NURS 5315 / NURS5315 Patho Endocrine Module 8 GRADED A+

Endocrine
Module 8

Endocrine Anatomy and Physiology
Analyze the anatomy and physiology of the endocrine system:
1. Examine the production and action of hormones produced by the thyroid,
pancreas, and adrenal glands.

 Thyroid: (pg. 701-702)
o Thyroxine (T4) ~90% & Triiodothyronine (T3) ~10%:
 Controlled by TSH (from anterior pituitary) and released in
response to metabolic demand
 Influences (based on amount secreted):
 Gender
 Pregnancy
 Gonadal and adrenocortical-increased steroids (Increases
levels),
 Exposure to extreme cold (Increases levels)
 Nutritional state
 Dopamine (Decreases levels)
 Chemicals
 Catecholamines (Increases levels)
 Growth Hormone-Inhibiting Hormone (Decreases levels)
 Functions:
 Regulates metabolic rate of all cells
 Regulates protein, fat, and carbohydrate catabolism in all
cells
 Regulates body heat production
 Maintains growth hormone secretion/skeletal maturation
 Insulin antagonist
 Affects CNS development
 Necessary for muscle tone/vigor
 Maintains cardiac rate/force/output
 Maintains secretion of GI tract
 Affects respiratory rate and oxygen utilization
 Maintains calcium mobilization
 Affects RBC production
 Stimulates lipid turnover/ free fatty acid release/ cholesterol
synthesis

, o Calcitonin:
 An elevated serum calcium is the major stimulant for calcitonin;
Other stimulants include:
 Gastrin, Calcium-rich foods, Pregnancy, Lowered serum Ca
(suppresses Calcitonin release)
 Functions:
 Lowers serum Ca by opposing bone-resorbing effects of
PTH, prostaglandins, calciferols by inhibiting osteoclastic
activity
 Lowers serum phosphate levels
 May decrease Ca and P absorption in GI tract
 Deficiencies of Calcitonin do NOT lead to hypocalcemia
 Used to treat osteoporosis, osteoarthritis, Paget bone
disease, hypercalcemia, osteogenesis imperfecta, metastatic
cancer of bone
 Pancreas (pg. 703-704)
o Houses the islets of Langerhans which has 4 types of hormone-secreting
cells (Alpha, Beta, Delta, F(PP) Cells)
o The following hormones regulate carbohydrate, fat, and protein
metabolism
o Glucagon
 Secreted from Alpha Cells and cells lining GI tract
 High glucose levels can inhibit glucagon release; Low glucose
levels and sympathetic stim glucagon release
 Amino acids stim glucagon secretion; Protein rich meal can do the
same
 Excess of glucagon just as important as deficiency of insulin in
diabetes
 Functions:
 Acts primarily in the liver and increases blood glucose; Acts
as an antagonist to insulin
 Stimulates lipolysis
o Insulin
 Anabolic hormone secreted from Beta Cells
 Functions mainly in liver, muscle, adipose tissue (see Table 21-7);
Brain, RBCs, kidney, and lens of eye do NOT require insulin for
glucose transport
 Secretion promoted when blood levels of glucose, amino acids, and
gastrointestinal hormones increase AND when Beta Cells are
stimulated parasympathetically; Secretion is decreased in response
to low glucose levels, prostaglandin, high levels of insulin (through
negative feedback), and Sympathetic stimulation of Alpha Cells
 Metabolized in liver and kidney
 Functions:

,  Promotes synthesis of proteins, carbs, lipids, nucleic acids;
goal is to stimulate protein/fat synthesis and decrease blood
glucose levels
 Facilitates rate of glucose uptake in body cells- Activates
GLUT for entry of glucose into the cell (pg. 705); associated
with a 10-21x increase in glucose diffusion into cell
o Amylin
 Secreted from Beta Cells; co-secreted with insulin
 Function:
 Regulates blood glucose levels by delaying nutrient uptake
and suppressing glucagon after meals
 Has satiety effect and antihyperglycemic effect
 Used in treatment of Type 1 & 2 diabetes
o Gastrin
 Secreted from Delta Cells
 Function not established; likely plays role in controlling glucagon
secretion
o Ghrelin
 Levels rise before meal to stimulate appetite, then fall after to
promote satiety
 Hyperinsulinemia and hyperleptinemia are associated with
decreased levels in Type 2 diabetes
 Decreased circulating levels have been links to alterations with
insulin secretion, insulin resistance, and obesity
 Function:
 Stimulates GH secretion and plays a role in obesity and
regulation of insulin sensitivity
o Somatostatin
 Secreted from Delta Cells
 Function:
 Involved in regulating Alpha and Beta cell function within the
islets by inhibiting secretion of insulin, glucagon, and
pancreatic polypeptide
o Pancreatic Polypeptide
 Secreted from F (PP) Cells in response to hypoglycemia and
protein-rich meals
 Function:
 Stimulates Y-receptors in gallbladder, exocrine pancreas,
parietal cells in gut
 Stimulates gastric secretion and antagonizes cholecystokinin
 Usually increased in pancreatic tumors and in diabetes
 Adrenal Glands (pg. 706-710)