Chapter 18 Powerpoints/Endocrine Quiz#2

ADRENAL GLANDS

PYRAMID SHAPED glands that lie SUPERIOR to each kisney •Each gland is surrounded by a connective tissue capsule •Each gland consists of 2 structurally and functionally distinct regions -Adrenal Cortex -Adrenal Medulla

ZONA GLOMERULOSA

-Directly under capsule -Produces group of hormones called mineralocorticoids •regulate homeostasis of different "minerals". •Aldosterone is a major mineralocorticoid and the one we will focus on. It regulates Na+, K+, and H+ ions. •Secretion of aldosterone is regulated via a pathway called the Rennin Angiotensin Aldosterone Pathway (RAA pathway). •The pathway helps to counter decrease in blood volume and therefore decrease in blood pressure.

FIBROBLAST GROWTH FACTOR (FGF)

-Found in pituitary gland and brain; -stimulates proliferation of many cells derived from embryonic mesoderm (fibroblasts, adrenocortical cells, smooth muscle fibers, chondrocytes, and endothelial cells); -stimulates formation of new blood vessels (angiogenesis).

How does CALCITROL (VIT D) body help maintain calcium levels in blood?

-Increases calcium and phosphate absorption by small intestine -increases calcium RESORPTION from bones by stimulating differentiation of osteoblasts into osteoclasts -stimulates calcium reabsorption by kidneys causing less excretion of calcium -promotes both mineralization and resorption

ZONA RETICULARIS

-Inner most zone -Produces group of androgen hormones •Androgens -Dehydroepiandrosterone (DHEA) -In males, after puberty, the hormone testosterone is secreted in much larger quantities so DHEA has virtually no effect -In females, DHEA and other adrenal androgens play a major role in promoting libido and are converted to estrogens •In menopausal women, all female estrogens come from adrenal androgens

ZONA FASCICULATA

-Middle and widest zone of cortex -Produces group of hormones called glucocorticoids •These hormones are given their name because one role they play is in glucose homeostasis. -Important glucocorticoids include cortisol (hydrocortisone) and cortisone. •In terms of glucose homeostasis they can trigger gluconeogenesis and breakdown of glycogen. •One important and major function is their ability to suppress inflammation and the immune system. •These hormones are sometimes called "stress hormones".

MINERALOCORTICOIDS

-One of the major groups of steroid hormones produced by adrenal cortex. -Regulates water and electrolyte balance in extracellular fluid -regulates sodium reabsorption by the kidney tubules. Chiefly aldosterone.

How does PTH help maintain calcium levels in blood?

-PTH increases blood calcium levels by stimulating osteoclasts, which resorbs bone to release calcium into the blood stream. -PTH increases blood calcium levels by increasing amount of calcium resorbed by kidneys before its excreted in urine. -PTH increases blood calcium levels by inhibiting collagen production hence causing inhibition of bone deposition -PTH stimulates final stage of calcitrol synthesis

Explain flight or fight response and the specific changes triggered by adrenaline

-Physiological response to perceived threat which triggers hormone production and secretion in order to react or retreat -initiated by nerve impulses in Hypothalamus ADRENALINE effects: - increased heart output thus increasing blood pressure -increases blood flow to heart, liver, skeletal muscles, & adipose tissues -dilates airways in lungs -dilates pupils -increases blood levels of glucose and fatty acids -decreases blood supply to non-vital organs such as digestion, elimination, and sex organs

TUMOR ANGIOGENESIS FACTORS (TAFs)

-Produced by normal and tumor cells; -stimulate growth of new capillaries, organ regeneration, and wound healing

TRANSFORMING GROWTH FACTORS (TGFs)

-Produced by various cells as separate molecules; T -TGF-alpha has activities similar to epidermal growth factor; -TGF-beta inhibits proliferation of many cell types.

