BM 41055 Q2 Answers to questions of the Study Sheet from the book edition 11 PDF

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Chapter 16 Endocrine system – hormones: chemical messenger secreted into extracellular fluid (travel trough blood) regulate metabolic function of other cells in the body summaryslow last longer target most cell of body (not locally)**- Reproduction Growth Water and nutrient balance in blood Energy b...

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Chapter 16 Endocrine system – hormones: chemical messenger secreted into extracellular fluid (travel trough blood) regulate metabolic function of other cells in the body summary

slow last longer target most cell of body (not locally) - Reproduction - Growth - Water and nutrient balance in blood - Energy balance - Mobilization of body defenses

Exocrine glands: nonhormonal : sweat, salvia: duct carry to membrane surface Endocrine glands : ductless glands, produce hormones but luck ducks -> blood

Anterior pituitary hormones Tropic (regulate secretion of other endocrine – tropi = turn on -

thyroid stimulating hormone TSH, -> Thyroid Hormone TH (T3 and T4)

-

adrenocorticotropic hormone, (ACTH) (gonadotropins)regulate function of gonads (ovaries and testes) activated during puberty) activated by gonadotropin releasing hormone (GnRH)

-

follicle stimulating hormones, (FSH) stimulate production of gametes (eggs and sperm) luteinizing hormone (LH), promotes production of gonadal hormones (ovulation and produce testosteron)

non tropic -

prolactin (PRL) stimulate milk production controlled bu prolactin inhibiting hormone (PIH = dopamine) growth hormone, (GH): tissue building – metabolic and growth (divide cells and bone and skeletal muscle – stimulated by growth hormone releasing hormone (GHRH) and growth hormone inhibiting hormone (GHIH)

posterior pituitary -

-

antidiuretic hormone (ADH) (posterior pituitary) water regulation of urine , prevent urine production, avoid dehydration. Drink alcohol prevent adh and lead to releasing water that body needs -> hang over: dry mouth and thirst oxytocin (posterior pituitary) childbirth (oxy = rapid, tocia = childbirth) and milk ejection

Thyroid gland (control metabolism) thyroid hormone (TH) T4 and T3; (T3 is converted from T4) increase metabolic rate and heat production(calorigenic effect) tissue growth and development maintaining blood pressure Calcitonin: released due to rise of Ca2+ in blood role not known, but if to much: inhibit osteoclast (bone release Ca2+, destroy of bone )

Parathyroid gland (regulate bold calcium level) Parathyroid hormone (PTH)control Ca2+ level in blood – critical for transmission of nerve impuls, blood clotting, muscle contraction (low Ca2+ level -> release PTH, high level: inhebit PTH)

 PTH stimulate osteoclast -> release calcium from bone in blood  Enhance kidney reabsorption (instead of passing out in urine) of Ca2+  Promote activation of vitmind D -> increase absorption of Ca2+

Pancreas: Endocrine but also other major functions 2 different hormone producing cells ,- regulate blood glucose level

Alpha: release glucagon: hyperglycemic gormone (increase blood glucose) In liver: glucagon breaks down glycogen to glucose Falling blood glucose levels (hmoral stimuli) -> alpha cells secrete glucagon Beta: release insulin: hypoglycemic hormone ( decrease blood glucose) Inhibits the breakdown of glycogen to glucose Pancreatic beta cells secrete insulin when -> elevated blood glucose level

Answers 1. The endocrine system is more closely associated with growth and development, and its responses tend to be long-lasting, whereas nervous system responses tend to be rapid and discrete. 2. The thyroid (schilddrüse) and para-thyroid (nebenschilddrüse) glands are found in the neck.

Parathyroid hormone (also known as parathormone) is a small protein that takes part in the control of calcium and phosphate homeostasis, as well as bone The thyroid gland is a vital hormone gland: It plays a major role in the metabolism, growth and development of the human body. It helps to regulate many body functions by constantly releasing a steady amount of thyroid hormones into the bloodstream

3. Hormones are released into the blood and transported throughout the body, whereas paracrine act locally, generally within the same tissue. Paracrine signaling is a form of cell signaling, a type of cellular communication in which a cell produces a signal to induce changes in nearby cells, altering the behaviour of those cells. Signaling molecules known as paracrine factors diffuse over a relatively short distance (local action), as opposed to cell signaling by endocrine factors, hormones which travel considerably longer distances via the circulatory system; juxtacrine interactions; and autocrine signaling.

