Transport in Humans & Respiration Flashcards

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1
Q

What does the heart do?

A

It provides the pressure to pump blood through the circulatory system. This pressure is generated by the squeezing of the walls of the heart against the blood which is possible because these walls are made of muscle, and the muscle contracts rhythmically.

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2
Q

What is the left atrium?

A

It is the part of the left side of the heart that receives oxygenated blood returning from the lungs through the pulmonary vein.

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3
Q

What is the right atrium?

A

It is the part of the right side of the heart that receives deoxygenated blood from the vena cava returning from the tissues in the body.

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4
Q

What are the semi lunar valves?

A

They are the valves found in the pulmonary artery and aorta that prevent blood running back into the left and right ventricle when pressure falls during relaxation

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5
Q

What are the tricuspid valves?

A

They are the valves found between the right atrium and ventricle that prevent blood flowing back from the right ventricle to the right atrium during contraction, forcing the blood through the pulmonary artery.

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6
Q

What are the bicuspid valves?

A

They are the valves found between the left atrium and ventricle that prevent blood running back from the left ventricle to the left atrium during contraction, forcing the blood out through the aorta.

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7
Q

What is the aorta?

A

It is the main artery of the body. It carries oxygenated blood from the left ventricle out to the tissues. Blood pressure is at its highest in the aorta, and the strongest pulse is felt here.

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8
Q

What is the pulmonary artery?

A

It carries deoxygenated blood from the right ventricle to the lungs.

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9
Q

What is the pulmonary vein?

A

It returns oxygenated blood from the lungs to the left atrium. A vein from each lung join before entering the left atrium.

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10
Q

What is the vena cava?

A

It is the main vein of the body. It returns deoxygenated blood from the head and lower body to the right atrium.

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11
Q

What is the septum?

A

It is the wall between the left and right sides of the heart. This separates oxygenated and deoxygenated blood.

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12
Q

What special characteristic does the wall of the left ventricle have?

A

It is thick and muscular since it must force blood through the aorta and other arteries to all the tissues of the body.

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13
Q

Why isn’t the wall of the right ventricle as thick and muscular as the wall of the left ventricle?

A

Since it need only force blood along the pulmonary arteries to the lungs.

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14
Q

What are the atriums?

A

They receive blood at low pressure from the veins.

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15
Q

What are the ventricles?

A

They pump blood at high pressure out to the arteries.

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16
Q

What are the valves?

A

These pocket-like flaps make sure that the blood flows in the right direction.

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17
Q

What side of the heart deals with deoxygenated blood? Which deals with oxygenated blood?

A

The right side of the heart deals with deoxygenated blood whilst the left side deals with oxygenated blood.

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18
Q

Describe how blood flows through the right side of the heart.

A
  1. Blood travels through the vena cava
  2. Blood enters the right atrium
  3. The right atria contracts
  4. Blood travels through the tricuspid valve
  5. Blood enters the right ventricle
  6. The right ventricle contracts (the tricuspid valves close)
  7. Blood travels through the semilunar valves and into the pulmonary artery
  8. Blood travels to the lungs to collect O2 and deposit CO2
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19
Q

Describe how blood flows through the left side of the heart.

A
  1. Blood travels through the pulmonary veins
  2. Blood enters the left atrium
  3. The left atria contracts
  4. Blood travels through the bicuspid valve
  5. Blood enters the left ventricle
  6. The left ventricle contracts (the bicuspid valves close)
  7. Blood travels through the semilunar valves and into the aorta
  8. Blood travels to the body
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20
Q

What are arteries?

A

They always carry blood away from the heart to the tissues. Blood in the arteries is at high pressure, rich in oxygen and low in carbon dioxide (except in pulmonary artery).

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21
Q

What are some of the important characteristics of arteries?

A
  • Thick outer wall withstands the high pressure of the blood
  • Thick layer of rings of muscles (narrow or widen the artery and control the blood flow in it according to the body’s needs)
  • Elastic fibers (expand and relax as blood is forced out the heart, help to squeeze blood through – causes the pulse you can feel if you press an artery against a bone a bone, e.g. in the wrist)
  • Smooth lining (no obstruction to the flow of blood)
  • Narrow central tube (lumen)
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22
Q

What are veins?

A

They always carry blood towards the heart. Blood in the veins is at low pressure, low in oxygen and high in carbon dioxide (except in pulmonary vein).

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23
Q

What are some of the important characteristics of veins?

A
  • Thin walls reduce resistance to blood flow and allow skeletal muscles to squeeze the blood along
  • Large diameter reduce resistance to the flow of blood and ensures transport of large volume of blood
  • Valves prevent backflow of blood.
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24
Q

What are capillaries?