PLATELET-DERIVED GROWTH FACTOR (PDGF)

-Produced in blood platelets; -stimulates proliferation of neuroglia, smooth muscle fibers, and fibroblasts; -has role in wound healing; -may contribute to atherosclerosis development

NERVE GROWTH FACTOR (NGF)

-Produced in submandibular (salivary) glands and hippocampus of brain; -stimulates growth of ganglia in embryo; -maintains sympathetic nervous system; -stimulates hypertrophy and differentiation of neurons

EPIDERMAL GROWTH FACTOR (EGF)

-Produced in submaxillary (salivary) glands; -stimulates proliferation of epithelial cells, fibroblasts, neurons, and astrocytes; -suppresses some cancer cells and secretion of gastric juice by stomach.

Explain other hormones involved in long term stress resistance

-also known as RESISTANCE REACTION -initiated by Hypothalmic releasing hormones -Hormones involved include: *CORTICOTROPIN-RELEASING HORMONE (CRH): -stimulates anterior pituitary to secrete ACTH which stimulates adrenal cortex to increases release of cortiso which stimulates gluconeogenesis by liver cells *GROWTH HORMONE-RELEASING HORMONE (GHRH) -causes anterior pituitary pituitary to secrete GROWTH HORMONE (GH) which stimulates LIPOLYSIS & GLYCOGENOLYSIS in liver *THYROTROPIN-RELEASING HORMONE (TRH) -stimulates anterior pituitary to secrete THYROID-STIMULATING HORMONE (TSH) which promotes secretion of thyroid hormones which cause increase in usage of glucose for ATP production

HYPOCALCIUM

-calcium is tied to phosphate in bone tissue. -When osteoclasts break down bone calcium and PHOSPHATE are released

Why is it important to maintain appropriate levels of calcium in blood?

Calcium plays profound roles in neuron communication, muscle activity, blood clotting, exocytosis, Messenger systems, and needed as a co-factor of certain enzymes

Diabetes effects the ability of cells to use_GLUCOSE_ and therefore results in elevated levels of_GLUCOSE_ in the blood which spills over to urine. Therefore cells react as if they were being starved and resort to using _LIPIDS_ as an energy source. This can lead to an elevated level of _KETONES_ in the blood which also spills over into urine and can lead to acidosis. There are two major types of Diabetes. Type I and Type II. Type I Diabetes results when the _BETA_ cells of the pancreas is destroyed by the immune system leaving the body unable to produce enough _INSULIN_(hormone). Without this hormone the cells are not stimulated to produce glucose transporters and take up the glucose and "use it" or "store it". Type II Diabetes is associated with a down regulation of _INSULIN_ receptors. It is associated with obesity.

Diabetes effects the ability of cells to use ___1__ and therefore results in elevated levels of __1___ in the blood which spills over to urine. Therefore, cells react as if they were being starved and resort to using __2___ as an energy source. This can lead to an elevated level of ___3__ in the blood which also spill over into urine and can lead to acidiosis. There are two major types of diabetes. Type I and Type II. Type I diabetes results when the ___4__cells of the pancreases are destroyed by the immune system leaving the body unable to produce enough __5___(hormone). Without this hormone the cells are not stimulated to produce glucose transporters and take up the glucose and "use it" or "store it". Type II diabetes is associated with a down regulation of __6___ receptors. It is associated with obesity. 1. glucose 2. lipids (triglycerides) 3. ketones 4. Beta cells 5. insulin 6. insulin

ESTROGEN directly inhibits bone resorption by inducing apoptosis of osteoclasts. •Why would this be a factor in postmenopausal osteoporosis?

ESTROGEN DEFICIENCY, leads to accelerated bone resorption, and is primary cause of postmenopausal bone loss and osteoporosis.

Explain functions of glucocorticoids and androgens

GLUCOCORTICOIDS: -Increase rate of protein breakdown & liberate amino acids into bloodstream -Stimulate liver cells to convert amino acids or lactic acid to glucose which aid production of ATP in cells (GLUCOGENESIS) -stimulate breakdown of triglycerides & release of fatty acids into bloodstream (LIPOLYSIS) -provide resistance to stress by aiding supply of ATP, make vessels sensitive to hormones that cause vasoconstriction thus increasing blood pressure -inhibit WBCs hence decreases inflammation -depresses immune reactions ANDROGENS: -assist in axillary & pubic hair in both sexes -contribute to female libido -source of estrogens after menopause -contribute to bone and muscle development and metabolism

