Learning Objectives – Endocrine System

Identify the endocrine glands and their hormones.

Gain an understanding of the functions of these hormones in the body.

Analyze medical terms related to the endocrine glands and their hormones.

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Learning Objectives (cont’d.)

Identify abnormal conditions resulting from excessive and deficient secretions of the endocrine glands.

Describe laboratory tests and clinical procedures related to endocrinology, and recognize relevant abbreviations.

Apply your new knowledge to understanding medical terms in their proper contexts, such as medical reports and records.

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The Endocrine System – p. 746 Glands release hormones

Hormones regulate the many and varied functions of an organism

Hormones bind to receptors

Receptors are recognition sites in the various target tissues on which hormones act

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Two Types of Glands ENDOCRINE glands

Secrete their hormones directly into the bloodstream

EXOCRINE glandsSend chemical substances (tears, sweat, milk, saliva) via ducts to the outside of the body.

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Glands page 747

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Thyroid Gland – page 748

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Thyroid Function – page 748

Two hormones secreted by thyroid:

thyroxine or tetraiodothyronine (T4)

triiodothyronine (T3)

Thyroid hormones aid cells in their uptake of oxygen and regulate metabolic rate

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Thyroid Gland

Calcitonin: stimulates calcium to leave the blood and enter the bone

New hormone recently discovered

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Thyroid Gland: Hormones and Actions

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Parathyroid Gland: - page 749

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Parathyroid Glands – page 750

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Parathyroid Function

Parathyroid hormone (PTH):

causes calcium to mobilize from bones into the bloodstream

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Adrenal Glands – page 751

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ADRENAL GLANDS:

Each gland has two parts

an outer portion, the adrenal cortex○ Secretes corticosteriods or steriods,

chemicals derived from cholesterol

an inner portion, adrenal medulla○ Secretes catecholamines

chemicals derived from amino acids

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Adrenal CORTEX Secretes Glucocorticoids: influence metabolism of

sugars, fats, and proteins (cortisol) and are anti-inflammatory (cortisone).

Influences--SUGAR

Mineralocorticoids: regulate electrolytesAldosterone: reabsorption of sodium/excretion of

potassium. Influences--SALT

Gonadocorticoids: androgens and estrogens. Influences--SEX

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Adrenal MEDULLA Secretes Two types of catecholamine hormones

Epinephrine (adrenaline): increases heart rate and blood pressure, dilates bronchial tubes, releases glucose from storage

Norepinephrine (noradrenaline): constricts vessels to raise blood pressure

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The Adrenal Cortexand Adrenal Medulla

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Pancreas – page 752 Located near and partially behind

stomach Exocrine and endocrine organ

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Pancreas Function islets of Langerhans produce:

Insulin: promotes movement of glucose into cells and promotes storage as glycogen

Glucagon: promotes movement of glucose into the blood by breaking down glycogen stored in liver cells

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Pancreas Function

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Pituitary Gland – page 753 Pea-sized gland in depression of skull (sella

turcica) also called the hypophysisAnterior lobe (adenohypophysis)Posterior lobe (neurohypophysis)

Hypothalmus controls secretions of the pituitary via releasing factors (hormones)

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Pituitary Gland

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Pituitary Function – page 754

Anterior Pituitary secretes the following hormomes:

Growth hormone (GH) – increases bone and tissue growth

Thyroid-stimulating hormone (TSH; thyrotropin)

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Pituitary FunctionAdrenocorticotropic hormone

(ACTH) – stimulates cortisol secretion

Gonadotropic hormones (FSH, LH)

Prolactin (PRL)

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Pituitary Function (cont’d.)

Posterior pituitary: stores and releases hormones synthesized in the hypothalamus

Antidiuretic hormone (ADH; vasopressin) – increases water reabsorption by kidneys

Oxytocin (OT)

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Pituitary Gland: Hormones and Actions – page 755

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Ovaries and Testes: Hormones and Actions – page 755-756

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Table 18-2

See page 756 for summary of major endocrine glands, hormones they produce, and their actions.

