Harmones ppt

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Presented by…

JAYESH RAUTPAWAN SHARMAABHISHEKKHANDU CHAUDHARINARENDRA D.DR.RAKESH SINGH

Guided by.. Mr. PRASHANT PANDEY

HORMONES

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Endocrine System Parts•Hypothalamus

•Pituitary Gland•Thyroid•Parathyroids•Adrenal Glands•Pineal Body•Reproductive Glands

 Endocrine System Introduction

The endocrine system is made up of glands that produce and secrete hormones, chemical substances produced in the body that regulate the activity of cells or organs. These hormones regulate the body's growth, metabolism (the physical and chemical processes of the body), and sexual development and function. The hormones are released into the bloodstream and may affect one or several organs throughout the body. The major glands of the endocrine system are the hypothalamus, pituitary, thyroid, parathyroids, adrenals, pineal body, and the reproductive organs (ovaries and testes). The pancreas is also a part of this system; it has a role in hormone production as well as in digestion.

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The Endocrine System General Functions of Hormones

• Help regulate:– extracellular fluid

– metabolism

– biological clock

– contraction of cardiac & smooth muscle

– glandular secretion

– some immune functions

• Growth & development• Reproduction

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Endocrine Glands Defined

• Exocrine glands– secrete products into ducts which empty into body

cavities or body surface– sweat, oil, mucous, & digestive glands

• Endocrine glands– secrete products (hormones) into bloodstream– pituitary, thyroid, parathyroid, adrenal, pineal– other organs secrete hormones as a 2nd function

• hypothalamus, thymus, pancreas,ovaries,testes, kidneys, stomach, liver, small intestine, skin, heart & placenta

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Hormones

• The endocrine system is a collection of glands that secrete chemical messages we call hormones.

• These signals are passed through the blood to arrive at a target organ, which has cells possessing the appropriate receptor.

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What Does the Endocrine System Do? Once a hormone is secreted, it travels from the endocrine

gland that produced it through the bloodstream to the cells designed to receive its message. These cells are called target cells.

Along the way to the target cells, special proteins bind to some of the hormones. These proteins act as carriers that control the amount of hormone that is available for the cells to use.

The target cells have receptors that latch onto only specific hormones, and each hormone has its own receptor, so that each hormone will communicate only with specific target cells that have receptors for that hormone.

When the hormone reaches its target cell, it locks onto the cell's specific receptors and these hormone-receptor combinations transmit chemical instructions to the inner workings of the cell.

When hormone levels reach a certain normal amount, the endocrine system helps the body to keep that level of hormone in the blood.

Another example of this process is : parathyroid hormone. Parathyroid hormone increases the level of calcium in the blood. When the blood calcium level rises, the parathyroid glands sense the change and reduce their secretion of parathyroid hormone. This turnoff process is called a negative feedback system.

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Circulating & Local Hormones

• Circulating hormones– act on distant targets– travel in blood

• Local hormones– paracrines act on

neighboring cells– autocrines act on same

cell that secreted them

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General Mechanisms of Hormone Action

• Hormone binds to cell surface or receptor inside target cell

• Cell may then– synthesize new molecules– change permeability of membrane– alter rates of reactions

• Each target cell responds to hormone differently– liver cells---insulin stimulates glycogen synthesis– adipose---insulin stimulates triglyceride synthesis

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Mechanism of Hormone Action

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Control of Hormone Secretion

• Regulated by signals from nervous system, chemical changes in the blood or by other hormones

• Negative feedback control (most common)– decrease/increase in blood level is reversed

• Positive feedback control– the change produced by the hormone causes

more hormone to be released

• Disorders involve either hyposecretion or hypersecretion of a hormone

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Overproduction of a hormone Underproduction of a hormone Nonfunctional receptors that cause target

cells to become insensitive to hormones

Endocrine-related Problems

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• The hypothalamus contains neurons that control releases from the anterior pituitary.

• Seven hypothalamic hormones are released into a portal system connecting the hypothalamus and pituitary, and cause targets in the pituitary to release eight hormones.

HYPOTHALAMUS

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The location and roles of the hypothalamus and pituitary glands.

