Answer the following questions
17. Name the respiratory organs of flatworm, earthworm, fish, prawn, cockroach and cat.
- Body surface
- Body wall
18. Name the enzyme that catalyses the bicarbonate formation in RBCs.
Answer: Carbonic anhydrase
19. Air moving from the nose to the trachea passes through a number of structures. List in order of the structures.
nostrils, Nasal cavity, pharynx Larynx, trachea, the bronchi bronchioles and the
20. Which structure seals the larynx when we swallow?
21. Resistance in the airways is typically low. Why? Give two reasons.
the cartilagenous rings present in the trachea provides easy way for air. The bronchi
which have ‘C’ shaped curved cartilage plates to ensure that the air passage does
not collapse. The rigidity of bronchioles prevent them from collapsing. Thus the
air reaches the lungs with out any disturbances.
22. How the body makes long–term adjustments when living in high altitude.
• When a person travels from sea level
to elevations where the atmospheric pressure and partial pressure of O2
lowered there is a poor binding of O2 with haemoglobin leads to acute
• When the person lives there for long
time the kidney synthesizes the erythropoietin which stimulates the bone marrow
to produce more RBCS
23. Why is pneumonia considered a dangerous disease?
pneumonia there is inflammation of the lungs leads to the damage of alveoli. As
there is sputum production Nasal congestion, sore throat and shortness of breath
it is considered as a dangerous disease.
24. Diffusion of gases occurs in the alveolar region only and not in any other part of the respiratory system. Discuss.
• The other parts of respiratory system does the work of passing the air in to the lungs only.
• The real respiration takes place between alveolei and blood capillaries.
• The diffusion membrane of alveolus is made up of three layers.
1. The thin squamous epithelial cells.
2. The endothelium of the alveolar capillaries.
3. The basement substance found in between them.
• The thin squamous epithelial cells of the alveoli provide space for gaseous exchange
25. Sketch a flow chart to show the path way of air flow during respiration.
Atmospheric air enters into external nostrils → enters in to Nasal cavity → passes in to → the pharynx crosses→ the larynx and then enters in to the → trachea reaches→ the bronchus into enters→ bronchioles enter→ into the lungs there→ enters in to the alveoli where exchange of gases taking place.
26. Explain the conditions which creates problems in oxygen transport.
a person travels from sea level to elevations above 8000 feet where the atmospheric
pressure and partial pressure of 02 are lowered, he will have symptoms
of accute mountain sickness, headache, stortness of breath nausea and dizziness
due to poor binding of O2 with haemoglobin.
When a person descends deep in to the sea the pressure in the surrounding water
increases which causes the lungs to decrease in volume.
It leads to keep more oxygen in the circulation.
But that leads to increase in blood nitrogen leads to nitrogen narcosis.
When he ascends to the surface he will suffer from condition called bends.
Large bubbles can lodge in small capillaries blocking blood flow or can press on
Symptom: Pain in joints and muscles, Stroke.