradient, there is a need for energy.

Symporter

Secondary active transporters that move two solutes in the same direction.

Na, K, 2Cl Cotransporter

Example of Symporter that is found in ascendal limb or renal tubule.

Na glucose transport protein

Example of Symporter that is found in proximal tubule cells where exchange of sodium and glucose happen.

Antiporter

Transport two solutes in opposite directions across the cell membrane

Ca/Na Antiporter

Example of Antiporter that can be found in cardiac muscle

Cl/HCO3 Antiporter

Example of Antiporter that prevents cytosol to be not too basic during the intracellular accumulation of bicarbonate. It takes Cl and removes bicarbonate.