Question

The most important function of diaphragm of the mammals is
A)To divide the body cavity into compartment
B)To protect lungs
C)To aid in ventilation
D)None of the above

Answer 1

Mammals ('breast' from Latin mamma) are a category of vertebrate animals that make up the Mammalia class and are distinguished by the presence of mammary glands that provide milk for feeding (nursing) their young in females, a neocortex (a brain region), fur or hair, and three middle ear bones.

Complete answer:
The diaphragm is a muscular organ that is dome-shaped. The thoracic portion and the abdominal part of the body are divided. The diaphragm's key purpose is to assist with breathing. It contracts and relaxes concurrently through the period of inspiration and expiration to adjust the volume of the thoracic cavity, which produces a pressure differential between the lungs and the outside atmosphere that allows it to inhale and exhale.

The diaphragm expands during inspiration and raises the thickness of the thoracic cavity and reduces the pressure within the lungs so that oxygen reaches the lungs. The diaphragm relaxes and reduces the thickness of the thoracic cavity after expiration and raises the pressure within the lungs, thereby pushing oxygen out of the lungs.

Hence, the correct answer is option (C)

Note: The appearance of sweat glands, including those that are specialized in producing milk to nourish their young, will classify living mammal species. However, other characteristics must be included in classifying fossils, since soft tissue glands and certain other features are not evident in fossils. Among the earliest members of the group, several characteristics shared by all living mammals appeared: Occipital condyles, jaw bone, middle ear, tooth replacement, prismatic enamel.