Chapter 16: The Endocrine System

Pheochromocytoma

A tumor of the adrenal medulla that produces episodes of uncontrolled sympathetic nervous system activity is called a _________________.

Synergism

A type of hormone interaction in which more than one hormone produces same effects on target cells. Therefore, combined effects are amplified.

Permissiveness

A type of hormone interaction in which one hormone needs another hormone to produce its full effects.

Antagonism

A type of hormone interaction in which one hormone opposes action of another hormone.

Adrenocorticotropic hormone

ACTH

Kidneys, liver, urine, feces

After hormones have exerted their effects, most hormones are removed from the blood and broken down by the _____________ and ___________. The resulting breakdown products are excreted in the ___________ and _______________.

Water-soluble

Amino acid based hormones except thyroid hormones are ____________________ hormones.

Adenohypophysis

Anterior pituitary lobe is also known as:

Synergism

Glucagon from pancreas and epinephrine from adrenal glands cause liver to release glucose to the bloodstream, resulting in 150% of glucose in the blood is an example of what type of hormonal interaction?

Neural stimuli

Hormonal release caused by neural input.nerve fibers stimulate hormone release.

Humoral stimuli

Hormone release caused by altered levels of certain critical ions or nutrients.

Hormonal stimuli

Hormone released caused by another hormone (a tropic hormone).

Receptors

Hormones circulate through blood to all body cells, but only cells with _____________ for a specific hormone will respond to that hormone.

Amplification effect generates millions of product molecules

Hormones that bind to plasma membrane receptors are able to cause their effects at very low concentrations. How is this possible?

Local chemical messenger, not long distance, not part of endocrine system

How do autocrines and paracrines differ from hormones?

Increase heart rate, bronchial dilation, blood glucose levels

How do epinephrine and norepinephrine hormones prolong the fight-or-flight response?

Posterior is nervous tissue, anterior is epithelial tissue

How do the anterior and posterior pituitary glands differ ANATOMICALLY?

Posterior releases only neurohormones, anterior releases many hormones

How do the anterior and posterior pituitary glands differ PHYSIOLOGICALLY?

Overrides normal negative feedback functions

How does cortisol function during prolonged stress?

Mediates growth via production of Insulin-like Growth Factors (IGFs)

How does growth hormone regulate growth?

Decrease rate of glucose uptake, keeping blood glucose high

How does growth hormone regulate metabolism?

Hypophyseal portal system: capillary, vein, capillary

How does the hypothalamus communicate with the anterior pituitary? What is this communication system called?

Hypothalamic-hypophyseal tract

How does the hypothalamus communicate with the posterior pituitary? What is this communication system called?

Direct gene activation

Lipid-soluble hormones act in which signaling mechanism?

Development of skeletal, muscular and nervous system and promotes normal function, maintains blood pressure

List metabolic functions of thyroid hormone.

Polyuria, polydipsia, polyphagia

List three cardinal signs of diabetes mellitus.

Decreasing blood volume or blood pressure, increasing blood levels of potassium

List three conditions that stimulate aldosterone secretion.

Low levels of TH or exposure of infants to cold

List two things that stimulate the release of thyrotropin releasing hormone (TRH) from the hypothalamus.

FSH, LH, ACTH, TSH

Name the four tropic hormones.

GH, Prolactin, FSH, LH, ACTH, TSH

Name the hormones released by the anterior pituitary.

Oxytocin and ADH

Name the hormones released by the posterior pituitary.

Zona glomerulosa, zona fasciculata, zona reticularis

Name the three layers of the adrenal cortex (from superficial to deep).

Amino acid-based hormones and steroids

Name the two chemical classes of hormones.

Islet cell tumor (insulinoma), overdose of insulin

Name two causes of hypoglycemia.

Epinephrine, norepinephrine, mineralocorticoids, glucocorticoids. Adrenal medulla and adrenal cortex.

Name two hormones involved in the stress response. Which glands produce these hormones.

Glucagon and insulin

Name two hormones produced by the pancreas.

Lipid-soluble

Steroid and thyroid hormones are ______________________ hormones.

Tropic hormone

Stimulating hormones.

Negative

Synthesis/release of most hormones is controlled by ____________ feedback mechanisms.

