gas exchange test

Question 1

How do we breathe (ventilation)

Answer 1

1. Air enters our nose/mouth and passes down the trachea
2. When you breathe in your ribs move upwards and outwards by the intercostal muscles. The outer (external) intercostals contract, pulling the ribs up.
3. At the same time, the muscles of the diaphragm contract, pulling the diaphragm down into a more flattened shape.
4. Both these movements increase the volume of the chest and cause a slight drop in pressure inside the thorax compared with the air outside. Air then enters the lungs (inhalation).
5. The opposite happens when you breathe out deeply. The external intercostals relax, and the internal intercostals contract, pulling the ribs down and in.
6. At the same time, the diaphragm muscles relax and the diaphragm goes back to its normal dome shape.
7. The volume of the thorax decreases, and the pressure in the thorax is raised slightly above atmospheric pressure. This time the difference in pressure forces air out of the lungs.
8. Exhalation is helped by the fact that the lungs are elastic, so that they have a tendency to collapse and empty like a balloon.

Question 2

What does the trachea split into? Then what?

Answer 2

Two tubes called the bronchi, one leading to each lung. Then it splits in smaller tubes, called bronchioles, eventually, ending at the alveoli.

Question 3

What’s the thorax?

Answer 3

The thorax is the upper part of the body.
The inside of the thorax is separated from the lungs by two thin, moist membranes called the pleural membranes.

Question 4

What is the pleural membranes and cavity?

Answer 4

They make up a continuous envelope around the lungs, forming an airtight seal. Between the two membranes is a space called the pleural cavity, filled with a thin layer of liquid called pleural fluid. This acts as lubrication, so that the surfaces of the lungs don’t stick to the inside of the chest wall when we breathe.

Question 5

What supports the airways?

Answer 5

(C-shaped) cartilage (The open part of the ring is at the back of the Chakya, next to where the oesophagus lies as it passes through the thorax. When food passes along the oesophagus by peristalsis the gaps, and the rings, allow the lumps of food to pass through more easily)

Question 6

% Inhaled air:

Answer 6

Nitrogen 78%, oxygen, 21% carbon dioxide 0.04%, other gases (mainly argon) 1%

Question 7

% Exhaled air:

Answer 7

Nitrogen 79%, oxygen, 16%, carbon dioxide, 4%, other gases (mainly argon), 1%

Question 8

Alveoli process

Answer 8

1. Deoxygenated blood is pumped from the heart to the lungs and passes through the capillaries surrounding the alveoli.
2. The blood has come from the respiring tissues of the body, where it has given up some of its oxygen to the cells, and gained carbon dioxide.
3. Around the lungs, the blood is separated from the air inside each alveolus by only two cell layers; the cells making up the wall of the alveolus, and the capillary wall itself. This is a distance of less than a thousandth of a millimetre. 4. Because the air in the alveolus has a higher concentration of oxygen than the blood entering the capillary network, oxygen diffuses from the air, across the wall of the alveolus and into the blood.
4. At the same time there is more carbon dioxide in the blood than there is in the air in the lungs. This means that there is a diffusion gradient for carbon dioxide in the other direction, so carbon dioxide diffuses the other way, out of the blood and into the alveolus.
5. The result is that the blood which leaves the capillaries and flows back to the heart has gained oxygen and lost carbon dioxide. The heart then pumps the oxygenated blood around the body again, to supply the respiring cells

Question 9

How do ciliated cells and goblet cells keep their airways clean?

Answer 9

Ciliated cells have hair that wafts the mucus and pathogens up and out of the trachea. Goblet cells produce mucus to trap dust pathogens.

Question 10

Three most harmful substances in cigarettes.

Answer 10

Tar- a black sticky substance, which contains carcinogens. It destroys the Celia and irritates our airway lining leading to inflammation and overproduction of mucus.
carbon monoxide – a poisonous gas. It binds to haemoglobin in preference, two and more tightly than oxygen forming carboxyhaemoglobin
nicotine – a highly addictive stimulant drug.

Question 11

The heart and smoking

Answer 11

Carbon monoxide affects this organ by blocking its blood vessels when smoking. When someone smokes adrenaline causes organ to work harder to pump more oxygen around the bloodstream.

Question 12

The brain and smoking

Answer 12

Smokers can be in danger of suffering a stroke whether this organs blood supply is cut off. Nicotine causes this organ to create adrenaline and make a person feel relaxed. 

Question 13

The stomach and smoking

Answer 13

Chemicals with smoke can cause organs to look older. Smoking can cause ulcers, which can cause problems with digestion in this major organ.

Question 14

The lungs and smoking

Answer 14

Smoking can cause condition, such as emphysema and cancer in these breathing organs. Smoking and caused tar to collect in this organ which causes breathing difficulties.

Question 15

Bronchitis

Answer 15

Tar, destroys, Celia and irritates the airways, causing inflammation. This leads to the overproduction of mucus which accumulates in the airways leading to: smokers cough, increased risk of infection (bronchitis), reduced airflow -> reduced gas exchange

Question 16

Emphysema

Answer 16

Alveoli walls, breakdown and fuse together, forming in large of regular airspaces. This causes: reduces surface area for gas exchange, less oxen delivered to cells for aerobic respiration, parson gets fatigue easily.

Question 17

Lung cancer

Answer 17

Chemicals and taco carcinogens cause DNA in lung cells to mutate and divide rapidly and uncontrollably. This is a tumour which can spread to other organs via the blood.

