Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  • Level: GCSE
  • Subject: Science
  • Document length: 1262 words

The process of gaseous exchange at the lungs and the muscles and the effect of exercise on this process.

Extracts from this document...

Introduction

Task 3 - The process of gaseous exchange at the lungs and the muscles and the effect of exercise on this process. Once the air has passed through the airways and reached the alveoli the process of gaseous exchange will begin. The oxygen must go into the capillaries by passing through the alveoli and capillary walls and the carbon dioxide must go into the alveoli by passing through the capillary walls and the alveoli walls to then be expired from the lungs. These gases move by diffusion; which is the movement of gaseous particles along a partial pressure gradient. http://www.schools.sandwell.net/menzies/subjects/biology/ks3/images/alveoli.png The blood supply going around the alveoli is constant, so that oxygen and carbon dioxide can be continuously moving in and out of the capillaries. Because the blood is moving quickly past the alveoli it means that one same red blood cell is never staying at the same point so the movement of gases can be constant; as deoxygenated blood is constantly coming through the gradient of oxygen will go from high in the alveoli to low in the deoxygenated blood so that the concentration gradient is very good so oxygen will diffuse more quickly. ...read more.

Middle

the gradient into the muscles as they have a low partial pressure of oxygen but as the partial pressure in the muscles reaches around 40mm Hg the gradient from blood to muscle tissue will be much more equal so no oxygen will be able to pass down the partial pressure gradient which is required for diffusion to take place. Obviously during gaseous exchange at the muscles the carbon dioxide which is formed during muscular contractions must be taken away by the blood. 10% of the total carbon dioxide taken form the muscles is just carried by dissolving into the plasma. Another 20% is carried away by the red blood cells by combining with the carbon dioxide to form carbaminohaemoglobin (binds to the iron atoms) and the remaining 70% is carried in the form of bicarbonate ions. This is when the carbon dioxide combines with the water to form the plasma to form carbonic acid (H2CO3); this is then broken down by an the enzyme carbon anhydrase (which is found in the red blood cells) leaving one free hydrogen atom and a bicarbonate ion (HCO3) This remaining free hydrogen atom can then be used to bind with the oxyhaemoglobin and thus displacing the oxygen atom (due to their contrasting places in the reactivity series) ...read more.

Conclusion

The temperature receptors within the body can recognise that heat is being produced as a result of exercise and can then do various things to aid the body, such as increasing the electrical impulses travelling to the muscles in use, bring the blood vessels closer to the surface of the skin to release more heat and also make the body sweat in order to cool down. The stretch receptors in the lungs will also be used to detect any increase in lung volume as a result of exercise; the brain can then use this information to regulate the contractions happening at the diaphragm and intercostals so that the lungs are not over stretched. It does this by initiating expiration when the lungs become over stretched; it is called the Hering-Breur Reflex. The main result of all these sensory detections is that the lungs can work efficiently so that the muscles are getting enough oxygen for the production of ATP as energy and also so that carbon dioxide and acidity levels in the muscles/blood don't rise too high. This means the muscles can keep exercising effectively as any lack of oxygen or increase in carbon dioxide/acidic substances would cause the muscles to stop working and cramp up which would obviously restrict our ability to exercise. ...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. Marked by a teacher

    Synoptic Biology Essay - "The transport of oxygen from air in the alveoli of ...

    3 star(s)

    Considering Fick's law of diffusion, the body has adapted to maximise diffusion by increasing the surface area for gas exchange (many alveoli, and capillaries), by having a small diffusion pathway (blood supply is very close to gas exchange surface, alveoli are only one

  2. Stem Cell Research

    because the embryonic stem cells are able to form any type of tissue, even those that would not usually be able to be cultured (such as muscle cells or nerve cells). These cell lines are important for the testing of drugs because they give the opportunity to safely test the

  1. The effect of exercise on gas exchange and breathing

    There are two alpha peptide chains and two beta peptide chains. Each subunit consists of a polypeptide chain and a haem group, which contains a central iron atom, which is the binding site for oxygen. The iron atom is kept in a hydrophobic environment to prevent the deterioration of haemoglobin to methemoglobin, which cannot bind to oxygen.

  2. The effect of exercise on gas

    These then divide again 22 times until the alveoli are reached. The alveoli are microscopic blind-ended sacs and are the site of gas exchange between the atmospheric air and blood. There are around 3-6 x 108 alveoli in the lungs and each alveolus is made up of a single layer of epithelium.

  • Over 180,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work

Marked by a teacher

This essay has been marked by one of our great teachers. You can read the full teachers notes when you download the essay.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review on the essay page.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review under the essay preview on this page.