the functions of the cells in the human body need to be continuously regulated however the nerve fibers of the neural system do not innervate all the body's cells therefore the function of regulating the body's cells is performed by the hormones secreted by the endocrine system the endocrine system in association with the neural system functions in a coordinated way to maintain the physiological functions of the body both the endocrine and the nervous systems collectively formed the neuro endocrine system of the body and the combined study of these two systems is called neural endocrinology did you know that endocrinology is a branch of medicine dealing with the study of the endocrine glands and the actions of their hormones Edison scientist is popularly known as the father of endocrinology the human endocrine system consists of various endocrine glands present in different parts of the body the four brain houses the hypothalamus which is the basal part of the diencephalon just below the hypothalamus is a small pinkish we shaped gland called the pituitary gland also known as the master gland of the endocrine system another gland located on the dorsal side of the forebrain is the pineal gland which is a small reddish gray gland shaped like a pinecone the neck has the largest endocrine gland in the body the thyroid gland it lies on the ventral and lateral sides of the upper part of the trachea the thyroid gland has four p8 glands embedded wholly or partially in its dorsal surface these glands are called the parathyroid glands [Music] just above the heart a soft pinkish by lobed massive lymphoid tissue is present called the thymus gland in the loop of the duodenum is located an elongated yellow colored gland called the pancreas the second-largest endocrine gland in our body on the upper border of both the kidneys like the adrenal glands which are yellowish and triangular in shape the gonads are also end my lens in males the scrotal sac bears the gonads which is a pair of testes in females the abdomen bears the gonads which is a pair of ovaries the endocrine glands pour their secretions directly into the venous blood for passage to different body organs to control and coordinate their functions due to the absence of ducts the endocrine glands are also known as ductless glands and the secretions of these glands are called hormones hormones are non nutrient chemical messengers secreted in trace amounts by glands or neurons they are soluble in water and blood phones come into contact with essentially all the cells as they circulate in the blood however each hormone usually affects only a limited number of cells called target cells where it regulates a definite physiological effect they'll response to a hormone because it bears receptors for that hormone a hormone receptor is a receptor protein that binds to a specific hormone these hormone receptors are found either on the surface of a cell or within its cytoplasm vending on the type of hormone selves that do not have receptors cannot be directly influenced by that hormone moreover hormone secretions are induced by a stimulus and have an activating influence on the neighboring or distant tissues the hormones are degraded by tissues and are excreted by the liver into bile and by the kidneys into urine also secreted by the exocrine glands such as the saliva glands wetlands and sebaceous glands these glands contrast two endocrine glands release their secretions through ducts and are hence called duct glands there are also a few glands in the human body such as the pancreas and gonads that have both exocrine and endocrine properties these glands are known as hetero crime glands in these glands the exocrine part releases its secretions through ducts while the endocrine part releases its hormones directly into the blood in addition to these glands and organs treated by the gastrointestinal tract liver kidneys and heart thus the human endocrine system along with the eggs of crime and hetero crime glands helps in the control and coordination of the body the human endocrine system is composed of several endocrine glands in different parts of the body the three endocrine glands in the brain are the hypothalamus pituitary and pineal glands the hypothalamus is a part of the forebrain and appears as the floor of the diencephalon is formed of gray matter that contains neurosecretory cells called nuclei which produce hormones called neuro hormones neurohormones regulate the synthesis and secretion of pituitary hormones they are of two types releasing hormones and inhibiting hormones the releasing hormones of the hypothalamus stimulates the anterior pituitary to secrete its hormones for example gonadotrophins releasing hormone stimulates the release of follicle stimulating hormone or FSH and luteinizing hormone or LH from the pituitary on the other hand the inhibiting hormones of the hypothalamus stopped the anterior pituitary from secreting hormones for example somatostatin inhibits the release of the growth hormone from the pituitary these hypothalamic hormones passed through the axons and are released from their nerve endings into the pituitary and into the portal circulatory system this hypothalamic pituitary system is direct proof of coordination between the hormonal and nervous