Low blood glucose (hypoglycemia) stimulates alpha cells to secrete GLUCAGON

Glucagon acts on hepatocytes (liver cells) to:• convert glycogen into glucose (glycogenolysis) • form glucose from lactic acid and certain amino acids (gluconeogenesis) Glucose released by hepatocytes raises blood glucose level to normal If blood glucose continues to rise, hyperglycemia inhibits release of glucagon

High blood glucose (hyperglycemia) stimulates beta cells to secrete INSULIN

Insulin acts on various body cells to: • accelerate facilitated diffusion of glucose into cells • speed conversion of glucose into glycogen (glycogenesis) • increase uptake of amino acids and increase protein synthesis • speed synthesis of fatty acids (lipogenesis) • slow glycogenolysis • slow gluconeogenesis Blood glucose level falls If blood glucose continues to fall, hypoglycemia inhibits release of insulin

HOW DOES PTH AID WITH RELEASE OF CALCIUM & PHOSPHATE?

PTH is controlled by negative feedback of calcium levels in blood by the parathyroid glands. Low calcium levels in blood stimulate parathyroid hormone secretion, which increases # of osteoclasts that in turn increases BONE RESORPTION that increases level of blood calcium PTH reduces reabsorption of phosphate from kidneys, which causes more excretion of phosphate through urine, while increasing uptake of phosphate from intestines and bones and moving it into bloodstream.

TYPE I DIABETES

TYPE I Diabetes occurs when pancreatic beta cells are destroyed by an immune-mediated process. -Pancreatic beta cells sense plasma glucose levels and respond by releasing insulin, individuals with type 1 diabetes have a complete lack of insulin.

ADRENALINE from Adrenal Medulla

•Adrenaline is involved in the flight or fight response. This response is a reaction to provide energy and heighten senses to allow an organism to respond to a potentially threatening situation. •Adrenaline will -Increase heart rate (#beats/min) and increase force of each contraction (by causing influx of Ca2+ into the cardiac muscle cells). This allows the heart to eject a greater volume of blood -Increase blood flow to the heart, lungs (will need to exhale CO2 and get O2), liver (glycogen is stored there and needed for energy), skeletal muscle (help react) -Increase blood pressure -Dilate airways, dilate blood vessels in skeletal muscle, lungs, liver, brain, and heart -Decrease digestion (divert energy and resources to more vital functions)

TYPE 1 DIABETES

•Autoimmune destroys pancreas •Insulin injections •Usually develops young (under 20) Type 1 Diabetes occurs when pancreatic beta cells are destroyed by an immune-mediated process. Because the pancreatic beta cells sense plasma glucose levels and respond by releasing insulin, individuals with type 1 diabetes have a complete lack of insulin. In this disease, daily injections of insulin are needed. Also affected are those who lose their pancreas. Once the pancreas has been removed (because of cancer, for example), diabetes type 1 is always present.

HYPERCALCIUM

•Calcitonin from parafollicular cells of thyroid gland inhibits bone resorption and promotes uptake of calcium by bone

STRESS RESPONSE

•Eustress is helpful, everyday stress that prepares us to meet challenges •Distress is any type of harmful stress that may be damaging -The fight-or-flight response (first stage of the stress response) stimulates the body's resources to prepare for immediate activity -The resistance reaction is the second stage in the stress response and lasts longer than the fight-or-flight response •If this lasts too long, exhaustion will result

OXYPHIL CELLS of Parathyroid Gland

•Have no known function •Lots of mitochondria •Few secretory granules and sparse ER

CUSHING'S SYNDROME

•Hyper secretion of cortisol •Caused typically by tumor of adrenal gland or tumor of anterior pituitary (too much ACTH produced therefore too much cortisol) •Results in breakdown of muscle proteins •Redistribution of body fat (slim arms/legs, hump back, moon face) •Easily bruised, poor wound healing •Hyperglycemia, osteoporosis, hypertension, susceptible to infection and reduced resistance to stress (mood swings)

ADDISON'S DISEASE

•Hyposecretion of gluccocortoids and aldosterone •Autoimmune disease •Hypoglycemia, nausea, weight loss •Aldosterone loss results in low sodium and therefore hypotension, high potassium which can lead to irregular heart beat •Skin bronzed (tanned) appearance

