• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Homeostasis is the process which maintains a constant internal body environment. The process relies on the mechanisms which keep this internal environment within very narrow limits, despite fluctuating external conditions

Extracts from this document...

Introduction

Homeostasis Homeostasis is the process which maintains a constant internal body environment. The process relies on the mechanisms which keep this internal environment within very narrow limits, despite fluctuating external conditions. This is achieved by a process called negative feedback to maintain the set point. Whenever a change occurs in a system, receptors detect the change and activate the effectors, which automatically cause a corrective mechanism to start. This brings about changes of a factor to restore the system back to normal. The bigger the change of a factor from its set point, the larger the corrective mechanism. However an efficient homeostatic system minimises the size of the fluctuations about the set point. This process ensures that cells within the internal environment of an organism are constantly surrounded by a fluid with temperature, pH and water potential which is relatively constant despite changes which try to alter them. ...read more.

Middle

As well as this, pressure receptors can cause vasoconstriction or vasodilation of arterioles. This example of homeostasis allows a person to undergo exercise without experiencing problems due to lack of oxygen etc by being able to change their heart rate and stroke volume. * Osmoregulation - water potential of blood must be kept constant to prevent osmotic damage to cells by the movement of water. In this instance, levels are controlled by osmoreceptor cells in the hypothalamus in the brain, which detect changes in water potential of blood. For example if water potential falls as water is lost through sweating, receptor cells would detect this and make the organism feel thirsty. The receptor cells would also cause the pituitary to release more ADH to allow increased water reabsorption in the kidneys. Both of these changes all of which resulting in more water in the blood so water potential would return to its normal levels. ...read more.

Conclusion

This is either insulin to decrease concentration in blood or glucagons to increase the concentration in blood. At the same time the liver and muscle cells respond by either: 1. Removing more glucose from the blood and activating enzymes which convert glucose to glycogen to decrease blood sugar level to normal concentrations. 2. Activating enzymes which convert glycogen to glucose and returning more glucose to the blood to increase blood sugar level to normal concentrations. It is clear from these examples that the cells in any living organism would not function properly without homeostasis to maintain correct conditions internals. Without is we see conditions such as hyperthermia when body temperature falls too low, osmotic damage when water balance is uncontrolled, or severe diseases such as diabetes when homeostasis goes wrong. A great deal of the hormonal system and the autonomic nervous system are dedicated to homeostasis. We could not survive without it unless we had some kind of alternate method to maintain our internal conditions. ?? ?? ?? ?? Joanne Phillips ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Humans as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Humans as Organisms essays

  1. human body system

    This cause the air sacs in the lungs don't get infected, dirty or dried. After passing down the back of the throat the air travels through the windpipe into the branches, the bronchioles. Each bronchioles ends in the branch of tiny air sacs called alveoli.

  2. Heat Balance in a Hot Environment.

    Inspiratory and expiratory valve Barometer Wide bore tubing Stop clock Scales Method The subject was weighed before the experiment started One subject was needed for this experiment, who was wearing shorts and training shoes. The subject was weighed before the experiment started.

  1. Homeostatic mechanisms I have monitored.

    The pulse will become shallow and slow and the blood pressure will drop as the blood will not be pumped around the body but conserved. Respirations will become shallow as well. Alternatively, with hyperthermia the skin reacts by sending messages to the brain which sends messages to the vessels and capillaries in the skin to dilate.

  2. The thyroid gland.

    in the neck. The majority of these thyroid nodules are benign (non cancerous). The presence of a thyroid nodule does not mean one has thyroid disease. Most thyroid nodules do not cause any symptoms, and most are discovered on an incidental exam.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work