systems it maintains homeostasis inside the body and regulates most of its physiological activities the pituitary gland which is also known as the hypothesis lies in the sella turcica of the sphenoid bone it is attached to the hypothalamus by a stork with usury is the smallest endocrine gland yet it is called the master of endocrine glands because it produces hormones that control the thyroid gland the adrenal cortex and the gonads anatomically the pituitary is divided into the Adonal hypothesis or the anterior pituitary and the neuro hypothesis or the posterior pituitary the adeno hypothesis develops as an outgrowth of the ectoderm called rut gaze pouch in the roof of the buccal cavity of the developing embryo it includes an intermediate lobe or pars intermedia and anterior lobe or pass dist Alice the pars intermedia atrophies during human fetal development did you know that in humans the paws intermedia is almost merged with the paws dis Telus while the pasta stylist produces several important hormones such as the growth hormone or gh prolactin or PRL thyroid stimulating hormone or TSH adrenocorticotropic hormone or ACTH luteinizing hormone or LH and follicle stimulating hormone or FSH the pars intermedia secretes only one hormone called melanocytes stimulating hormone or MSH let's learn about the various hormones secreted by the past dis Dallas of the anterior pituitary the growth hormone or somatic traffic hormone acts on the liver skeletal muscle cartilage bone and causes cells to grow and multiply hypo secretion of this hormone during the growth years or puberty causes dwarfism in which both bone and organs failed to grow moreover body proportions become childlike conversely hypersecretion of the growth hormone during childhood causes gigantism which leads to an abnormal increase in the length of the bones persons affected by gigantism have extraordinarily long limbs such people grow very tall but their body proportions are about normal hypersecretion of the growth hormone causes acromegaly in adults condition is characterized by the abnormal growth of the hands feet and face especially of the lower jaw prolactin is known as the maternity hormone because it stimulates the development of the mammary glands during pregnancy and lactation after childbirth TSH stimulates the synthesis and secretion of hormones such as thyroxine and triiodothyronine by the thyroid gland ACTH acts on the adrenal cortex it controls the production and secretion of steroid hormones like glucocorticoids and the six corticoids in females LH stimulates ovulation of the graafian follicle x' the formation of the corpus luteum and the secretion of progesterone by the corpus luteum hypo secretion of this hormone leads to sterility in females in males LH is known as the interstitial cell stimulating hormone it stimulates the Leydig cells in the testes to secrete androgens FSH stimulates the development of several ovarian follicles in the ovaries in males FSH and androgens stimulate spermatogenesis in the seminiferous tubules of the testes together FSH and LH are called gonadotrophins because their target organs are the gonads MSH or inter Medan is the only hormone secreted by the pars intermedia and is also known as inter Medan MSH regulates skin pigmentation by stimulating the melanocytes neuro hypothesis develops from the terminal region of an extra dermal outgrowth of the hypothalamus it is also known as Paz nervosa or the posterior lobe of the pituitary gland it is under the direct neural control of the hypothalamus it stores and releases two hormones called oxytocin and vasopressin these hormones are actually synthesized by the hypothalamus and are transported to the neuro hypothesis through axons in females oxytocin enhances contraction of smooth muscle cells in the wall of the uterus at the time of childbirth and milk ejection from the mammary glands therefore oxytocin is known as the birth hormone and milk ejection hormone vasopressin stimuli the kidneys to reabsorb water and electrolytes into the blood by the distal tubules it thereby reduces the loss of water through urine hence it is also called the antidiuretic hormone hypersecretion of the antidiuretic hormone leads to diabetes insipidus it is characterized by the excretion of dalia children several times a day resulting in excessive thirst and dehydration another endocrine gland in the brain is the pineal gland it is a small rounded land located on the dorsal side of the forebrain it secretes a hormone called melatonin which regulates the 24-hour rhythm of the body it maintains the normal rhythms of the sleep/wake cycle body temperature etc and also influences metabolism pigmentation the menstrual cycle and our defense capability the endocrine glands of the brain are very crucial in regulating mood growth and development metabolism sexual functions and reproductive processes in the human body sigh roid and parathyroid glands play a crucial role in various metabolic reactions taking place in the human body in humans the thyroid gland is a median endocrine gland located in the neck between the trachea and larynx it has two lobes interconnected by a transverse non glandular connective tissue called the Isthmus which is h-shaped the thyroid gland is the largest endocrine