The phrase homeostasis originates from the Greek language. “Homeo” defined as “similar” and “stasis” meaning “stable”. Homeostasis is vital for us humans as it maintains equilibrium in the body, which may be caused due to extrinsic changes. Homeostasis happens to sustain the bodies activity, health and functioning. Homeostasis can occur to organs like skin, kidney or liver and it usually contains a system of feedback controls. The body has various sensors; it can detect many physiological variables like blood pressure, temperature and the amount of salt levels in the blood.
These sensors send signals to the brain, the brain is known as the control centre, as a variable diverges from normal conditions. This can also alert changes to compensate for the diverge in order to restore the variable again back to its normal. An example of this is when the human body controls its temperature of 98. 6 degrees Fahrenheit. This occurs when the body shivers; this produces heat for when the outside conditions are low and sweating in order to cool down in high temperatures. The endocrine and nervous system are vital for homeostasis. These two systems regularly deliver crucial feedback to the brain.
Many components are responsible for homeostatic response mechanisms that include the receptors in the body, which evaluate the inner environment and informs an incentive to the integrator. The integrator assesses information from the receptors and chooses whether something has to be done. In the event that it does, the effectors activity then alters the bodies’ condition. In this essay, I will be describing two homeostatic systems and why they are vital for the functioning of us humans. In a positive homeostatic system, the effector reinforces the stimulus; this grows and assembles a product.
An example of this in the human body is blood clotting. In the event of when there is a cut on the skin, the blood vessels break, because of this the platelets in the blood begin to gather at the location of the cut. The platelets start to discharge various different chemicals, this alerts more platelets and therefore more signals that are chemical are given out. The platelets and proteins combine together to aid the clotting of the cut on the surface of the skin. The process that causes such bleeding to terminate is called hemostasis. Hemostasis occurs in several ways.
Another word that is also used for clotting of the blood is known as coagulation. Many specialised molecules and cells are vital in the process of clotting such as platelets, vitamin K, proteins and antithrombin. Veins, arteries and blood vessels are composed of three surfaced walls, which are known as tunics, the blood vessel outer most tunic is made up by connective tissues, connective tissues are important for the structure of blood vessels as it supports its columnar structure. The second wall is called the tunica muscularis, which is composed of smooth muscular tissue.
The inner tunic permits the blood to flow directly in the channel. As well as the tunic, there is a surface of elastic tissue, which lets the tissues to enlarge or tighten in order for blood to flow. However, when a wound is implied the nerves in the tissue make the muscle in the vessel wall to constrict, the lumen of the vessel also contracts which limits the amount of blood flow from the injury. Another mechanism in coagulation is when chemical substances like serotonin and epinephrine are set free, the platelets begin to assemble around the site of the wound and peruse to contract the vessel wall for a couple of minutes.
During injury, neighbouring tissues reveal a substance called collagen to the blood. When an injury occurs fibrinogen, which is established from collagen, and prothrombin, which is established from the membrane of the platelets (also known as thrombocytes) are instantaneously initiated to activate, resulting the thrombocyte to stick to the collagen already in the blood. This is platelet activation. Crucial substances like adenosine diphosphate (ADP) are also allowed to leave from the platelets; consequently, the platelets begin to close up over the blood vessel wall by a thrombocyte plug.
A thrombus clot occurs in order to seal bigger damaged blood vessels. It is crucial for a thrombus to retain the seal in arteries, as the blood pressure in the arteries is immensely bigger than the pressure in the veins. Antithrombin stop the blood clot from pursuing to grow, if the clot increased in size this will obstruct the flow of blood within the vessel. When substances such as prothrombin are activated, it is introduced as thrombin. As well as prothrombin various other substances such as thromboplastin, calcium and vitamin K perform a vital position in the activation process of prothrombin to thrombin.
Thrombin converts fibrinogen to fibrin, fibrin is a non-globular protein that is also involved in clotting of the blood, and fibrin combines to make thin fibrin network strands of a thrombus. This fibrin mesh like strands becomes important in the healing process as they bring leukocytes to the sight of the cut or injury to minimise the threat of an infection. The termination of a clot is called fibrinolysis, this happens when a negative feedback mechanism indicates an adequate amount of healing upon the vessel wall, plasminogen becomes active.
Plasminogen informs the clotting mechanism to immobilise the coagulation (clotting) procedure called heparin. A thrombus primary component is fibrin. Soon after the body goes back to its normal equilibrium state, otherwise known as homeostasis. The second homeostatic system that I am going to describe is called osmoregulation. Osmoregulation is crucial especially during the digestion of food that contains high levels of electrolyte. The most common example of an electrolyte is sodium chloride, table salt. The nervous system is responsible for recognising an imbalance of electrolytes.
To resolve this brain communicates to the body to maintain the water balance. When an organism intake many fluids, the electrolyte in the body become diluted, the water levels increase in the cells, which they were sustaining in order to remain homeostasis. The hypothalamus is responsible for distinguishing the volume of water in the blood. When there is a small amount of water the blood becomes very concentrates, this alarms the pituitary gland to secrete an efficient amount of ADH hormone. The ADH hormone signals the kidney to consume water.
Large amounts of this hormone make the kidneys to perform vigorously to absorb as much water as possible, making the urine very condensed (concentrated) and decrease the concentration of blood. During a negative feedback, the pituitary gland produced less ADH hormone. On the other hand, if there is too much water present in the blood, it becomes weaker (dilute) and our cells take in the water by the process of osmosis. When blood is too diluted the pituitary gland pauses the production of ADH, stopping the kidneys from in taking water, while allows diluted urine to exit the body.
When very concentrated blood begins to increase, the production of ADH also rises causing another negative feedback. Gradually the concentration of blood goes back to normal. Moreover, other distinct hormones control the level of salt and sugar in the blood, an excess amount of glucose is reformed in to glycogen by the liver. Very little amounts of glycogen to glucose again. To conclude I think that coagulation and osmoregulation are two critical homeostatic systems that are needed for the functioning of humans as it allows a balance of substances such as water and minerals at a biological level regardless of its external conditions.
