Respiration & the human transport system

Objectives:* Define and compare aerobic and anaerobic

respiration **State the equation for both, using either words or

symbols.***Name and describe the uses of energy in the

body of humans

Starter: Is there a difference between respiration and breathing?Respiration releases energy so does burning why is respiration not burning?

Breathing involves inspiration and expiration of air. Where as respiration involves number of chemical reactions controlled by specific enzymes that breakdown nutrient molecules such as glucose in living cells to release energy in a controlled way .Burning does not release energy in a controlled way and does not involve enzymes.In situations where there isn’t enough Carbohydrate cells also respire fat and protein

Respiration can be in presence of oxygen (……….) or in absence of oxygen (………….)Write down a word and a symbol equation for aerobic respiration. Clue: (opp of

Photosynthesis)

Gas Exchange System

Objectives:*Identify and name the structures of the gas exchange system**Describe the functions of each structure

A. _______________

B. _______________

C. _______________

D. _______________

E. _______________

F. _______________

G. ______________

H.

I.

Exercise : Label the Diagram of the Left LungA.

B.

C.

D.

E.

F.

G.

Trachea

Left bronchus

Bronchiole

Alveoli (air sacs)

Rib

Intercostal muscles

Diaphragm

H.

Larynx (voice box)

Pleural membrane

I.

Lungs are very spongy organs found inside the chest (thorax) and protected by ribs and sternum (breast bones)

A. Connects the throat to the lungs and branches to form B. It is the passage through which inspired air go in and expired air come out.

B. These take in the air directly to the lung and vice versa. They divide into C

C. These help to take air in and out of every part of the lungs and ends in D.

D. It is here the gas exchanges take place between the air in the alveoli and the blood in the surrounding capillaries.

•Protects the lungs.

•Placed between the ribs they move the ribs during breathing especially during deep breathing.

•It is a sheet of fibrous tissue and muscle that separates the thorax from the abdomen.

•It contains the vocal cords when air passes over these you make sounds. Epiglottis is a flap which covers the larynx when you swallow. That is why you can’t breathe and swallow at the same time.

•Surround the two lungs with fluid in between them . This prevents the lungs from rubbing against the ribs.

Breathing

Objectives:* Describe how volume and pressure changes lead to the ventilation of the lungs** Explain the role of mucus and cilia in protection of respiratory system from pathogens and dust particles*** Describe effects of exercise on the CO2 concentration and pH in the tissues and how it affects the rate and depth of breathing

A. _______________

B. _______________

C. _______________

D. _______________

E. _______________

F. _______________

G. ______________

H.

I.

J.

Exercise : Label the Diagram of the Left LungA.

B.

C.

D.

E.

F.

G.

Trachea

Left bronchus

Bronchiole

Alveoli (air sacs)

Rib

Intercostal muscles

Diaphragm

H.

Larynx (voice box)

Pleural membrane

I.

Lungs are very spongy organs found inside the chest (thorax) and protected by ribs and sternum (breast bones)

J

Epiglottis

Ventilation

Inhalation

InspirationContraction of the diaphragm muscles pulls it downwards, increasing the volume of the thorax, during expiration the relaxed diaphragm being pushed back up by the compressed abdominal organs.

The external intercostal muscles between the ribs contract during inspiration, expanding the ribcage and increasing thoracic volume.

Bullet point the process of Inspiration

Inspiration• External intercostal muscles contract and the internal intercostal muscles

relax raising the ribs upwards and outwards• the diaphragm contracts and flattens at the same time• Together they increase the volume inside the thorax• So lungs occupy a larger volume• Pressure inside the thorax and the lung decrease• The atmospheric pressure is greater• Air moves into the lungs through mouth and nose• Lungs inflate

Expiration

The internal intercostal muscles contract during forced expiration, pulling the ribcage downward and increasing thoracic pressure. Diaphragm is pushed back to relax state.