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Hypothalamus and Pituitary Gland• Both are master endocrine glands since their hormones control

other endocrine glands• Hypothalamus is a section of brain above where pituitary gland

is suspended from stalk (surrounds 3rd ventricle)• Hypothalamus receives input from cortex, thalamus, limbic

system & internal organs• Hypothalamus controls pituitary gland with different releasing &

inhibiting hormones (gonadotropin-releasing hormone, growth hormone-releasing hormone, growth hormone-inhibiting hormone)

• Major integrating link between nervous and endocrine systems

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STIMULUS

HypothalamusReleasing Hormone

(Release-Inhibiting Hormone)

PituitaryStimulating Hormone

GlandHormone

Target

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Pituitary gland

MASTER GLAND• Anterior and posterior

portions1. Posterior connected to

hypothalamus by infundibulum

2. Anterior connected via blood stream

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Thyroid gland

Hypothalamus

Anteriorpituitary

Gonadotropic hormones:Follicle-stimulatinghormone (FSH) & luteinizing hormone (LH)

Mammaryglandsin mammals

Musclesof uterus

Kidneytubules

Posteriorpituitary

Thyroid-stimulating Hormone(TSH)

Antidiuretic hormone(ADH)

Adrenalcortex

Boneand muscle Testis

Ovary

Melanocytein amphibian

Adrenocorticotropic

hormone (ACTH)

Melanocyte-stimulating hormone

(MSH)

Oxytocin

Prolactin (PRL)

Gro

wth

hor

mon

e (G

H)

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Anterior Pituitary & Flow of Blood

• Controlling hormones enter blood• Travel through portal veins• Enter anterior pituitary at capillaries

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1.Human Growth Hormone (HGH)

• Produced by somatotrophs (somatostatin) of anterior pituitary

• Within target cells increases synthesis of insulin like growth factors that act locally or enter bloodstream– common target cells are liver, skeletal muscle,

cartilage and bone– increases cell growth & cell division

What can go

wrong

• Too much or too little of any hormone can be harmful to your body.

For example, if the pituitary gland produces too much growth hormone, a teen may grow excessively tall. If it produces too little, a teen may be unusually short. Doctors can often treat the problems by controlling the production of hormones or replacing certain hormones with medication.

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2.Thyroid Stimulating Hormone (TSH)

• Hypothalamus regulates thyrotroph cells

• Thyrotroph cells produce TSH

• TSH stimulates the synthesis & secretion of T3 and T4

• Metabolic rate stimulated

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3.Follicle Stimulating Hormone (FSH)

• GnRH from hypothalamus controls gonadotrophs

• Gonadotrophs release FSH

• FSH functions – initiates the formation of follicles within the ovary– stimulates follicle cells to secrete estrogen– stimulates sperm production in testes

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4.Luteinizing Hormone (LH)

• GnRH from hypothalamus stimulate gonadotrophs

• Gonadotrophs produce LH

• In females, LH stimulates– secretion of estrogen– ovulation of oocyte from ovary– secretion of progesterone

• In males, stimulates interstitial cells to secrete testosterone

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5.Prolactin (PRL)

• Hypothalamus regulates lactotroph cells (PRH)

• Lactotrophs produce prolactin

• Under right conditions, prolactin causes milk production

• Suckling reduces levels of hypothalamic inhibition and prolactin levels rise along with milk production

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6.Adrenocorticotrophic Hormone (ACTH)

• Corticotrophin-RH stimulate corticotrophs

• Corticotrophs secrete ACTH & MSH

• ACTH stimulates cells of the adrenal cortex that produce glucocorticoids

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7.Melanocyte-Stimulating Hormone (MSH)

• Secreted by corticotroph cells

• Releasing hormone from hypothalamus increases its release from the anterior pituitary

• Function not certain in humans (increase skin pigmentation in frogs )

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Posterior Pituitary Gland

• Does not synthesize hormones

• Consists of axon terminals of hypothalamic neurons and pituicytes (neuroglia)

• Neurons release two neurotransmitters that enter capillaries– antidiuretic hormone– oxytocin

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Posterior Pituitary Hormones

• Manufactured in Hypothalamus, released from Post. Pit.

