How is respiration regulated?
Respiration is under both nervous and chemical regulation. The respiratory centre in brain is composed of groups of neurons located in the medulla oblongata and pons varolii. The respiratory centre regulates the rate and depth of the breathing. Dorsal respiratory group of neurons are located in the dorsal portion of the medulla oblongata. This group of neurons mainly causes inspiration. Ventral group of neurons are located in the ventrolateral part of the medulla oblongata. These can cause either inspiration or expiration. Pneumotaxic centre is located in the dorsal part of pons varolii. It sends signals to all the neurons of dorsal respiratory group and only to inspiratory neurons of ventral respiratory group. Its job is primarily to limit inspiration. Chemically, respiration is regulated by the large numbers of chemoreceptors located in the carotid bodies and in the aortic bodies. Excess carbon dioxide or hydrogen ions mainly stimulate the respiratory centre of the brain and increases the inspiratory and expiratory-signals to the respiratory muscles. Increased C02 lowers the pH resulting in acidosis. The role of oxygen in the regulation of respiratory rhythm is quite insignificant.
For completion of respiration process, write the given steps in sequential manner.
(a) Diffusion of gases (O2 and CO2) across alveolar membrane.
(b) Transport of gases by blood.
(c) Utilisation of O2 by the cells for catabolic reactions and resultant release of CO2 .
(d) Pulmonary ventilation by which atmos-pheric air is drawn in and C02 rich alveolar air is released out.
(e) Diffusion of 02 and CO2 between blood and tissues.
What will be the p02 and pCO2 in the atmospheric air compared to those in the alveolar air?
(i) pO2 lesser, pCO2 higher
(ii) pO2 higher, pCO2 lesser
(iii) pO2 higher, pCO2 higher
(iv) pO2 lesser, pCO2 lesser
What is tidal volume? Find out the tidal volume (approximate value) for a healthy human in an hour.
Diffusion of gases occurs in the alveolar region only and not in the other parts of respiratory system. Why?
Complete the missing terms
(a) Inspiratory Capacity (1C)=_____+IRV
(b)_____= TV + ERV
(c) Functional Residual Capacity (FRC) = ERV +_____
Have you heard about hypoxia? Try to gather information about it, and discuss with your friends.
Match the following and mark the correct options
Animal Respiratory Organ
A.Earthworm (i)Moist cuticle
B.Aquatic Arthropods (ii)Gills
C.Fishes (iii)Lungs
D.Birds/Reptiles (iv)Trachea
(a) A-(ii), B-(i), C-(iv), D-(iii)
(b) A-(i), B-(iv), C-(ii), D-(iii)
(c) A-(i), B-(iii), C-(ii), D-(iv)
(d) A-(i), B-(ii), C-(iv), D-(iii)
Arrange the following terms based on their volumes in an ascending order:
(a) Tidal Volume (TV)
(b) Residual Volume (RV)
(c) Inspiratory Reserve Volume (1RV)
(d) Expiratory Capacity (EC).
Name the organs of respiration in the following organisms:
(a) Flatworm ____________
(b) Birds ____________
(c) Frog____________
(d) Cockroach____________
A major percentage (97%) of O2 is transported by RBCs in the blood. How is the remaining percentage (3%) of O2 transported?
Name the important parts involved in creating a pressure gradient between lungs and the atmosphere during normal respiration.
Compared to O2 , diffusion rate of CO2 through the diffusion membrane, unit difference in partial pressure is much higher. Explain.
The oxygen – haemoglobin dissociation curve will show a right shift in case of ,
(a) High pCO2 (b) High pO2
(c) Low pCO2 (d) Less H+ concentration.
What is the amount of O2 supplied to tissues through every 100 mL of oxygenated blood under normal physiological conditions?
Arrange the following terms based on their volumes in an ascending order:
(a) Tidal Volume (TV)
(b) Residual Volume (RV)
(c) Inspiratory Reserve Volume (1RV)
(d) Expiratory Capacity (EC).
Define oxygen dissociation curve. Can you suggest any reason for its sigmoidal pattern?
A fluid filled double membranous layer surrounds the lungs. Name it and mention its important function.
Distinguish between
(a) IRV and ERV
(b) Inspiratory capacity and expiratory capacity.
(c) Vital capacity and total lung capacity.
Differentiate between
(a) Inspiratory and expiratory reserve volume
(b) Vital capacity and total lung capacity
(c) Emphysema and occupational respiratory disorder.