Bullet point the process of Expiration

Expiration• The internal intercostal muscle contract and the external intercostal

muscle relax• This lowers the rib downwards and inwards• The diaphragm muscle relaxes and it bulges up due to pressure from the

organs below and the contraction of the abdominal muscles• Both these decrease the volume inside the thorax lung volume decreases • Pressure inside the thorax and the lungs increase is now greater than the

atmospheric pressure• Elastic recoil of the alveoli helps to force air out of the lungs• Lungs deflate

Cleaning the air

• As you breathe air is moistened and warmed from the evaporation of water from nose lining

• The nose is lined by hair• Hairs filters the air removing particles and some pathogens• The gas exchange system is lined with ciliated epithelial cells and mucus

secreting cells• Dust particles and pathogens get trapped in the slimy mucus• Cilia beat to carry a stream of mucus up to the nose and throat removing the

particles and pathogens• Which you then swallow

Ciliated cells

Cilia moves mucus along

Mucus producing cells

Dust particles

Investigation

Breathing rate

(breaths/min)

At rest Light exercise Heavy exercise

1

2

3

Average =

1. Count your breathing rate at rest2. Do step ups for 1 min (light exercise)3. As soon as you finish sit down and count your breathing rate4. Wait until your breathing rate comes to its resting value5. Now do step ups as quickly as you can for 3mins (heavy exercise)6. Count your breathing rate as before7. Record all results8. Repeat the whole experiment three times.9. Write a conclusion on the effect of different exercise s on breathing rate

exercise Rate of respiration in muscle increases

Rate and depthof breathingincreases

More carbondioxide produced and quickly removed from muscles

Heart beats faster to deliver more oxygen quickly so pulse rate increases

List the changes happening in the body and especially in the muscles heart and lungs during exercise.

Vital capacity- the maximum volume of air that is breathed out after breathing in as much air as possible. An adult can take in 5L of air in his deepest breath. At rest 1/2L of air is breathed in and out. While exercising 4.5 L of extra air can be taken in

Control of Breathing

When you breathe faster you produce more CO2 and sometimes lactic acid is produced lowering the pH of the blood. A part of the brain detects this change and send nerve impulses to the diaphragm and the intercostal muscles so that they contract faster and further to increase the rate and depth of breathing to remove CO2 so the pH is back to normal. This is an example of how body controls its internal environment. (homeostasis)

Gas Exchange

Objectives:*Compare the composition of inspired and expired air**List the features of gas exchange surfaces***Describe gas exchange at the alveolus

What are the differences between inhaled and exhaled air?

inhaled air

nitrogen (78%)oxygen (21%)carbon dioxide (0.04%)water vapour(variable)

Comparing inhaled and exhaled air

How could you test for the differences between inhaled and exhaled air?

exhaled air

nitrogen (78%)oxygen (17%)carbon dioxide (4%)water vapour(saturated)

Name gas exchange surface of a fish and a mammal

Features:1. A very large surface area for diffusion of gases2. Moist surfaces so gas can dissolve before diffusion3. Thin walls (1cell thick) for easy diffusion4. A good blood supply so that lot of O2 is supplied and

lots of CO2 is removed quickly. This maintains the

concentration gradients for these gases.

Gills, alveoli

Thin film of moisture

Thin wall of alveolus

To cellsFrom cells

Combine with Hb of red blood cells

Alveolus is surrounded by elastic tissue. This stretches while breathing in and recoils while breathing out to help remove air from the lungs.

For each experiment:1. What result would you expect? Explain2. Explain the set up in each case

Lime waterKOH or soda lime

Anaerobic Respiration

Objectives:*State equations for anaerobic respiration in muscles and in yeast**Describe the role of anaerobic respiration in in yeast during brewing and bread making***Describe the effect of lactic acid in muscles during exercise

Anaerobic respiration of yeast is called fermentation.Brewing:In beer making sugar is supplied by barley grain. Grains are allowed to germinate by malting. The starch is broken down to maltose by enzymes. Maltose is dissolved in water to give a brown liquid called wort.Next process is mashing yeast is added to the wort and fermentation begins. The flower of hop plant is added to give flavour.

