Choose the correct answer from the options given below:

Which of the following hypothalamic nuclei were considered as hunger regulator?
(a) Supra optic nucleus
(b) Ventromedial hypothalamus
(c) Medial
(d) Lateral
(e) Paraventricular

Correct option is C

The correct answer is (3).
1. Ventromedial Hypothalamus (VMH): This nucleus is associated with satiety regulation. Lesions in this area have been shown to cause hyperphagia (excessive eating) in animals, leading to obesity. Hence, the VMH functions as a satiety center, and plays a crucial role in inhibiting hunger.
2. Lateral Hypothalamus (LH): The lateral hypothalamus is regarded as the hunger center. Damage to this region causes aphagia (lack of eating) and weight loss. Activation of the lateral hypothalamus leads to increased food intake, making it a key area in initiating hunger behavior.

Together, these two regions (VMH and LH) work in oppositional balance to regulate food intake and energy balance in the body.

Information Booster

1.1 Structure of Hypothalamus:

The hypothalamus is a small, cone-shaped structure made up of multiple nuclei. Each nucleus serves specific physiological functions such as hunger, thirst, temperature regulation, emotional behavior, and hormone control.
Key nuclei include the lateral nucleus (hunger center), ventromedial nucleus (satiety center), paraventricular nucleus, supraoptic nucleus, and arcuate nucleus, each involved in critical neuroendocrine regulation.

1.2 Location of Hypothalamus:
The hypothalamus is located in the diencephalon region of the brain, situated below the thalamus and above the pituitary gland, forming the floor of the third ventricle.
It acts as a major link between the nervous system and the endocrine system, connecting the brain and the pituitary gland via the infundibulum (pituitary stalk).

1.3 Hormones of Hypothalamus:
The hypothalamus produces releasing and inhibiting hormones that control the activity of the anterior pituitary gland. These include:
a. Thyrotropin-Releasing Hormone (TRH) – Stimulates the release of TSH (thyroid-stimulating hormone) from the anterior pituitary.
b. Gonadotropin-Releasing Hormone (GnRH) – Stimulates the release of LH (luteinizing hormone) and FSH (follicle-stimulating hormone).
c. Growth Hormone-Releasing Hormone (GHRH) – Stimulates growth hormone secretion.
d. Somatostatin (GHIH) – Inhibits the release of growth hormone and TSH.
e. Corticotropin-Releasing Hormone (CRH) – Stimulates the release of ACTH (adrenocorticotropic hormone).
f. Prolactin Inhibitory Hormone (Dopamine) – Inhibits prolactin secretion.
g. Oxytocin and Vasopressin (ADH) – Although synthesized in the hypothalamus, these are stored and released by the posterior pituitary.
-Oxytocin regulates uterine contractions and lactation.
-Vasopressin (ADH) regulates water balance and blood pressure.