Answer the following questions

Zoology

Respiration

Evaluation

Answer the following questions

17. Name the respiratory organs of flatworm, earthworm, fish, prawn, cockroach and cat.

Flatworm - Body surface

Earthworm - Body wall

Fish - Gills

Prawn - Gills

Cockroach - Trachea

Cat - Lungs

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.

External nostrils, Nasal cavity, pharynx Larynx, trachea, the bronchi bronchioles and the lungs (alveoli)

20. Which structure seals the larynx when we swallow?

Epiglottis.

21. Resistance in the airways is typically low. Why? Give two reasons.

As 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 mountain sickness.

• 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?

In 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.

When 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.

1. When a person descends deep in to the sea the pressure in the surrounding water increases which causes the lungs to decrease in volume.

2. It leads to keep more oxygen in the circulation.

3. But that leads to increase in blood nitrogen leads to nitrogen narcosis.

4. When he ascends to the surface he will suffer from condition called bends.

5. Large bubbles can lodge in small capillaries blocking blood flow or can press on nerve endings.

Symptom: Pain in joints and muscles, Stroke.