Breadmaking: The dough a mixture of flour, water, salt, sugar and yeast is kept at a warm temperature for fermentation. The dough rises because of ……….of ……… trapped inside it. The gas is………… When it is baked in hot oven this gas expands and gives the bread a light texture. The heat causes the………… to …………. , leaving the taste of bread intact.

Oxygen debt:This is the extra oxygen needed to break down lactic acid in muscles.Sprinters build up lactic acid in their muscles. They often hold their breath during a 100m race. Afterwards they need about 7L of oxygen to get rid of the lactic acid. They breath deeply after the race to repay their oxygen debt. So the heart rate remains high after the rate. Why?

Smoking

*Describe the effects of tobacco smoke and its major toxic components on the respiratory system

Chemicals in smoke

Effect on body Diseases Description of disease

Q. What is the addictive chemical in cigarette smoke?

A. Nicotine

Nicotine is an addictive drug that acts directly on the brain. It is the reason smokers find it difficult to give up. It also raises the heart rate and blood pressure which can lead to other health problems.

Q. Name a harmful chemical that cigarette smoke contains

A. Carbon monoxide

The haemoglobin in your red blood cells will pick up carbon monoxide rather than oxygen. This reduces the amount of oxygen carried to the cells in your body.

Q. Cigarette smoke contains tar which is a carcinogen. What is a carcinogen?

A. A cancer-causing chemical

We know that tobacco smoke contains a lot of carcinogens, and as a result many more smokers than non-smokers suffer from lung and throat cancers .

Q. If a pregnant woman smokes, what effect can the carbon monoxide in the smoke

have on her unborn baby?

A. Low birth mass

If a pregnant woman smokes, the haemoglobin in her red blood cells will pick up carbon monoxide rather than oxygen. This means the unborn baby will get less oxygen than it should which can affect its growth

Q. Name three diseases that can be caused by smoking

A. Lung cancer, emphysema, bronchitis

Emphysema is the destruction of the air sacs (alveoli) for gas exchange. The sufferer will be very short of breath

Lung cancer develops when cells become abnormal and grow out of control. Over time they form a clump, also known as a tumour.

Bronchitis is an inflammation of the air passages within the lungs. The sufferer will have a very bad cough

Q. How does the tar in cigarette smoke affect a smoker’s lungs?

A. It damages the cilia which clean the lungs, making chest infections more likely

Cilia are tiny hair-like structure which line the airways. They move to waft mucus and microbes out of the lungs.

If they are damaged, they don’t move and the goblet cells which produce excess mucus and microbes stay in the lungs

Q. What is the best method to give up smoking?

A. Hypnosis

Q. What percentage of lung cancer is caused by smoking?

A. 90%

Q. What is emphysema?

A. A disease where the alveoli (air sacs) in the lungs break down

Sufferers often feels short of breath usually have an oxygen tank with them wherever they go to help them breathe

Across 3. This is a poison in tobacco smoke that causes cancer 8. You inhale this gas if you smoke. It takes the place of oxygen in the red blood cells. 9. The type of cancer most often seen in smokers.

Down 1. A cancer-causing chemical 2. A lung infection that smokers can get. 4. Smokers are at risk of developing this, as nicotine encourages the build-up of cholesterol on the artery walls. 5. Smokers do this often to try to remove the build-up of mucus in the lungs. 6. A lung disease where the walls of the air sacs in the lungs get broken down by smoking. 7. The addictive chemical found in tobacco smoke

Across 3. This is a poison in tobacco smoke that causes cancer 8. You inhale this gas if you smoke. It takes the place of oxygen in the red blood cells. 9. The type of cancer most often seen in smokers.

Down 1. A cancer-causing chemical 2. A lung infection that smokers can get. 4. Smokers are at risk of developing this, as nicotine encourages the build-up of cholesterol on the artery walls. 5. Smokers do this often to try to remove the build-up of mucus in the lungs. 6. A lung disease where the walls of the air sacs in the lungs get broken down by smoking. 7. The addictive chemical found in tobacco smoke

Across:3. Tar8. Carbon monoxide9. Lung

Down:1.Carcinogen2.Bronchitis4. Heart disease5. Cough6. Emphysema7. Nicotine