Question

Match the following
$\begin{array}{cc}\text{1. Carotid Body}& \text{i) Lower part of pons}\\ \text{2. Pneumotaxic centre}& \text{ii) Superior part of pons}\\ \text{3. Apneustic centre}& \text{iii) Bifurcation of artery located in neck}\\ \text{4. Chemosensitive area}& \text{iv) Adjacent to rhythm centre}\end{array}$

• A. 1-ii, 2-iii, 3-iv, 4-i
• B. 1-iv, 2-iii 3-i, 4-ii
• C. 1-iv, 2-ii, 3-i, 4-iii
• D. 1-iii, 2-ii, 3-i, 4-iv

Answer 1

The correct option is D 1-iii, 2-ii, 3-i, 4-iv

Receptors associated with the aortic arch and carotid artery are called the aortic body and carotid body respectively. The carotid bodies are located on the bifurcation of one of the main arteries of the neck called the carotid artery. While the aortic body is located on the aortic arch, which is the portion of the main artery (aorta) that bends between the ascending and descending part of the aorta. These can recognize changes in carbon dioxide and hydrogen ion concentration in the blood and send necessary signals to the respiratory rhythm centre for remedial actions.
The pneumotaxic centre is located in the superior part of the pons (present in the brain). It helps in moderating the functions of the respiratory rhythm centre present in the medulla.
The apneustic centre is located in the lower part of the pons (present in the brain). It helps in moderating the functions of the respiratory rhythm centre present in the medulla.
Chemosensitive area which is highly sensitive to hydrogen ions as well as carbon dioxide is located adjacent to the rhythm centre. This rhythm centre is a specialised region in the medulla (part of hindbrain) which helps in regulating respiration rate.