Question

Chapter 13- Respiratory System

1. Watch this video to see the transport of oxygen from the lungs to the tissues. Why is oxygenated blood bright red, whereas deoxygenated blood tends to be more of a purple color?

2. Compare and contrast the conducting and respiratory zones

3. A smoker develops damage to several alveoli that then can no longer function. How does this affect gas exchange?   

4. Describe the neural factors involved in increasing ventilation during exercise   

Answer 1

1. The oxygenated blood is the blood rich in oxygen. The oxygen binds to hemoglobin present in the blood and forms a compound known as oxyhemoglobin. Oxyhemoglobin is red in colour imparting a bright red colour to blood.
The deoxygenated blood have a higher level of CO2 and les oxygen. The content oxyhemoglobin is less as hemoglobin has higher affinity to CO2 resulting in formation of carbaminohaemoglobin. The hemoglobin has a blue purple colour and in lack of oxyhemoglobin hemoglobin imparts dark maroon colour to blood.
2. The respiratory system is divided into conduction zone and respiratory zone.
The conduction zone consists of trachea, bronchi, bronchioles and terminal bronchioles whereas the respiratory zone consists of respiratory bronchioles, alveolar ducts and alveoli.
The conducting zone functions to humidify , warm and filter the inspired air and acts as a conducting passage of air to the respiratory zone.
Respiratory zone is the area where the exchange of gases between the alveoli and blood takes place.

3. The alveoli are tiny saces present inthe lungs. Alveoli consists of a very thin membrane that helps in exchange of gases. The oxygen diffuses out of alveolar membrane to the surrounding capillaries and CO2 moves from capillaries into the alveoli and is then expelled out of the body through expiration. When the alveoli are impaired in smokers it causes impaired exchange of gases resulting in increased pCO2 and decreased pO2.
4. During exercise the skeletal muscles performer greater work. As the muscle cells works harder during exercise they consume more oxygen. Also the increased metabolism of cells produces more amount of CO2. The increase in CO2 and decreased oxygen in blood activates the chemoreceptors preseng in blood vessel walls. The chemoreceptors fire action potential which are carried as sensory afferent impulses to the respiratory centre in the medulla oblongata. The medulla oblongata processes the information and sends motor impulses to the respiratory muscles namely, intercostals amd diaphragm via phrenic nerve and intercostal nerve to increase their activity. This causes increase in rate and depth of respiration. This results in increased amount of inspired oxygen and increased amount CO2 removal from body.