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Essentials of Pathophysiology
CHAPTER 32
DISORDERS OF ENDOCRINE
FUNCTION
PRE LECTURE QUIZ TRUE/FALSE
Hypopituitarism is characterized by a decreased
secretion of pituitary hormones.
F  Hypothyroidism is evidenced by an increased
metabolic rate, restlessness, irritability,
tachycardia, diarrhea, and heat intolerance.
T  Primary adrenal insufficiency, or Addison
disease, is caused by destruction of the adrenal
gland.
T  Moon facies, buffalo hump, obesity,
amenorrhea, and increased facial hair are
manifestations of Cushing syndrome.
F  Addison disease is a temporary condition.
T 
PRE LECTURE QUIZ
Acromegaly
Cushing

In children, _____________ hormone deficiency
interferes with linear bone growth, resulting in short
stature or dwarfism.

When growth hormone excess occurs in adulthood or
after the epiphyses of the long bones have fused, the
condition is referred to as ______________.

Precocious ______________ is the early activation of the
hypothalamic-pituitary-gonadal axis, resulting in the
development of appropriate sexual characteristics and
fertility.

______________ disease is a state of hyperthyroidism
that is often accompanied by goiter and exophthalmos.

______________ syndrome refers to the manifestations
of excess cortisol.
Graves
growth
puberty
HYPOTHALAMUS- PITUITARY AXIS
Releasing
hormones from
hypothalamus tell
the pituitary what
to release into the
blood
 Trophic hormones
from the pituitary
tell specific
peripheral glands
to grow and
produce their
hormones

Releasing Hormones
Trophic Hormones
HORMONE DISORDERS
Tertiary: abnormality in
stimulation from the
hypothalamus
Secondary: abnormality
in stimulation from the
pituitary
Primary: abnormality in
the gland
PITUITARY
HORMONES
Growth
hormone
FSH
and LH
TSH
stimulate
gonads
stimulates
thyroid
ACTH
stimulates
adrenal
cortex
QUESTION
Which hormone(s) stimulate the ovaries and
testes?
a. GH
b. FSH and LH
c. TSH
d. ACTH and GH
ANSWER
FSH and LH
Rationale: Gonads are sex organs (ovaries and
testes). These organs are stimulated by folliclestimulating hormone (FSH) and luteinizing
hormone (LH).
b.
THE HYPOTHALAMUS CONTROLS GROWTH
HORMONE RELEASE


GH secretion
stimulated by:
Hypothalamus
 Hypoglycemia,
fasting,
starvation
 Stress
Next
Slide
GHRH
stimulates
Somatostatin GHIH
inhibits
GH inhibited by:
 Increased
glucose
levels, free fatty acid
release, and obesity
 Cortisol
Anterior pituitary
Growth
hormone
GROWTH HORMONE SITIMULATED BY ?






Hypoglycemia, fasting, starvation, Stress ??
It would seem that adequate energy supply would be
needed for Growth ?
A baseline level of GH exists during normal nutrition
mildly stimulated by Deep Sleep, Exercise, and Protein
Consumption. GH stimulates IGF-1
During fasting etc. and increased release of GH occurs
due to a decrease in GHIH.
This produces a protective effect preventing muscle
wasting by stimulating lipolysis and FFA metabolism
maintaing blood glucose for the CNS
Without GH significantly more muscle wasting occurs
FUNCTIONS OF GROWTH HORMONE
Promotes Growth
Inhibits Insulin
GROWTH HORMONE DEFICIENCY



Idiopathic GH deficiency
 Lacks hypothalamic GHRH
Pituitary tumors, agenesis of the pituitary
 Cannot produce GH
Laron-type dwarfism
 Hereditary defect in IGF production
GROWTH HORMONE EXCESS
 In
childhood: gigantism
 In
adulthood: acromegaly
QUESTION
Tell whether the following statement is true
or false.
GH deficiency may result in dwarfism.
ANSWER
True
Rationale: Laron-type dwarfism is caused by a
genetic inability to produce normal amounts of
GH. Not True. Normal GH abnormal IGF
THE HYPOTHALAMUS CONTROLS GONADAL
HORMONE RELEASE

