1. Chapter 20
The Endocrine Glands

2. Endocrine Functions and Dysfunctions
Endocrine glands release hormones directly into the blood to regulate various metabolic functions
The major endocrine glands
Pituitary
Thyroid
Parathyroid
Adrenal cortex and medulla
Pancreatic islets
Ovaries and testes

3. Endocrine Functions and Dysfunctions
Feedback mechanisms
The amount of hormone synthesized and released by a gland may be regulated:
Directly:
Indirectly:
Negative feedback systems are most commonly used
An increase in hormone or hormone-regulated substance leads to:

4. Pituitary Gland Suspended by stalk from hypothalamus at base of brain
Composed of:
Anterior lobe:
Growth hormone:
Prolactin:
Thyroid-stimulating hormone (TSH):
Adrenocorticotrophic hormone (ACTH):
Follicle-stimulating hormone (FSH):
Luteinizing hormone (LH):
Posterior lobe:
Antidiuretic hormone (ADH):
Oxytocin:

6. Pituitary Gland

7. Normal mechanisms controlling elaboration of tropic hormones by the pituitary gland

8. Pituitary Hypofunction
Panhypopituitarism is a condition in which the:
Leads to impaired function of:
Pituitary dwarfism is a condition that occurs when a child has a deficiency of:
Causes:

9. Pituitary Hypofunction
Diabetes insipidus is a disease caused by failure of the:
Can be caused by:
Unable to absorb:
Causes excretion of:
Person will compensate by:

10. Pituitary Tumors
Many pituitary endocrine disturbances caused by anterior lobe pituitary tumors
Functional tumors:
Clinical manifestations depend on:
Nonfunctional tumors:
May encroach on important surrounding structures
Treatment determined by type, size, and hormone produced by tumor
Drugs to suppress tumor growth
Surgical resection: usual surgical approach is through the nasal cavity

11. Pituitary Tumors Growth hormone overproduction caused by a tumor
Causes excessive growth in length of bones at growth plate (epiphyses) in children which is called:
The effected person will become too tall
Causes thickening of bones and enlargement of viscera in adults which is called:
Does not alter height since epiphyses are closed
Prolactin overproduction caused by a tumor
Causes:
galactorrhea:
Amenorrhea:

12. Acromegaly Gigantism
Fig.20-3

13. Thyroid Gland Found in the neck overlying the upper section of trachea
Consists of two lateral lobes connected by a narrow isthmus
Composed of thyroid follicles that produce and store thyroid hormone
Hormone production regulated by:
Actions
Controls rate of:
Required for normal:

14. Thyroid Gland

15. Normal thyroid gland, illustrating two lateral lobes connected by narrow isthmus
Fig. 20-4

16. Thyroid Gland Hyperthyroidism: Hypothyroidism: Hyperthyroidism
Rapid pulse
Slow pulse
Increased metabolism
Decreased metabolism
Hyperactive reflexes
Sluggish reflexes
Emotional
Placid
GI effect: diarrhea
GI effect: constipation
Warm, moist skin
Cold, dry skin

17. Nontoxic Goiter Thyroid gland enlarges to increase hormone secretion
Caused by inadequate secretion of:
3 major factors predispose
Iodine deficiency
Iron is needed to:
Enzyme deficiency or impaired enzyme function
Enzyme is needed to:
Increased hormone requirements
Treatment: administer thyroid hormone; may need surgical removal

18. The pathogenesis of nontoxic goiter
Fig. 20-5

19. Toxic Goiter/Hyperthyroidism
Excess secretion of:
Usually caused by an autoimmune disease in which autoantibodies target cells of the:
Autoantibodies bind to TSH receptors and cause:
Normal control mechanisms are lost
This condition is also called:
Treatment
Antithyroid drugs, thyroidectomy, large doses of radioactive iodine

20. Toxic Goiter Large nodular goiter
Fig. 20-7
Fig. 20-6

21. Hypothyroidism In adult In an infant
Individuals have low levels of: & high levels of:
Causes slowing of:
Treatment:
In an infant
May be caused by:
Failure of the thyroid gland to:
Deficiency of enzymes needed for:
If left untreated will cause perm stunting of growth and mental retardation which is called:
All newborn infants are screened
Early diagnosis and treatment required for normal development

22. Chronic Thyroiditis Preferably referred to as:
Immune system develops autoantibodies that destroy:
Results in hypothyroidism
Cant stop disease progression of disease but can give thyroid hormone

23. Parathyroid Glands
Blood calcium levels are in equilibrium with calcium in bones
Adequate blood calcium levels are needed for normal cardiac & skeletal muscle contraction, nerve impulse transmission, & blood clotting
Parathyroid hormone regulates calcium levels by:
Regulating the release of calcium from:
Absorption of calcium in the:
Excretion of calcium by the:

24. Hyperparathyroidism Increased levels of parathyroid hormone
Usually from a hormone-secreting parathyroid tumor
Increased output of hormone causes:
Hypercalcemia:
Excessive calcium is withdrawn from:
Bones become:
Excessive calcium excreted in urine
Treatment:

25. Hypoparathyroidism Decreased levels of parathyroid hormone
Usually from accidental removal of parathyroid glands during thyroid surgery
Decreased output of hormone causes:
Hypocalcemia:
Leads to neuromuscular:
Treatment: raise calcium levels
High-calcium diet
Supplementary vitamin D

26. Adrenal Gland Adrenals: paired glands above kidneys
Consists of an inner medulla and outer cortex
Each region secretes different hormones

27. Adrenal Cortex Secretes 3 major classes of hormones Glucocorticoids
Raise blood glucose by
Promoting glucose utilization in tissues
Promoting fat and protein breakdown
Suppress inflammation
Major hormone is:
Mineralocorticoids
Regulate electrolyte & water balance by promoting absorption of sodium & water, & excretion of potassium in the kidneys
Sex hormones
Produce small amounts of estrogen & testosterone in males and females

28. Addison Disease Addison Disease occurs with:
Results from:
Most cases are caused by an:
Glucocorticoid (cortisol) deficiency results in:
Mineralocorticoid deficiency results in an inability to regulate:
Sodium concentration of the blood falls as well as:
Treat by administering deficient hormones

29. Cushing Disease and Syndrome
Glucocorticoid excess causes:
Blood glucose:
Protein synthesis is impaired & proteins are:
Leads to:
Fat accumulates on trunk & extremities appear:
Skin becomes thin and easily:
Face appears full & round which is referred to as:
Mineralocorticoid excess leads to increase in:

30. Cushing’s disease before treatment.
Fig

31. Adrenal Medulla
Produces catecholamines that stimulate the sympathetic nervous system
Norepinephrine (noradrenaline)
Epinephrine (adrenaline)
Pheochromocytoma is a tumor that secretes large amounts of:
Produces high blood pressure (hypertension) & increased heart rate
May cause cerebral hemorrhage from:
Symptoms may come and go or may be continuous
Treatment:

32. Pancreatic Islets
Diabetes Mellitus was discussed in Chapter 16

33. Gonads Two functions Tumors may secrete hormones
Production of germ cells
Production of sex hormones: controlled by gonadotropic hormones of pituitary gland FSH and LH
Tumors may secrete hormones
Treatment: surgical excision

34. ??Questions??