Which gland is commonly known as the “master gland”?

Absorption of calcium from the digestive tract. This is because vitamin D is essential for maintaining bone density and healthy bone growth, and it stimulates calcium and phosphate uptake from the food we eat. Vitamin D is produced when the skin is exposed to ultraviolet rays from the sun, which convert a precursor molecule in the skin to an active form that travels to the liver and kidneys.

Choice A is wrong because elimination of toxins from the blood is not related to vitamin D, but to the kidneys and liver functions.

Choice B is wrong because increase in red blood cell production is not related to vitamin D, but to erythropoietin, a hormone produced by the kidneys.

Choice D is wrong because conservation of water in the plasma is not related to vitamin D, but to antidiuretic hormone, a hormone produced by the pituitary gland.

Carotid artery.

The carotid artery is a major blood vessel that supplies blood to the head and neck. It can be felt as a pulse on either side of the neck, just below the jawline.

Choice A is wrong because the subclavian artery is located below the clavicle (collarbone) and cannot be felt as a pulse on the neck.

Choice C is wrong because the brachiocephalic artery is a large vessel that branches into the right subclavian and right carotid arteries. It is located deep in the chest and cannot be felt as a pulse on the neck.

Choice D is wrong because the basilar artery is a vessel that forms at the base of the brain from the union of the two vertebral arteries. It cannot be felt as a pulse on the neck.

The normal range for pulse rate in adults is 60 to 100 beats per minute.

The esophagus is located in the thoracic cavity, which is the space between the lungs and the chest wall. The thoracic cavity also contains the heart, aorta, trachea, thymus gland, bronchial tubes, and many lymph nodes.

Choice A is wrong because the ventral cavity is a general term for the body cavity that includes the thoracic and abdominal cavities.

Choice B is wrong because the abdominal cavity is the space below the diaphragm that contains the stomach, small and large intestines, spleen, pancreas, liver, and gallbladder.

Choice D is wrong because the dorsal cavity is another general term for the body cavity that includes the cranial and spinal cavities.

The dermis is the layer of the cutaneous membrane that contains nerve endings, blood vessels, glands, and hair follicles.

The cutaneous membrane is another name for the skin, which is composed of two main layers: the epidermis and the dermis.

Choice A is wrong because fascia is not a layer of the cutaneous membrane, but a type of connective tissue that surrounds muscles, organs, and other structures.

Choice B is wrong because subcutaneous is not a layer of the cutaneous membrane, but a layer of fat and connective tissue that lies below the dermis.

Choice D is wrong because epidermis is the outermost layer of the cutaneous membrane, which provides protection and waterproofing, but does not contain nerve endings.