Question

49. Which of the following are correct regarding various hypothalamic nuclei A. the ventromedial nucleus is the feeding center B. the ventrolateral nucleus is responsible for temperature regulation C. hypothalamic obesity involves a lesion in the satiety center D. all of the above E. none of the above 50. Which of the following are correct regarding respiration A. the respiratory control center is in the structure immediately above the pons B. fibers from cranial nerves, 3,4,5 gives rise to the nerve that innervates the diaphragm C. Innervation to the diaphragm creates a negative intra-thoracic pressure which allows for exhalation D. all of the above E none of the above are: 51. The cells responsible for calcium homeostasi a. Osteoblast b. Osteocyte c. osteoclast d. All of the above Choice

Answer 1

Ans-49. C. Hypothalamic obesity involves a lesion in satiety centre.

Hypothalamic obesity results due to damage or lesion in ventromedial nucleus which is the satiety centre. A constellation of loss of satiety and reduction in metabolic rate, thermogenesis, and physical activity and increased vagal tone leads to weight gain.

a is wrong because feeding centre is located in arcuate nucleus of medial area of hypothalamus.

b is wrong because thermoregulation centre is the preoptic area and anterior hypothalamic nucleus.

Ams-50. B.fibres from cranial nerve 3,4,5 gives rise to nerve that innervates diaphragm

A. Respiratory area is in the medulla oblongata which is situated lower to the pond.

B- Phrenic nerve is a mixed motor/ sensory nerve which originates from C3-C5 spinal nerves in the neck. The nerve is important for breathing because it provides exclusive motor control of diaphragm.

C- innervation to diaphragm creates negative intrathoracic pressure which leads to inhalation, that is air moves from high pressure to low pressure area.

Ans-51.d. all of the above

A. When blood calcium rises it leads to formation of bone by osteoblasts which are bone forming cells leading to deposit of calcium in the bones thus maintaining calcium homeostasis.

B. Besides regulate phosphate homeostasis level, osteocytes maintain calcium homeostasis in mature skeleton. Osteocyte- cell death and local loss of control of bone mineralisation is cause of bone hypermineralisation and osteoporosis.

C. When blood calcium lowers, bone remodelling occurs by osteoclasts also called bone eating cells and calcium is dissolved from the bone to the blood this maintaining calcium level.