Types of Endocrine System

The endocrine system is the most important part of SSC , banking and other one-day exams. in this topic, we are covering the endocrine system of human body 

The endocrine system, like the low-speed circulatory service, regulates activity communication by transmitting information in the blood via chemical messengers. Endocrine glands and other parts of organs in placed hormone-released tissue or cells produce the endocrine system.

Endocrine glands and organs make hormones and release them directly into the blood so they can travel to tissues and organs throughout the body. The endocrine system is made up of one or more glands. Your brain contains the hypothalamus, pituitary, and pineal glands. Your neck constitutes the parathyroid and thyroid glands.

The thymus is present between your lungs. Your pancreas is located behind your stomach, and your adrenals are on top of your kidneys. In addition to these, a few additional organs, including the heart, liver, kidney, and gastrointestinal system, also produce hormones. Homeostasis is a crucial mechanism provided by the endocrine system.

Hemostasis combines bodily functions while also ensuring that the makeup of the body fluids that bathe the constituent cells doesn’t change.

This article helps to clarify your competitive exam and to understand how to endocrine system are work. This article provides a solution for your competitive exam like -SSC, Banking ad more exams. To know more details about the Endocrine System which is mentioned below.

Endocrine Glands

Due to the loss of epithelial connection these glands are also called ductless glands. The substance secreted from them is called Hormone. The fact of the ductless gland is that its secretions are released directly into the blood, not to any tubes or ducts.

• Hypothalamus
• Thyroid
• Parathyroid
• Adrenal Gland
• Pituitary Gland
• Pineal Gland
• Thymus
  

Hypothalamus

The hypothalamus is a component of the brain that has played a major role in regulating many bodily functions including the release of hormones from the pituitary gland. The hypothalamus is the fundamental part of the diencephalon, the forebrain.
Hypothalamus maintains an internal temperature of 98.6 °Fahrenheit (ºF)s of neurosecretory cells called nuclei that produce hormones.
These hormones control the synthesis and secretion of hormones secreted from the pituitary gland

The hormones generated by the hypothalamus are of two types

Releasing hormones -stimulating the secretion of pituitary hormones.

Inhibiting hormones-which inhibits secretions of pituitary hormones.

For Example,

The hypothalamic hormone called Gonadotrophin releasing hormone (GnRH)  stimulates the pituitary synthesis and release of gonadotropins The somatostatin from the hypothalamus inhibits the release of growth hormone from the pituitary.

Pituitary Gland

The pituitary gland is located in a bony cavity called Sella tunica and is connected to the hypothalamus a small infundibulum by a stalk. Another name for the pituitary gland is the “master” gland. It is divided anatomically into two types.

• Adenohypophysis 
• Neurohypophysis

Adenohypophysis

Adenohypophysis is also known as Anterior Pituitary. Adenohypophysis consists of Qf two-portion is,

Pars distalis 

• Pars distalis are also called simple Piyush glands. It releases growth hormones and many hormones releases etc

Pars intermedia

• Pars intermedia release a secretion of only melanocyte-stimulating hormone or melanotropin

Neurohypophysis

Oxytocin and vasopressin are two hormones that are stored and released by the neurohypophysis (pars nervosa), often known as the posterior pituitary. In reality, they are produced by the hypothalamus and sent axonally to the neurohypophysis.

Hormone Released From Hypothalamus	Stimulated Cell  From Pituitary Gland
Thyrotropin Releasing Hormone( TRH)	Thyrotroph cells
Growth Releasing Hormone (GRH)	Somatotroph Cells
Growth Releasing Inhibit Hormone {GRIH)	Somatotroph Cells
Prolactin Release Hormone ( PRH)	Lactotroph Cells
Adrenocorticotropic Hormone (ACTH)	Adrenocorticotropic Cells
Melanocyte Stimulating Hormone (MSH)	Adrenocorticotropic cells
Luteinizing hormone (LH)
Follicle Stimulating Hormone (FSH)
Thyroid Stimulating Hormone (TSH)

List Of Hormone

At the axon terminals, the hormones are released, diffuse into the capillaries, and then travel throughout the body in the bloodstream. It primarily affects the kidney and encourages the distal tubules to absorb water and electrolytes.