4. Gland (a) is an exocrine gland

and

gland (b) is an endocrine gland. Endocrine glands are ductless glands of the endocrine system that secrete their products, hormones, directly into the blood. Exocrine glands are glands that secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary In gland (a), you can see the duct that is characteristic of exocrine glands. The duct conveys glandular secretions either out of the body onto the skin or into a hollow organ. Endocrine glands, on the other hand, do not have ducts and instead secrete hormones into the blood. Notice the prominent blood vessels around gland (b). 8. Hormone release can be triggered by humoral, neural, or hormonal stimuli. Humoral, Hormonal, and Neural Stimuli The release of hormones can be triggered by changes in the blood (“humor”), by the actions of other hormones, (hormonal) or by neurological stimuli. (neural) Humoral in the sense of "humoral defense", i.e. based on the non-cellular parts of the immune system, i.e. above all substances dissolved in the blood serum such as immunoglobulins and antibacterial substances such as lysozyme. A neural stimulus is a hormone that is released by the glands of the endocrine system. This is a nonvoluntary process in which the nervous system stimulates the endocrine system to release neural stimuli. Hormonal – triggered by hormones to increase hormones

Humoral Stimuli Some endocrine glands secrete their hormones in direct response to changing blood levels of certain critical ions and nutrients. These stimuli are called humoral stimuli (from the Latin term humor, which refers to moisture or bodily fluids). Humoral stimuli are the simplest endocrine controls. For example, cells of the parathyroid glands monitor the body's crucial blood Ca2+ levels and release parathyroid hormone as needed (Figure 16.4a). Other hormones released in response to humoral stimuli include insulin (released in response to increased blood glucose) and aldosterone (released in response to low Na+ or high K+ blood levels). Neural Stimuli In a few cases, nerve fibers stimulate hormone release. The classic example of neural stimuli is the response to stress, in which the sympathetic nervous system stimulates the adrenal medulla to release norepinephrine and epinephrine (Figure l 6.4b). Hormonal Stimuli Many endocrine glands release their hormones in response to hormones produced by other endocrine organs. For example, releasing and inhibiting hormones produced by the hypothalamus regulate the secretion of most anterior pituitary hormones, and many anterior pituitary hormones in turn stimulate other endocrine organs to release their hormones (Figure 16.4c). As blood levels of the hormones produced by the final target glands increase, they inhibit the release of anterior pituitary hormones and thus their own release.

10. The hypothalamus communicates with the anterior pituitary via hormones released into a special portal system of blood vessels. In contrast, it communicates with the posterior pituitary via action potentials traveling down axons that connect the hypothalamus to the posterior pituitary. 11. Drinking alcoholic beverages inhibits ADH secretion from the posterior pituitary and causes copious urine output and dehydration. The dehydration causes the hangover effective. Das Hormon ADH wird im Hypothalamus (Abschnitt des Zwischenhirns) gebildet und in den Hinterlappen der Hirnanhangsdrüse (Hypophyse) gespeichert und von dort in das Blut abgegeben. Es reguliert im Körper den Wasser- und Elektrolythaushalt, indem es vor allem auf die Nieren einwirkt 12. P646 Anterior pituitary hormones Tropic hormones are hormones that have other endocrine glands as their target. Most tropic hormones are produced and secreted by the anterior pituitary.[1]: 719 The hypothalamus secretes tropic hormones that target the anterior pituitary, and the thyroid gland secretes thyroxine, which targets the hypothalamus and therefore can be considered a tropic hormone. 6 hormones: -

growth hormone, thyroid stimulating hormone, adrenocorticotropic hormone, follicle stimulating hormones, luteinizing hormone, and prolactin

LH and FSH are tropic hormones that act on the gonads, TSH (thyroid-stimulating hormone) is a tropic hormone that action the thyroid, and

ACTH is a tropic hormone that action the adrenal cortex. (If you said growth hormone, that's also a good answer, as GH causing the liver to relca.se IGFs might also be considered a tropic effect.) 13. T4 has four bound iodine atoms, and T3 has three. T4 is the major hormone secreted, but T3 is more potent. T4 is referred to as thyroxine. Thyroid Hormone (TH) Often referred to as the body's major metabolic hormone, thyroid hormone (TH) is actually two iodine-containing amine hormones, thyroxine (thi-rok'sin), or T 4, and triiodothyronine (tri"i-o"do-thi' ro-nen), or T3 . T4 is the major hormone secreted by the thyroid follicles. Most T 3 is formed at the target tissues by conversion ofT4 to T3. Both T4 and T3 are constructed from two linked tyrosine amino acids, but T4 has four bound iodine ato1ns, and T3 has three (and so the names T4 and T3) . 14. Thyroid hormone (TH) must be carried through blood by plasma proteins because it is lipid soluble and so does not readily dissolve in blood, which is mostly water. The receptors for TSH (thyroid-stimulating hormone) are located on the plasma membrane of the thyroid follicular cells (are the major cell type in the thyroid gland )(on the sides facing away from the colloid). (Recall that TSH is a water-soluble hormone from the anterior pituitary.) 15. Thyroid hormone increases basal metabolic rate (and heat production) in the body. (ref to question 14) Parathyroid hormone increases blood Ca2+ levels in a variety of ways. Parathyroid hormone (PTH), or parathormone, the protein hormone of these glands, is the single most important hormone controlling calcium balance in the blood. Precise control of calcium levels is critical because Ca2+ homeostasis is essential for so many functions, including transmission of nerve impulses, muscle contraction, and blood clotting. Falling blood Ca2+ levels trigger PTH release, and rising blood Ca2+ levels inhibit its release. PTH increases Ca2+ levels in blood by stimulating three target organs: the skeleton, the kidneys, and the intestine

