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Urinary System Diseases and Disorders 277
Summary
T
he urinary system includes the kidneys, ureters, bladder, and urethra. This system maintains homeostasis in
the body by excreting and reabsorbing important electrolytes, compounds, and water. Urinary disorders range
from mild infections to very serious diseases such as cancer. The most common signs and symptoms of urinary
dysfunction include an abnormality in the urine or in the individual’s ability to urinate. The most common dis
orders of the urinary system include infections and incontinence.
Some diseases are diagnosed by urinalysis or urine culture and sensitivity, but radiologic examinations are also
used. A cystoscopy can be performed for diagnostic or treatment purposes. In the older adult, urinary incontinence
is the most frequent problem of the system. Urinary disorders can be the result of urinary system pathology or of
disease or malfunction of other body systems.
Review Questions
Short Answer
1. What are the functions of the urinary system?
2. Which signs and symptoms are associated with common urinary system disorders?
3. Which diagnostic tests are most commonly used to determine the type and cause of urinary system disorders?
4. What is the most common urinary problem in the older adult population?
Matching
5. Match the disorders listed in the left column with the correct definition in the right column:
_____ Urethritis a. Most commonly used diagnostic test for urinary system disorders
_____ Pyuria b. Pus in the urine
_____ Oliguria c. An inflammation of the filtering components of the kidney
_____ Anuria d. Difficulty urinating
_____ Nocturia e. Excision of the kidney
_____ Cystectomy f. Inflammation of the urethra
_____ Dysuria g. Frequent urination at night
_____ Nephrectomy h. Surgical removal of the bladder
_____ Urinalysis i. Scanty urine output
_____ Pyelonephritis j. Absence of urine output
_____ Glomerulonephritis k. Inflammation of the kidney pelvis
278 Chapter 13
Case Studies
■ Ms. Hayden, age 55, has been noticing a small amount of urine leakage at intervals when she participates
in her low-impact aerobics class. She has noticed this problem for about a year now, but thinks it is nothing to
worry about. She tells you that this occurs every time she does aerobics and asks what you think the cause might
be. She is also embarrassed to ask her physician about it. How would you respond to Ms. Hayden? Do you
think this is a problem for concern? Should she seek medical advice?
■ Jeremy is a 30-year-old truck driver who has had several episodes of kidney stones. Although he states the
episodes are extremely painful, he has been able to pass the stones each time he has been afflicted and has not
had to have surgery or lithotripsy treatment. He asks you how he might be able to prevent kidney stones from
developing in the future. Are there some lifestyle interventions he can institute to prevent the recurrence of kidney
stones? What would you tell him? Where could he find additional information about this?
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14
Endocrine
System Diseases
and Disorders
Key Terms
Acromegaly (p. 284)
Adenoma (p. 287)
Aldosterone (p. 290)
Amenorrhea (p. 291)
Androgens (p. 282)
Cortisol (p. 282)
Cortisone (p. 290)
Cretinism (p. 288)
Diabetic retinopathy
(p. 296)
Dwarfism (p. 285)
Estrogen (p. 282)
Exophthalmos (p. 287)
Giantism (p. 284)
Glucagon (p. 282)
Glucocorticoids (p. 290)
Glycogen (p. 293)
Glycosuria (p. 294)
Goiter (p. 287)
Goitrogenic (p. 288)
Gonad (p. 298)
Gynecomastia (p. 291)
Hirsutism (p. 291)
Hydrocortisone (p. 290)
Hyperglycemia (p. 294)
Hypoglycemia (p. 292)
Insulin (p. 282)
Islets of Langerhans
(p. 292)
Ketoacidosis (p. 293)
Ketones (p. 293)
Lipids (p. 296)
Mineralocorticoids
(p. 282)
Myxedema (p. 288)
Panhypopituitarism
(p. 286)
Polydipsia (p. 286)
Polyuria (p. 286)
Precocious (p. 291)
Progesterone (p. 282)
Sex hormones (p. 290)
Striae (p. 291)
Tetany (p. 289)
Thyroid storm (p. 287)
Vasopressin (p. 282)
Virilism (p. 291)
Learning Objectives
Upon completion of the chapter, the learner should be able to:
1. Define the terminology common to the endocrine
system and the disorders of the system.
