Lexture Exam 1: Chapter 13: The Endocrine System

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Ivy Tech Community College, Anatomy and Physiology 102 (APHY102), Lab and Lecture Exam 1, Chapter 13, The Endocrine System
Kyla S
Flashcards by Kyla S, updated more than 1 year ago
Kyla S
Created by Kyla S over 7 years ago
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Question Answer
What are the major endocrine glands? (5) Hypothalamus, thyroid gland, adrenal glands, pancreas, and pituitary gland Remember the mnemonic: Hate to address pancreatic problems
What determines the strength of hormone responses and what causes change? The strength of response is changed by the number of receptors. The number of receptors is altered based on how much hormone is needed and/or available.
Upregulation vs. Downregulation Upregulation (to get enough hormone): Receptors on target cell increase BECAUSE the hormone level decreases Downregulation (to prevent overload of hormones): Receptors on target cell decrease BECAUSE the hormone level increases
What is the chemical makeup of steroid hormones? Where do steroid hormones originate? What are examples of steroid hormones? Steroid hormones are lipids containing complex rings of hydrogen and carbon atoms. Steroid hormones originate from cholesterol (which are necessary for lipids in the cell wall) Examples of steroid hormones are sex hormones (testosterone, estrogen) and adrenal cortex hormones (coritsol, aldosterone)
What are the four types of non-steroid hormones and what is their individual chemical makeup? Amines: Originates from tyrosince (epinephrine and norepinephrine) Proteins: Made up of long amino acid chains (growth hormone) Peptides: Made of short amino acid chains (oxytocin) Glycoproteins: Carbohydrates and proteins (TSH)
What are the differences between steroid(thyroid) and nonsteroid hormones? Steroids (thyroid): Water in-soluble (Steroid enters cell by diffusion, thyroid enters cell by specific transport); each binds to receptors within the cell, typically in the nucleus Nonsteroids: Water soluble; binds to receptors on target cell membrane; the hormone is the 1st messenger, the chemical causing change in the hormone's effect is 2nd messenger, typically cyclic adenosine monophosphate
What are steroids most commonly used for? Why can the use of steroids become dangerous? Steroids are most commonly used for increasing muscular strength. If abused, steroids can decrease natural testosterone production; stunt growth; develop male breast tissue; develop male characteristics in females; damage the kidneys, liver, or heart; can increase LDL cholesterol; and can cause psychiatric problems.
What is growth hormone used for? Growth hormone is used for specifically enlarging muscles. It can be used instead of or with steroids.
What is erythropoietin used for and why can it become dangerous is abused? Erythropoietin can be used to increase the number of RBCs and oxygen delivered to the muscles. More oxygen = more energy. However, the increase of RBCs thickens the blood and can easily lead to heart attack and/or death.
Describe a hormone secretion: How long does it last? How is it stopped? How is it controlled? Hormone secretions are typically a negative feedback mechanism (positive feedback mechanisms in the reproductive system). They can last from a few minutes to a few days, and are stopped by enzymes which break down the hormone. After the hormone's effect ceases, the waste is excreted in the urine.
What is a negative feedback mechanism, and what are the three ways it controls hormone secretion? A negative feedback mechanism occurs when the rising level of a hormone causes a decrease in the hormone levels secreted. The three ways it controls the hormone secretion are trophic hormones (these are hormones that act on other glands to regulate the hormone secretion); nervous system control (the nervous system acts on glands via nerve impulses to secrete hormones); and changes in composition of the internal environment (this occurs when a difference substance, such as an ion or glucose, in the blood stimulates or inhibits the secretion of certain hormones).
Describe and locate the pituitary gland. What are the two lobes? The pituitary gland is inferior to the hypothalamus and is connected by the infundibulum (NOTE: Image says "stalk."). The two lobes of the pituitary gland are the anterior lobe (adenohypophysis) and the posterior lobe (neuropophysis).
The hypothalamus is the master of the __________ _________. The hypothalamus is the master of the pituitary gland.
The pituitary gland is master of the _________ ________. The pituitary gland is master of the endocrine system.
The pituitary gland has two lobes. Identify their function and relationship to one another. The anterior lobe (adenohypophysis) is controlled by the hypothalamus. The hypothalamus tells the adenohypophysis to release or inhibit a hormone. The posterior lobe (neurohypophysis) receives nerve impulses (Hypothalamichypophyseal Portal System -- axons) from the hypothalamus through the infundibulum. Then, the pituitary gland releases the hormone indicated.
Identify examples of hormones secreted by the adenohypophysis. -Growth hormone (hGH, GH) -Prolactin (PRL) -Thyroid-stimulating hormone (TSH) -Adrenocorticotropic hormone (ACTH) -Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH) -Melanocyte-stimulating hormone (MSH)
What is the function of the hGH/GH? The growth hormone stimulates cells to grow and quickly divide. This rapid division increases the amino acid uptake and protein synthesis, decreases the rate of carbohydrate usage, and increases the rate of fat usage. (Remember, growth hormone is very active during adolescence. This is why typical adolescents grow quickly and are often extremely lean.)
