Which sensory receptor is primarily responsible for detecting changes in temperature?

A. Connective tissue: Connective tissue provides structural support and connects other tissues, but it does not contract to produce movement. It cannot generate the force needed for breathing.

B. Skeletal muscle: The diaphragm is a skeletal muscle that contracts voluntarily and involuntarily to facilitate breathing. Its rhythmic contraction increases thoracic volume, allowing air to enter the lungs.

C. Smooth muscle: Smooth muscle is found in the walls of internal organs and blood vessels, controlling involuntary movements such as peristalsis, but it is not involved in respiratory mechanics.

D. Cardiac muscle: Cardiac muscle is found only in the heart and is responsible for pumping blood. It does not participate in ventilation or diaphragm movement.

A. Cranial cavity: The cranial cavity houses the brain and associated structures. It does not contain organs responsible for digestion, so it is not involved in the digestive system.

B. Thoracic cavity: The thoracic cavity contains the heart and lungs within the ribcage. While it is critical for respiration and circulation, it does not house the primary organs of digestion.

C. Pelvic cavity: The pelvic cavity contains the bladder, reproductive organs, and the rectum. While part of the lower digestive tract (rectum) is present here, the majority of digestive organs are located in the abdominal cavity.

D. Abdominal cavity: The abdominal cavity contains the major digestive organs, including the stomach, liver, pancreas, intestines, and gallbladder. It provides the primary space for digestion and nutrient absorption.