2. Discuss the basic anatomy and physiology of the
endocrine system.
3. Identify the important signs and symptoms
associated with common endocrine system
disorders.
4. Describe the common diagnostics used to
determine the type and cause of endocrine system
disorders.
5. Identify common disorders of the endocrine
system.
6. Describe the typical course and management of
the common endocrine system disorders.
7. Describe the effects of aging on the endocrine
system and the common disorders associated with
aging of the system.
279
280 Chapter 14
Overview
T
he endocrine system is a highly complex system of glands that secrete important hormones for a variety
of body functions. The glands of the system work in harmony, discharging the hormones into the
bloodstream as needed. The disorders of the system can be caused by problems in the primary gland or in
another gland whose secretions control the primary gland. Disorders of the endocrine system can be related
to oversecretion or undersecretion of the gland’s hormones. ■
Anatomy and Physiology
The endocrine system consists of many glands located
throughout the body (Figure 14-1). It includes the fol
lowing glands:
1. Hypothalamus—located beneath the thalamus
in the area of the third ventricle of the brain
2. Pituitary or hypophysis—located at the base of
the brain
3. Pineal—located behind the midbrain
4. Thymus—located in the mediastinal cavity
under the sternum, near the heart
5. Thyroid—located in the neck on each side of
the trachea
6. Parathyroids—usually four glands, embedded
in the posterior part of the thyroid
7. Adrenals—two glands, one on top of each kidney
8. Pancreatic islets—embedded in the pancreas
9. Ovaries (female) and testes (male)—one ovary
on each side of the uterus and one testis in each
side of the scrotal sac
Each of these glands has a unique function and
delivers its secretion as needed into the bloodstream.
Table 14-1 lists the glands, their hormones, and the
functions of each hormone. The mechanism known
as negative feedback controls the amount of hormones
secreted into the bloodstream. Although the hypo
thalamus monitors the hormone secretions, negative
feedback regulates the amount secreted. In the nega
tive feedback system, levels of the particular hormone
in the bloodstream trigger the release of the hormone
as needed. If the concentration of the hormone in the
blood is low, the sequence of events stimulates the gland
HUMAN ENDOCRINE SYSTEM
Figure 14-1 The endocrine system.
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Endocrine System Diseases and Disorders 281
TABLE 14-1 The Endocrine Glands: Their Hormones and Hormone Functions
Endocrine Gland Hormone Hormone Function
Hypothalamus Inhibiting hormones and releasing
hormones
Inhibits or releases hormones from the anterior
pituitary
Hypophysis (Pituitary)
Adenohypophysis
Thyrotropin hormone (TSH)
Stimulates release of thyroid gland hormones
(Anterior Pituitary)
Adrenocorticotropin hormone (ACTH)
Somatotropin hormone (STH)
Melanocyte-stimulating hormone (MSH)
Lactogenic hormone (prolactin)
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH; also called inter
stitial cell-stimulating hormone, ICSH)
Stimulates release of adrenal cortex hormones
Stimulates growth
Stimulates melanin production
Stimulates mammary glands and lactation
Induces ovulation in females and testosterone
secretion in males
Stimulates estrogen production in females and
testosterone production in males
Neurohypophysis
(Posterior Pituitary)
Antidiuretic hormone (ADH)
Oxytocin
Increases reabsorption of water in the distal tubules
of the kidneys
Stimulates uterine contraction and the initiation
of breast milk flow in females and increases the
ejection of sperm into the seminal fluid in males
Pineal Melatonin Affects circadian rhythms
Thymus Thymopoietin Causes immune response development in the
newborn and maintains it in the adult
Thyroid Triiodothyronine (T3)
Thyroxine (T
4
)
Calcitonin
Stimulates growth and development
Regulates metabolism
Increases calcium deposits into the bones
Parathyroid Parathormone (PTH) Regulates calcium and phosphate levels and
increases reabsorption of calcium from the bones
Adrenals
Adrenal Cortex Glucocorticoids
Mineralocorticoids
Sex hormones
Affect stress reactions; promote protein and fat use
to raise blood sugar; affect sodium and water
reabsorption
Promote sodium and water reabsorption
Develop secondary sex characteristics
Adrenal Medulla Epinephrine
Norepinephrine
Fight or flight response
Increases blood pressure and metabolism
Causes vasoconstriction and increases blood pressure
Pancreas Islets
Alpha Cells Glucagon Increases blood glucose levels and is
counterregulatory to insulin
Beta Cells Insulin Regulates protein, carbohydrate, and fat metabolism
Delta Cells Somatostatin Counterregulatory to insulin, glucagon, and
somatotropin (STH)
Ovaries Estrogen
Progesterone
Regulate development, maturation, secondary
sex characteristics, and the reproductive cycle
in females
Testes Testosterone Regulates growth and development, maturation,
secondary sex characteristics, and the
reproductive system in males
282 Chapter 14
to secrete more hormones. In like manner, if the con
centration of the hormone in the blood is higher than
normal, the feedback mechanism triggers the gland to
suppress the release of more hormones.