What is the function of PRL? Prolactin is used for lactation, therefore it promotes milk production in females. This hormone is also present in males but the function is unknown.
What is the function of TSH? The thyroid-stimulating hormone stimulates the secretion of the thyroid hormones (T3 and T4) from the thyroid gland.
What is the function of ACTH? Adrenocorticotropic hormone stimulates secretion of cortisol and other glucocorticoids from the adrenal cortex. Cortisol controls stress levels, such as blood sugar and blood pressure throughout the day. Glucocorticoids also control these, as well immune responses. For example, you have most likely treated a skin rash with over-the-counter hydrocortisone cream. This rash occurs because corticosteroids become inflamed. The hydrocortisone cream is a topical steroid that counteracts the immune response.
What is the function FSH? The follicle-stimulating hormone causes growth and development of the ovarian follicles in females and sperm production in males.
What is the function of LH? The luteinizing hormone causes ovulation in females, and sex hormone production in both genders.
What is the function of MSH? The melanocyte-stimulating hormone causes the secretion of melanin.
Identify and summarize three abnormalities regarding hGH. Hypopituitary Dwarfism: This is caused by a deficiency of hGH during childhood. This causes a short stature, although proportions and mental development are normal. This is very treatable if caught before bones completely ossify. Gigantism: This is caused when there is too much hGH during childhood. This causes height often nearing 8 feet, as well as metabolic problems. This is often caused by a pituitary tumor. Gigantism puts terrible pressure on major joints, causing arthritis and often requiring surgery, such as knee replacements. Acromegaly ("ak-roe-MEH-guh-lee"): This is caused by oversecretion of hGH during adulthood, after epiphyseal ossification. This does not increase the height, but thickens the bones which often results in an enlargement of the tongue, nose, hands, feet, jaw, heart, and thyroid gland.
Identify the two hormones produced by the Hypothalamichypophyseal Portal System and their functions. Antidiuretic hormone (ADH, vaspressin): This conserves water in the kidneys, thus decreases the urine production. It also causes vasoconstriction to increase the blood pressure. Ocytocin (OT): This causes muscle contraction in the uterine wall during childbirth and milk ejection during lactation. Int he male, this causes smooth muscle contractions in the prostate gland and the ductus deferens.
Identify the parts of the thyroid gland. What are the two hormones produced by the thyroid and what are their functions? 1. Follicular cells: These are the T3 (triiodothyronine) and T4 (thyroxine, tetraiodothyronine) which controls the absorption of iodine. 2. Parafollicular cells: Secrete calcitonin, which is a weak hormone controlling the levels of calcium. When removed as a result of thyroid cancer, the lack of parafollicular cells does not affect calcium regulation in the body.
Identify the location of the four parathyroid glands. What hormone do they secrete and what is it's function? The four parathyroid glands are located posteriorly on the right and left lobes of the thyroid gland. There are typically two parathyroid glands on each lobe. They secrete the parathyroid hormone (PTH, parathormone). PTH acts on bones, kidneys, and intestines to regulate calcium and potassium concentration in the blood. Remember, calcium is most important for muscle contractions (which includes your heart!). If your body was deficient of calcium, what good does having strong bones mean if your heart is no longer pumping?
Identify the location of the adrenal glands (think of their alternative name). Identify the two major areas of the gland. The adrenal (suprarenal) glands are located on the top of the kidneys, like a cap. The two major areas of the adrenal glands are the adrenal cortex (which makes up the outer portion of the gland and secretes steroid hormones) and the adrenal medulla (which makes up the central portion of the gland, and secretes amine hormones).
Identify and summarize the three zones of the adrenal cortex. Remember that the adrenal cortex makes up the outer portion of the adrenal glands. Zona golumerulosa: This is the outer layer of the adrenal cortex. It produces mineralocorticoids (Aldosterone is the most important mineralocorticoids, which promotes the reabsorption of sodium in the kidney). Zona fasciculata: This is the middle layer of the adrenal cortex. This produces glucocorticoids, such as cortisol, cortisterone, and cortisone. Remember that glucocorticoids control stress in the body. Zona reticularis: This is the inner layer of the adrenal cortex. This produces weak androgens (sex hormones), which influence the early growth of pubic and axillary hair, increases libido, and increases post-menopausal estrogens.
Briefly summarize the Renin-Angiotensin System. The Renin-Angiotensin System maintains normal blood pressure. The product of this system is Angiotensin II, which increases blood pressure and promotes secretion of aldosterone. Remember that aldosterone is the most important mineralocorticoid because it causes reabsorption of sodium and retains water by osmosis, as well as promoting excretion of potassium.
