• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12

With reference to specific examples and mechanisms assess the significance of homeostasis to the human body.

Extracts from this document...

Introduction

WITH REFERENCE TO SPECIFIC EXAMPLES AND MECHANISMS ASSESS THE SIGNIFICANCE OF HOMEOSTASIS TO THE HUMAN BODY What is homeostasis? According to the 'Oxford Colour Medical Dictionary, Third Edition' homeostasis is the "the physiological process by which the internal systems of the body (e.g. blood pressure, body temperature, acid-base balance) are maintained at equilibrium, despite variations in the external conditions" Homeostasis is the maintenance of a stable internal environment within tolerance limits, this is the restricted range of conditions where cellular operations effectively work at a consistent rate and maintain life. These conditions include temperature, blood glucose levels, pupil diameter control and many more. Homeostasis actually means 'unchanging', but that is not a true description of biological systems. DYNAMIC EQUILIBRIUM is a more accurate description. (1) "An amoeba, a single celled organism, needs to be able to take in oxygen, food and nutrients and to excrete waste products. It needs a constant state of hydration and a controlled temperature for a happy life. Man is complex and multicellular but each cell has the same needs as the amoeba and we have developed complex mechanisms to provide each cell with all that it needs" (2) The human animal is a very complex multi-cellular organism in which the maintenance of life depends upon various physiological and biochemical activities. ...read more.

Middle

It receives an input from the detector, and integrates the incoming information. An effector-when the incoming signal indicates that an adjustment is needed the effector responds and the input is changed (corrective response) e.g. this could be the release of a hormone that lowers blood glucose levels for example i.e. insulin. (5) Source: http://www.biology-online.org/4/1_physiological_homeostasis.ht This type of homeostatic mechanism is known as negative feedback where the body opposes the departure of a controlled variable from the normal range and restores the variable to its normal range. This is the most common type of regulation in the body. The outcome is to maintain a relatively constant or stable environment. An example could be in thermal homeostasis, which maintains normal cell function and normal metabolism where during cold stress (below body core temperature) which could potentially slow down chemical reactions and slow down neural signals, the body would engage in many activities to reduce this stress, these include: -Stimulation of skeletal muscles by the brain's hypothalamus (control centre) to contract and shiver to produce body heat -Stimulation of smooth muscle tissue (effectors) in blood vessels in skin by the brain (control centre) to contract to reduce blood flow to skin and slow down loss of heat by skin's surface (response). In heat stress (above normal core temperature), which disrupts structure of body proteins, the hypothalamus (control centre) ...read more.

Conclusion

On the other hand if pupil constriction happened during dim light, insufficient light would go into the eye to activate the photosensitive pigments in the rods and cons, which stimulate nerve endings in the retina. The iris contains one layer of circular muscle and one layer of radiating smooth muscle fibres. Contraction of the circular fibres constricts the pupil, and contraction dilates it. The size of the pupil is regulated by the autonomic nervous system and it demonstrates an example of a nervous-control mechanism. Sympathetic stimulation causes dilation while parasympathetic stimulation causes constriction of the pupil. (9) Source: Marieb EN, 2003, Human Anatomy & Physiology, sixth edition, San Francisco, Pearson Benjamin Cummings, page 566 Significance of homeostasis Homeostasis is so important that most disease is regarded as a result of its disturbance, a condition called homeostatic imbalance. As we get older, the body's internal environment becomes progressively less stable. As a result we are more vulnerable to illnesses and they produce the changes we associate with ageing. Homeostatic imbalance takes place when the usual negative feedback mechanisms are overwhelmed and the destructive positive feedback mechanisms take over. An example of this phenomenon is heart failure. Illnesses such as hypertension, diabetes are all a result of failed homeostatic mechanisms, this demonstrates the importance of homeostasis to an individual. (10) Put simply, it is the difference between health and illness. Word count =1649 (excluding reference) Student Id Number:03235386 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Exchange, Transport & Reproduction 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 AS and A Level Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    Human Reproductive System

    4 star(s)

    * After the release of the egg or ovulation, the egg is captured by finger-like projections present at the end of the fallopian tubes called fimbrae. The fimbrae sweep the egg into the tube. * During this phase, the amount and thickness of mucus produced by the cervix is increased.

  2. Marked by a teacher

    What is Type 1 diabetes

    3 star(s)

    For Type 2, this rises to 30 per cent. If you are experiencing any of the above symptoms on a consistent basis, it is important to seek medical attention and be tested for diabetes. How is the diagnosis made? The diagnosis is made by examining glucose levels in blood samples using one or more of the following tests (World

  1. Marked by a teacher

    Beetroot pigments

    3 star(s)

    The effect of temperature on a membrane is similar to that of an enzyme, in that they both denature at high temperatures. The protein pumps allow any molecule through as they lose their specific shape and denature as the bonds that hold their tertiary structures together are broken, and they increase in kinetic energy.

  2. Peer reviewed

    Effect of Caffeine on the Heart Rate of Daphnia

    3 star(s)

    or beating of legs of the Daphnia as soon as it is ready to be observed. * The results of the experiment would be more accurate and valid if a "blind study" is done. This is because the experimenter who is counting the heart beat of the Daphnia (water flea)

  1. Fundamental human anatomy and physiology.

    them to make molecules so then it can be packaged in the vesicles so then later on it can send messages out to the cells. Reference: http://www.ivy-rose.co.uk/References/glossary_entry90.htm Viewed on 25/ 2 / 2008 Endoplasmic Reticulum The endoplasmic reticulum is smooth and rough.

  2. The Skeletal and Muscular System

    Scoliosis. The side to side curvature of the vertebral column. The spine bends either to the left or to the right. It is more common in women than men and mostly occurs at the start of adolescence. Normally scoliosis is not a serious condition but if left untreated the

  1. Urinary system

    are the bodies communication system for the purpose of homeostasis. The main hormones involved in the homeostasis process are: * Sodium and water reabsorption are under the influence of antidiuretic hormone (ADH).

  2. The Endocrine System

    Examples are triiodothyronine (T3) and thyroxine (T4). The final type of lipid soluble hormone is nitric oxide. Oxytocin is manufactured in the hypothalamus and then it stored and secreted from the posterior pituitary gland. Production of oxytocin is triggered by dilation of the uterus, cervix and vagina as the foetus

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