The hypothalamus, located in the third ventricle
area of the brain, contains neurosecretory cells that
secrete hypothalamic hormones. These hormones reg
ulate the function of the anterior pituitary gland. The
hypothalamus also produces the two hormones stored
in the neurohypophysis or posterior pituitary gland.
The pituitary gland, also known as the hypophy
sis gland, is divided into two distinct parts. The ade
nohypophysis, or anterior part of the gland, produces
several hormones that affect other endocrine glands.
These include adrenocorticotropin hormone (ACTH),
thyrotropin hormone (TSH), somatotropin hormone
(STH), melanocyte-stimulating hormone (MSH), lac
togenic hormone (prolactin), follicle-stimulating hor
mone (FSH), and luteinizing hormone (LH; also called
interstitial cell-stimulating hormone, ICSH).
The posterior pituitary, also called the neurohy
pophysis, stores two hormones that are secreted by
the hypothalamus. Oxytocin (Pitocin) helps the prog
ress of labor in the pregnant female and causes uter
ine contractions after childbirth. It also affects the cells
in the breasts, causing a release of milk during lacta
tion. Antidiuretic hormone (ADH), also known as
vasopressin, is also released from the neurohypophy
sis. It affects the reabsorption of water from the renal
tubules.
The pineal gland, located behind the midbrain,
secretes melatonin. It might also secrete other hor
mones that interact with the hypothalamus and the
pituitary gland to cause the secretion of hormones from
other glands.
The thymus gland, located just below the clavicle
behind the sternum, secretes thymopoietin, a hormone
that stimulates the development of lymphocytes. Lym
phocytes are important for immunity development and
prevention of infections.
The thyroid gland, located in the neck on either side
of the trachea, secretes thyroxine (T
4
), triiodothyronine
(T
3
), and calcitonin. These hormones are released as
needed in response to the thyroid-stimulating hormone
secreted by the pituitary gland. T
4
and T
3
increase met
abolic activity. Calcitonin affects the regulation of cal
cium and works in opposition to the hormone secreted
by the parathyroid gland.
Embedded in the posterior part of the thyroid gland
are the parathyroid glands. There are usually four of
these, but there can be more. The parathyroid glands
secrete parathormone, important in the regulation of
calcium and phosphorus in the body.
The adrenal glands, located on top of each kid
ney, have two distinct parts. The cortex, the outer part,
secretes mineralocorticoids, glucocorticoids, and
androgens. The mineralocorticoids promote sodium
retention. The glucocorticoids affect the metabolism of
protein, glucose, and fats. Cortisol is the main gluco
corticoid and is important for metabolism of carbohy
drates. The androgens enhance masculinization. The
most common androgen hormone is testosterone. The
adrenal medulla or middle section secretes epinephrine
and norepinephrine.
The beta cells located in the pancreas secrete insulin,
another important hormone. Insulin is most important
in the metabolism of glucose, but it also promotes fatty
acid synthesis and amino acid entry into cells. Insulin
secretion is regulated by the feedback mechanism and
by counterregulatory hormones such as glucagon, cor
tisol, epinephrine, and the growth hormone.
The ovaries and testes secrete the sex hormones,
as they are commonly known. The ovaries secrete
estrogen and progesterone, important for develop
ment and maturation and maintaining the functions of
the reproductive system. The testes secrete testosterone,
important for growth and development, secondary sex
characteristics, and maintaining the reproductive sys
tem functions. See Chapter 17, “Reproductive System
Diseases and Disorders,” for more information about
the reproductive system.