Used for inflammation, allergies, and autoimmune disorders

Synthetic glucocorticoids such as prednisone are often given for arthritis or after tissue transplant surgery. Why?

Second messenger system

Water-soluble hormones act in which signaling mechanism?

Catalyze oxidation of glucose for ATP production, join glucose molecules to form glycogen, convert excess glucose to fat, stimulate amino acid uptake/protein synthesis in muscle

What are four primary effects of insulin after it enters a cell?

Sex hormones, onset of puberty, sex drive in women, axillary and pubic hair development

What are gonadocorticoids and what are their effects?

Depress cartilage and bone formation, inhibit tissue repair, depress immune system

What are the adverse effects of excessive levels of cortisol?

Maturation of female reproductive organs, breast development

What are the effects of estrogen and progesterone?

Maturation of male reproductive organs, responsible for sex drives, normal sperm production

What are the effects of testosterone?

Dramatic rises in blood levels of glucose, fatty acids, and amino acids

What are the primary functions of cortisol?

Kidneys release renin, forms angiotensin II, adrenal cortex releases aldosterone, kidneys reabsorb sodium and water

What are the steps of this mechanism beginning with decreased blood volume and pressure and ending with increased blood volume and pressure.

Infertility in females, impotence in males, inappropriate lactation in both

What are the three most frequent symptoms of an anterior pituitary tumor?

Lack of iodine

What causes goiter?

Fats are used for cellular fuel causing ketones to develop dropping blood pH

What causes lipidemia and ketoacidosis in diabetes mellitus?

Increases absorption of calcium by intestines

What effect does parathyroid hormone have on the intestines?

Stimulates reabsorption of calcium by kidneys and activation of vitamin D

What effect does parathyroid hormone have on the kidneys?

Stimulates osteoclasts to dissolve bone matrix and release calcium into blood

What effect does parathyroid hormone have on the skeleton (bones)?

Iodine

What element is necessary for the production of thyroid hormone?

Glucocorticoids, cortisol

What hormone is released in the zona fasciculata?

Mineralocorticoids, aldosterone

What hormone is released in the zona glomerulosa?

Gonadocorticoids, sex hormones

What hormone is released in the zona reticularis?

Most hormones

What hormones are amino acid-based hormones?

Estrogen, progesterone, testosterone

What hormones are produced by the ovaries and testes?

Gonadal and adrenocortical

What hormones are steroids?

Hypothalamus hormones stimulate anterior pituitary hormones

What is an example of hormonal stimuli?

Blood CA2+ monitored by parathyroid gland

What is an example of humoral stimuli?

Stress response

What is an example of neural stimuli?

Posterior pituitary secretes hormones made by the hypothalamus

What is the FUNCTIONAL relationship between the hypothalamus and POSTERIOR pituitary gland?

Pituitary gland connected to hypothalamus by infundibulum

What is the STRUCTURAL relationship between the hypothalamus and the pituitary gland?

Diabetes insipidus is caused by problems related to ADH

What is the difference between diabetes mellitus and diabetes insipidus?

Increases blood glucose

What is the function of glucagon?

Decreases blood glucose

What is the function of insulin?

Energy metabolism and stress resistance

What is the major function of glucocorticoids, specifically cortisol?

Converted to testosterone, onset of puberty, sex drive in women

What is the major function of gonadocorticoids, specifically sex hormones?

Regulates electrolytes, sodium and potassium

What is the major function of mineralocorticoids, specifically aldosterone?

Decreasing blood glucose levels

What is the specific stimulus for GLUCAGON?

Rise in blood sugar, after a meal

What is the specific stimulus for INSULIN?

Increases blood calcium levels

What is the ultimate effect on blood calcium levels when parathyroid hormone is released?

Bone, kidneys and intestines

What organs are the major targets parathyroid hormone?

Adrenal cortex

What other endocrine gland secretes hormones belonging to the same chemical class as gonadal hormones (steroids)?

Steroids

What other hormones act by the same mechanism as thyroid hormone (direct gene activation)?

Beta cells

What specific cells produce glucagon?

Alpha cells

What specific cells produce insulin?

Low blood calcium

What stimulates the release of parathyroid hormone?