Calcitonin at high (pharmacological) levels has a Ca2+ -lowering, bone-sparing effect. (Al normal blood levels its effects in humans are negligible.) Calcitonin, a polypeptide hormone released by the parafollicular, or C , cells of the thyroid gland in response to a rise in blood Ca2• levels, does not have a known physiological role in humans. In fact, calcitonin does not need to be replaced in patients whose thyroid gland has been removed. However, at pharmacological doses ( doses higher than normally found in the body), calcitonin has a bone-sparing effect and is given therapeutically to patients to treat Paget's disease and sometimes osteoporosis (bone diseases; ~ pp. 193- 194). At these high concentrations, calcitonin targets the skeleton, where it ( 1) inhibits osteoclast activity, inhibiting bone resorption and release of Ca2• from the bony matrix, and (2) stimulates Ca2• uptake and incorporation into bone matrix. 16. Thyroid follicular cells release thyroid hormone, parathyroid cells in the parathyroid gland release parathyroid hormone, and parafollicular (C) cells in the thyroid gland release calcitonin. 20. Melatonin is used by some individuals as a sleep aid, particularly to counter jet Jag. melatonin (mel"ah-to'nin), an amine hormone derived from serotonin. Melatonin concentrations in the blood rise and fall in a diurnal (daily) cycle. Peak levels occur during the night and make us drowsy, and lowest levels occur around noon. Recent evidence suggests that melatonin also controls the pro-duction of protective antioxidant and detoxification molecules within cells.

RQ

1. b; humoral,

(hypocalcemia (low blodd Ca2 triggers PTH)

2. a; antidiuretic hormone 3. c; aldosterone (Cortison ist die durch Oxidation inaktivierte Form des Glucocorticoids Cortisol, das im Kohlenhydrathaushalt, dem Fettstoffwechsel und dem Proteinumsatz ) 4. d; demineralizes bone and raises blood calcium levels.

5. (a) aldosterone (b) antidiuretic hormone (Das Antidiuretische Hormon (ADH), auch Adiuretin oder Vasopressin (INN) bzw. Arg(inin)-vasopressin (AVP) genannt, ist ein Peptidhormon.[1][2][3] Es wird von Nervenzellen

des Hypothalamus im Gehirn gebildet und im Hypophysenhinterlappen (Neurohypophyse) freigesetzt) (c) growth hormone (from ant pit) (d) luteinizing hormone (from ant pit) (e) oxytocin (Oxytocin ist ein Hormon, das im Gehirn gebildet wird, genauer gesagt vom Hypothalamus. Es kommt natürlich im Körper von Säugetieren vor und spielt unter anderem bei der Paarbindung, Orgasmen, mütterlicher Bindung, Gruppen- und Angstverhalten eine Rolle.) (f) prolactin (from ant pit) (g) T4 and T3 (throid – stimulated by ant pit) (h) TSH (from ant pit) (1)c, growth hormone: important anabolic hormone; many of its effects mediated by IGFs: (2)a and b, aldosterone and antidiuretic hormone cause the kidneys to conserve water and/or salt: (3)f, prolactin, stimulates milk production: (4)d, luteinizing hormone tropic hormone that stimulates the gonads to secrete sex hormones: (5)e, oxytocin increases uterine contractions during birth (6)g, T4 and T3 are major metabolic hormone(s) of the body: (7)a, aldosterone causes reabsorption of sodium ions by the kidneys (8)h, TSH are tropic hormone that stimulates the thyroid gland to secrete thyroid hormone: (9)b and e, antidiuretic hormone and oxytocin are secreted by the posterior pituitary: (10)a, the only steroid hormone in the list: aldosterone 6. Epinephrin (Adrenalin) gehört zur Wirkstoffgruppe der Katecholamine und ist ein natürliches Hormon des Nebennierenmarks. Als Arzneimittel wird Epinephrin zur Behandlung einer Anaphylaxie (anaphylaktischer Schock), Asthma, zur Blutstillung und für die Reanimation angewendet. d; increase heart rate, increase blood pressure, dilate the bronchioles, and decrease digestive activity. 8. b ; become a dwarf but have fairly normal body proportions 9. d; all of these 11. d; all of these. 12. b; depression of the CNS and lethargy 13. Hormones are chemical messengers secreted by cells into the extracellular fluid. They travel through the blood and regulate the metabolic function of other cells in the body. 15. *Anterior pituitary: Protrudes from the inferior surface of the brain, encased in the sella turcica of the sphenoid bone. Produces: -A) Growth Hormone(GH) which causes overall body growth but particularly skeletal & muscular growth. A lack during childhood leads to pituitary dwarfism. Oversecreting produces gigantisms (kids) or acromegaly (adult). -B) Prolactin (PRL) which stimulates lactation in females. An excess leads to inappropriate lactation. -C) Gonadotropic hormones LSH and LH, which stimulate the production of