Question 18

Carbon monoxide poisoning

Answer 18

It binds to haemoglobin in preference to, and more tightly than oxygen, forming carboxyhaemoglobin, which reduces the oxygen carrying capacity of the blood, and it causes a reduced rate of aerobic respiration, which can lead to rapid death

Question 19

Coronary heart disease

Answer 19

Nicotine increases blood pressure which damages arteries, leaving fatty deposits on artery walls. This means blood is more likely to clot increasing the risk of heart, heart attacks and strokes.

Question 20

Why does our breathing rate increase when we exercise?

Answer 20

Gas exchange can have a faster at the alveoli. So more waste carbon dioxide can diffuse from the blood into the lungs and be excreted from the body and more oxygen can diffuse from the lungs into the blood and travel to the muscles which need to contract. The muscles can use the oxygen to carry out more aerobic respiration. Therefore more energy can be released in the muscles in the form of ATP. The muscles can carry out stronger/longer lasting exercises. The low levels of oxygen also prevent aerobic respiration occurring which would lead to the release of lactic acid, which can be toxic to the muscles.

Question 21

What is the larynx known as?

Answer 21

The voice box

Question 22

What connects the ribs?

Answer 22

The intercostal muscles

Question 23

Why does gas exchange take place?

Answer 23

The alveoli

Question 24

What is another word for breathing?

Answer 24

Ventilation

Question 25

Ventilation 2/ gas exchange

Answer 25

Through your nose and mouth. Warm dump air from your nose and mouth goes into your windpipe. The egg goes into the bronchi. Then it goes into your lungs. Your diaphragm contracts and moves down. The space inside your chest gets bigger and you breathe in. Oxygen is taken from the air into the blood vessels surrounding your lungs. The blood loses waste carbon dioxide into the air in your lungs. Your diaphragm relaxes and moves up. The iris squeezed out of your lungs and you breathe out. That the space in your chest gets smaller. This is called gas exchange 

Question 26

What increases the rate of diffusion in the alveoli?

Answer 26

Large surface area to volume ratio, one cell, thick, and width, meaning, a short, diffusion pathway, thin selectively, more oxygen outside the body than cells), constant ventilation and good blood supply and dense capillary network, maintains the steep concentration gradient.

Question 27

Alveoli and diffusion 

Answer 27

I’ve like a small ass axe fan at the end of the bronchials here at moose into the bloodstream, and CO2 moves into the air in the alveoli, by the process of diffusion. The oxygen is needed in the body cells for aerobic respiration, and the CO2 needs to be excreted in the body. 

Question 28

Respiration

Answer 28

Chemical reaction, which living cells release energy from glucose by producing ATP (in mitochondria)

Question 29

Gas exchange

Answer 29

Processes, by which oxygen and carbon dioxide is diffuse in and out of the lungs ( in the cell)

Question 30

Breathing/ventilation definition

Answer 30

The process of moving into an out of the lungs to facilitate gas exchange

Question 31

Which gases need to be exchanged into the lungs between the air and the bloodstream? Why does each gas need to be exchanged?

Answer 31

O2 is diffuse into a bloodstream and travels to the muscle so they can contract for aerobic respiration. CO2 is diffuse from the blood into the lungs so it can be excreted.

Question 32

Lungs

Answer 32

Large spongy organ, specialised for gas exchange

Question 33

Trachea

Answer 33

Large airway that carries air from the mouth to the lungs, commonly known as windpipe

Question 34

Bronchus

Answer 34

Two large airways that carry air into each lung

Question 35

Bronchioles

Answer 35

Smaller, highly branched allies that carry out further into the lungs 

Question 36

Alveoli

Answer 36

Airsacs were gas exchange takes place

Question 37

Rings of cartilage

Answer 37

Prevents the larger airways collapsing during the pressure changes

Question 38

Ribs/ Ribcage

Answer 38

Protects the lungs & heart; involved in ventilation

Question 39

Intercostal muscles

Answer 39

2 sets (external and internal) between the ribs that contract and relax to move the ribcage during ventilation

Question 40

Diaphragm

Answer 40

Muscular sheets of tissue (fibrous middle, muscular edges) separating the thorax and abdomen that helps the lungs to inflate and deflate

Question 41

Pleural membrane

Answer 41

Separated the inside of the thorax from the lungs; from an airtight seal around the lungs

Question 42

Pleural fluid

Answer 42

Fills the pleural cavity; lubricators so that the surface of the lungs don’t stick inside of the chest wall whilst we breathe

Question 43

Gas exchange in the fish

Answer 43

Water is capable capable of holding only low concentrations of O2, so fish need a different type of exchange system. The exchange surfaces in the fish are gills.
1. Water rid taken through the fish’s mouth, passes over the gills, and then out of the operculum

Question 44

What makes gas exchange efficient in fish?

Answer 44

1. Each gill filament has a network of blood capillaries-> high surface area to volume ratio (Large surface area of blood capillaries in each gill filament)
2. Water that flows over the girls flows in the opposite direction to the blood. This is called countercurrent flow. It means the exchange of O2 and CO2 is more efficient than if the water and blood were both blowing in the same direction.
3. Large surface area of gills.
4. Short diffusion distance (the outer layer of the filament and capillary wall is one cell thick).
5. Moving blood and ventilated, gills surfaces mean that gases that are exchanged are continually removed and enters the blood