gland and it weighs 25 grams the size of the thyroid gland varies with differences in diet age and sexual development the thyroid gland is made up of follicles and stromal tissues further each steroid follicle is composed of cuboidal follicular cells that enclose a cavity the thyroid follicular cells produce two hormones namely triiodothyronine or t3 tetra iota Phi Ronan both I Roxon 44 the para follicular cells scattered between the follicles and the stroma produce Thyra calcitonin or TCT the synthesis and secretion of t3 and t4 hormones is regulated by the thyroid stimulating hormone or TSH produced by the anterior pituitary gland sigh roid hormones helped regulate tissue growth and development they support the formation of red blood cells and control the metabolism of proteins carbohydrates and fats sigh right hormones also maintain the water and electrolyte balance and regulate the basal metabolic rate to ensure a normal rate of synthesis of these thyroid hormones the presence of iodine in one's diet is a must deficiency of iodine in our diet can lead to hypothyroidism which causes simple or colloid Gotha it is characterized by the enlargement of the thyroid gland vojta is a non genetic disease commonly found in people in hilly regions to prevent goiter table salt is iodized to these days in pregnant women hyperthyroidism can lead to defective development of the growing fetus this results in stunted growth in children and leads to a disease called ism presen ISM is characterized by mental retardation [Music] at normal skin deafness mutism a low intelligence quotient [Music] reagent chest and refueling tongue Britain ISM can be congenital that is the absence of a thyroid gland due to a genetic defect it can also be endemic or caused due to the absence of iodine in the diet in a particular geographical area in adult women hypothyroidism may cause the menstrual cycle to become irregular sometimes there is hypersecretion of thyroid hormones due to cancer or development of nodules in the thyroid glands this hypersecretion of thyroid hormones leads to a medical condition called hyperthyroidism hyperthyroidism causes Graves disease or exothermic goiter in adults it is characterized by an enlarged thyroid gland protrusion of the eyeballs increased BMR physical and mental restlessness and insomnia creation of Thoreau calcitonin causes osteoporosis it is characterized by increasing calcium deposition in the bones this results in decreased reabsorption of calcium from the urine thereby increasing the excretion of calcium thus it prevents hypercalcemia let's study about parathyroid glands now in humans there are two pairs of parathyroid glands which are partially embedded in the thyroid lobes dorsally they are small pea-sized glands two of them present on each side of the thyroid lobes endocrine cells of these glands are known as chief cells they secrete a peptide hormone called parathyroid hormone or PTH it is also known as marathon moon or collapse hormone the circulating levels of calcium ions regulate the secretion of parathyroid hormone parathyroid hormone increases the activity of osteoclasts this results in elevated bone resorption which releases ionic calcium and phosphates into the blood parathyroid hormone also slows the loss of calcium and magnesium and increases the loss of phosphates in urine it's retards bone dissolution and stimulates the excretion of calcium in the urine moreover it stimulates the reabsorption of calcium by the renal tubules and increases calcium absorption from digested food pens parathyroid hormone is known as a hypocalcemic hormone as it increases the level of calcium in the blood along with TCT it plays a significant role in balancing calcium in the body hypo secretion of the parathyroid hormone causes a medical condition called nano thyroid tetany it is characterized by muscle spasms twitching contraction of the muscles of the face hands feet etc on the other hand hypersecretion of the parathyroid hormone causes a skeletal disorder called Asti titus fibrosis cystic a' this disorder replaces normal bones with cysts and fibrous tissues and it causes the destruction of bones also known as osteoporosis increased levels of calcium are deposited in various parts of the body which brings about classification of soft tissues hypersecretion of parathyroid hormone also produces stones in the kidneys and Doritos causing renal inefficiency therefore the proper secretion of hormones from the thyroid and parathyroid glands is essential for the smooth functioning of the human body the thymus gland is a lobular lymphoid organ situated on the dorsal side of the heart and the aorta the gland plays a vital role in the development of the immune system it is active in young individuals but degenerates gradually resulting in weak immune responses in old individuals the thymus gland secretes a peptide hormone called dye motion that plays a vital role in the differentiation of T lymphocytes which provides cell mediated immunity my motions also help in the production of antibodies that provide humoral immunity another important hormone secreting gland is the adrenal gland these yellowish triangular-shaped glands are also called suprarenal glands because they are situated on the top of the anterior part of