Which of the following integrates the nervous and endocrine systems?

Which gland releases the hormone that initiates the process of spermatogenesis?

What are $P$ and $Q$ in the given chart?

Hypothalamus controls:
$I.$ Urge for eating and drinking
$II.$ Body temperature
$III.$ Hormone production that regulates the secretion of the pituitary gland
$IV.$ Creative thinking and consciousness

The neurosecretory cells of the hypothalamus which produce hormones are called

The neural centre which controls sexual behaviour and the urge for drinking is associated with $:-$