TYPE 2 DIABETES

•More common •Associated with obesity (over 35) •Down regulation of insulin receptors •Have insulin but cells can't respond -far more common than type 1. It makes up most of diabetes cases. It usually occurs in adulthood, but young people are increasingly being diagnosed with this disease. In type 2 diabetes, the pancreas still makes insulin, but the tissues do not respond effectively to normal levels of insulin, a condition termed insulin resistance. Over many years the pancreas will decrease the levels of insulin it secretes, but that is not the main problem when the disease initiates. Many people with type 2 diabetes do not know they have it, although it is a serious condition. Type 2 diabetes is becoming more common due to increasing obesity and failure to exercise, both of which contribute to insulin resistance.

DIABETES MELLITUS

•Not producing or not having ability to use insulin •Because insulin is not telling cells to use/store the glucose it builds up in blood, hence "high sugar" or high blood glucose levels •Glucose spills over in urine- glycosuria •2 types of diabetes -Type 1 -Type II •Cells react as if being starved -Cells cannot use Glucose without insulin or insulin receptors so they turn to fatty acids for energy (ATP) production -By products of pathway are ketones which build in blood •Acidic •Aromatic

PINEALOCYTES

•Produce hormone melatonin - amine hormone derived from serotonin -Makes you sleepy •Appears to contribute to setting biological clock •More melatonin liberated during darkness than light

CHIEF CELLS of Parathyroid Gland

•Produce hormone parathyroid hormone (PTH) • Major regulator of calcium, magnesium, and phosphate ions in blood • Increases number and activity of osteoclasts •Increases bone resorption •Blood calcium level directly controls secretion of both calcitonin and PTH via negative feedback

PANCREATIC ISLETS (Islets of Langerhans)

•Roughly 99% of cells (acini) produce digestive enzymes •Pancreatic islets or islets of Langerhans produce hormones •Consist of 4 types of cells -Alpha or A cells secrete glucagon - raises blood sugar -Beta or B cells secrete insulin - lowers blood sugar -Delta or D cells secrete somatostatin - inhibits both insulin and glucagon -F cells secrete pancreatic polypeptide - inhibits somatostatin, gallbladder contraction, and secretion of pancreatic digestive enzymes

ADRENAL MEDULLA

•The adrenal medulla consists of special cells called chromafin cells that produce adrenaline. •These cells function as modified neurons and therefore are controlled by the neurotransmitter Ach. This also means they release the adrenaline quickly.

ADRENAL CORTEX

•The cortex is divided into 3 zones which are also structurally and therefore functional distinct -Each zone makes a different "group" of hormones. These are mostly steroid based hormones and are therefore derived from cholesterol. -Zona Glomerulosa -Zona Fasciculata -Zona Reticularis

RAA PATHWAY (renin-angiotensin-aldosterone)

•The kidneys filter blood. We will learn all the specifics of how this happens when we get to the urinary section. For now, know that there is a special part of the kidneys called the guxtaglomerular apparatus (cells). When there is a decrease in blood volume and therefore blood pressure these cells will sense the situation and release the enzyme rennin into the blood. The levels of rennin will increase. • There is also a plasma protein made by the liver in the blood. Angiotensin. A plasma protein is a general term for a protein that circulates in blood plasma. Rennin converts angiotensin into an inactive hormone called Angiotensin I. •Special endothelial cells in lungs and kidneys produce and release another enzyme into the blood stream called Angiotensin Converting Enzyme (ACE). •ACE converts inactive Angiotensin I into the active hormone Angiotensin II. •Angiotensin II has two targets that will help counter the decrease in blood volume and blood pressure. -Smooth muscle in walls of arterioles, stimulating vasoconstriction which directly increase blood pressure -Zona Glomerulosa of Adrenal Cortex, where it stimulates release of aldosterone -A third target, the posterior pituitary gland, results in the release of ADH -How does this help counter the dehydration, loss of fluids, blood volume decrease, and so on? •Aldosterone targets the kidneys and stimulates -Reuptake of Na+ and therefore H2O, which increases blood volume and therefore blood pressure -Excretion of excess K+ and H+ ions (recall H+ ions are associated with pH)

PARATHYROID GLANDS

•The parathyroid glands are not part of the thyroid gland but are partially embedded in lateral, posterior lobes of thyroid gland. •Most people usually have four but some will have 3. -Consists of 2 Major Cell types: OXYPHIL CELLS CHIEF CELLS

PANCREAS

•has both exocrine and endocrine function. The exocrine function is involved with production of digestive enzymes and juices and will be covered with the digestive system. •located in curve of duodenum, (the first part of the small intestines). •divided into three parts, the head, which is the broadest part and located in curve of duodenum, the body and the tail or the tapered end farthest away from the tail.