the kidneys each adrenal gland is formed of two types of tissues the outer adrenal cortex and the inner or central adrenal medulla the adrenal cortex is formed of three layers of cells called zona glomerulosa which is the outer layer zona fasciculata the middle layer and zona reticularis the inner layer the adrenal cortex secretes many hormones called corticoids based on their functions these corticoids are differentiated as mineralocorticoids and glucocorticoids the primary function of mineralocorticoids is to regulate the balance of water and electrolytes in our body the primary mineralocorticoid is aldosterone which is a steroid hormone aldosterone acts on the renal tubules of the kidneys and stimulates the reabsorption of sodium and water and the removal of potassium and phosphate ions aldosterone also helps to maintain the body's fluid volume electrolytes osmotic pressure and blood pressure the glucocorticoids secreted by the adrenal cortex are involved in carbohydrate metabolism function of glucocorticoids is to stimulate gluconeogenesis lipolysis and proteolysis it also inhibits the utilization of amino acids and cellular uptake glucocorticoids include cortisol Corazon and corticosteroid hormones of these cortisol is the main glucocorticoid Corozal provides anti-inflammatory reactions and also helps to maintain the cardiovascular system and the functions of the kidneys moreover cortisol stimulates RBC production and suppresses the immune response [Music] apart from mineralocorticoids and glucocorticoids the adrenal cortex also secretes small amounts of the androgenic hormone testosterone which is a male hormone testosterone stimulates the development of secondary sexual character such as eggs eel hair pubic hair facial hair and deepening of the voice like the adrenal cortex the adrenal medulla which forms the central part of the gland also secretes hormones adrenaline or epinephrine and noradrenaline or norepinephrine are the two main hormones secreted by the adrenal medulla these hormones are the mean hormones and are derivatives of catechol and are collectively called catecholamines these hormones increase the strength of heart contractions heartbeat and the rate of respiration they also increase alertness sweating and papillary dilation moreover catecholamines cause below erection ethically means also stimulate the breakdown of glycogen proteins and lipids in short and Acala means are rapidly secreted in response to stress and emergency situations and are thus also called emergency hormones or hormones of fight or flight in fact the adrenal glands are also known as 3f glands where the three FS stand for fright fight and flight these glands are also called glands where the four SS stand for sugar metabolism salt metabolism sex hormones and source of energy apart from the adrenal and thyroid glands there are certain tissues in our body that secrete hormones these tissues are present in the heart kidneys and gastrointestinal tract and they are not categorized as endocrine glands in the heart the atrial wall secretes a peptide hormone called atrial natriuretic factor or ANF which helps to decrease blood pressure when that pressure increases enf is secreted this dilates the blood vessels we're by reducing blood pressure the juxtaglomerular cells present in the kidneys produce a hormone called erythropoietin that stimulates the formation of erythrocytes or red blood corpuscles this formation of erythrocytes is known as erythropoiesis the gastrointestinal tract secretes four major peptide hormones namely gastrin secreting cholecystokinin or CCK and gastric inhibitory peptide or GIP gastrin is secreted by the gastrin cells of the stomach the gastric glands of the stomach wall and stimulates the secretion of pepsinogen and hydrochloric acid secretin is secreted by the duodenal wall it stimulates the eggs of crying region of the pancreas to secrete water and bicarbonate ions into the duodenum through the pancreatic duct cholecystokinin is secreted by the small intestine and stimulates the pancreas and gallbladder to secrete pancreatic enzymes and bio juice respectively which helps in the digestion of food gastric inhibitory peptide or GIP is also secreted by the small intestine and inhibits gastric secretion and motility there are also several other non tissues that secrete hormones called growth factors such as angiogenic and vascular endothelial growth factors or VEGF responsible for the repair or regeneration of tissues and their normal growth the thymus and adrenal glands along with other tissues secrete several hormones which traveled through the bloodstream and coordinate and control the activity of target organs the human body has both endocrine and exocrine glands however it also has a few glands that are both endocrine and exocrine such glands are called hetero crying or composite glands for example the pancreas des teas and ovaries the pancreas is an elongated yellow colored gland located in the loop of the duodenum the endocrine part of the pancreas is formed of about one or two million epithelial cell groups called the islets of Langerhans as the name suggests it was discovered by lye hands in 1869 the islet of Langerhans comprises different types of cells let's secrete hormones four cells or