A

They link arteries and veins. They are present in all organs and tissues and are the site of exchange of materials between blood and tissue fluid (by diffusion): oxygen and nutrients diffuse into cells and CO2 and wastes diffuse into the blood from the cells. Very thin walls (one cell thick) allow for a short diffusion distance, speeding up the process. Networks or beds of capillaries extend through all the tissues, so every body cell is near to a capillary

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25
Q

What are arterioles?

A

They connect arteries to capillaries.

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26
Q

What are venules?

A

They connect capillaries to veins.

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27
Q

What are shunt vessels?

A

They provide an alternative pathway for the blood (e.g. shunt vessels in skin allow less heat to be lost by redirecting blood away from the skin surface)

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28
Q

What does the hepatic artery do?

A

It carries oxygenated blood to the liver.

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29
Q

What does the hepatic vein do?

A

It returns blood with a regulated, optimum concentration of food substances to the circulation.

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30
Q

What does the hepatic portal vein do?

A

It carries blood containing variable amounts of the absorbed products of digestion from the digestive system to the liver.

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31
Q

What does the renal artery do?

A

It carries oxygenated blood with a high concentration of urea to the kidneys.

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32
Q

What does the renal vein do?

A

It returns blood with reduced urea concentration to the circulation.

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33
Q

What do the coronary arteries do?

A

They branch of the aorta, supplying the heart with its own supply of blood (which it needs to respire to create energy for the muscle contractions).

34
Q

What are the three techniques used to measure the activity of the heart?

A
  • Measuring pulse rate: This should be regular, allowing for exercise or activity. Any unusual changes could indicate problems in the heart’s nervous system
  • Making an ECG (electrocardiogram): There should be a regular pattern of the flow of electric current through the heart muscle
  • Heart sounds: The regular ‘lub-dup’ sound of the heart is caused by the heart valves closing in sequence (cuspid the semilunar). Leaking valves can make the sound less clear
35
Q

How do the coronary arteries become blocked and what happens when this occurs?

A

Coronary arteries become blocked due to a buildup of plaque (fatty deposits). If any of the coronary arteries become blocked, the supply of blood to the heart muscle may be interrupted. If there is a complete blockage, then a heart attack could result as the heart is deprived of oxygen and glucose.

36
Q

What are some of the risk factors of CHD?

A
  • Poor diet: high levels of cholesterol or saturated fatty acids in the body
  • Poor lifestyle: smoking, lack of exercise, stress
  • Genetic factors: being male, having a family history of heart disease
37
Q

How can one prevent CHD?

A
  • Aspirin: Some chemicals in the blood trigger events that cause blood clots which can clog the arteries. When aspirin stops those chemicals, it helps slow the formation of the clots.
  • Drinking red wine: Resveratrol is found in the skin of red grapes, and is said to prevent immature fat cells from fully maturing and helps activate a protein that protects the heart from inflammation.
38
Q

What are some of the methods of treatment for CHD?

A
  • Angioplasty: A special cable is passed into the narrowed artery and used to insert a metal ‘cage’ which forces the artery open. Blood can now flow more easily.
  • Coronary artery bypass: A blood vessel is removed from another part of the body and stitched into place between the aorta and the unblocked part of the coronary artery. Sometimes an artificial vessel is used. The bypass increases blood flow and reduces the likelihood of angina (chest pain).
39
Q

What is the effect of exercise on one’s pulse rate?

A

As you exercise, your muscles require more energy to contract. The energy is obtained through respiration in the muscles and the muscles require more oxygen and glucose to be able to respire more rapidly. The blood delivers the glucose an oxygen and so the heart must beat faster to provide the muscles with extra glucose and oxygen.

40
Q

What do red blood cells do?

A

They transport oxygen from lungs to all respiring tissues. Prepare CO2 for transport from all respiring tissues to lungs.

41
Q

What are red blood cells’ important characteristics?

A

They contain haemoglobin, an iron-containing pigment which picks up oxygen at the lungs and lets go of it at the tissues. They have no nucleus, leaving more space for haemoglobin. These cells are small and flexible, so they can squeeze through narrow capillaries

42
Q

What do phagocytes do?

A

They are attracted to wounds or sites of infection by chemical messages. They remove any microorganisms that invade the body and might cause infection. The phagocyte engulfs and digests the microorganism. Sometimes, phagocytes die as they accumulate toxins from the pathogens.

43
Q

What are phagocytes’ important characteristics?