DIABETES SYMPTOMS

-polyuria-frequent urination, -polydipsia-excessive thirst, -unexplained weight loss, -polyphagia-extreme hunger, -vision changes, -numbness/tingling in hands/feet -fatigue, -very dry skin, -sores that don't heal well or quickly, -frequent infections

How does CALCITONIN help maintain calcium levels in blood?

-stimulates mineralization which decreases blood Calcium levels/more-so in children

•Before moving on make sure you can: -Name the three zones of the adrenal cortex •Name the group of hormones from each zone -Explain in detail the steps in the RAA pathway and the function of aldosterone

3 ADRENAL CORTEX ZONES; -Zona Glomerulosa= Mineralocorticoids (EX: Aldosterone) -Zona Fasciculata= Glucocorticoids (Ex: Cortisone & Cortisol) -Zona Reticularis= Androgens (Ex: DHEA)

T3 and T4 are hormones made by _1___cells in the __2__gland in response to __3___(hormone) which comes from the anterior pituitary gland. To synthesize T3 and T4, these cells actively bring __4___atoms into the cells. They also synthesize thyroglobulin, which is a protein with many __5___ amino acids. The ___6__ atoms are oxidized by __7___ (enzyme) as they are sent across the membrane to the colloid. The protein is also sent across the membrane. The __8___atoms bind to the _9____ amino acids on thryroglobulin protein. The protein is sent back into the cell. Upon entering the cell, the vesicle carrying the protein, fuses with _10____ (a structure inside the cell). Essentially, the protein is degraded and all that is left is T3 and T4. Because T3 and T4 are lipid soluble hormones they require a _11____upon being released into the blood.

1. follicular cells 2. thyroid gland 3. thyroid stimulating hormone (remember it is the hypothalamus that will send thyrotropin releasing hormone (TRH) to the thyrotrophs of ant pit gland when there are low levels of T3 and T4 in blood) 4. iodine 5. tyrosine 6. iodine 7. peroxidase 8. iodine 9. tyrosine 10. lysosome 11. transport protein

Calcium has many important and essential bodily functions. It is needed for contraction of ___1__, including cardiac muscle tissue, for proper blood clot formation, as a co-factor for ___2__, serves as an intracellular signaling molecule, and is an important structural component for ___3__. Therefore, it is essential that appropriate levels of calcium in the blood be maintained. The majority of the body's calcium is stored in _4___. When blood calcium levels rise above normal, the ____5_ cells of the ___6_ gland release the hormone calcitonin. This hormone acts on the bone to inhibit the action of ____7_(a cell) and promote uptake of extra calcium by promoting the activity of ___8__(a cell). When blood calcium levels fall below normal, the chief cells of the ___9__gland release the hormone ___10__. This hormone acts on the bone to increase the number and activity of ___11__(a cell) which promotes bone resorption and results in a release of calcium. This hormone also acts on the ___12__to reduce the amount of calcium lost in urine, promote the excretion of ___13__, as well as stimulates the synthesis of ___14__,which acts on the small intestines to promote absorption of calcium.

1. muscle 2. enzymes 3. bone 4. bone 5. parafollicular cells 6. thyroid gland 7. osteoclasts 8. osteoblasts 9. parathyroid gland 10. PTH 11. osteoclasts (what is bone resorption and how do the cells break down the bone? refer to the notes if you can't recall) 12. kidneys 13. phosphate 14. calcitriol (remember this is the active form of vitamin D)

•Some medications, such as lisinopril, used to treat hypertension are ACE inhibitors. •How would these mechanisms work? -Why would frequent urination sometimes occur with such medications?

