Homeostasis
Homeostasis
Walter cannon coined the term 'homeostasis ' to describe how the human body regulates its internal environment at normal and constant level. the word Homeostasis (homeo-="same, resembling", stasis=("standing still or state" ) refers the ability of living organism or a cell to maintain its internal environment and keep it at an equilibrium it is a dynamic biological process which stabilizes and maintain internal variable in steady state condition. the common variable such as temperature, pH of body fluids and water, sugar ,level, blood pressure ,hormones respiratory gases ,nutrition etc . are constantly monitored and balanced by body's homeostasis.
Homeostatic control system and components
Homeostatic control system is an important part of the human body to maintain the physical and chemical state at constant equilibrium by constantly monitoring the internal variable. the normal level of such variable in the body is collectively referred to a set point. in other words, the set point is the normal physiological value or range of value necessary for body function.
The homeostasis control center regulate the set point of variable for optimum function of the body and life processes. for example, our body has the set point of 70-100mg/dl for blood glucose and the 37 C (98.6F) for body temperature at which our healthy body works the best. At the conditions below or above these set point, the body fails to work optimally. some physiological factor, such as body 's temperature and the blood pressure (normal BP 120/80mmHg), through tend to vary slightly below or above the normal range. However, the homeostatic control system recognizes these altered chemical signals in order to regulate variable in the body.
Homeostatic is regulated by the four components of the homeostatic control mechanism. these are stimulate (variables), receptors or senser, control center and effectors.
1.Stimulus
2.Senser
3.Control center
4.Effector
1.Stimulus :-
stimulus is an internal and external variable that causes change in a set point in the body and required a cell to react. such variable stimulate the homeostatic control system through receptors.
2.senser or sensory receptors
sensors are specialized chemical structure in organ which detect the change in the set point of variable receptors send information to the control center to counteract. for example, beta cells of the pancreas detach the change in blood pressure and sensory nerve cells monitor change in the body temperature etc. receptors produces a signal and send impulse to the central center for action.
3.Control center
The control center are located in the brain which monitor the normal range of variable in the body and act to maintain homeostatic condition. as soon as the control center receives sensory impulses from the receptors, it sends instructions to the effectors to counteract the change in the environment. for example, hypothalamus, a small region in the brain is the thermoregulatory center of the body as it regulates the body temperature and maintains at 37C when the body temperature alerts it receives information for sensory receptor and sends signal to the effectors to stabilize the body temperature at set point 37C (98.6 F).
4.Effectors
The cells, tissue or organs that responds to the instructions received from the control center serve as the effectors. after receiving the specific signal, effectors reverse the change to normal value and maintains homeostatic. these regulatory mechanisms are termed as feedback.
.png)
0 Comments