A

Their irregular shaped nucleus allows them to squeeze through gaps in walls of capillaries. An enzyme in their cytoplasm digest microorganism once engulfed. Their sensitive cell surface membrane can detect microorganisms.

44
Q

What do lymphocytes do?

A

They produce antibodies (proteins made by the body in response to an antigen). Antibodies help to defend the body in two ways: by recognizing, binding to and helping to destroy pathogens and to destroy them by phagocytosis.

45
Q

What are antigens?

A

Antigens are found on the surface of harmful pathogens and on foreign substances entering the body (such as in organ transplants). Different antigens have different shapes and so cause different antibodies to be produced such that each antibody is specific to a particular antigen.

46
Q

What is one of lymphocytes’ important characteristics?

A

Lymphocytes have large nuclei which contain many copies of genes for the control of antibody protein production.

47
Q

What are platelets?

A

They are cell fragments involved in blood clotting. They can release blood-clotting enzyme.

48
Q

What purpose does plasma hold?

A

It carries dissolved food molecules such as glucose and amino acids, waste materials such as urea, and some control molecules such as hormones. This watery liquid has a very high shc which means that it can distribute heat around the various parts of the body.

49
Q

Summarise the regulatory functions (homeostasis) of the blood.

A

The blood solute level regulates the movement of water between blood and tissues. Water plays a part in the distribution of heat between heat-producing areas such as the liver and areas of heat loss such as the skin. Blood also helps maintain an optimum pH in the tissues.

50
Q

Summarise the protective functions of blood.

A

Platelets, plasma proteins and many other plasma factors protect against blood loss and the entry of pathogens by the clotting mechanism. White blood cells protect against disease-causing organisms: phagocytes engulf them whilst lymphocytes produce and secrete specific antibodies against them.

51
Q

Summarise the transport functions of the blood.

A

Soluble products of digestion/absorption are transported from the gut to the liver and then to the general circulation. Waste products of metabolism (e.g. urea, creatinine and lactate) are transported from sites of production to sites of removal, such as the liver and kidney. Respiratory gases (i.e. O2 and CO2) are transported from their sites of uptake or production to their sites of use or removal. Hormones (e.g. insulin) are transported from their sites of production in the glands to the target organs where they have their effects.

52
Q

What is respiration?

A

It is the process of releasing energy from food and oxygen. Respiration happens in all living cells all the time as all living cells in the body need energy, and so glucose and oxygen must be transported throughout the body. Several different enzymes control the reactions of respiration.

53
Q

Describe (and provide the equations) for the two types of respiration in humans.

A

Aerobic respiration – This is the type of respiration that usually occurs. It releases lots of energy.
Word equation: glucose + oxygen – energy + carbon dioxide + water
Balanced chemical equation: C6H12O6 + 6O2 – energy + 6CO2 + 6H2O

Anaerobic respiration – This is the type of respiration carried out by humans when there is not much oxygen available. It happens in our muscles during vigorous exercise. It produces less energy than aerobic respiration.
Word equation for this reaction in humans: glucose – lactic acid + a little energy
Balance chemical equation: C6H12O6 – 2C3H6O3 + a little energy

54
Q

What is the energy made in respiration used for in humans?

A
  • Muscle contraction such that is needed during the walking and running
  • Sending nerve impulses around the body to transmit messages
  • Growth (increase in number of cells)
  • Maintaining a constant a body temperature
  • Cell division
55
Q

How does yeast respire?

A

Yeast respires anaerobically when there is not enough oxygen available.
Word equation for this reaction in yeast cells: glucose – alcohol + carbon dioxide + a little energy
Balanced chemical equation: C6H12O6 – 2C2H5OH + 2CO2

56
Q

What is the larynx?

A

Air passes through here during breathing.

57
Q

What is the trachea?

A

It is the tube that carries air towards the lungs. C-shaped rings of cartilage prevent the trachea from collapsing during inhalation.

58
Q

What are the bronchi?

A

They are the first branches leading off from the trachea. There is one bronchus to each lung

59
Q

What are the bronchioles?

A

They are the final, very fine branches leading into the alveoli.

60
Q

What are the alveoli?

A

They are air sacs lined by the membranes where gas exchange takes place. Their surfaces are moist, thin, and have an enormous area.

61
Q

What are the ribs?

A

The bones which protect the lungs.

62
Q

What are the intercostal muscles?

A

They are muscles in between the ribs that contract and relax to ventilate the lungs.

63
Q

What do the pleural membranes do?

A

They reduce friction and allow lungs to inflate during breathing.

64
Q

What is ventilation (of the lungs)?

A

It is the process of taking air into and out of the lungs.

65
Q

How does inspiration/inhalation occur?

