What is a gland?

Well, hello again everyone! It’s Matt from Kenhub. Have you ever wondered what a gland is? Well, on this tutorial, I will answer that question. Glands are organs that secrete substances into the body for use or discharge and function as part of either the endocrine system or the exocrine system. On the image, you can see a well-known gland highlighted in green known as the parotid. The endocrine glands are ductless and their hormonal secretions are absorbed directly into the blood. The exocrine glands secrete via ducts for external functions of the body. Though the list in this video is not all inclusive, it will give you a better understanding of glands and their purpose.

First, let's talk about some of the key players in the endocrine system. The pituitary gland is basically the boss of the entire endocrine system. This gland stands center stage at the base of the brain as it takes on the immense responsibility of regulating the activity of the six other major endocrine glands that release hormones integral for growth and development.

The hypothalamus is at the center of a plethora of physiological processes including but not limited to thermoregulation, osmoregulation, and hormonal regulation. It also works closely with the pituitary gland to modulate endocrine activity based on the body's physiological demands.

The thymus is closely associated with the immune system helping to develop an important white blood cell called the T-cell.

The pineal gland – a small, cone-like flattened body – is also called the epiphysis cerebri. This endocrine gland located deep within the brain in the posterior cranial fossa is responsible for altering your state of wakefulness and sleep by releasing hormones such as melatonin.

The testes, or testicles, are part of the male genitalia, or sexual reproductive organ. These bilateral, though not always symmetrical, anatomical structures are the site of sperm production.

Gametogenesis in human females is a hormonally-regulated process carried out in the ovaries. These reproductive organs – analogous to the testes in males – are uniquely designed for the production of viable gametes and their expulsion for fertilization.

The thyroid gland is an essential organ whose functions include growth development, increased muscle gain, decreased fat storage, hormone production, increased metabolism, and increased catecholamine effect, to name a few.

This asymmetrical organ seen highlighted in green and sitting above the kidney is known as adrenal gland or suprarenal gland. You have one on top of each kidney. They are located in the retroperitoneal space and are responsible for secreting stress hormones that stimulate the physiological adaptations necessary to mitigate the change in the external environment.

The pancreas is an accessory organ of the gastrointestinal tract whose function is to release various substances that help regulate the blood content levels as well as digestion.

Now onto the exocrine system. This includes the salivary glands, the sweat glands, and the prostate gland.

The salivary glands are positioned in and around the oral cavity and secrete their salivary contents into the mouth to help keep the oral mucosa protected and lubricated as well as to help in the initial stages of digestion during chewing so that a food is ready for swallowing.

The prostate is made possible as a result of primary and secondary sexual characteristics that develop at birth and during puberty respectively. In males, they are a group of accessory reproductive organs that facilitate the process of reproduction.

Sweat glands lie throughout the skin and are used as a cooling system for the body releasing sweat to regulate temperature.