Aqsa fills beta cells cells and F cells alpha cells secrete the hormone glucagon while the beta-cells see insulin hormone Delta cells secrete the hormone somatostatin whereas f cells secrete the pancreatic polypeptide hormone beuker gun secreted by the alpha cells is a peptide hormone as well as a hypoglycemic or diabetic Anik hormone its target organs are the hepatocytes liver cells and adipose tissue the secretion of glucagon by the alpha cells is stimulated by low blood glucose levels the glucose level in the blood is increased by glycogenolysis and gluconeogenesis as well as by inhibiting the conversion of glucose into lactic acid the breakdown of glycogen into glucose in the liver is known as glycogenolysis whereas the male and female primary sex organs teas and ovaries are other examples of hetero crime glens we are also known as the gonads the exocrine part of these gonads produces gametes while the endocrine part secretes hormones a pair of testes is present in the scrotal sac of males it is formed of interstitial cells or Ladak cells that lie between sperm producing seminiferous tubules the interstitial cells stimulating hormone or ICS H of the anterior pituitary stimulates the testes to secrete androgens the male sex hormones there are four main types of antigens testosterone and roster on Eppie Andrew stone and dehydroepiandrosterone [Music] oh these desta stirone is the main androgen and is a steroid hormone controls the growth and development of the male secondary sex organs such as the epididymis less difference prostate gland seminal vesicles urethra and penis apart from the development of statistics such as a beard moustaches deepening of the voice broadening of the shoulders increased height and aggressiveness desta stirone also stimulates Genisys that is the formation of spermatozoa moreover it acts on the central nervous system to influence male sexual behavior or libido produces anabolic effects on protein and carbohydrate metabolism like males females also have a pair of gonads called ovaries that service both primary sex organs and endocrine glands the ovaries are located in the abdomen each ovary is composed of ovarian follicles and stromal tissues each ovary secretes two types of steroid hormones estrogen and progesterone estrogen is produced and secreted by growing ovarian follicles several important functions for example it stimulates the growth and functioning of the female secondary sex organs such as the fallopian tubes uterus vagina etc each ovary also produces one ovum during each menstrual cycle after ovulation the ruptured follicle converts into a yellow colored structure called the corpus luteum which secretes the hormone progesterone progesterone secretion is stimulated by the luteinizing hormone of the anterior pituitary gland progesterone is also known as the pregnancy hormone it stimulates the proliferation of the endometrium of the uterus and prepares it for implantation moreover it helps in placenta formation and the development of the fetus in the uterus Jeron also acts on the mammary glands and stimulates the formation of alveoli which store milk pens all three hetero crime glands Chris des T's and [Music] secrete hormones sniff account for the human body every hormone has certain effects on the target tissues attacks on based on their chemical nature hormones are divided into groups such as protein hormones steroids iota thyrion-- ins and amino acid derivatives while insulin glucagon pituitary hormones without make hormones etc are examples of protein hormones cortisol testosterone dial and progesterone belong to a group called steroids tyroid hormones are iota thyrion-- ins whereas epinephrine is an example of an amino acid derivative hormones act on target organs by binding to specific proteins called hormone receptors the receptors are located in target cells and each receptor is specific to one hormone only to enter the target cells hormones need to bind to the by lipid layer of the plasma membrane on the basis of their solubility hormones can either bind to plasma membrane receptors called extracellular receptors or receptors present within the cell called intracellular receptors non-steroid hormones such as protein and amino acid derivative hormones they are unable to enter that it sells through the bilipid layer of the plasma membrane therefore such hormones bind to extracellular receptors forming a hormone receptor complex this complex in turn generates second messengers such as cyclic adenosine monophosphate inositol triphosphate gasps ooh Mayans etc these messengers bring about certain biochemical changes in the target tissue and regulate the cellular metabolism in contrast to non steroid hormones steroid and thyroid hormones are lipid soluble they can therefore enter the target cells through the bilipid layer of the plasma membrane by binding to intracellular receptors in the cytoplasm or nucleus to form a hormone receptor complex this hormone receptor complex in turn binds to a specific part of the DNA to regulate the synthesis of proteins called gene expression these biochemical actions result in an overall physiological and developmental change in the target cell therefore hormones act on their target cells by binding to two types of hormone receptors you