ova/estrogen/progesterone in females and sperm/testosterone in males. A lack results in sterility. Overproduction of FSH leads to under stimulation of adrenal cortex hormones. For LH, hypersecretion also leads to infertility & miscarriage in women D) TSH, which stimulates the production of thyroxin by the thyroid gland. A lack results in hypothyroidism (cretinism in kids, myxoedema in adults). TSH hypersecretion to cause disease is rare. Can lead to increased metabolism. E) ACTH, which regulates the activity of the adrenal cortex. Hypersecretion results in Cushing's Syndrome. Hyposecretion results in Addison’s disease. *Posterior Pituitary: Releases 2 hormones made by the hypothalamus, ADH & oxytocin. A lack of ADH leads to insipidus, while oversecreting leads to hyponatremia or low blood sodium concentration. For oxytocin, hyposecretion leads to failure to progress in labour contractions as well as difficulty in milk let-down, while hyper secretion isn't commonly observed, but can lead to suppression of ACTH. *Pineal Gland: Found at the superimposition end of the 3rd ventricle in the brain. the pineal gland release melatonin, which is important for regulating sleep& wake cycles and inhibits precocious sexual development in humans. Early hyposecretion results in sexual maturity earlier than normal, while hyposecretion can lead to depression & sleepiness. *Thymus: Found in the anterior thorax, overlying the trachea and heart. Its hormone, thymosin, serves to program the T-lymphocytes of the immune system for recognition of self from oneself. Athymic individs lack the ability to mount an effective immune response. Hypersecretion isn't observed. *Pancreases: Located in the abdomen, in the mesentery btw the stomach & duodenum. Produces, insulin, (basically a hypoglycemics hormone that promotes the uptake & metabolism of glucose by body cells. lack of insulin leads to diabetes mellitus. Hypersecretion may lead to hypoglycaemia or 'insulin shock'.) Glucagon (basically a hyperglycaemic that promotes the release of glucose by liver when blood glucose levels are low. NO documented hypersecretion or hyposecretion problems. *Ovaries: Located in abdominopelvic cavity, lateral to uterus. Produces estrogen & progesterone. Lack of these hormone leads to inability to conceive kids & reduced development of secondary female characteristics. Hypersecretion can lead to premature sexual development in females & infertility. *Testes: Located in the scrotal sac, medial to the superior thighs. Produces testosterone, a lack of which leads to a reduction in sperm count & reduced development of secondary male characteristics. Hypersecretion can lead to premature sexual development in males & muscle hypertrophy. 16. The release of anterior pituitary hormones is controlled by hypothalamic-releasing (and hypothalamic-inhibiting) hormones. 17 It is a neuroendocrine organ because the hypothalamic hormones are stored in a nerve bundle called the hypothalamic-hypophyseal tract that runs from the hypothalamus to the posterior pituitary gland

18. Iodine deficiency (goiter, is a swelling in the neck resulting from an enlarged thyroid gland.) 21. The adrenal medulla and the adrenal cortex are the two most important endocrine glands in stress response. The adrenal medulla produces adrenaline which causes the following, increased heart rate, increased blood pressure, dilated bronchioles, and increased metabolic state. The adrenal medulla and the adrenal cortex are the two most important endocrine glands in stress response. The adrenal medulla produces adrenaline which causes the following, increased heart rate, increased blood pressure, dilated bronchioles, and increased metabolic state. The adrenal cortex produces glucocorticoids and mineralocorticoids, which causes the following, increased blood sugar, suppression of the immune system, increased blood volume and blood pressure, and the retention of sodium and water by the kidneys. 23. -Aging brings about changes in the rates of hormone secretion, break-down, and excretion, or in the sensitivity of target cell receptors -amt. of connective tissue increases -vascularization decreases -muscle atrophy -memory deterioration 24. Insulin should be injected because ketones accumulated in her blood, which caused her blood pH to drop resulting in acidosis, and the ketone bodies began to spill into her urine. 25. (a). The pituitary tumour is secreting out excessive amounts of the growth hormone. (b). Johnny will exhibit structural abnormities, namely gigantism, if the proper corrective measures are not taken. (c). The probable ...