Consider This...
There are about 30 hormones in our body
being produced by the various glands of
the endocrine system.
Common Signs and Symptoms
Most endocrine disorders are due to hypo- or hyperse
cretion by a gland; diagnosis depends on matching the
signs and symptoms with the hormone dysfunction. The
difficulty in diagnosing endocrine disorders is related
to tracking the problem to the correct source. For
instance, a pituitary dysfunction can easily lead to signs
and symptoms of multiple gland disorders; a decreased
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Endocrine System Diseases and Disorders 283
secretion of thyroid-stimulating hormone from the pitu
itary might initially lead one to believe that the thyroid
gland itself is dysfunctional. Some common signs and
symptoms of endocrine system disorders include mental
abnormalities, lethargy or fatigue, and tissue atrophy.
Diagnostic Tests
The only endocrine glands that can be physi
cally examined are the thyroid glands and testes;
enlargement or atrophy of these glands can be felt,
and severe enlargement can be seen. Assessment
of proper function of the endocrine organs can be
accomplished with blood or urine testing for the hor
mones they produce. Blood glucose and hemoglobin
A1C (HbA1C) are used to diagnose diabetes melli-
tus and to monitor the progression of the disease.
Computerized tomography (CT), magnetic reso
nance imaging (MRI), positron emission test (PET),
radioactive iodine (RAI), and sestamibi scans can be
used to check for presence of tumors or alteration
in organ size. Fine needle aspiration can be done to
Pharmacology
Common Drugs for Endocrine Disorders
■ ■ ■ Bill ^^1 f
Highlight
Category Examples of Medications
Antidiabetics (also known as hypoglycemic or antihyperglycemic agents)
Drugs used to treat diabetes
Alpha-glucosidase inhibitors Acarbose or miglitol
Biguanides Metformin and combinations of metformin with
other medications
Hormones Insulin (many types; short acting, rapid acting,
intermediate acting, and long acting)
Peptide analogs Albiglutide, dulaglutide, exenatide, or liraglutide
Thioglitazones Pioglitazone, rosiglitazone, or troglitazone
Sulfonylureas Chlorpropamide, glipizide, glyburide,
tolazamide, or tolbutamide
Dipeptidyl peptidase-4 inhibitors Alogliptin, linagliptin, saxagliptin, or sitagliptin
Meglitinides Repaglinide
Other types Acarbose, bromocriptine, miglitrol, or
pramlintide
Hormones
Drugs used to treat low hormone
levels or other types of endocrine
disorders
Hydrocortisone, fludrocortisone, prednisone,
prednisolone, triamcinolone, methimazole,
levothyroxine, oxytocin, pramlintide, premarin,
progesterone, testosterone, desmopressin, or
vasopressin
Hormone agonists Estrogen: leuprorelin, megestrol acetate,
and polyestradiol-depending on the specific
disorder
Hormone antagonists Anti-estrogens: tamoxifen or reloxifene
Anti-androgens: flutamide
Enzyme inhibitor: anastrozole
Anti-cancer agents Varies significantly with the location of the
cancer
284 Chapter 14
evaluate a thyroid nodule. Endoscopic ultrasound
can be done by inserting an ultrasound probe into
the stomach and duodenum to visualize the pancre
atic tumors.
Common Diseases of the
Endocrine System
Endocrine diseases are the result of abnormally high or
low hormone secretion by endocrine glands. Abnormal
secretion might be due to the size of the gland: abnor
mally large or hypertrophied glands tend to produce
abnormally high hormone levels, whereas abnormally
small or atrophied glands tend to produce abnormally
low levels. Abnormal gland size can be the result of
injury to the gland by surgery, trauma, infection, or
radiation. Abnormal function of endocrine glands leads
to many physical and mental abnormalities. Abnor
malities vary with the amount of hormone secreted
(hypersecretion or hyposecretion) and the age of the
individual involved.
Consider This...
1
The physician specialist of the endocrine
system is called an endocrinologist.
Pituitary Gland Diseases
The anterior pituitary gland produces tropic (going
toward or changing) hormones. These hormones
stimulate target organs to grow or produce specific
hormones. Growth hormone (GH or somatotropin)
promotes growth and development of all body tissues.
