The question asks about the formation of oxyhaemoglobin. This involves understanding the primary function of haemoglobin in the blood, which is to transport gases. We need to identify which gas haemoglobin binds with to form oxyhaemoglobin.
Correct Option: B) Oxygen. Haemoglobin binds reversibly with oxygen in the lungs to form oxyhaemoglobin, which is then transported to the body's tissues.
The 'respiratory centre' that regulates the rate and depth of breathing is located in:
Cerebral cortex
Hypothalamus
Medulla oblongata
Cerebellum
The question asks to identify the location of the 'respiratory centre' in the brain, which is responsible for regulating the rate and depth of breathing. This requires knowledge of the functions of different parts of the brain.
Correct Option: C) Medulla oblongata
The question asks for the normal breathing rate in a healthy adult at rest. This is a standard physiological value that competitive exam aspirants are expected to know.
The generally accepted normal breathing rate for a healthy adult at rest is between 12 and 20 breaths per minute. Option A falls within this range.
A) 12–16 breaths/min is the correct range for a normal breathing rate in a healthy adult at rest. While the upper limit can sometimes extend to 20 breaths/min, 12-16 is a very common and accurate representation of the typical resting rate.
This question tests knowledge about the cellular components of the alveoli and their specific functions, particularly the production of surfactant. Understanding the roles of different cell types in the respiratory system is crucial.
Correct Option: C) Type II pneumocytes are the cells responsible for producing surfactant in the alveoli. This surfactant is vital for reducing surface tension and preventing alveolar collapse.
The question asks about the primary stimulus for an increased breathing rate. This relates to the body's homeostatic mechanisms for regulating blood gas levels, specifically the role of chemoreceptors.
B) Rising CO₂ levels (hypercapnia) — Rising carbon dioxide levels in the blood lead to an increase in hydrogen ion concentration (a drop in pH) in the cerebrospinal fluid, which is detected by central chemoreceptors. This is the most potent stimulus for increasing the rate and depth of breathing to expel excess CO₂.
The question asks to identify the correct definition of the pleura. We need to recall the basic anatomy of the respiratory system to answer this question.
A) A double-layered membrane surrounding the lungs
This option accurately describes the pleura. The pleura is indeed a double-layered serous membrane that encloses the lungs and lines the thoracic cavity, facilitating smooth movement of the lungs during respiration.