Pineal Gland

The pineal gland is placed on the dorsal side of the forebrain. This gland is present in the posterior area of the cranial fossa in the brain, it is also known as the epiphysis cerebri. The retina’s reception of light, which the pineal gland then transforms from cerebral input into endocrine output, affects the gland’s functioning.

Due to the histological similarities between the pineal gland and the lateral eyes of prenatal vertebrates, the pineal gland has also been referred to as “The Third Eye.” Melatonin is a hormone that the pineal secretes.

In order to maintain our body’s 24-hour (diurnal) rhythm, melatonin is crucial.
Both melatonin and serotonin, which are derived chemically from the alkaloid substance tryptamine, are synthesized in the pineal gland. The pineal gland may also produce neurosteroids.

Pineal Gland Hormone function

Melatonin

This hormone slows down women’s menstrual cycles This causes the chromatophore pigments located in the skin to collect in the centre, and the skin colour is light.

Serotonin

Anxiety, insomnia, and depression may be brought on by low serotonin levels in the brain.

Thyroid Gland

The thyroid gland is located in front of the windpipe called the trachea just below the larynx in the neck. The thyroid gland is the largest “H-shaped” endocrine gland that is present in the human body.
Two lobes make up the thyroid gland, which is situated on either side of the trachea. A tiny flap of connective tissue known as the isthmus connects both lobes. The thyroid gland’s basic structural component is the follicle. The thyroid follicle is composed of follicular cells, enclosing a cavity.

Thyroid Hormone

These follicular cells synthesize two hormones. 

• Tetraiodothyronine or thyroxine T4 
• Triiodothyronine (T3) 
• Thyroid Stimulating Hormone
• Iodine is necessary for the normal rate of hormone Synthesis.

The function of the Thyroid Hormone

Tetraiodothyronine or thyroxine

Metabolic rate, Heart rate, Digestive functions, Muscle control, Brain development and function, Maintenance of bones

Triiodothyronine 
 Body temperature, Protein Synthesis
Thyroid Stimulating Hormone
Regulate the production of Hormone

Parathyroid Gland

It is a granule gland of the shape of a pea, which develops from the third and fourth pharyngeal gland. On the rear of the thyroid gland in humans, there are four parathyroid glands—one pair in each of the two lobes.
There is made up of two cells, Chief Cells-chief cells are the synthesis and release of the proenzyme pepsinogen, and Oxyphil Cells-observed either singly or in small groups interspersed between chief cells. 
A peptide hormone known as the parathyroid hormone is secreted by the parathyroid glands (PTH). hormone parathyroid-The secretion of PTH is regulated by the circulating levels of calcium ions

Thymus Gland

The thymus gland is a lobular organ situated on the ventral side of the aorta, between the lungs, and behind the sternum. An important factor in the immune system’s development is the thymus. The age then increases as this gland’s shape changes.
The age of 14-16 decreases the shape of the thymus gland This gland secretes the peptide hormones called thymosins. Thymosins have a significant impact on how T-lymphocytes differentiate. It contributes significantly to immunity by generating immune cells.

Thymosins

T cells develop in the thymus and are unable to defend against pathogens, germs, and foreign antigens. Before the T cells leave the thymus, thymosin ensures that they are properly developed.

Adrenal Gland

One adrenal gland is located at the front of each kidney in our body. The gland is made up of two different kinds of tissues. The tissue in the middle is referred to as the adrenal medulla. The adrenal cortex is located outside of this.
Adrenal cortex
The adrenal cortex are make up 75% of this Gland. There are three layers in the adrenal cortex.
1. zona reticularis (inner layer)

• It is the inner part of the adrenal cortex Here the part is with spherical cells like a net. This portion release many hormones. like-  Estrogen, Progestogen, etc.