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GLANDS

aden/o gland

adren/o adrenal glands

adrenal/o adrenal glands

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Combining FormCombining Form MeaningMeaning

COMBINING FORMS – page COMBINING FORMS – page 760760

Combining Forms Combining Form Meaning

gonad/o sex glands (ovaries, testes)

pancreat/o pancreas

parathyroid/o parathyroid gland

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pituitar/o pituitary gland;

thyr/o thyroid gland

thyroid/o thyroid gland

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Combining FormCombining Form Meaning Meaning

Page 760 - GlandsPage 760 - Glands

andr/o male

calc/o, calici/o calcium (hypocalcemia)

cortic/o cortex, outer region

crin/o secrete (endocrine)32

Combining FormCombining Form MeaningMeaning

Combining Forms - Page Combining Forms - Page 760-761760-761

Combining Forms Combining Form Meaning

dips/o thirst (poly dipsia)

estr/o female

gluc/o, glyc/o sugar

(hyperglycemia)

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home/o sameness

hormon/o hormone

kal/I potassium (an electrolyte)

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Combining FormCombining Form MeaningMeaning

Glands - Page 761Glands - Page 761

Glands

Combining Form Meaning

lact/o milk

myx/o mucus

natr/o sodium

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phys/o growing

somat/o body (somatotropin)

ster/o solid structure

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Combining FormCombining Form MeaningMeaning

Glands - Page 762Glands - Page 762

Glands

Combining Form Meaning

toc/o childbirth

toxic/o position

ur/o urine

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-agon assemble, gather together

-emia blood condition

-in, -ine a substance

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SuffixSuffix Meaning Meaning

Suffixes - page 763Suffixes - page 763

Suffixes

Suffix Meaning

tropin stimulating the function of

-uria urine condition

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eu- good, normal (euthyroid)

hyper- excessive, above

hypo- deficient, below

oxy- rapid, sharp, acid

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PrefixPrefix Meaning Meaning

Prefixes - page 763Prefixes - page 763

Prefixes

Prefix Meaning

pan- all

tetra- four

tri three

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QUICK QUIZ:

4. Which term means a blood condition of too little potassium?

A. hyperkalemia

B. hypocalcemia

C.hypercalciuria

D.hypokalemia42

Thyroid Abnormalities – page 764

Goiter: Enlargement of the thyroid

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Thyroid Abmormalities

HypersecretionHyperthyroidism Graves disease – Autoimmune

○Exophthalmos and proptosis

Thyroid Abnormalities

HyposecretionHypothyroidismMyxedemaCretinism

NeoplasmsThyroid carcinoma

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Parathyroid Abnormalities – page 765

HypersecretionHyperparathyroidismLoss of bone densityKidney stonesHypercalcemia

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Parathyroid AbnormalitiesHyposecretion:

HypoparathyroidismDeficient production of

parathyroid hormone leads to hypocalcemia which leads to tetany

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Abnormalities of Adrenal Cortex – page 766

Hypersecretion

adrenal virilism – excessive androgens amenorrhea, hirsutism, acne, voice deepening

Cushing syndrome – excessive cortisol Obesity, moon-face, thoracic fat deposition

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Abnormalities of Adrenal Cortex

Hyposecretion

Addison disease – low cortisol and aldosterone levels

hyponatremia, fatigue, weakness, low blood pressure

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Abnormalities of Adrenal Medulla – page 767

Pheochromocytoma:

Benign tumor of adrenal medulla

Excess epinephrine and norepinephrine

Hypertension, palpitations, severe headaches, sweating, flushing of the face, and muscle spasms

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Abnormalities of the Pancreas

Hypersecretion

Hyperinsulinism – excessive secretion of insulin causing;

Hypoglycemia, convulsions, fainting

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Pancreas

Hyposecretion Diabetes mellitus

Lack of insulin secretion or resistance of insulin in promoting sugar, starch and fat metabolism in cells

Type 1 : childhood onset typically

Type 2 : adult onset typically

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Comparison of Type 1 and Type 2 Diabetes

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Abnormalities Pituitary Gland: (Anterior Lobe)

Hypersecretion acromegaly gigantism

Hyposecretion dwarfism panhypopituitarism

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Abnormalities Pituitary Gland: (Posterior Lobe)

Hypersecretion Syndrome of inappropriate ADH (SIADH)

Excess ADH

Excess water retention

Hyposecretion Diabetes insipidus

Deficient ADH

Polyuria and polydipsia

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Review Abnormal Conditions of Endocrine Glands – page 748

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Laboratory Tests – page 748

Fasting blood sugar (FBS) Measures circulating glucose in a patient

who has fasted at least 4 hours Serum and urine tests

Measures hormones, electrolytes, glucose, etc. in blood and urine as indicators of endocrine function

Thyroid function testsMeasures T3, T4, and TSH in the

bloodstream

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Clinical Procedures – page 749

exophthalmometry computed tomography (CT) scan magnetic resonance imaging (MRI) of the

head radioactive iodine uptake thyroid scan ultrasound examination

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QUICK QUIZ:

5. What is the pathologic condition in which enlargement of the extremities is caused by hypersecretion of the anterior pituitary after puberty?

A. Addison disease

B. acromegaly

C.Cushing syndrome

D.Graves disease

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