Other target organs are the thyroid, adrenal gland, tes
tes, and ovaries.
The posterior pituitary gland produces ADH and
oxytocin. Diseases of the posterior gland are rare.
One worth mentioning is the syndrome of inap
propriate antidiuretic hormone secretion (SIADH).
It is usually related to head trauma, brain tumors,
or stroke and is characterized by excessive release
of ADH, resulting in water retention and elevated
sodium levels.
Hyperpituitarism
■ Description. Hyperpituitarism is an abnormal
increase in the activity of the pituitary gland. This over
secretion especially affects GH production, leading to
excessive growth of bones and tissues.
■ Etiology. The most common cause is benign pituitary
tumors, which lead to excessive secretion of the adeno-
hypophyseal trophic hormones. Carcinoid tumors can
also cause hyperpituitarism. This condition often affects
other areas controlled by the pituitary such as thyroid
and prolactin hormones.
■ Symptoms. If hyperpituitarism occurs before puberty,
giantism occurs (Figure 14-2). Children affected with
hyperpituitarism can grow as much as 6 inches in a year.
Sexual development is usually slowed; mental develop
ment might be average or slowed.
If hyperpituitarism occurs in an adult, acromegaly
(ACK-roh-MEG-ah-lee; acro = extremity, megaly =
Figure 14-2 (A) Giantism as demonstrated by 7 feet 6 inches basketball player Yao Ming compared to a dwarf individual
(dwarfism). (B) Dwarfism.
© Nolte Lourens/Shutterstock.com
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Endocrine System Diseases and Disorders 285
enlargement) occurs: the long bones are unable to
grow in length, but the small bones of the hands, feet,
and face enlarge. Common symptoms include large,
doughy hands and large feet. Abnormal facial fea
tures include enlarged jaw with widely spaced teeth,
tongue enlargement leading to slurred speech, large
forehead, and oily, tough skin with skin pigmentation
changes—darker or lighter. Females can also have
excessive hair growth.
Acromegaly is a chronic, disfiguring disease that
usually shortens life expectancy and often leads to con
gestive heart failure and respiratory and cerebrovascu
lar diseases.
■ Diagnosis. Diagnosis is made through examination
of physical characteristics of abnormal or excessive
growth in children and acromegaly in adults. Blood
testing reveals high levels of GH, thyroid, and prolactin.
MRI often reveals a pituitary tumor.
■ Treatment. In children, microsurgical removal, radi
ation, and drug therapy can decrease the secretion of
GH and slow the growing process. Prognosis for giant
ism is usually good. In adults, surgical removal of pitu
itary tumors often leads to hypo-pituitarism, and these
tumors tend to recur.
■ Prevention. There is no known prevention for hyper
pituitarism except to prevent injury or trauma to the
gland.
Hypopituitarism
■ Description. Hypopituitarism is an abnormal decrease
in the activity of the pituitary gland, leading to a defi
ciency or absence of any or all of the tropic hormones.
■ Etiology. A common cause is a tumor on the pitu
itary gland. As the tumor increases in size, damage to
the gland interferes with hormone production. Other
diseases and traumas can also damage the pituitary,
including radiation treatments, head injuries, stroke,
brain surgery, brain tumors, and infection.
■ Symptoms. Because the pituitary gland is the master
gland, hypopituitarism can lead to a variety of problems
involving the function of all target organs (Figure 14-3).
GH and gonadotropin are the most common deficien
cies in hypopituitarism. The degree of hypopituitarism
can range from mild to severe.
A decrease in growth hormone leads to impaired
growth of all body tissues with the most severe decreases
causing dwarfism (Figure 14-2). Children affected
with dwarfism are proportionately small and underde
veloped sexually and might or might not suffer from
mental challenges. Gonadotropin deficiency can lead to
abnormal development or absence of secondary sexual
characteristics.
In women, this deficiency can cause amenorrhea
and infertility. Men might have a lowered testosterone
Pituitary
Decreased growth hormone (GH)
Decreased adrenocorticotropic
hormone (ACTH)
Decreased thyroid stimulating
hormone
Affects all body tissues
Thyroid
Leads to impaired growth
and dwarfism
Adrenal gland
Affects adrenal glands
Decreased gonadotropin
hormones (FSH, LH)
Testis
Ovary
Affects testes and ovaries
Affects thyroid
I
Leads to decreased
metabolic rate
Leads to altered metabolism
and sexual abnormalities
Leads to sexual dysfunction
Figure 14-3 Effects of hypopituitarism.
