Copyright 2003 by Mosby, Inc. All rights reserved. CHAPTER 17 ENDOCRINE SYSTEM.

Copyright 2003 by Mosby, Inc. All rights reserved.

CHAPTER 17

ENDOCRINE SYSTEM


Structure and Function

• Primary function of the endocrine system– To produce hormones that monitor and

coordinate body activities

• Endocrine glands secrete hormones directly into the bloodstream

• Three hormone categories – Tropic hormones – Sex hormones – Anabolic hormones


Figure 17-1 Endocrine System


Glands and Their Hormones • Hypothalamus

– Structure located above the pituitary gland that translates nervous system impulses into endocrine system messages

• Pituitary gland – Produces the hormones that regulate the

secretion of other glands

• Pineal body– Produces the hormone melatonin


Glands and Their Hormones (continued)

• Thyroid– Produces hormones that regulate body

metabolism

• Parathyroid– Secretes parathyroid hormone, which affects

the amount of calcium in the blood

• Thymus– Produces the hormone thymosin that

stimulates the lymphoid organs to produce T-lymphocytes or antibodies in newborns and young children



• Pancreas– Produces the hormones insulin and

glucagon. Insulin regulates transportation of sugar, fatty acids, and amino acids into the cells.

• Adrenal glands– Produce about 30 hormones

• Gonads – The primary sex glands



• Prostaglandins – Known to decrease blood pressure, cause

fever, increase hydrochloric acid secretion in the stomach, increase uterine contraction during pregnancy, and influence intestinal peristalsis


Hormonal Changes of Puberty • Adrenal gland secretes the hormones

that begin the development of secondary sexual characteristics

• In a man, the voice deepens and facial hair begins to grow

• In a woman, the breasts enlarge and fatty tissue is deposited around the hips

• In both men and women height and weight increase


Hormonal Changes of Pregnancy

• The placenta, or interfacing organ between the fetal and maternal circulation, produces a hormone called human chorionic gonadotropin (hCG)

• Increased estrogen and progesterone from the ovaries are maintained until the placenta begins to produce these hormones

• Progesterone increases the mobility of the pelvic and lower back bones to allow the birthing process

• The pituitary and thyroid glands increase in size, resulting in a higher metabolic rate


Hormonal Changes of Menopause • Menopause occurs following a decrease

in secretion of the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

• A decrease in the secretion of the hormone estrogen by the ovaries occurs

• Hot flashes, periods of feeling extreme heat, are the only universal symptom of menopause


Assessment Techniques

• Basal metabolic rate (BMR) • Protein-bound iodine (PBI) • Immunoassay• Radioiodine uptake (RAIU) studies• Glucose tolerance testing (GTT)


Disorders of the Endocrine System • Acromegaly

– An enlargement of the bones of the hands, feet, and jaws

• Addison's disease – Caused by hyposecretion of the hormones

produced by the cortex of the adrenal gland

• Cretinism – Condition resulting from a congenital

deficiency of thyroid secretion or hypothyroidism


Disorders of the Endocrine System (continued)

• Cushing’s syndrome – Disorder that causes hyperactivity of the

adrenal glands, which is triggered by the oversecretion of the pituitary hormone ACTH

• Diabetes insipidus– From an acquired or inherited decrease in the

antidiuretic hormone secreted by the pituitary

• Diabetes mellitus – A disorder of carbohydrate, fat, and protein

metabolism resulting from insufficient insulin production by the pancreas



• Dwarfism – Results from hyposecretion of the growth

hormone of the pituitary gland, which has been caused by a tumor, infection, genetic factors, or trauma

• Gigantism – An excessive growth of the long bones

caused by hypersecretion of the somatotropic hormone

• Graves’ disease – Caused by hyperthyroidism or thyrotoxicosis



• Hyperparathyroidism – Causes hypercalcemia, an increased

calcium blood level

• Hypoglycemia – Results from increased insulin production by

the pancreas

• Hypoparathyroidism – A decreased secretion of parathyroid

hormone that causes tetany



• Hypothyroidism– Also called Hashimoto's disease, results from

an insufficient production of thyroxine

• Syndrome of inappropriate antidiuretic hormone (SIAD) – Involves water intoxication and the dilution of

intracellular and extracellular body tissues, usually resulting from lung cancer

• Virilism – Results from increased secretion in the

adrenal glands


Issues and Innovations

• Steroid abuse– Causes problems for men such as stunted growth, liver tumors, and decreased sperm production– Causes problems for women such as loss of menstrual cycle and baldness

Copyright 2003 by Mosby, Inc. All rights reserved. CHAPTER 17 ENDOCRINE SYSTEM.

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Transcript of Copyright 2003 by Mosby, Inc. All rights reserved. CHAPTER 17 ENDOCRINE SYSTEM.