Endocrinology tests

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Endocrinology tests

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Endocrinology tests. Female sex hormones. Physiology: There are two main hormones in this category: Estrogen, Progesterone Estrogen: formation of female secondary sex characteristics, maintains uterus lining for implantation of fertilized egg, ovulation, thickening of endometrial lining - PowerPoint PPT Presentation

Transcript of Endocrinology tests

Endocrinology tests

Female sex hormones Physiology:• There are two main hormones in this category: Estrogen, Progesterone• Estrogen: formation of female secondary sex characteristics, maintains

uterus lining for implantation of fertilized egg, ovulation, thickening of endometrial lining

• Progesterone: decreases maternal immune response during pregnancy, aids in implantation, facilitates the onset of labor

Pathology:• Infertility• Abnormal menstrual cycle• Unsual sex organ development• Signs of feminization in men • Hormone imbalance

Tests performed: 24- hour urine sample, vein puncture

Principle: By collecting all urine for 24 hours, the amount of the substance being

measured in the urine can be averaged over the entire day and will give a better indication of what is going on in the body.

Significance: Estrogen: To monitor estrogen levels in case of unexplained abnormal

menstrual cycles, infertility, symptoms of menopause,to test for fetal-placental status during early stages of pregnancy and to evaluate feminization, the presence of female-like characteristics in males

Progesterone: To help determine the cause of infertility, track ovulation, help diagnose an ectopic or failing pregnancy, monitor the health of a pregnancy, and help diagnose the cause of abnormal uterine bleeding

Male sex hormones Physiology:• The primary and well known androgen is: testosterone, dihydro-testosterone is also of

secondary importance• Testosterone: 1. Anaboloic effects: growth of muscle mass and strength, increased bone density and

strength, and stimulation of linear growth and bone maturation 2. Androgenic effects: maturation of the sex organs, a deepening of the voice, growth of

the beard and axillary hair

Pathology:• abnormal testosterone level in males and females• erectile dysfunction,• infertility• premature or delayed puberty; in females• masculine physical features (virilization), • polycystic ovary syndrome (PCOS)

Tests performed: 24- hour urine sample, vein puncture

Principle: By collecting all urine for 24 hours, the amount of the substance being

measured in the urine can be averaged over the entire day and will give a better indication of what is going on in the body.

Significance: to diagnose infertility or delayed puberty, diagnosis of male characters in

females

Renin Angiotensin Aldosterone System

Significance• The renin–angiotensin system (RAS) or the renin–angiotensin–aldosterone system (RAAS) is

a hormone system that regulates blood pressure and water (fluid) balance.

• When blood volume is low, juxtaglomerular cells in the kidneys secrete renin directly into circulation. Plasma renin then carries out the conversion of angiotensinogen released by the liver to angiotensin I. Angiotensin I is subsequently converted to angiotensin II by the enzyme angiotensin converting enzyme found in the lungs. Angiotensin II is a potent vaso-active peptide that causes blood vessels to constrict, resulting in increased blood pressure. Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood. This increases the volume of fluid in the body, which also increases blood pressure.

• If the renin–angiotensin–aldosterone system is abnormally active, blood pressure will be too high. There are many drugs that interrupt different steps in this system to lower blood pressure. These drugs are one of the main ways to control high blood pressure (hypertension), heart failure, kidney failure, and harmful effects of diabetes.

Physiology

Pathology

Principle

Hypothallamus and pituitary gland

Significance• The hypothalamus is located in the middle of the base of the brain, and encapsulates the ventral

portion of the third ventricle. The pituitary gland, also known as the hypophysis, is a roundish organ that lies immediately beneath the hypothalamus. The anterior and posterior pituitary secrete a battery of hormones that collectively influence all cells and affect virtually all physiologic processes.

• The pituitary gland may be king, but the power behind the throne is clearly the hypothalamus. As alluded to in the last section, some of the neurons within the hypothalamus - neurosecretory neurons - secrete hormones that strictly control secretion of hormones from the anterior pituitary. The hypothalamic hormones are referred to as releasing hormones and inhibiting hormones, reflecting their influence on anterior pituitary hormones.

• Hypothalamic releasing and inhibiting hormones are carried directly to the anterior pituitary gland via hypothalamic-hypophyseal portal veins. Specific hypothalamic hormones bind to receptors on specific anterior pituitary cells, modulating the release of the hormone they produce.

• Hormones secreted from the pituitary gland help control the following body processes: Growth (Excess of HGH can lead to gigantism and acromegaly) Compared with the hand of an unaffected person (left), the hand of someone with acromegaly (right)

is enlarged. Blood pressure Some aspects of pregnancy and childbirth including stimulation of uterine contractions during

childbirth Breast milk production Sex organ functions in both males and females Thyroid gland function The conversion of food into energy (metabolism) Water and osmolarity regulation in the body Water balance via the control of reabsorption of water by the kidneys Temperature regulation Pain relief•

Physiology

Pathology

Anti diuretic hormone: irregular body water retentionOxytocin, prolactin: problem in milk production from

mammary glandsGrowth hormone: gigantism, dwarfism

Principle• Blood or urine tests to determine levels of hormones such as:• Cortisol• Estrogen• Growth hormone• Pituitary hormones• Prolactin• Testosterone• Thyroid• Other possible tests:• Hormone injections followed by timed blood samples• MRI or CT scans of the brain• Visual field eye exam (if there is a tumor)

• Thyroid function tests are currently the most accurate way to diagnose and manage thyroid disorders

TESTSBlood tests to measure TSH, T4, T3 and Free T4 are readily available and widely used.NON-BLOOD TESTSRadioactive iodine uptake

Thyroid Function Test(M.Nasir Younis)

Test / Name Normal Range Interpretation "TSH" Test -- Thyroid

Stimulating Hormone 0.4 to 6

0.3 to 3.0 (as of 2003)

<.4 can indicate possible hyperthyroidism. > 6 is considered indicative of hypothyroidism.

