Endocrine Glands
Endocrine glands produce hormones and release them straight into the bloodstream.
Hormones are the products of secretion of endocrine glands. They control varied activities within the human body, therefore the significance of those glands.
Endocrine glands are regulated by the Nervous System, particularly by the hypothalamus.
Glands are a part of the Endocrine System and may be categorized into three varieties:
- Exocrine: They release their products outside the body by way of ducts. They’re glands of external secretion. Examples: mammary, sweat and sebaceous glands.
- Endocrine: They release their products into the bloodstream. They’re glands of inner secretion.
- Combined or Amphicrine: They act as each exocrine and endocrine glands. Example: pancreas.
See Also: List of Endocrine Glands
Main Glands and Hormones
The main endocrine glands within the human body are:
Pituitary gland
The pituitary gland is taken into account the body’s master gland. It’s a small gland, concerning the measurement of a pea, located on the base of the brain.
The pituitary gland is divided into two parts: the anterior or adenohypophysis and the posterior or neurohypophysis.
In it, a number of hormones with completely different activities are produced, see the table under:
Hormones Produced by the Pituitary Gland
| Portion | Hormone | Action |
| Adenohypophysis | Adrenocorticotropin | Stimulates and releases hormones from the adrenal glands, primarily cortisol. Additionally releases glucocorticoid hormones. |
| Adenohypophysis | Thyroid-Stimulating Hormone or Thyrotropin | Stimulates the synthesis and secretion of thyroid hormones. |
| Adenohypophysis | Follicle-Stimulating Hormone | Stimulates the event of ovarian follicles and sperm within the testes. |
| Adenohypophysis | Luteinizing Hormone | Works with follicle-stimulating hormone to advertise development and performance of the gonads (ovaries and testes). |
| Adenohypophysis | Prolactin | Performs a role in milk production in mammary glands. In males, its function will not be effectively understood. |
| Neurohypophysis | Antidiuretic Hormone or Vasopressin | Stimulates water reabsorption within the kidneys, decreasing urine volume and preventing extreme water loss. |
| Neurohypophysis | Oxytocin | Acts on uterine muscle stimulation. |
Thyroid Gland
The thyroid is likely one of the largest glands within the human body, found within the neck area.
The thyroid releases three hormones:
- Triiodothyronine (T3) and Thyroxine (T4): Two associated hormones that contain iodine of their composition. A lot of the iodine is obtained from meals. They accelerate cellular metabolism and consequently improve oxygen consumption and heat production.
- Calcitonin: Lowers blood levels of calcium and phosphate, which most likely accelerates calcium absorption into bones.
The thyroid can also be associated to Hyperthyroidism and Hypothyroidism.
Hyperthyroidism is an overactive thyroid gland. This situation accelerates the body’s metabolism and the individual loses weight by expending extra energy.
Hypothyroidism happens when the thyroid gland works much less and produces much less thyroxine. The metabolism slows down and the individual makes use of much less energy, with a tendency to gain weight.
Pineal gland
The pineal gland is small, oval-shaped and situated between the cerebral hemispheres.
The functions of the pineal gland are nonetheless fairly controversial in drugs. One in every of its recognized functions is to secrete the hormone melatonin, a type of accountable for sleep cycles.
Melatonin production is said to the amount of sunshine acquired by the retina, along with the action of the pineal gland. With eyes closed and in a darkish and calm atmosphere, melatonin production will increase.
See Additionally: Parathyroids
Adrenal Glands
The adrenal glands are pyramidal in form and are located above every kidney.
The hormones produced by the adrenal glands are adrenaline and noradrenaline. The 2 act independently.
- Adrenaline: Adrenaline serves as a protection mechanism for the body, making ready it for an emergency scenario. It’s accountable for raising blood glucose levels.
- Norepinephrine: Hormone associated to reasoning and feelings. The action of norepinephrine within the body is to take care of blood pressure at normal levels.
Pancreas
The pancreas is a combined gland. Right here we are going to research its endocrine function.
It’s located behind the abdomen, between the duodenum and the spleen.
The endocrine portion of the pancreas secretes the hormones insulin and glucagon, that are present in structures referred to as the Islets of Langerhans and are released directly into the blood vessels of the pancreas.
- Insulin: Hormone accountable for reducing blood glucose levels.
- Glucagon: Stimulates the liver to interrupt down glycogen and launch glucose when the body wants energy.
Testicles
The testicles characterize the male gonads, which produce male intercourse hormones and sperm. They’re two oval-shaped glands located within the scrotum.
The primary hormone produced is testosterone, which is accountable for the looks of male secondary sexual characteristics, comparable to body hair, voice adjustments, and so forth.
Ovaries
The ovaries represent the feminine gonads.
The primary hormones produced are estrogen and progesterone.
- Estrogen: accountable for the development of feminine secondary sexual traits and for controlling the menstrual cycle. It prepares the uterus for a possible being pregnant.
- Progesterone: acts on the menstrual cycle and the uterus.