‫مدرسة المشرق الدولية‬
Mashrek International School
NAME:
CLASS: MYP 5 A/B/C/D
TOPIC: RESPIRATION & RESPIRATORY SYSTEM
DATE:
/
/ 2011
STUDY HANDOUT
BREATHING & RESPIRATION
1
UNIT QUESTION:
Why do living organisms respire?
SIGNIFICANT CONCEPTS
Before starting with this chapter you need to revise respiration chapter and be able to answer the following:
Distinguish between aerobic and anaerobic respiration
Name the uses of energy in humans
Differentiate between respiration and breathing
Understand the production and effects of lactic acid in human muscles during vigorous exercise
After completing this chapter, you will be able to:
Understand the mechanism of gaseous exchange in humans
To know the properties of an ideal gas exchange surface
Investigate the effect of exercise on rate of depth of breathing
Relate the features of alveoli to its gaseous exchange function
To list some of the respiratory problems related to smoking Tobacco
AREA OF INTERACTION: HEALTH AND SOCIAL EDUCATION
In this unit you will gain insight into the respiration and respiratory system within the human body. You will
also be encouraged to develop a better understanding of the possible medical problems associated with pollution
and smoking
SUMMATIVE TASKS:
-
Lab investigation: Criteria D, E & F
Investigate the factors that affect the respiration in yeast
-
Unit test: Criteria C
End unit test
Summative tasks will be given separately from this booklet
DURATION:
2 weeks
2
UNIT MAP
3
RESPIRATION:
Energy is needed by all living cells to be used in a wide range of processes such as active transport, cell division
and protein synthesis. ATP is an energy molecule that stores energy and used by cells.
Every cell produces its own ATP by CELLULAR RESPIRATION.
Define cellular respiration. …………………………………………………………………………………….
………………………………………………………………………………………………………………….
Cellular respiration has two types
CELLULAR RESPIRATION
Aerobic Respiration
-
Oxygen needs: …………………
Location in the cell: …………………………….
-
Amount of energy:………………………………
-
Word equation:
-
Symbol equation:
…………………………………………………………………………………………………………..
…………………………………………………………………………………………………………..
Anaerobic Respiration
-
Oxygen needs: ………………… Location in the cell:……………………
-
Amount of energy:………………………………
Types
Lactic acid Fermentation
(in muscle cells under stress)
Alcohol Fermentation
(in Yeast )
-
Word equation:
-
Word equation:
-
Symbol equation:
-
Symbol equation:
4
LACTIC ACID FERMENTATION (IN MUSCLE CELLS)
Work must be done to contract the muscle. The energy for this comes from aerobic respiration. The oxygen
comes from the air. It is taken in at the lungs and carried around the body in the blood, pumped by the heart.
Glucose comes from food digested and also carried by the blood. Muscles have blood capillaries that supply
glucose and oxygen for respiration, and to carry away carbon dioxide and heat that is produced during
respiration.
When the muscles work very hard they use up a lot of energy. The heart and the lungs, cannot supply enough
oxygen to provide this energy by aerobic respiration. In this case muscles can release energy by anaerobic
respiration.
Note: One measure of a person's fitness is how quickly their breathing and pulse return to normal after exercise.
This is because in a fit person aerobic respiration is more efficient, so they build up less of an oxygen debt while
exercising, and need less extra oxygen to breakdown any lactic acid in their muscles resulting from anaerobic
respiration.
TEST YOURSELF:
Q. Fill in the table below to compare between aerobic and anaerobic respiration
Aerobic respiration
Anaerobic respiration
Is oxygen needed
How much energy released
What are waste products
Animal cell:
In yeast:
Where does it occur in the
cell
5
GASEOUS EXCHANGE IN ANIMALS
Q1. Explain why mammals need a breathing system and other unicellular organisms don’t, although they both
respire?
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………...
…………………………………………………………………………………………………………………
Q2. Distinguish between breathing (ventilation), gas exchange and respiration
Ventilation:…………………………………………………………………………………………………………
…………………………………………………………………………………………………………………….
Gas Exchange:……………………………………………………………………………………………………..
…………………………………………………………………………………………………………………….
Respiration:………………………………………………………………………………………………………...
…………………………………………………………………………………………………………………
 FUNCTION OF THE RESPIRATORY SYSTEM
1. Enriching the blood with oxygen and getting rid of the carbon dioxide.
2. Excreting the excess water from the body as water vapor.
3. Smelling odors
6
 STRUCTURE OF THE RESPIRATORY SYSTEM :
Figure 1: Respiratory system
1. Nose
The air can enter the body through either the nose or the mouth. The nose and the mouth are separated by
the PALATE .