Total T4 / Serum thyroxine 4.5 to 12.5 < 4.5 can be indicative of an underfunctioning thyroid when TSH is also elevated. > 12.5 can indicate hyperthyroidism. Low T4, TSH can sometimes indicate a pituitary problem.

Free T4 / Free Thyroxine - FT4 0.7 to 2.0 <0.7 is considered indicative of possible hypothyroidism.

T3 / Serum triiodothyronine 80 to 220 < 80 can indicate hypothyroidism.

TFT results: Hyperthyroidism TestCause TSH T3/T4 TSI RAIU

Graves’ disease ▼ ▲ + ▼Thyroiditis (early stage) ▼ ▲ _ ▼Thyroid nodules (hot, or toxic) ▼ ▲ _ ▲ or N

TFT results: Hyperthyroidism TestCause TSH T3/T4 Antithyroid Antibody

Hashimoto’s (thyroiditis) disease ▲ ▼ +

Hashimoto’s (thyroiditis) disease (later stage)

▲ ▼ +

Pituitary abnormality ▼ ▼ _

Parathyroid Hormone Test• Parathyroid Gland:

The major function of the parathyroid glands is to maintain the body's calcium level within a very narrow range, so that the nervous and muscular systems can function properly.Parathyroid hormone (PTH) test:The parathyroid hormone (PTH) test is a blood test performed to determine the serum levels of a hormone secreted by the parathyroid gland in response to low blood calcium levels. PTH works together with vitamin D to maintain healthy bones. The parathyroid glands are small paired glands located near the thyroid gland at the base of the neck.

• PTH is done to Identify:Hyperparathyroidism.Find the cause of an abnormal blood calcium level.Problem with the parathyroid glands is causing the abnormal calcium level.Problems in people who have chronic kidney disease.

Abnormal results:When measured with serum calcium levels, abnormally high PTH values may indicate primary, secondary, or tertiary hyperparathyroidism, chronic renal failure, malabsorption syndrome, and vitamin D deficiency. Abnormally low PTH levels may indicate hypoparathyroidism, hypercalcemia, and certain malignancies.

Calcium PTH Interpretation

Normal Normal Calcium regulation system functioning OK

Low High PTH is responding correctly: may run other

tests to check hypocalcaemia

Low Normal/Low PTH not responding correctly: probably have

hypoparathyroidism

High High Parathyroid gland producing too much PTH:

may do imaging studies to check for

hyperparathyroidism

High Low PTH is responding correctly: may run other

tests to check for non-parathyroid-related

reasons for elevated calcium

Adrenal GlandOROOJ SURRIYA

ENDOCRINE GLAND

HORMONES FUNCTION

ADRENAL CORTEX

ALDOSTERONE Fluid & electrolyte balance; Na reabsorption; K excretion

CORTISOL Glycogenolysis;GluconeogenesisNa & water reabsorptionAnti-inflammatoryStress hormone

SEXHORMONES

Slightly significant

Adrenal Insufficiency Primary adrenal insufficiency. Addison's disease, congenital adrenal

hyperplasia or an adenoma (tumor)

Secondary adrenal insufficiency pituitary gland or hypothalamus

Tertiary adrenal insufficiency Hypothalamic disease and decrease in CRF

TESTS ?

Insulin tolerance test Metyrapone test CRH stimulation test

Adrenal Hyper-secretion Pheochromocytoma Excessive production of catechol amines Blood Tests, Urine Tests

Hyper Aldosteronism Aldosterone over-production Blood test

Virilization High amounts of androgens Blood tests, CT scan, MRI, or ultrasound

Cushing's syndrome Over-production of cortisol

PANCREAS

Isra Mahmood

PHYSIOLOGY

Exocrine • Enzyme secretion (Gastrin)

Endocrine • Hormone secretion (Insulin and Glucagon)

What can go WRONG with our PANCREAS???

The pathological basis of the disease is due to an INADEQUATE INSULIN

EFFECT either due to an insufficient release or due to a resistance to its

actionsType I (IDDM)

Type II (NIDDM)

Gestational Diabetes

ORAL GLUCOSE TOLERANCE TEST

An insulinoma is a rare tumor derived from the

beta cells of the pancreas producing

large amounts of insulin

Excessive insulin production causes a

persistently low glucose blood concentration

(hypoglycaemia) that results in a diverse array of symptoms

TESTSO Measuring glucose and insulin

levelsO Fasting testO Glucagon testO Glucose Tolerance TestO Calcium Infusion Test