Homeostasis PDF

Homeostasis 1 1  Homeostasis (Homeo = same - Stasis = staying) It is the maintenance of constant conditions in the internal environment of the body. The internal environment is the ICF as well as ECF (Intra And Extra cellular Fluid). It is essential to mai...

Homeostasis 1 1  Homeostasis (Homeo = same - Stasis = staying) It is the maintenance of constant conditions in the internal environment of the body. The internal environment is the ICF as well as ECF (Intra And Extra cellular Fluid). It is essential to maintain constant conditions in this internal environment, since normal cell function depends upon this constancy. 2 Factors in the Internal Environment that must be Homeostatically maintained pH: 7.4 Blood volume: 5 L. Blood pressure: 120/80 mmHg Temperature: 37 ◦C 3  The body Systems and Contribution to Homeostasis The Nervous System: Sending impulses to control all body systems. The Endocrine System: Regulates cellular functions by hormones. 4  Components of Homeostatic Control Systems 1. Sensor (receptor): Detect the changes in the environment & informs the center. 2. Control (center): Compares information and Generates signals for correction of error. 3. Effector (organ): Responds to the center and corrects the error. 5 Components of Homeostatic Control Systems 6 Feedback Mechanism 7 1- Negative Feedback mechanism (90%) Opposes an initial change & promotes stability 1. Blood Pressure changes. 2. Body temperature changes. 3. Blood glucose changes. 8 A- Body temperature changes 9 B- Blood glucose changes 10  2- Positive Feedback mechanism Amplifies an initial change, and is temporary Examples: 1. During the birth of a baby. 2. Blood Clotting ( later in blood ). 11  Birth Of a Baby ( + Feedback mechanism) 12 13 14