Angiotensin-converting enzyme (ACE) inhibitors relax veins and arteries which lowers blood pressure. ACE inhibitors prevent ACE from producing angiotensin I into angiotensin II, a substance that narrows blood vessels Frequent urination occurs due to lack of aldosterone being produced as a result of decreased levels of Angiotensin II. ( Angiotensin II stimulates Adrenal Cortex to stimulate ALDOSTERONE) -Aldosterone effects in kidneys, increase reabsorption of Na+, hence water reabsorption...without Angiotensin II there is lower level of Aldosterone. With lower levels of Aldosterone there is decrease in Na+ and H20 reabsorption thus producing more frequent urination and accumulation of K+ and H+.

How does bone buffer blood calcium levels?

By MINERALIZATION and RESORPTION. The bones osteoclasts and osteoblasts respond to level of serum calcium

WHAT IS KETOACIDOSIS AND WHY MIGHT A DIABETIC EXPERIENCE THIS?

KETOACIDOSIS: happens when body doesn't have enough insulin and cells can't use glucose in blood for energy, so it breaks down fat and uses for fuel instead while the sugars build up in blood -Burning fat makes acids called ketones Without adequate insulin, the body begins to break down fat as fuel which produces a buildup of acids in the bloodstream called ketones, eventually leading to diabetic ketoacidosis

WHAT IS DIABETES

Metabolic dysfunction of insulin production and secretion, as well as the target cells' responsiveness to insulin

How does body maintain calcium levels in blood?

Parathyroid Hormone regulates Blood Calcium levels, that acts on bones, kidneys, and intestines to keep consistent levels

CALCIUM IS NEEDED FOR CONTRACTION OF muscle, INCLUDING CARDIAC MUSCLE TISSUE, FOR PROPER BLOT CLOT FORMATION, AS A CO-FACTOR FOR enzymes, AND ALSO SERVES AS A CELLULAR SIGNALING MOLECULE. THEREFORE IT IS ESSENTIAL THAT APPROPRIATE LEVELS OF CALCIUM IN BLOOD BE MAINTAINED. THE MAJORITY OF THE BODY'S CALCIUM IS STORED IN THE bone. WHEN LEVELS RISE ABOVE NORMAL THE thyroid gland RELEASES THE HORMONE calcitonin. THIS HORMONE ACTS ON THE BONE TO INHIBIT THE ACTION OF osteoclasts (A CELL) AND PROMOTE UPTAKE OF EXTRA CALCIUM. IT ALSO ACTS ON KIDNEYS TO SLOW THE PRODUCTION OF calcitrol, WHICH SLOWS THE ABSORPTION OF CALCIUM. WHEN BLOOD CALCIUM LEVELS FALL BELOW NORMAL THE parathyroid gland RELEASES THE HORMONE PTH. THIS HORMONE ACTS ON BONE TO INCREASE THE NUMBER AND ACTIVITY OF osteoclasts ( A CELL) WHICH BREAKS BONE DOWN AND RESULTS IN RELEASE OF CALCIUM. THIS HORMONE ALSO ACTS ON THE kidneys TO REDUCE THE AMOUNT OF CALCIUM LOST IN URINE AS WELL AS STIMULATES THE SYNTHESIS OF calcitrol WHICH ACTS ON THE SMALL INTESTINES TO PROMOTE ABSORPTION OF CALCIUM. THE KIDNEYS WILL ALSO BE STIMULATED TO EXCRETE EXCESS phosphate THAT RESULTED FROM BONE RESORPTION.

Use the following terms to help complete the sentences. Choices may be used more than once or not at all. 1-Enzymes 2-Calcium 3-Bone 4-Osteoclast 5-Oxyphil 6-Liver 7-Osteoblast 8-Chief 9-Kidneys 10-Parathyroid Gland 11-PTH 12-Muscle 13-Pituitary Gland 14-Calcitonin 15-Phosphate 16-Thyroid Gland 17-Calcitrol

TYPE II DIABETES

type of diabetes which body produces insulin but insulin cannot be used by body cells

PINEAL GLAND

•Attached to roof of 3rd ventricle of brain at midline