Test 6 Endo Adrenal Medulla, etc... Slides 187-238 Flashcards by Christopher Waller

What is the inner region of the Adrenal Gland called?

Adrenal Medulla

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What are the functional units of the adrenal medulla?

Chromaffin Cells

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Chromaffin cells are modified sympathetic ganglion of the autonomic nervous system (ANS), and are formed from what?

Same embryonic tissue as sympathetic ganglia but lack axons

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Chromaffin cells form clusters around what and release what?

Cluster around blood vessels in adrenal medulla

-Release hormones (very quickly due to control of ANS)

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What do Chromaffin cells secrete?

Catecholamines

Epinephrine (80%)- Adrenaline
Norepinephrine (20%)- Noradrenaline

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What role do Catecholamines have?

Intensify Sympathetic responses throughout the body

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During what situations and how are catecholamines from Chromaffin cells stimulated for release?

During stress

1) Impulses from hypothalamus stimulate sympathetic preganglionic neurons
2) Which stimulate Chromaffin cells to release catecholamines

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Catechaolamines are responsible for causing what effects throughout the body?

Increase heart rate, force of contraction, output of heart, BP
Increases blood flow to heart, liver, skeletal muscles
Dilates airways to lungs
Increases blood glucose and fatty acids

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This is usually caused by a benign tumor of the chromaffin cells, arises in adrenal medulla (Most often) but can arise anywhere along sympathetic paraganglia?

Pheochromocytoma

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Pheochromocytoma increases production and secretion of what?

Epinephrine

Norepinephrine

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The increased epinephrine and norephinephrine caused by pheochromocytoma causes what?

Prolonged “Fight or Flight” response in the body

Increased BP, HR
Elevated Basal Metabolic Rate
Hyperglycemia
Nervousness
Sweating
Headache

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What controls the release of hormones Glucagon and Insulin from the Pancreas?

Glucagon:
-Stimulated: low blood glucose, exercise, and protein meals
-Inhibited: Somatostatin (GHIH) and insulin
(Concentration based)
Insulin:
-Stimulated: Increase blood glucose, acetylcholine, arginine and leucine (AA), glucagon, GIP, hGH, ACTH
-Inhibited: Somatostatin (GHIH)

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What will inhibit Somatostatin (GHIH) secretion?

Pancreatic Polypeptide

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What stimulates and inhibits Pancreatic Polypeptide?

Stimulated: Protein meals, fasting, exercise, acute hypoglycemia
Inhibited: Somatostatin (GHIH)

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Which organ is a flattened organ located in the curve of the duodenum, 5-6 inch in length, w/head, body, and tail, and is both an endocrine gland and exocrine gland?

Pancreas
Endocrine: secrete hormones, directly to blood, faster
Exocrine: Secrete enzymes, directly to SOA, slower

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The pancreas is 95% exocrine cells arranged in what way?

Acini: clusters of exocrine cells that produce digestive enzymes

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Where do the Endocrine cells of the pancreas lie and what are they called?

Middle of the acini (1-2 million endocrine cells)

Called: Pancreatic islets (Islets of Langerhans)

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What are the 4 types of islet cells in the pancreas?

Alpha (A) Cells: 17%- secrete Glucagon
Beta (B) Cells- 70%- secrete Insulin
Delta (D) Cells- 7%- secrete somatostatin (GHIH)
F Cells- 6%- secrete pancreatic polypeptide

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What are the functions of the pancreatic hormones, Glucagon and Insulin?

Glucagon: Raises blood glucose levels
Insulin: Lowers blood glucose levels

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What is the function of Somatostatin?

Paracrine function: inhibiting both insulin and glucagon release
Endocrine function: inhibit release of hGH

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What is the function of Pancreatic Polypeptide?

Inhibits:
Somatostatin release
Gallbladder contraction
Secretion of digestive enzymes by pancreas

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What occurs in a hypoglycemic state to bring blood glucose levels up?

1) Alpha cells release glucagon and Beta cells are inhibited from releasing insulin
2) Glucagon acts on hepatocytes
-Accelerated conversion of glycogen into glucose
(Glycogenolysis)
-Promotes formation of glucose from lactic acid and AA
(Gluconeogenesis)
3) Hepatocytes release glucose into blood stream

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What occurs in a hyperglycemic state to bring blood glucose level down?