Q3. List the advantages of breathing in from the nose?
1. ………………………………………………………………………………………………………………….
2. …………………………………………………………………………………………………………………..
3. …………………………………………………………………………………………………………………..
2. Larynx
Larynx is the voice box of the body that contains the vocal cords for production of sound when air passes over
them.
7
3. Trachea
The trachea goes down through the neck and into the thorax (upper part of the body from the neck down to the
bottom of the ribs and diaphragm)
The air enters the trachea (windpipe) that strengthened by rings of cartilage to prevent it from collapsing; also
it is all covered with ciliated cells and goblet cells.
Q4. Describe the function of cilia and mucus that lines the respiratory tract?
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
4. Lungs :
Each lung lies in the pleural cavity which is lined by elastic membrane called pleural membrane. The thin
layer of lubricating fluid between the membrane decrease friction with the chest walls while the lungs expand
and contract during breathing.
5. Bronchi ( singular bronchus)
In the thorax trachea divides into two bronchi, one
goes to each lung and the branches out into many
smaller tubes called Bronchioles
Both bronchi and bronchioles supported by rings of
cartilage, and covered with ciliated cells and mucus
to filter the air
Figure 2: Inside the Lungs
8
6. Alveoli (singular : Alveolus)
At the end of each bronchiole are tiny sacs called alveoli. This is where gas exchange takes place.
Figure 3: Alveoli
Q5. State and explain the main characteristics that make the alveoli suitable for rapid gas exchange?
1. ………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
2. ………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
3. ………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
4………………………………………………………………………………………………………………..
. ………………………………………………………………………………………………………………..
9
How does oxygen diffuse from alveoli to blood?
As air full of oxygen enters fills the alveolus the
concentration gradient of oxygen is higher than in the
blood. The O2 will dissolve in the moisture lining the
alveolar walls then diffuse into the RBC and combines
with the hemoglobin to form an unstable compound
called oxy-hemoglobin, to be carried along to the heart
through pulmonary vein.
Hemoglobin + oxygen  oxy-hemoglobin
Note: This is a reversible reaction
Figure 4: Gas Exchange
Q6. Describe how does CO2 diffuse out of the blood into alveolus?
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
 MECHANISM OF VENTILATION
 Ventilation involves two very important muscles:
1. The diaphragm which is a large sheet of elastic tissue which stretches across your body, underneath
the lungs and heart.
2. The intercostal muscles made up of enternal and external intercostal muscles
Figure 5: The process of Ventilation
10
A.
INHALATION or (INSPIRATION): The process by which air enters the lungs:
Q6. Describe and explain process of inhalation?
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
B.
EXHALATION or (EXPIRATION): The process by which air leaves the lungs. The steps are:
Q7. Describe and explain process of exhalation?
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
 Comparison of inspired and expired air
As a result of gas exchange, the proportion of oxygen and carbon dioxide in the inhaled/exhaled air changes with the air we breathe in containing a higher percentage of oxygen and a lower percentage of carbon dioxide
than the air we breathe out. (Nitrogen, the main component of air, remains unaffected by breathing and stays at
the same percentage.)
11
 BREATHING RATE AND LUNG CAPACITY
The amount of air that enters and leaves the lungs is measured using a SPIROMETER. A person breathes in
and out of a mouthpiece connected to a chamber. Inside the chamber a piston moves up and down, and its
movements are measured electronically. The changes in volume during breathing are pointed on a graph called
a SPIROGRAM shown below
Q7. List the factors that affect lung volume (capacity)
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
Q8. Define the following terms:
-
Tidal Volume: ……………………………………………………………………………………
…………………………………………………………………………………………………………
-
Vital Capacity: ………………………………………………………………………………………
………………………………………………………………………………………………………………..
-
Residual volume: ………………………………………………………………………………………
………………………………………………………………………………………………………………..
Q9. Explain what stimulates the body to breath faster or slower?
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
………………………………………………………………………………………………………………..
12
 EFFECT OF SMOKING TOBACCO ON THE HEALTH OF THE RESPIRATORY SYSTEM
When tobacco is smoked, it gives out certain chemicals that are harmful to the human body. These chemicals
are the following:
1. Nicotine
2. Tar
3. Carbon monoxide
Tobacco is a plant that is dried and rolled into cigarettes and smoked. The smoke given out from burning the
cigarette can harm the lungs and respiratory passages for a number of reasons
a. It is hot
b. It has a drying effect
c. It contains harmful chemicals like, Nicotine, Tar and Carbon monoxide and sulphur dioxide
Nicotine is another chemical that is released when tobacco is smoked. Nicotine is a stimulant that makes the
person more alert and active which affects the heart rate.
