Question

The respiratory centre leading to faster breathing is on account of ___________
A. Venous blood entering the respiratory centre
B. Arterial blood entering respiratory
C. Venous blood leaving the respiratory centre
D. Arterial blood leaving the respiratory centre

Answer 1

Hint: The main respiratory control centre is medulla oblongata. Its function is to send signals to the respiratory controlling muscles for breathing to occur.

Complete answer:
Let’s discuss the options and find out the correct answer.
A. Venous blood entering the respiratory centre: The respiratory control centre increases the rate of respiration on the grounds of decrease in pH level of blood. As the oxygenated blood enters the system through the veins, there is a fall in the level of carbon dioxide which results in an increase in the respiratory rate.
B. Arterial blood entering respiratory: Blood is forced from the left side of the heart to the blood vessels of the lungs. As the blood enters the pulmonary capillaries of the lungs, fresh oxygen starts to enter the blood and the carbon dioxide is removed.
C. Venous blood leaving the respiratory centre: As soon as the oxygen leaves the blood and enters the tissue, there is a decrease in the level of oxygen in the blood. Blood is then pumped through the blood vessels of the lungs where new oxygen enters the blood.
C. Arterial blood leaving the respiratory centre: When blood enters the pulmonary capillaries of the lungs, addition of new oxygen and removal of carbon dioxide takes place.
Hence, option A: Venous blood entering the respiratory centre is the correct answer.

Note: The respiratory centre creates and maintains a specific pattern of respiration. Respiratory centre is made up of three broad respiratory groups out of which two are located in medulla and one in pons.