286 Chapter 14
level, decreased libido (la-BE-doe; sex drive), and
abnormal loss of facial and body hair. A decrease in
ACTH and TSH can lead to metabolic disorders.
If the pituitary gland is destroyed or nonfunctional,
a condition called panhypopituitarism (pan = all,
hypo = decreased) exists and can lead to all the preced
ing disorders and result in fatal complications.
■ Diagnosis. Diagnosis and area of dysfunction can be
confirmed by clinical history and blood testing. The
dysfunction could involve the pituitary, the individual
target organ, or both. Specific blood hormone tests to
determine pituitary function can include each tropic
hormone (GH, TSH, FSH, LH, and ACTH). Target
organ function can be assessed by testing blood levels
of each individual organ hormone (T
3
, T
4
, estrogen,
progesterone, testosterone, and cortisol).
■ Treatment. Treatment of hypopituitarism involves
hormone replacement of needed hormones. Constant
monitoring and adjusting of hormone levels are needed
for optimum results.
■ Prevention. There is no known prevention for hyper
pituitarism except to prevent injury or trauma to the
■ Description. Diabetes is a general term meaning
“passing through,” and describes a variety of disorders
characterized by polyuria (POL-ee-YOU-ree-ah; poly =
many, uria = urine), excessive urination. There are sev
eral types of diabetes, but diabetes mellitus, a disorder
of the pancreas, is the disease most often thought of as
diabetes. Diabetes mellitus and gestational diabetes will
be discussed later in the chapter.
DI is a disorder characterized by severe thirst and
polyuria. There are two types of insipidus, depending
on the cause, central DI (pituitary related) and nephro
genic DI (kidney related).
■ Etiology. Central DI is caused by a decrease in the
release of vasopressin, or ADH, by the posterior portion
of the pituitary gland. The cause is damage to the pitu
itary gland by tumor, surgery, traumatic head injury, or
infection.
Nephrogenic DI occurs when there is a defect in
the kidney tubules, which eventually makes the kidney
unable to respond to ADH. The defect can be an inher
ited (genetic) disorder or related to chronic kidney dis
ease or kidney damage caused by certain medications.
In many cases, the cause is unknown.
■ Symptoms. Without antidiuretic (anti = against, di =
run through, uri = urine) hormone, the individual has
excessive polyuria and might urinate between 2 and
15 gallons of urine in 24 hours. The urine quality is col
orless and dilute. The individual experiences excessive
polydipsia (POL-ee-DIP-see-ah; poly = many, dipsia =
thirst or drinking) in an effort to overcome dehydra
tion. Other symptoms include hypotension, dizziness,
and constipation.
■ Diagnosis. Testing for DI includes a urinalysis and a
water restriction test. The urinalysis of an affected indi
vidual will show colorless urine with a very low specific
gravity. The water restriction test includes limiting the
suspected individual’s water intake for several hours
while measuring the urine output, blood pressure, and
urine concentration. After several hours, the individ
ual is given vasopressin medication. If the medication
decreases urine output and increases urine concentra
tion, the diagnosis of DI is confirmed. MRI of the kid
ney and pituitary gland assists in locating the cause.
■ Treatment. Central DI can be controlled with vaso
pressin administered as either a nasal spray or as tablets.
Nephrogenic DI is treated with fluid intake to match
urine output and drugs that lower urine output. Prog
nosis is generally good.
■ Prevention. Many cases might not be preventable.
Prompt treatment of infections, injuries, and tumors
can reduce risk, however.
Thyroid Gland Diseases
The activity of the thyroid gland affects the entire body.
The hormone released by the thyroid gland (T
4
) regu
lates metabolism, the rate at which calories are used. In
this way, T
4
also regulates body heat, ensuring that the
body is kept warm even in a cold environment. T
4
also
stimulates the gastrointestinal system by increasing gas
tric secretions and peristalsis. To make T
4
, the thyroid
gland requires iodine. Diseases of the thyroid gland are
primarily those of hypersecretion and hyposecretion.
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