Transcript ENDOCRINE SYSTEM

CHAPTER 17
ENDOCRINE SYSTEM
Copyright 2003 by Mosby, Inc. All
rights reserved.
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
Copyright 2003 by Mosby, Inc. All
rights reserved.
Figure 17-1 Endocrine
System
Copyright 2003 by Mosby, Inc. All
rights reserved.
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
Copyright 2003 by Mosby, Inc. All
rights reserved.
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
Copyright 2003 by Mosby, Inc. All
rights reserved.
Glands and Their Hormones
(continued)
• 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
Copyright 2003 by Mosby, Inc. All
rights reserved.
Glands and Their Hormones
(continued)
• Prostaglandins
– Known to decrease blood pressure, cause fever,
increase hydrochloric acid secretion in the
stomach, increase uterine contraction during
pregnancy, and influence intestinal peristalsis
Copyright 2003 by Mosby, Inc. All
rights reserved.
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
Copyright 2003 by Mosby, Inc. All
rights reserved.
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
Copyright 2003 by Mosby, Inc. All
rights reserved.
Hormonal Changes of
Menopause
• Menopause occurs following a decrease in
secretion of the gonadotropins folliclestimulating 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
Copyright 2003 by Mosby, Inc. All
rights reserved.
Assessment Techniques
•
•
•
•
•
Basal metabolic rate (BMR)
Protein-bound iodine (PBI)
Immunoassay
Radioiodine uptake (RAIU) studies
Glucose tolerance testing (GTT)
Copyright 2003 by Mosby, Inc. All
rights reserved.
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
Copyright 2003 by Mosby, Inc. All
rights reserved.
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
Copyright 2003 by Mosby, Inc. All
rights reserved.
Disorders of the Endocrine
System (continued)
• 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
Copyright 2003 by Mosby, Inc. All
rights reserved.
Disorders of the Endocrine
System (continued)
• 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
Copyright 2003 by Mosby, Inc. All
rights reserved.
Disorders of the Endocrine
System (continued)
• 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
Copyright 2003 by Mosby, Inc. All
rights reserved.
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.