A

When you breathe in, your external intercostal muscles contract. The diaphragm is pulled downwards and the ribs move up and out. This increases the volume and decreases the pressure inside the thorax. The pressure inside the thorax becomes lower than the air pressure outside so air rushes into the lungs.

66
Q

How does expiration/exhalation occur?

A

When you breathe out, your internal intercostal muscles contract. The diaphragm springs upwards and the ribs move down and in. This decreases the volume and increases the pressure inside the thorax. The pressure inside the thorax becomes higher than the air pressure outside so the air rushes out of the lungs.

67
Q

What is gas exchange (in the lungs)? Explain the process.

A

Gas exchange is the swapping of oxygen for carbon dioxide. Oxygen diffuses from inside the alveoli of the lungs into the blood and carbon dioxide diffuses from the blood into the alveoli of the lungs due to the presence of a concentration gradient: there is a higher concentration of oxygen in the alveoli than in the blood; vice versa for carbon dioxide. When oxygen diffuses into the blood, it combines with haemoglobin in the red blood cells, forming oxyhaemoglobin. A branch of the pulmonary artery from the heart delivers deoxygenated blood at high pressure from the right ventricle of the heart whilst a branch of the pulmonary vein returns oxygenated blood to the heart for pumping out to the tissues.

68
Q

What are the requirements for efficient gas exchange?

A

For efficient gas exchange, there must be a large surface area which is provided by the millions of alveoli in the lungs. Also, the distance for diffusion of the gases must be small. The alveoli must be close to a good blood supply so that the exchange of gases is more efficient. The exchange surface needs to be moist to allows oxygen to dissolve and by transported into the blood easily. The lungs need to be well ventilated to maintain the concentration gradients.

69
Q

How are the lungs kept clean?

A

The trachea is lined with goblet cells and ciliated cells which stop too many unwanted particles, such as dust particles and pathogens such as bacteria, getting into the alveoli, where they could cause damage.

70
Q

What do goblet cells do?

A

They produce mucus - many of the dust particles and bacteria in the air get trapped in the mucus.

71
Q

What are ciliated cells?

A

Ciliated cells have microscopic ‘hairs’ on them called cilia – these sweep the mucus upwards, by moving rhythmically in on towards the back of the throat. This mucus is then either swallowed or coughed out.

72
Q

What do phagocytes in the lungs do?

A

In the lungs, phagocytes destroy viruses and bacteria that you might breathe in, often before they have a chance to make you ill.

73
Q

Why is there less oxygen in expired air compared to inspired air?

A

Because some of it has diffused into the body.

74
Q

Why is there more carbon dioxide in expired air compared to inspired air?

A

Because some of it has diffused into the lungs from the blood and exhaled.

75
Q

Explain what is meant by a ‘double circulatory system’.

A

This is when the blood passes through the heart twice for each complete circuit of the body

76
Q

Name three ways in which smoking can harm the lungs and respiratory passages

A
  1. It is hot
  2. It has a drying effect
  3. It contains harmful chemicals
77
Q

List some of the chemicals found in burning tobacco

A

tars, carbon monoxide, sulfur dioxide, nicotine, small quantities of arsenic and plutonium

78
Q

How does carbon monoxide affect the body?

A

It reduces the oxygen supply - it reduces oxyhaemoglobin formation because it binds tightly to haemoglobin; effect is permanent since carboxyhaemoglobin is very stable. This reduces aerobic respiration (bad for sport) and reduces oxygen transport to the placenta (babies born to smokers have low birth-weight)

79
Q

How does nicotine affect the body?

A

It’s the chemical that causes addiction. Also a stimulant which makes heart beat faster and blood vessels narrow, resulting in a rise in blood pressure (causing long-term damage to the circulation). Increased heart rate increases demand for oxygen, but carbon monoxide reduces oxygen availability – so heart muscle is more likely to be damaged

80
Q

How does tar affect the body?

A

It causes cancer. Also an irritant which makes coughing more likely, causing physical damage to the lungs and making the effects of emphysema even worse.

81
Q

What effect does the cilia being destroyed by smoking have?

A

Means that mucus accumulates in respiratory tubes. Dust and microbes trapped in the mucus slide down towards the lungs making the person cough, inflaming the lining of the bronchi, causing bronchitis.

82
Q

How does smoking cause emphysema? What effects does this illness have?

A

Results when walls of the air sacs in the alveoli are destroyed. This happens because smoke affects white blood cells which then destroy lung tissue. When the walls break down, there is less surface for gas exchange, and breathing becomes very difficult. Somebody with emphysema will usually only be able to walk 2-3 meters before becoming breathless