1) Beta cells release insulin and alpha cells are inhibited from releasing glucagon
2) Insulin acts on cells throughout the body to:
-Facilitates diffusion of glucose into cells
-Speeds conversion of glucose into glycogen (glycogenesis)
-Increases uptake of AA to increase protein synthesis
-Speeds synthesis of FA (lipogenesis)
-Slows conversion of glycogen to glucose (glycogenolysis)
-Slows formation of glucose from lactic acid and AA
(Gluconeogenesis)
3) Blood glucose levels fall

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What is the most important regulator of release of glucagon and insulin?

Blood glucose levels

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What hormones stimulate release of insulin indirectly because they both elevate blood glucose levels?

hGH | ACTH

Acetylcholine (neurotransmitter) liberated from axon terminals of parasympathetic vagus nerve fibers that innervate the pancreatic islets cells stimulate what?

Insulin

What affect do the AA arginine and leucine present in the blood after a protein containing meal have on insulin?

Stimulate Insulin

This is released in the small intestine in response to glucose presence?

Glucose-dependent insulinotropic peptide (GIP)

Glucose-dependent insulinotropic peptide has what effect on insulin?

stimulate Insulin

Increased activity of the sympathetic division of the ANS (i.e. exercise) and a rise in AA due to a meal containing mainly protein will stimulate what to be released?

Glucagon

What is required for growth because they have a synergistic effect?

hGH and Insulin

If a defect occurs in hGH or insulin secretion during development what may occur?

Growth can be stunted or stopped

What is the 4th leading cause of death in the US and results from the inability to produce or use insulin (B-cell destruction)?

Diabetes Mellitus

What are the three Poly's that characterized Diabetes Mellitus?

Polyuria: Excessive urine production Polydipsia: excessive thirst Poylphagia: excessive eating

What type of Diabetes Mellitus is caused by auto-immune response that attacks beta cells (80-90% destruction before symptoms show), pancreas is unable to produce little to no insulin, Levels of blood glucose fasting >126 and random >200?

Type 1 Diabetes (used to called Insulin Dependent diabetes mellitus)

When does Type I Diabetes Mellitus develop and what are some sign/symptoms?

Early in life (under 20) | -Polyuria, polydipsia, weight loss, weakness, Can initially present in DKA

How is Diabetes Type I cellular metabolism similar to a starving person?

- No Insulin: no entry of glucose into cells - Cells use FA for ATP - Triglycerides in adipose tissue catabolized for FA - FA broken down yield Ketone by-product (Accumulate causing decrease in blood pH (ketoacidosis)) - Wt. loss - lipid deposits left on vasculature walls

What conditions/disease may arise from the mobilization of cholesterol stores and lipid deposits that are left on the vessel walls?

- Atherosclerosis - Cerebrovascular Insufficiency - Ischemic Heart Disease - Peripheral Vascular Disease - Cataracts - Kidney Failure

What is the typical treatment for Diabetes Type I?

-Blood Glucose Monitoring (7-8x's/day) -Meals 45-50% carb -Meals less 30% fat -Exercise -Insulin injections (up to 3x's/day) (Pancreatic transplant, Transplantation of islet cells only)

What form of Diabetes is more common than Type I but is not an issue of insulin but rather target cells have less receptors which causes increased blood glucose and increased insulin levels?

Diabetes Type 2

What age group does Diabetes Type 2 typically occur in and what recent change to this has been seen?

Obese over age 35 Recently: -Spike in children and teenagers

What are the symptoms associated w/ Diabetes Type 2?

Mild to none | -Typically found with fasting glucose/random glucose

How is Diabetes Type 2 controlled?

Diet Exercise Weight Loss -Sometimes medication for refractory cases

What occurs when a diabetic injects too much insulin, which in turn causes hypoglycemia?

Hyperinsulinism

Hypoglycemia causes secretion of what which in turn causes what symptoms?

- Epinephrine, glucagon, hGH - Symptoms: Anxiety, Sweating, Tremor, Tachycardia, Hunger, Weakness - Without Glucose: Mental Disorientation, convulsions, unconsciousness, shock, death

What hormones do the Ovaries produce?

Estrogen Progesterone Inhibin Relaxin

What hormones regulate the menstrual cycle, maintain pregnancy, and prepare the mammary glands for lactation?

Estrogen Progesterone LH (From Ant Pituitary) FSH (From Ant Pituitary)

What hormone is used to inhibit FSH?

Inhibin

What hormone is only produced in large quantities when pregnancy occurs

Relaxin

The hormone Relaxin is produced by what and what effect does it have?

Produced: Ovaries and Placenta Effect: Relax cartilage of pubic symphysis for passage of baby and help relax cervix

What hormones are produced by the Testes?

Testosterone | Inhibin

What does Testosterone Stimulate?

