Which part of the human brain controls the body temperature and blood pressure?

Hint: The brain consists of three parts: cerebrum, cerebellum and medulla. Diencephalon is situated below the main stem and the cerebrum consists of the thalamus, hypothalamus and epithalamus. It helps in transmitting sensory impulses from the peripheral nervous system. It is the centre of autonomic control.

Complete answer:
The autonomic nervous system controls all the autonomic functions/ involuntary of the body such as heartbeat, respiration etc. The hypothalamus present in the brain controls the autonomic function.

 Hypothalamus serves a number of functions which are described as follows:
1. Hypothalamus contains a number of centres that control body temperature, urge for eating and drinking, sexual drive rage and anger etc, it keeps the body temperature at roughly 37°C by means of a complex thermostat system. It keeps the water content of the body constant by controlling the amount of urine and by controlling thirst. Similarly, it controls hunger by arousing hunger pangs so that the person becomes aware of the need of eating. The sexual drive, feeling of satiety, expression of love, anger, rage, fear, etc. Are also controlled by the hypothalamus.
2. The hypothalamus not only has nervous activity but also controls endocrine functions. The hypothalamus contains several groups of neurosecretory cells, which secrets hormones. These cells are called neurosecretory cells because these are in fact the hypothalamic neurons that produce the hormones. The hormones secreted by hypothalamic neurons or neurosecretory cells are called the hypothalamic hormones.

So, the hypothalamus has the centre for controlling the body temperature and blood pressure.

Note: The hypothalamic hormones pass through the axon of these neurons and are released through their nerve endings. Gonadotropin-releasing hormones, oxytocin and Antidiuretic hormones (ADH) are some of the hypothalamic hormones. These hormones then control various body functions.