1. Chapter 32 Disorders of Endocrine Control of Growth and Metabolism

2. 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

3. Hormone Disorders
Tertiary: abnormality in stimulation from the hypothalamus
Secondary: abnormality in stimulation from the pituitary
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Primary: abnormality in the gland

4. Pituitary Hormones Growth ACTH FSH TSH hormone and LH stimulates
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Growth
ACTH
FSH
TSH
hormone
and LH
stimulates
stimulates
adrenal
stimulate
thyroid
cortex
gonads

5. Question Which hormone(s) is/are secreted by the ovaries and testes?GH
FSH & LH
TSH
ACTH & GH

6. Answer
FSH & LH
Gonads are sex organs (ovaries and testes). These organs secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

7. The Hypothalamus Controls Growth Hormone Release
GH secretion stimulated by:
Hypoglycemia, fasting, starvation
Stress
GH inhibited by:
Increased glucose levels, free fatty acid release, and obesity
Cortisol
GHRH
Somatostatin
stimulates
inhibits
Anterior pituitary
Growth
hormone

8. Functions of Growth Hormone

9. 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

10. Growth Hormone Excess
In childhood: gigantism
In adulthood: acromegaly

11. Question Tell whether the following statement is true or false:
GH deficiency may result in dwarfism.

12. Answer
True
Laron-type dwarfism is caused by a genetic inability to produce normal amounts of GH.

13. The Hypothalamus Controls Gonadal Hormone Release
Excessive GnRH secretion can be stimulated by:
Hypothalamus tumors
Pituitary tumors
Giving high levels of GnRH causes the pituitary to become less responsive and reduces the effects of abnormal GnRH secretion
GnRH
stimulates
anterior pituitary
FSH LH
production of gametes
and gonadal hormones

14. Thyroid Control Thyroid releases T3 and T4
Both are carried by binding proteins
T3 stimulates metabolism
T4 is inactive until converted into T3 in the tissues
Both exert negative feedback on the hypothalamus

15. 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

16. Thyroid Imbalances Hypothyroidism Congenital Acquired
Hashimoto thyroiditis
Thyroidectomy
Hyperthyroidism (thyrotoxicosis)
Graves disease
Thyroid tumors

17. Question Tell whether the following statement is true or false:
Simple goiter is caused by increased production of thyroid hormone.

18. Answer
False
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).

19. Major Adrenal Cortical Hormones

20. Actions of Cortisol cortisol catabolism increased plasma immune/
proteins
inflammatory
increased
systems
suppressed
muscle
breakdown
SNS response
increased
free fatty
acids
blood glucose
increased
increased

21. Adrenal Cortical Disorders
Adrenal cortical insufficiency: inability to make all 3 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

22. Clinical Manifestations of Addison Disease
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23. Clinical Manifestations of Cushing Syndrome

24. 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?

25. 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 pre- diabetic
Question
What hormones are being secreted by the pituitary tumors in these patients? Why?