Excessive thirst, excessive urination

What symptoms do diabetes mellitus and diabetes insipidus have in common?

Glucose

What would be found in the urine of a patient with diabetes mellitus but not in a patient with diabetes insipidus?

Overdose of insulin

Which cause of hypoglycemia is most common?

Steroid or lipid-soluble

Which chemical class of hormones do the gonadal hormones belong to?

Parathyroid gland, Parathyroid hormone

Which gland and hormone is the major regulator of blood calcium homeostasis?

Epinephrine and norepinephrine

Which hormones are produced by the adrenal medulla?

FSH, LH, ACTH, TSH

Which of the anterior pituitary hormones are tropic hormones?

Catalyze oxidation of glucose for ATP production

Which of the effects of insulin is most important?

Hypothalamus

Which organ is considered a "neuroendocrine" organ?

Nervous

Which organ system can override the endocrine system and make adjustments to maintain homeostasis?

Nervous

Which organ system works with the endocrine system to control or regulate body functions?

Pancreas, gonads, placenta

Which organs or glands have both exocrine or endocrine functions?

Parafollicular cells of thyroid gland

Which specific cells produce calcitonin?

Thyrotropic cells

Which specific cells produce thyroid hormone?

Adrenal medulla

Which specific gland intensifies the activities of the sympathetic nervous system during acute, short-term stress?

Glucose is unable to enter cells so it cannot be used to make ATP

Why do blood glucose levels remain high in diabetes mellitus?

Can enter cell, receptors inside target cells

Why do lipid-soluble hormones act via direct gene activation?

Cannot enter cell, receptors ON target cell plasma membrane

Why do water-soluble hormones act via second messenger systems?

Release of ADH is inhibited by alcohol

Why does drinking alcoholic beverages cause a person to urinate more?

Acinar cells have exocrine functions, pancreatic islets have endocrine functions

Why is the pancreas classified as both an exocrine and endocrine organ?

Does not manufacture hormones

Why is the posterior pituitary not considered a true endocrine gland?

Thyroid hormone

The body's major metabolic hormone is ______________________.

Insulin is needed to make membrane more permeable to sugar

The brain, liver, kidneys, and red blood cells can use glucose without the help of insulin. Why is insulin necessary for other cells to be able to use glucose?

Bone, skeletal muscle

The major targets of growth hormone are _____________ and _____________.

Direct gene activation

By what mechanism does thyroid hormone affect its target cells?

Hormone

Chemical messengers secreted by cells into extracellular fluids and transported in blood to specific distant target cells.

Under severe stress insulin control is overridden to raise blood glucose level for fight or flight

Describe a situation in which the endocrine system might be overridden.

On top of kidneys

Describe the LOCATION of the adrenal glands.

Adrenal cortex which has three layers and adrenal medulla

Describe the STRUCTURE of the adrenal glands.

2 tyrosine amino acids + 3/4 iodine atoms

Describe the structure or thyroid hormone.

Goiter

Enlarged thyroid gland.

Hypothalamus releases CRH, anterior pituitary releases ACTH, adrenal gland releases cortisol

Explain the hypothalamic-pituitary-target organ feedback loop as it relates to CORTISOL.

Hypothalamus releases GnRH, anterior pituitary releases LH and FSH, testes or ovaries release testosterone or progesterone

Explain the hypothalamic-pituitary-target organ feedback loop as it relates to FSH and LH.

Hypothalamus releases TRH, Anterior pituitary releases TSH, Thyroid gland releases thyroid hormone

Explain the hypothalamic-pituitary-target organ feedback loop as it relates to the THYROID HORMONE.

Renin-angiotensin-aldosterone

The release of aldosterone in response to low blood volume and blood pressure is regulated by the _______________________________________ mechanism.

Antagonism

Insulin lowering blood glucose levels and glucagon raising blood glucose levels is an example of what type of hormonal interaction?

Humoral

Is the stimulus for insulin and glucagon release hormonal, humoral, or neural?

Neurohypophysis

Posterior pituitary lobe and the infundibulum are also known as:

Permissiveness

Reproductive hormones and thyroid hormone are both necessary for normal development of reproductive structures is an example of what type of hormonal interaction?