Chapter 8- Respiratory System

Question 1

Organs included in the respiratory system

Answer 1

Nose (where the air is taken in)
Windpipe (which branches into two tubes)
The bronchi
The two lungs

Question 2

The lungs

Answer 2

• take up whole chest cavity

- except spot in the middle occupied by heart and blood vessels

Question 3

What is the pluera

Answer 3

• a membrane that covers the lungs surface and lines the inside of the chest
• between two layers of membrane is a thin layer of fluid called pleural fluid
• pleural fluid holds lungs against inside the chest wall and allows lungs to slide along the wall when breathing

Question 4

Inside the lungs

Answer 4

• the bronchi that branch of many times and end in fine tubes called bronchioles
• bronchioles open up into tiny air sacs called alveoli

Question 5

Alveoli

Answer 5

• the exchange surface for respiratory gasses
• each alveolus is surrounded by network of blood capillaries used for exchange of oxygen and carbon dioxide
• air sacs that make up most of lung
• occur in thin clusters
• .

Question 6

Parts of the respiratory system are

Answer 6

Pharynx
Larynx
Trachea
Ribs
Intercostal muscles
Lungs
Nasal cavity
Epiglottis
Bronchi
Diaphragm
Bronchioles
Alveoli

Question 7

Nasal cavity

Answer 7

• contains projections that increase internal surface area
• filters, warms and moistens air before it enters the lungs
• contains smell receptors
• hairs and mucous trap dust

Question 8

Pharynx

Answer 8

• place where air from nasal cavity passes through

Question 9

Epiglottis

Answer 9

• a flap of tissue that during swallowing, closes of the trachea so that no food or liquid can enter the lungs

Question 10

Larynx

Answer 10

• organ of voice
• air passes through larynx
• air goes to and from lungs through larynx
• contains vocal chords that vibrate to make sounds

Question 11

Trachea

Answer 11

• carries air to and fluid
• lined with mucous membrane and cells with cilia
• cilia move mucous and trapped particles upwards

Question 12

Bronchi

Answer 12

• two bronchi branch from trachea and then they further divide

Question 13

Ribs

Answer 13

Framework for the chest

Question 14

Intercostal muscles

Answer 14

Muscles between the ribs

Move ribcage upwards and outwards to increase volume of chest cavity and lungs when breathing in

Question 15

Bronchioles

Answer 15

• fine tubes with walls of smooth muscle

- smallest ones end in groups of air sacs the alveoli

Question 16

Diaphragm

Answer 16

• muscle that separates chest from abdomen

- contracts and flattens downwards which increases volume of chest cavity and lungs when breathing in

Question 17

Why are lungs suited to their function of gas exchange

Answer 17

• because the alveoli give lung huge internal surface area
• each alveolus is well supplied with blood vessels
• the membrane that forms alveoli is very thin so materials can easily pass through
• lungs are positioned deep inside the body so it can prevent excess evaporation of fluid that covers the respiratory surfaces
• the movement can be changed by the movements of the respiratory muscles so that air is made to flow in and out of the lungs

Question 18

Ventilation

Answer 18

• process by which air is moved into and out of the blood

- air flows from areas of high pressure to low pressure

Question 19

Inspiration

Answer 19

• the process of taking air into the lungs
• for air to flow into lungs the pressure of air inside the lungs must be different to air pressure in environment
• decreasing air pressure in lungs is done by increasing lung volume
• to increase lung volume, the diaphragm and intercostal muscles contract therefore the diaphragm becomes flatter and the ribcage moves upwards and outwards which increases volume of chest cavity
• because the pleura sticks to chest wall the lungs expand with the chest cavity
• increased lung volume means the pressure in the lungs is slightly lower than the pressure outside and air flows through the nose and the trachea until the pressure becomes equal
• during normal quiet breathing the diaphragm is responsible for for changes in chest volume
• movements of ribcage become more important during heavy breathing

Question 20

Expiration

Answer 20

• breathing out
• occurs in opposite way to inspiration
• diaphragm and external intercostal muscles relax so the diaphragm bulges more out of the chest cavity and rib cage moves downwards this reduces volume of chest cavity and lungs
• air pressure in lungs is now greater than it outside of the body so air flows out of the trachea and nose cavity until pressures are equal
• when breathing quietly and at rest expiration is a passive process involving relaxation of muscles
• heavier breathing involves more forceful expiration and the intercostal muscles contract to actively lower the rib cage
• same happens when forcibly exhaling like blowing up a balloon

Question 21

Gas exchanges

Answer 21

• blood in capillaries surrounding lungs is brought by the pulmonary arteries
• this blood has been through the capillaries of the body where much of the oxygen has been taken up by the body cells
• the blood the comes to capillaries of lungs has long oxygen concentration
• the concentration is lower than the air in the alveolus
• oxygen therefore dissolves in the moisture on the inside of the alveolus and diffuses through the membrane and into the blood
• the blood that is delivered to alveolus has high carbon dioxide concentration and the air in the alveoli has long carbon dioxide concentration so therefore they can diffuse

Question 22

How is the concentration gradient maintained

Answer 22

• a constant flow of blood through the capillaries

- the movement of air into and out of the alveoli as we breath in and out

Question 23

Emphysema

Answer 23

• disease cause by long term exposure to irritating particles in the air taken into the lungs
• you cant control what you breath in everyday but some people are exposed to high amounts of dangerous particles
• smokers tend to get emphysema and people who live in polluted areas
• irritating particles cause damage to the alveoli
• they lose their elasticity snd may break down
• breathing out requires voluntary effort and is no longer a passive process
• emphysema people have to problems: insufficient surface area for gas exchange and difficulty in ventilating the lungs
• once you have it it cant be stopped and there is no cure

Question 24

Lung cancer

Answer 24

• involves development of a tumour (a mass of cells that divides uncontrollably)
• can be caused by tobacco smoking and exposure to pollutants
• most common form begins in walls of air passages
• inhaled smoke particles constantly irritate the mucous which involves excessive mucous production and the cells at the base of the membrane begin to divide more rapidly snd the accumulating mucous cannot be removed which results in smokers cough
• trapped mucous causes rupture of alveoli

Question 25

Pneumonia

Answer 25

• a lung infection
• caused by bacteria, viruses, fungi or other organisms
• inflammation resulting from infection causes secretion of fluid and mucous into the alveoli which reduces the amount of air they contain
• surface area for gas exchange is also reduces and you have difficulty breathing

Question 26

Tuberculosis

Answer 26

• infection of the lung by mycobacterium tuberculosis
• one of the top three infectious diseases in the world
• spread by moisture containing the bacteria like sneezing or coughing

Question 27

Asthma

Answer 27

• allergic response to foreign substances that enter the body
• things like animal skins house dust mites or pollen grain
• substances in food may also trigger an asthma attack
• during an attack the muscles around the bronchioles spasm which causes difficulty in breathing
• irritation of the membranes lining the air passage causes secretion of excessive mucus and it also restricts movement of air
• reduced volume of air going into and put of the lungs mean that gas exchange is impaired and blood does jot carry the usual amount of oxygen