- Decent of testes before birth - Regulates sperm production - Regulates male secondary sex characteristics

What effect does Inhibin have?

Inhibits FSH

What gland is attached to the roof of the third ventricle of the brain, covered by capsule formed by pia mater, and consists of masses of neuroglia and secretory cells?

Pineal Gland

What are the masses of neuroglia and secretory cells of the Pineal Gland called?

Pinealocytes

What does the Pineal Gland secrete?

Melatonin

What affect does Melatonin have and when is it secreted?

- Contribute to body's biological clock | - More secreted at night to promote sleepiness

What type of disorder occurs in places where there is an increase of darkness which causes increased melatonin? What is the treatment?

Seasonal Affective Disorder (SAD) | -Bright Light therapy 3-6 hrs/day

What gland is located behind the sternum, between the lungs?

Thymus

What is produced by the Thymus during childhood?

- Thymosin - Thymic Humoral Factor - Thymic Factor - Thymopoietin

What is significant of the hormones produced by the Thymus and timeframe of production?

Promote maturation of T-cells | -All T-cells for life produced by puberty

What are the two families of eicosanoid hormones?

- Prostaglandins (PG) | - Leukotrienes (LT)

What affect do Prostaglandins (PG) have on the body?

Alter: - Smooth Muscle Contraction - Glandular Secretions - Blood Flow - Reproductive Processes - Platelet Function - Respiration - Nerve Impulse Transmission - Lipid Metabolism - Immune Responses

What affect do Leukotrienes (LT) have on the body?

Stimulates chemotaxis of WBC's and mediates inflammation

Where are Eicosanoid Hormones found?

- All cells in the body | - EXCEPT RBC's

Eicosanoid Hormones act as what type of hormones in response to chemical or mechanical stimuli?

Local | Paracrine and Autocrine

How long do Eicosanoid Hormones last within the blood?

Briefly due to rapid inactivation

What is good stress called?

Eustress

What is "harmful" stress called?

Distress

What is defined by: any stimulus that produces a stress response?

Stressor

The stress response is also called?

General Adaptation Syndrome (GAS) | -Controlled from Hypothalamus

What are the three stages of the Stress Response?

1) Initial Fight-or-Flight 2) Resistance Reaction 3) Exhaustion Response

In stage one, Initial Fight-or-Flight, of the stress response, what is occurring?

1) Initiated by nerve impulses from hypothalamus to SNS -Glucose and Oxygen mobilize to vital organs -Non-essential body function are inhibited (reduced blood to kidney initiates the RAA pathway=fluid retention=in case of dehydration or bleeding

What initiates the Resistance Reaction?

Hypothalamic hormones | -CRH, gHRH, TRH

What purpose does this longer lasting response of resistance reaction serve?

Helps continue to fight stressor even after removal

To reach stage 3 of the stress response, The exhaustion response what occurs?

-If stressor is not removed or resistance reaction was not sufficient body will move into exhaustion stage

The Exhaustion Response of stage 3 has what effect within the body?

- Prolonged exposure to cortisol and other hormones - Causes muscle wasting, suppression of immune system, ulceration of gastric tissues, and failure of pancreatic beta cells

What diseases may arise due to the inhibition of the immune system due to the Exhaustion Response?

``` Gastritis Ulcerative Colitis Irritable Bowel Hypertension Asthma Rheumatoid Arthritis Migraines Anxiety Depression ```

As we age hGH production is reduced causing what?

Muscle Atrophy

As we age the reduced production of T3/T4 causes what?

Reduction in metabolism leading to increase in body fat and hypothyroidism (TSH increases due to lack of Negative Feedback)

Aging Endocrine what might result due to decreased dietary calcium intake?

Increased PTH levels | Calcitriol and Calcitonin levels reduced leading to bone injury

What occurs to the adrenal glands as we age although the adrenal medulla is usually unaffected?

Becomes Fibrous leading to decreased cortisol and aldosterone

How does age affect the pancreas?

Insulin release is slower and receptor sensitivity to glucose declines (Glucose levels raise faster and return to normal slower)

Aging Ovaries change in what way?

Decrease in size and stop responding to gonadotropins - Decreased Estrogen, leads to osteoporosis, hyperlipidemia, atherosclerosis - Leads to menopause

Aging Testes change in what way?

-Decrease size still produce testosterone -Decrease Test usually not issue until late life -Sperm amount same (Morphologically abnormal and Motility decrease)

Test 6 Endo Adrenal Medulla, etc... Slides 187-238 Flashcards

(85 cards)