2.zona fasciculata (middle layer)

• It is the middle part of the adrenal cortex. It is established spherical cells of rope.
  Released hormones like-Glucocorticoids

3.zona glomerulosa (outer layer)

• It is the outer part of the adrenal cortex, It is established down at the centre of the capsule.
  Released Hormone Like – Steroid, Mineralocorticoids.

Adrenal Medulla

This is the innermost part of the adrenal gland. These cells are larger than the cells of the cortex. This is also called chromaffin Tissue. Adrenaline, also known as epinephrine, and noradrenaline, often known as norepinephrine, are two hormones secreted by the adrenal medulla. They are frequently referred to as catecholamines.

Pancreas

The pancreas is a composite gland, the pancreas is known as pancreatitis. which acts as both exocrine and Adrenaline, also known as epinephrine, and noradrenaline, often known as norepinephrine, are two hormones secreted by the adrenal medulla. They are frequently referred to as catecholamines. pancreas.
In a healthy human pancreas, there are roughly 1–2 million Islets of Langerhans, which account for just 1%–2% of the pancreatic tissue. The names “-cells” and “-cells” refer to the two primary cell types found on the Islet of Langerhans.

• Glucagon is a hormone that the beta cells release.
• Insulin is a hormone that is secreted by beta cells.

Exocrine System

Exocrine glands exude chemicals onto an epithelial surface via a duct. The exocrine system is what we call it.

Exocrine Gland

These types of glands are tubular, the secreted substance from them either reaches the surface of the body or goes into the cavity located in the body. This type of gland is called the exocrine gland

• Lachrymal glands
• Oil glands
• Mammary glands 
• Salivary glands
• Sweat glands 
• Gastric glands

Structure Of the Exocrine glands

Exocrine glands contain a glandular portion and a duct portion 

Ductal Portion

The ductal portion is tubular in shape.It is a single, thick, cuboidal cell wall that helps in the movement of the secretion. The duct may be branched or unbranched. It can also be found as a simple coiled structure.

Glandular Port

The glandular portion may be tubular or acinar or maybe a mix of the two (called tubuloacinar). If the glandular portion branches, then the gland is called a branched gland.

Lachrymal glands

Dacryoadenitis is the name for the lacrimal glands. The neurological reflex that is activated when stimuli are applied to the ocular surface controls the lacrimal gland secretion primarily.

Both efferent parasympathetic and sympathetic nerves are stimulated by these activated nerves as a result of a complicated neurological response. Tears are produced by the lacrimal gland and pass along the ocular surface before being released through the lacrimal ducts.

Sebaceous Oil Glands

The sebaceous glands originate from the epithelial cells of the hair follicle itself and are found in the dermis, the middle layer of the skin (the external root sheath of the hair follicle) Mammal skin contains a small oil-producing gland called a sebaceous gland. Acids that make up the acid mantle are secreted by sebaceous glands. This is a thin, mildly acidic layer that forms on the skin’s surface and serves as a defence against germs that could pierce the skin.

Mammary Gland

A highly developed and specialized organ, the mammary glands are found in pairs, one on each side of the anterior chest wall. The principal function of the organ is milk production. It is an important supporting organ of the female reproductive system as well.

Salivary gland

Salivary glands make saliva, which aids in digestion, keeps your mouth moist, and supports healthy teeth. The salivary gland has three pairs of major salivary glands under and behind your jaw

• Parotid-produce a serous, watery secretion.
• Sublingual-secrete saliva that is predominantly mucous in character.
• Submandibular glands produce a mixed serous and mucous secretion.

Sweat Gland

The function of sweat glands, which are coiled tubular structures, is to control body temperature. Although sweat glands are found throughout the body, they are most prevalent on the forehead, armpits, palms, and soles of the feet. While salts do appear in sweat, water makes up the majority of it. There are two types of sweat glands in humans:

• The majority of your body is covered in eccrine-eccrine glands, which open directly onto your skin’s surface.
• Apocrine-Apocrine glands protrude from the skin’s surface into the hair follicle.