• Oxytocin– Target = smooth ms. Uterus and Breast (&brain)– Function = labor and delivery, milk ejection,(pair

bonding)

• ADH (Vasopressin AVP)– Target = kidneys– Function = water reabsorption

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1.Oxytocin• Two target tissues both involved in neuroendocrine

reflexes

• During delivery– baby’s head stretches cervix– hormone release enhances uterine

muscle contraction– baby & placenta are delivered

• After delivery– suckling & hearing baby’s cry stimulates milk ejection– hormone causes muscle contraction & milk ejection

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Positive Feedback

• Classic example:

Action of OXYTOCIN on uterine muscle during birth.

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2.Antidiuretic Hormone (ADH)

• Known as vasopressin

• Functions– decrease urine production– decrease sweating– increase BP by retaining

water

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• The pineal gland, or the pineal body is in the middle of the brain. It secretes melatonin, a hormone that regulates when you sleep at night and wake up in the morning.

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• Pineal gland is a small, cone shaped gland found in the roof of the third ventricle of the brain.

• Melatonin hormone appears to be secreted in substantial amounts.

• It is believed to coordinate the hormones of fertility and to inhibit the reproductive system (especially the ovaries of females)

• so that sexual maturation is prevented from occurring before adult body size has been reached.

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THYMUS GLAND

.

• Located in the upper thorax region.

• Large in infants and children, it decreases in size throughout adult hood.

• By old age, it is composed mostly of fibrous connective tissue and fat.

• Thymus produces a hormone called thymosin.

• During childhood, it acts as an incubator for the maturation of a special group of whiteblood cells(T lymphocytes or T cells).

• T cells are play a great role in immune respose.

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Adult THYMUS

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Adult THYMUS

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Thyroid Gland

• On each side of trachea is lobe of thyroid• Weighs 1 oz & has rich blood supply

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• Location: Located close to thyroid cartilage. Has two lateral lobes connected by thyroid isthmus medially. Isthmus covers cricoid cartilage in ventral view.

• Development: first endocrine gland to apear during development. Develops from endodermal thickening in floor of early pharynx and epithelium of 3rd and 4th gill slit pouches as early as 24 days after fertilization. Starts out caudal to tongue, but ultimately comes to be wrapped around laryngeal cartilages.

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Actions of Thyroid Hormones

• T3 & T4 = thyroid hormones responsible for our metabolic rate, synthesis of protein, breakdown of fats, use of glucose for ATP production

• Calcitonin = responsible for building of bone & stops reabsorption of bone (lower blood levels of Calcium)

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Goiter

Iodine deficiency causes thyroid to enlarge as it tries to produce thyroxine

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Mechanism

• Goiters A thyroid goiter is a dramatic enlargement of the thyroid gland.

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PARATHYROID GLAND

Location: •Usually paired. •Very small (less than 5 mm). •Called parathyroid glands because of their position on posterior margins outer surface of thyroid gland.•More superior of each pair usually near middle of margin of lobe.•More inferior of each pair usually at inferior apex of lobe.

Development: Like thyroid gland, develop from endodermal thickening in floor of early pharynx and epithelium of 3rd and 4th gill slit pouches.

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Parathyroid Glands

• 4 pea-sized glands found on back of thyroid gland

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Parathyroid Hormone

• Raise blood calcium levels– increase activity of osteoclasts– increases reabsorption of Ca+2 by kidney– promote formation of calcitriol (vitamin D3) by

kidney which increases absorption of Ca+2 and Mg+2 by intestinal tract

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Regulation of Calcium Blood Levels

• High or low blood levels of Ca+2 stimulate the release of different hormones --- PTH or CT

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• Hyperthyroidism Hyperthyroidism means too much thyroid hormone.

• Hypothyroidism Hypothyroidism means too little thyroid hormone and is a common problem.

• Thyroid Cancer Thyroid cancer is a fairly common malignancy, however, the vast majority have excellent long term survival.

• Solitary Thyroid Nodules There are several characteristics of solitary nodules of the thyroid which make them suspicious for malignancy.

• Thyroiditis Thyroiditis is an inflammatory process ongoing within the thyroid gland.

