Introductionby

Eric Mayo Dagradi, dr, M.Kes,AIF(Head of Physiology Department)

•The term human physiology and its research objectives.• Fundamental characters of living organism: Metabolism, excitability and reproduction.• Regulation of physiological activities : Nervous regulation, humoral regulation, autoregulation.• Cybernetic & automatic control system : Negative feedback, positive feedback, feed forward control.

Specific characteristics and mechanisms of the human body make it a living being.

Levels of physiological research

Metabolism : It is the ability to use energy to perform vital functions such as growth, movement, and reproduction.

Excitability and Responsiveness : An organism is responsive if it can sense (excitability) changes in the environment and make adjustments that help maintain its life.

Reproduction : The formation of new cells or new

organisms. Is reproduction a homeostatic function???

Maintenance of static or constant conditions in the internal environment

Concentration of O2 and CO2 Concentration of nutrients and waste products pH of internal environment Concentration of salts and other electrolytes Volume, temperature and pressure of extra

cellular fluid

Nervous regulation

Humoral regulation

Autoregulation

Reflex

Knee jerk reflex

Receptor Afferent (sensory) nerve Reflex centre (Brain or spinal

cord) Efferent (Motor) nerve Effector

Humoral regulation by hormone

Intrinsic ability of an organ to maintain constant normal environment independent of neural and hormonal influences.

Eg: Autoregulation of blood flow despite of changes in perfusion pressure.

(By metabolic and myogenic mechanisms)

Cybernetics is the theoretical study of control processes in electronic, mechanical, and biological systems

The analysis of flow of information in a system

Negative feedback mechanism

Positive feedback mechanism

Feed forward mechanism

When some factor becomes excessive or deficient, a control system initiates negative feedback, which consists of a series of change that return the factor toward a certain mean value, thus maintaining homeostasis

Arterial pressure regulating mechanism by baroreceptors.

Regulation of CO2 in extracellular fluid.

Regulation of hormone release.

“Positive” implies that, when a deviation from a normal value occurs, the response of the system is to make the deviation even greater.

(Why is positive feedback also called “vicious cycle”)

Eg : Inadequate delivery of blood to cardiac muscle due to bleeding.

Stretching of uterine cervix during parturition.

Action potential propagation.

Hemostasis (Blood coagulation)

When response has to occur rapidly, the brain uses a principle called feed forward control.

Seen mainly in nervous system. Eg: Conditioned reflex

Adaptive control.

Text book of medical physiology, Guyton & Hall. 11th edition.

Review of Medical Physiology, William F. Ganong. 22nd edition.

Web sites: www.physiol.net www.biotopics.co.uk

1. Eric Mayo Dagradi, dr, M.Kes, AIF (Kepala Bagian Ilmu Faal )

2. S. Djoni Husodo, dr, M.Kes. (Koordinator Pendidikan Ilmu Faal)

3. Indri N. Rahayu, dr, M.Kes. (Koordinator Praktikum Ilmu Faal )

4. Dody Taruna, dr. (Koordinator Ilmu Kesehatan Olahraga)

5. Asami, dr.6. Nungki, drg, M.Kes (Koordinator Kedokteran Gigi)