Regulatory mechanisms have 4 essential features Name them an

Solution

Regulatory mechanisms have 4 essential features:

1. The internal system variable to be regulated (characteristic to be regulated)

2. An optimal value of set point

3. A detector to monitor the variable

4. homoeostatic correctional mechanism

Positive feedback mechanism is defined as the output response produced by the activity of input signal trough a specific amount of stimulus on the organ during the process of homeostasis. Positive feedback in isolation is not sufficient to maintain homeostasis because of set point alterations triggered by the stimulus. Sometimes, if the effect is not going to produce in time when the stimulus arrived to the organ, homeostasis cannot be reached as it may trigger harmful effects. This is due to incapability of the organ to maintain the adequate direction of a given stimulus result in severe acceleration of its effect sometimes finally disequilibrium in homeostasis. Therefore, homeostasis can be better achieved by negative feedback loop.

1. Temperature regulation- hypothalamus:

Fever mechanism: Initially pyrogens produced by the microbial species either bacteria or viruses or internal arachidonic acid metabolites such as prostaglandins and prostacyclins promote a raised \"set point\" on hypothalamus ((detector to monitor the temperature variable) in the brain followed by peripheral vasoconstriction associated with active generation of heat finally raise in ambient temperature (detector to monitor the variable). This vasoconstriction (before increasing temperature of the body) is going to enable reduction of heat loss via skin and makes person to feel cold.

2. Circadian rhythms:

Circadian rhythms and SCN: Suprachaismatic nuclei (SCN) that is receives inputs from retinas of the eyes and maintains equilibrium with the daily circadian rhythms. These SCN often produce neuronal impulses of circadian rhythms. It has clearly observed in hamster due to increase in circadian periods before surgery procedure and also increased in after surgery procedure but decreased in t hamster. Thereby it is concluded that SCN controls these rhythms via feedback loops and via hormones. Even sometimes after removal from brain, SCN produces impulses. There are “a few other components” outside the SCN that profoundly exhibit circadian patterns are pituitary body and pineal body in the brain.

Feedback mechanism involves the following events: Cells regulate their metabolic activity through positive & negative feedback mechanisms in which \"mainly enzymatic protein synthesis\" mediates regulation of cell metabolic activity. Negative feedback mechanism induce \"constant\" set point of a particular variable (temperature or solute concentration etc) value by dampening \"stimulus\" produced on effector cells and this variable be regulated, where sensor is \"receptor\" finally attains homeostasis. Positive feedback mechanism is going to induce fluctuations of a particular variable above and below the set point rather than being a constant. Anticipation and acclimatization balance any inadequacies in homeostasis in a system or humans by improving \"negative feedback mechanism\" system. Anticipation is a feedforward system & this mechanism is useful to reduce delay phenomenon by identifying an oncoming imbalance in the system finally it is going to determine effector output before reaching a set point. Acclimatization is going to increase when an animal is moving or migration by increasing its muscle mass, finally brings upregulation

Stimulus: It produced on effector cells and this variable be regulated

Receptor activity: The stimulus activates receptors such as nuclear receptors to trigger gene expression

Input via afferent nerves: Information passes through afferent nerves to the control center

Output via efferent nerves: Output effect produce by the control center via efferent pathway

Response: Finally, response in the form of either positive or negative produced via cellular organs

Sleep and leisure time activities are according to the living conditions where they are living for instance in some habitats, such as colder habitats they often possess tender skin and require more adaptation to survive. Thereby, the regulatory activities have changed according the environment followed by genetic variations to obtain tender skin whereas those living warmer habitat their leisure time activities have changed according to their environment. These features such as having tender skin in polar region are also a present characteristic of modern humans (Homo sapiens) who are living at Polar Regions. The similar pattern of diet is including consumption of more red meat followed by similar circadian rhythms according biological clock. Performing reproductive activities such as sexual activities during night and during day-time collecting food for diet and associated parenting are possessed by modern humans.