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

Write a detailed reasoned explanation of the physiology of the three systems (cardiovascular, respiratory and digestive) in relation to energy metabolism.

Extracts from this document...


Write a detailed reasoned explanation of the physiology of the three systems (cardiovascular, respiratory and digestive) in relation to energy metabolism. Respiratory system The thorax (chest), is n airtight box containing the lungs and their associated tubes, the bronchi and the heart. Air can enter the thorax via the nose or the mouth. The nose contains fine bones on its side walls which are curled like scrolls and covered with moist ciliated mucous membrane, rich in blood capillaries. This arrangement produces a large surface area over which incoming air flows. During the passage through the nose, the air is warmed and moistened by he close contact with the mucous membrane and filtered by the ciliated cells. By the time the air reaches the throat, it is warmed at almost body temperature, moistened to almost saturation point and most foreign materials such as dust, carbon particles and many pathogens have been filtered out. The trachea starts at the back of the throat, or pharynx, and divides into two main bronchi, each serving one lung on each side of the heart. ...read more.


This means that when the chest wall moves in breathing, the lungs move with it. Each bronchus after repeatedly dividing ends in a group of ingle-layered globe-shaped structures called alveoli. The wall of the alveoli consist o very thin, flat simple squalor epithelium, and each alveolus is surrounded by the smallest blood vessels known as capillaries. The walls of the capillaries are also composed of simple squamous epithelium, in a single layer. This means that the air entering the alveoli during breathing is separated from the blood by only two single-layered, very thin wall. There are elastic fibres around the alveoli enabling them to expnd and recoil with inspiration and expiration. A film of moisture lines the inside of each alveolus to enable the air gases to pass into solution. As the 2 layers of epithelium are very thin and semi-permeable, the dissolved gases can eaily ad rapidly pass through, in the process called gaseous exchange. Ventilation is the movement of air in and out of the thorax to replenish the oxygen supply and remove surplus waste products (carbon dioxide + water). ...read more.


Diffusion will stop in time, as the numbers o molecules become more evenly distributed. In the human body, where diffusion is a common of transport, the state of equilibrium is not desirable as it means overall transport would cease. To prevent equilibrium being attained, the high concentration must be continually kept high and the low concentration must also be maintained. Diffusion can only occur here there is no barrier at all to the molecules or where the barrier is thin. The rate of diffusion is enhanced with an increased surface area- usually by folds or similar structures to alveoli, and with temperature, since warmth increases the random motion of molecules. The oxygen in the air we breathe combines with the haemoglobin in red cells through the alveolar-capillary membrane. This O2 is delivered to the cellular capillaries via the circulatory system. There the O2 is utilized in glucogenesis. The waste product is CO2 which is combined in the blood with H2O making H2CO3 (carbonic acid). The CO2 disassociates into CO2 and H2O in the pulmonary capillary bed and the CO2 diffuses into the alveoli and is exhaled into the air. Kathryn Munnis M1 + D1 ...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 Energy, Respiration & the Environment 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 Energy, Respiration & the Environment essays

  1. Marked by a teacher

    Effect of nitrate concentration on the growth of Duckweeds

    5 star(s)

    The chain leads to different structures of proteins. Two kinds of proteins can be made fiborous or globular proteins. The globular proteins that are made are like enzymes such as the Rubisco used in the Calvin cycle. Enzymes in plants are needed to make parts of the plants like chloroplasts and pigments.

  2. Marked by a teacher

    To make sure we have plenty of energy in the future, it's up to ...

    4 star(s)

    When the wave goes down, air flows through the turbine and back into the chamber through doors that are normally closed. This is only one type of wave-energy system. Others actually use the up and down motion of the wave to power a piston that moves up and down inside a cylinder.

  1. Marked by a teacher

    Describe the role of energy in the body and the physiology of three named ...

    3 star(s)

    FAD molecule (The molecules of NAD and FAD mentioned here are electron carriers, and if they are said to be reduced, this means that they have had a H+ ion added to them). The things produced here are for each turn of the Krebs cycle.

  2. Marked by a teacher

    The Role of the Respiratory and Circulatory Systems in the Provision of Oxygen and ...

    3 star(s)

    They can be additionally stimulated by the presence of dust, smoke and viruses. Tissues and a huge blood supply within the nasal cavity are also able to warm or cool incoming air to within one degree of body temperature and to keep the area moist.

  1. The Pancreas is a large gland that forms part of the Endocrine System, but ...

    into its active form, Trypsin, so therefore the other enzymes become activated. Task 6: My technique for diagnosing these samples was limited and the main reason for this is because my results that I obtained were only qualitative and not quantitative.

  2. the effect of bile concentration on the activity of the enzyme lipase during the ...

    Subsequently because we used low concentrations of the enzyme lipase I believe this to be the most significant limiting factor the lipase that is used in the body will be at higher concentrations and so will the bile salts because the body is able to reuse both.

  1. Investigate the effect of bile salt concentration on the digestion of milk by the ...

    though the pH had dropped as expected, the rate of reaction was too small to measure accurately. This led me on to trial three. Here I doubled the amount of bile salts that I used and did the test on the 5% bile salt concentration.

  2. Explain how the digestive, cardiovascular and respiratory systems are interrelated

    The digestive system is also another system within the body that interrelates with the respiratory system. This is so that it is able to act like a defence mechanism to the body. An example of when these two systems interrelate is when micro-organisms enter the body, the cells within the

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