Tar is a brownish chemical that is released when tobacco is smoked. Tar is very harmful to the body, as it
-
sticks to the teeth to cause their discoloration. The teeth become yellowish to brown. It also causes gum
disease and plaque on the teeth.
-
damages the cilia that is found in the trachea, bronchi and bronchioles. When the cilia is damaged, the
dust , the bacteria and the dirty mucus cannot be filtered and causes extra mucus made by goblet cells.
These substances will remain in the lung causing infections mainly CHRONIC BRONCHITIS
-
will make the alveoli walls weak. Whenever the smoker coughs, the alveoli will burst. This is called
EMPHYSEMA. Loosing alveoli, will make the surface area of gas exchange less. This will make
patients breathless and exchausted.
-
Tar is the major cause of developing lung cancer and cancers of the bladder, and stomach
Carbon monoxide is a gas that attaches itself to the hemoglobin of the RBC much easier than the oxygen. This
means that when one smokes tobacco, less oxygen will reach the cells because carbon monoxide takes its place.
When less O2 is reaching the cells, the person will feel tired, breathless , dizzy and weak. This is why smokers
are tired when they do exercise.
CO and nicotine will cause the blood of smokers to clot faster causing artery blockage.
 PASSIVE SMOKERS ( NON-SMOKERS)
o People who do not smoke are called non-smokers. Non-smokers who live in an area where smoking is
taking place are called PASSIVE SMOKERS because they are being exposed to the smoke of tobacco.
o Non smokers are at risk of developing all the diseases that are caused by tobacco including lung cancer. For
every 10 cigarettes that a smoker smokes, a passive smoker will be smoking one cigarette.
o Passive smokers usually complain of the following: headaches, watery eyes and runny nose.
13
TEST YOURSELF:
Q1. Write true if the statement is true or false if the statement is false.
______ 1. All organisms on earth will die without a constant supply of oxygen.
______ 2. Energy released during the breakdown of cells is used to synthesize ATP.
______ 3. The energy released from the breakdown of a single molecule of glucose can be used to synthesize up
to 38 molecules of ATP
______ 4. When glucose is broken down during cellular respiration, a product is light energy.
______ 5. In eukaryotic cells, glycolysis occurs in the mitochondrion.
______ 6. All ATP synthesis in a eukaryotic cell happens in the mitochondria.
______ 7. Carbon dioxide is a product of both cellular respiration and photosynthes
_____ 8. Emphysema can result in the blood being low in hemoglobin.
_____ 9. The greatest contributing factor to lung cancer is inhaling the tar in cigarette smoke.
_____ 10. People who produce too much mucus in the bronchial tubes have a disease called emphysema.
_____ 11. A lung disorder often associated with allergies is called asthma.
_____ 12. The diaphragm is a muscle beneath the lungs.
_____ 13. The mucus lining of the trachea moves foreign particles to the esophagus.
_____ 14. When you inhale, your diaphragm relaxes
14
Exercises:
Q2
15
Q3. draw a section of an alveolus and capillary of a lung. Annotate the diagram to describe the movement of
oxygen when it enters the lungs
Q4. Fill in the blanks with the correct answer.
1. During respiration glucose is broken down to release…………………………
2. Energy is released in our cells inside these structures …………………………
3. The gas produced during respiration………………………
4. These structures are found inside your thorax and are used for breathing…………………
5. This happens to air as it passes along our air passages…………………….
6. Small air sacs that make up our lungs………………………
7. Write down the pathway along which air passes from the larynx to the alveoli.
…………………………………………………………………………………………………….
8. Which structures protect the lungs? …………………………………………
9. The muscles between the ribs………………………………………….
10. A sheet of muscle separating the thorax from the rest of the body…………………………………
11. What happens to gases in the alveolus? ……………………………………………
16
12. Respiration without oxygen ………………………………………..
13. A type of anaerobic respiration in yeast that makes alcohol……………………………………..
14. During vigorous exercise, our muscles make this substance because they can’t get enough
oxygen…………..
15. The extra oxygen needed to break down lactic acid is known as ……………………….
16. The smallest tubes in the lungs are the ____________________________ .
17. The ____________________________ prevents food from entering the larynx.
18. The pharynx is a passageway for ________________________ and ________________________ .
19. The alveoli are surrounded by ____________________________ .
20. Air entering your body is first moistened and warmed in the ___________________________ .
21. The trachea is kept open by rings made of ____________________________ .
17