What are the functions of cortisol? Cortisol is responsible for protein breakdown, glucose formation, triglyceride breakdown, resistance to stress, anti-inflammatory effects, and depression of immune responses. Remember the hydrocortisone cream for topical inflammation?
Identify and summarize two disorders of the adrenal cortex. Two disorders of the adrenal cortex are Addison's Disease and Cushing Syndrome. Addison's Disease is due to an insufficient hormone secretion from the adrenal cortex. This results in an electrolyte balance, dehydration, low blood pressure, fatigue, nausea, and increases skin pigmentation. It can be fatal if dehydration and the electrolyte balance are not carefully monitored. Cushing Disease is due to hypersecretion of cortisol due to an adrenal tumor or excess secretion of ACTH by the adenohypophysis. This can result in muscle wasting, loss of bone, elevated blood glucose, sodium retention (increased blood pressure) , water retention by osmosis (puffy skin), and abnormal distribution of adipose tissue in the face and back.
Describe the purpose of the adrenal medulla. The adrenal medulla receive direct innervation from the sympathetic nervous system. It produces epinephrine (adrenaline) and norepinephrine (noradrenaline). Both of these hormones are sympathomimetic, which is just a fancy way of saying they result from the body's "fight or flight" reaction.
Describe how the pancreas is both an endocrine and exocrine gland. The pancreas is an endocrine gland because it secretes hormones into the body fluids. The pancreas is also an exocrine gland because it secretes digestive juices through a duct.
What are the four hormones secreted from the (endocrine) pancreatic Islet of Langerhans cells? 1. Alpha cells: These secrete glucagon which increases the blood sugar. 2. Beta cells: These secrete insulin, which lowers the blood sugar. 3. Delta cells: These secrete somatostatin, which inhibits alpha and beta cells. This decreases GIT (gastrointestinal) absorption, another fancy term that really just means absorbing the contents from the digestive tract. 4. F cells: These secrete pancreatic polypeptide, which inhibits D cells, gallbladder contraction, and secretion of acini cells (which carries the fluid containing digestive enzymes).
Describe the structure of the pancreas. The pancreas is an elongated, flattened organ just posterior to the stomach. The pancreatic duct transports digestive juice to the duodenum.
List some examples of complications from diabetes. Hypoglycemia (which is commonly seen prior to the onset of diabetes), hypertension, dyslipidemia (fancy word for high cholesterol), cardiovascular disease (along with that comes heart attack, stroke, peripheral vascular disease, and death), blindness and other eye problems, kidney disease, gangrene and amputations
Identify and describe the three hallmarks of diabetes. Polyuria: Too much urine Polydipsia: Blood is too thick Polyphagia: Always hungry due to the blood not getting enough glucose to the cells (This is a nasty cycle because more food = more glucose, and more glucose worsens diabetes)
Identify and summarize the four hormones associated with the ovaries. Estrogens and progesterone: These regulate the reproductive cycle, maintain pregnancy, prepare breasts for lactation, and develop and maintain secondary female characteristics. Inhibin: This hormone inhibits FSH, which limits eggs. Human bodies are built for a maximum of two eggs, sometimes three. Unlike animals, humans cannot necessarily handle multiple pregnancies. Relaxin: This hormone relaxes the joints, and dilates the cervix during labor and delivery. This hormone plays a large part in childbirth.
Identify and summarize the two hormones associated with the testes. Testosterone: This hormone regulates sperm production, and develops and maintains secondary male characteristics. Inhibin: This, just like for women, inhibits FSH.
Identify the main hormone associated with the pineal gland. The main hormone associated with the pineal gland is melatonin, which regulates circadian rhythms.
Identify the main hormone associated with the thymus gland. The main hormone associated with the thymus gland is thymosins. This promotes the development of T-lymphocytes, which plays an important role in immunity.
The _______ responds to stress by General Adaption, or General Stress Syndrome. Hypothalamus
Identify and summarize the two stages of General Stress Syndrome. 1. Alarm stage: This is the body's immediate response (fight or flight). During this stage, the sympathetic impulses increase blood pressure, heart and breathing rate, dilate air passages, and shunt blood to skeletal muscles. Epinephrine intensifies and lengthens this response. 2. Resistance stage: This is a long-term response. During the resistance stage, increased cortisol spares glucose for the brain, glucagon and GH mobilize energy sources from other tissues and organs, and ADH and renin cause water retention.
Identify and explain examples of life span changes of the endocrine system. Endocrine glands reduce in size; muscular/skeletal strength decrease as GH levels decrease; ADH levels increase due to slower elimination from the liver and kidneys; calcitonin levels decrease, which increases the risk of osteoporosis; insulin resistance may develop; changes in melatonin may disrut tthe body clock; and thymosin production decreases, which increases the risk of infections.
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