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Adrenal gland

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Adrenal Gland

• Adrenal gland located atop kidney

• Outer part = cortex– Secretes Cortisol (stress), Androgens,

Aldosterone (electrolytes)

• Inner part = medulla– SNS control– Secretes EPI & NEPI (fight or flight)

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• Each kidney has an adrenal gland located above it. • The adrenal gland is divided into an inner medulla and

an outer cortex. • The medulla synthesizes amine hormones, the cortex

secretes steroid hormones. • The adrenal medulla consists of modified neurons that

secrete two hormones: epinephrine and norepinephrine.

• Stimulation of the cortex by the sympathetic nervous system causes release of hormones into the blood to initiate the "fight or flight" response.

• The adrenal cortex produces several steroid hormones in three classes: mineralocorticoids, glucocorticoids, and sex hormones.

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Mineralocorticoids maintain electrolyte balance. Glucocorticoids produce a long-term, slow response to stress by raising blood glucose levels through the breakdown of fats and proteins; they also suppress the immune response and inhibit the inflammatory response.

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The structure of the kidney as relates to hormones

Two diseases associated with the adrenal cortex:

1. Cushing’s Disease : Cushing's disease refers to a pituitary-dependent cause of Cushing's

syndrome: a tumor (adenoma) in the pituitary gland produces large amounts of ACTH, causing the adrenal glands to produce elevated levels of cortisol

SYMPTOMS:

WEIGT GAIN

HAIR LOSS

HYPERFPIGMENTATION

HYPRECALICMEIA

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Addison’s disease (also chronic adrenal insufficiency, hypocortisolism, and hypoadrenalism) is a rare, chronic endocrine disorder in which the adrenal glands do not produce sufficient steroid hormones (glucocorticoids and often mineralocorticoids). It is characterised by a number of relativelynonspecific symptoms, such as abdominal pain and weakness….

2. Addison’s disease

SYMPTOMS:

NAUSEAFEVER VOMITINGFATIGUE

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Adrenal Problems

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Hypersecretion of Adrenal Cortex

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PANCREAS

The pancreas is an elongated organ located toward the back of the abdomen behind the stomach. The pancreas has digestive and hormonal functions. One part of the pancreas, the exocrine pancreas, secretes digestive enzymes. The other part of the pancreas, the endocrine pancreas, secretes hormones called insulin and glucagon. These hormones regulate the level of glucose (sugar) in the blood.

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Pancreatic Endocrine Hormones and Their Purpose

1.Glucagon :    Assist insulin in regulating blood glucose (sugar) in the normal range (actions are opposite of insulin)

• Disease due to deficient action:     Some times nothing, sometimes hypoglycemiaDisease due to excess action:     HyperglycemiaDisease due to excess action:     Hyperglycemia

2.Somatostatin: Regulate the production and excretion of other endocrine tumors

• Disease due to excess action:     Diabetes (inhibits insulin production), gallstones, and dietary fat intolerance.

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• Diabetes results from inadequate levels of insulin. • Type I diabetes is characterized by inadequate levels of

insulin secretion, often due to a genetic cause. • Type II usually develops in adults from both genetic

and environmental causes. • Loss of response of targets to insulin rather than lack of

insulin causes this type of diabetes.• Diabetes causes impairment in the functioning of the

eyes, circulatory system, nervous system, and failure of the kidneys.

• Diabetes is the second leading cause of blindness in the US.

• Treatments involve daily injections of insulin, monitoring of blood glucose levels and a controlled diet.

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Regulation of Glucagon & Insulin Secretion

• Low blood glucose stimulates release of glucagon

• High blood glucose stimulates secretion of insulin

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Steroid Hormones

• Small

• Hydrophobic/Lipophilic

• Travel in blood w/carrier

• Cytoplasmic or nuclear receptors

• change protein synthesis

• Example: estradiol

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Too many steroids

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Reproductive Glands

The reproductive glands are the main source of sex hormones. In males, the testes, located in the scrotum, secrete hormones called androgens; the most important of which is testosterone.

These hormones affect many male characteristics (for example, sexual development, growth of facial hair and pubic hair) as well as sperm production.

In females, the ovaries, located on both sides of the uterus, produce estrogen and progesterone as well as eggs. These hormones control the development of female characteristics (for example, breast growth), and they are also involved in reproductive functions (for example,menstruation, pregnancy).

