**Anatomy and Physiology**:
– The hypothalamus is divided into four regions and three zones in different planes.
– It contains specific hypothalamic nuclei and is present in all vertebrate nervous systems.
– Magnocellular neurosecretory cells in the hypothalamus produce oxytocin and vasopressin.
– It is highly interconnected with the brainstem, limbic structures, and receives inputs bidirectionally.
– The hypothalamus controls anterior pituitary, regulating various endocrine glands and organs.
**Hormones and Regulation**:
– The hypothalamus produces releasing and inhibiting hormones for pituitary gland control.
– Hormones like oxytocin, vasopressin, and neurotensin are secreted from the hypothalamus.
– It regulates stress response through the HPA axis and influences growth, metabolism, and reproductive functions.
– Neurotransmitters like histamine and orexin play a role in hypothalamic regulation.
– Hypothalamic hormones bind to pituitary cell receptors to regulate hormone secretion.
**Sexual Dimorphism**:
– The hypothalamus exhibits sexual dimorphism with differences in structure and function between males and females.
– Gonadal steroids influence neuroendocrine hypothalamus development.
– Estrogen and progesterone influence gene expression in hypothalamus neurons.
– Studies show gender-specific distribution of hormones like luteinizing hormone-releasing hormone.
– The sexually dimorphic nucleus of the preoptic area is studied for gender differences.
**Pathophysiology and Disease**:
– Dysfunction in the hypothalamus can lead to hormonal imbalances and diseases like diabetes insipidus.
– Stress-related diseases can impact the hypothalamic-pituitary-adrenal axis.
– Anorexia and eating disorders may involve hypothalamic pathways.
– Skin diseases and stress-related conditions can also affect the hypothalamus.
– Hypothalamus is crucial for treating endocrine disorders and understanding the internal milieu.
**Research and Clinical Implications**:
– Research focuses on neuroendocrine control, gut-brain communication, and motivated behavior regulation by the hypothalamus.
– Animal models help study predator-related defensive responses mediated by the hypothalamus.
– Understanding the hypothalamus is crucial for treating endocrine disorders.
– Studies explore neural regulation of behaviors and the impact of hypothalamus on endocrine regulation.
– The hypothalamus plays a role in appetite regulation and stress response through various pathways.
The hypothalamus (pl.: hypothalami; from Ancient Greek ὑπό (hupó) 'under', and θάλαμος (thálamos) 'chamber') is a small part of the brain that contains a number of nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus is located below the thalamus and is part of the limbic system. It forms the ventral part of the diencephalon. All vertebrate brains contain a hypothalamus. In humans, it is the size of an almond.[citation needed]
| Hypothalamus | |
|---|---|
 Location of the human hypothalamus | |
 Location of the hypothalamus (cyan) in relation to the pituitary and to the rest of the brain | |
| Details | |
| Part of | Brain |
| Identifiers | |
| Latin | hypothalamus |
| MeSH | D007031 |
| NeuroLex ID | birnlex_734 |
| TA98 | A14.1.08.401 A14.1.08.901 |
| TA2 | 5714 |
| FMA | 62008 |
| Anatomical terms of neuroanatomy | |
The hypothalamus is responsible for regulating certain metabolic processes and other activities of the autonomic nervous system. It synthesizes and secretes certain neurohormones, called releasing hormones or hypothalamic hormones, and these in turn stimulate or inhibit the secretion of hormones from the pituitary gland. The hypothalamus controls body temperature, hunger, important aspects of parenting and maternal attachment behaviours, thirst, fatigue, sleep, circadian rhythms, and is important in certain social behaviors, such as sexual and aggressive behaviors.