Excessive GnRH
secretion can be
stimulated by:
Hypothalamic tumors
 Pituitary tumors


Giving high levels of
GnRH causes the
pituitary to become less
responsive and reduces
the effects of abnormal
GnRH secretion
hypothalamus
GnRH
stimulates
anterior pituitary
FSH
LH
production of gametes
and gonadal hormones
THYROID CONTROL
Thyroid releases T3
and T4
 Both are carried by
binding proteins Why?
 T3 stimulates
metabolism
 T4 is inactive until
converted into T3 in
the tissues
 Both exert negative
feedback on the
hypothalamus

THYROID INSUFFICIENCY DUE TO LACK OF I




T3 and T4 are
not made
There is no negative
feedback to the
hypothalamus
TRH and TSH continue to be
made
If it is able, the thyroid will
grow in response to the TSH
THYROID IMBALANCES

Hypothyroidism
 Congenital
 Acquired

º
Hashimoto thyroiditis
º
Thyroidectomy
Hyperthyroidism (thyrotoxicosis)
 Graves
disease
 Thyroid
tumors
QUESTION
Tell whether the following statement is true or
false.
Simple goiter is caused by increased production
of thyroid hormone.
ANSWER
False
Rationale: Simple goiter is the result of iodine (I)
insufficiency. Since I is necessary in order to
produce thyroid hormone, a deficiency results
in low serum levels of T3 /T4. This causes TSH
to stimulate the thyroid gland to make more
hormone (which it cannot do because it needs
I). The cells of the thyroid gland hypertrophy in
an effort to function (make thyroid hormone).
MAJOR ADRENAL CORTICAL HORMONES
• Cortisol
• What can cause Cortisol
Stimulation?
• Hypothalamus releases
??
• Causes the Anterior
Pituitary to release ??
• Causes the adrenal cortex
to release ??
MAJOR ADRENAL CORTICAL HORMONES
Hypothalamus
Corticotropin-releasing
hormone (CRH)
Negative
feedback
Negative
feedback
Anterior pituitary
Adrenal corticotrophic
hormone (ACTH)
Adrenal
cortex
Cortisol
Testosterone
Aldosterone
ACTIONS OF CORTISOL
cortisol
Increases catabolism
plasma
proteins
increased
muscle
breakdown
free fatty
acids
increased
immune/
inflammatory
systems
suppressed
SNS response
increased
blood glucose
increased
ADRENAL CORTICAL DISORDERS



Adrenal cortical insufficiency: inability to make all
three hormones
 Primary adrenal cortical insufficiency (Addison
disease)
 Secondary adrenal cortical insufficiency
 Acute adrenal crisis
Excessive adrenal secretion
 Glucocorticoid hormone excess (Cushing
syndrome)
 Hyperaldosteronism
Congenital adrenal hyperplasia
 Decreased cortisol synthesis; other hormones may
be increased or decreased
CLINICAL MANIFESTATIONS OF ADDISON
DISEASE (CHRONIC ADRENAL INSUFFICIENCY)
CLINICAL MANIFESTATIONS OF CUSHING
SYNDROME (HIGH LEVELS OF CORTISOL IN THE BLOOD)
SCENARIO
Three men have adrenal problems.
 One has hypoaldosteronism, one has an inability
to make cortisol, and one has an inability to
make testosterone.
Question:
 Which of them is most likely to develop:
 Hypotension?
 High CRH levels?
 Hypoglycemia?
 Hypervirilization?
 Decreased libido?
 Hyperkalemia?
SCENARIO
Two women have benign pituitary tumors.
 One woman has lost weight and complains of
being hot all the time; she presents as thin
and nervous, with tachycardia and
exophthalmos
 The second woman has gained weight in her
abdomen and presents with a round face
and thin arms and legs with stretch marks;
she says that at her last checkup her doctor
told her she was prediabetic
Question:
 What hormones are being secreted by the
pituitary tumors in these patients? Why?