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Gland Hormone Chemical

Class

Representative

Actions

Regulated By

Hypothalamus

Pituitary gland

Posterior pituitary

(releases hormones

made by hypo-

thalamus)

Anterior pituitary

Oxytocin

Antidiuretic hormone

(ADH)

Growth hormone (GM)

Prolactin (Pith)

Follicle—stimulating

hormone )FSII)

Luteinizing hormone

(LB)

Thyroid-stimulating

hormone (TSH)

Adrenocorticotropic

hormone (ACTH)

Peptide

Peptide

Protein

Protein

Glycoprotein

Glycoprotein

Glycoprotein

Peptide

Stimulates contraction of uterus and mammary gland cells

Promotes retention of water

by kidneys

Stimulates growth (especially

bones) and metabolic functions

Stimulates milk production

and secretion

Stimulates production of

ova and sperm

Stimulates ovaries and testes

Stimulates thyroid gland

Stimulates adrenal cortex

to secrete glucocorticoids

Nervous system

Water/salt balance

Hypothalamic

hormones

Hypothalamic

hormones

Hypothalamic

hormones

Hypothalamic

hormones

Thyroxine in blood;

hypothalamic hormones

Glucocorticoids;

hypothalamic hormones

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Gland Hormone Chemical

Class

Representative

Actions

Regulated By

Thyroid gland

Triiodothyronine (T1)

and thyroxine (T4)

Calcitonin

Amine

Peptide

Stimulate and maintain

metabolic processes

Lowers blood calcium level

TSH

Calcium in blood

Parathyroid glands

Parathyroid hormone

(PTH)

Peptide Raises blood calcium level

Calcium in blood

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Gland Hormone Chemical

Class

Representative

Actions

Regulated By

Pancreas Insulin

Glucagon

Protein

Protein

Lowers blood glucose level

Raises blood glucose level

Glucose in blood

Glucose in blood

Adrenal glands

Adrenal medulla

Adrenal cortex

Epinephrine and

Norepinephrine

Glucocorticoids

Amine

Steroid

Raise blood glucose level;

increase metabolic activities;

constrict certain blood vessels

Raise blood glucose level

Nervous system

ACTH

Gonads

Testes

Ovaries

Andrugens

Estrogens

Progesterone

Steroid

Steroid

Steroid

Support sperm formation;

promote development and

maintenance of male secondary

sex characteristics

Stimulate uterine lining growth;

promote development and

maintenance of female

secondary sex characteristics

Promotes uterine lining growth

FSH arid LH

ESH and LH

ESH and LH

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Gland Hormone Chemical

Class

Representative

Actions

Regulated By

Pineal gland

Melatonin Amine Involved in biological rhythms

Light/dark cycles

Thymus Thymosin Peptide Stimulates T lymphocytes

Not known

Endocrine Pharmacology

AND

Drugs Affecting

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Drugs Affecting the Pituitary Gland

DWARFISM

• BRAND NAME(S):

•  Genotropin,  Norditropin, Nutropin, 

• Somatropin is also used to increase height in children with a certain genetic disorder (Noonan syndrome).

• Side effect- Headache, nausea,vomiting, fatigue, muscle pain

• Other drugs- Humatrope Inj, Somatropin Inj,

GH = pituitary dwarfism

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GIGANTISM

Gigantism is abnormally large growth due to an excess of growth hormone during childhood, before the bone growth plates have closed. Symptoms: The child will grow in height, as well as in the muscles and organs.

Treatment :Stopping or reducing the overproduction of growth hormone is not easy; thus, doctors may need to use a combination of surgery, radiation therapy, and drug therapy.

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Drugs Affecting the Parathyroid & Thyroid Glands

Goiter

•LEVOTHYROXINE

Hyperthyroidism

•Typically a result of tumors•Most common cause is Grave’s Disease•Surgical removal of the diseased gland

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Drugs Affecting the Adrenal Cortex

Cushing’s Disease

1. Spironolactone (Aldactone)2. ACE inhibitors – Captopril

(Capoten)

Addison’s Disease

1. Fludrocortisone (florinef acetate)

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Drugs Affecting the Pancreas

1. Biguanides

2. Sulfonylureas

3. Tolbutamide

4. Glucagon

Diabetes

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