URGE Quiz and BOFs Flashcards
- Endorphin and ACTH are both produced from the same precursor protein POMC
The correct answer is:
- Which endocrine hormone is released by somatotrophs? → Growth hormone,
- Which hormone acts to increase the reabsorption of water from the collecting ducts and distal convoluted tubules of the kidney? → Antidiuretic hormone,
- Which hormone is co-released with adrenocorticotropic hormone? → Endorphin
Cortisol is a steroid hormone, which bind to an intracellular receptor. All other hormones are peptide hormones that bind to membrane receptors.
The correct answer is: Cortisol
A cytokine is a regulatory peptide, usually acting close to the site where it is secreted, to control cell development, differentiation and the immune response. In stress and inflammation, cytokines are transported in the circulation to act on distant targets. They differ from hormones in that they are made on demand and are not secreted from specialised glands. A paracrine is a chemical secreted by a cell to act on cells in its immediate vicinity. A chemical that acts on the cell that releases it is an autocrine. A neurotransmitter is a chemical released from a neurone and diffuses across a narrow extracellular space to act on its target cell.
The correct answer is: Hormone
The correct answer is: Pituitary : hypothalamus
The correct answer is: Negative feedback mechanisms
Prolactin is released from the anterior pituitary by PRH (prolactin releasing hormone) (vasoactive intestinal peptide) produced in the hypothalamus and released into the hypothalamic-pituitary portal system for circulation to the anterior pituitary. Dopamine is produced in the hypothalamus and released into the hypothalamic-pituitary portal system for circulation to the anterior pituitary where it acts to inhibit the release of prolactin. Calcitonin is released from the thyroid gland (from parafollicular “C” cells) in response to increasing plasma [Ca++]. Oxytocin and antidiuretic hormone are posterior pituitary neurohormones released from nerve terminals with direct neuro-connection to the hypothalamus and requiring no releasing factor.
The correct answer is: Prolactin
The release of growth hormone stimulating hormone (GHSH) is pulsatile and occurs principally during deep sleep. In turn the GHSH pulse stimulates pulsatile release of growth hormone during sleep.
The correct answer is: GH – Growth hormone / somatotropin
All steroid hormones are produced from cholesterol as a precursor. The initial common pathways occur in ALL steroid hormone producing cells. Not all lipophilic hormones are produced from cholesterol (thyroid hormone is formed from the amino acids tyrosine). Dehydrocholesterol is formed in the skin and is a precursor for Vitamin D, but this is not the rate limiting step in its pathway.
The correct answer is: Steroid hormone production because cholesterol is a precursor for all steroid hormones.
If there is a normal femoral pulse, this indicates there is not a significant blockage here, otherwise it would be a “water-hammer”, extra strong pulse. If there was a blockage in the deep femoral artery, then there would still be a popliteal pulse. If there was a femoral aneurysm, the femoral and/or popliteal pulses would actually be easier to feel. The most sensible location for a blockage in this case is the superficial femoral artery at the adductor hiatus. Blockages here are due to atherosclerotic processes, since this location of the artery is subjected to extra stress and forces due to passing through the connective tissue of the adductor hiatus. Embolus normally lodge at a bifurcation, so they are common in branching of the internal carotid or common femoral artery, but not likely in the location of the adductor hiatus.
The correct answer is: In the superficial femoral artery at the adductor hiatus due to atherosclerosis
The neurohypophysis (posterior pituitary) is derived from an evagination of diencephalic neurectoderm. This structure is responsible for releasing oxytocin and ADH to the general circulation. Both hormones are synthesized in cell bodies contained within the hypothalamus. ACTH, prolactin, and TSH are all synthesised and released by the anterior pituitary, or adenohypophysis, which is derived from an evagination of the ectoderm of Rathke’s pouch, a diverticulum of the primitive mouth. Epinephrine is synthesised and released into the circulation by the adrenal medulla, a neural crest derivative.
The correct answer is: Oxytocin
- Low levels of GHRH and growth hormone will retard growth but it is the GHBP that is genetically predetermined and its low levels will affect the circulating levels of growth hormone.
- In pregnancy, elevated oestrogen levels stimulate production of thyroxin binding globulin, which lowers the free circulating levels of thyroxin and triiodothyronine and reduces negative feedback inhibition of thyrotropin releasing hormone, thyroid stimulating hormone and T3 & T4. The result is increased production of triiodothyronine (T3) and thyroxine (T4) until equilibrium is restored.
- Thyroid hormone stimulates growth hormone production in childhood. Its absence leads to inadequate growth hormone and poor bone growth and mental retardation. With thyroxine treatment, the bone growth can be largely restored but mental function cannot.
The correct answer is:
1. A low circulating plasma level of what factor is the most likely non-pathological, genetic determinant of short stature in this case? → Growth hormone binding protein,
- During her pregnancy, Eloise’s total circulating triiodothyronine was elevated. This is a normal response that arises indirectly following the stimulatory effect of which pregnancy related factor? → Oestrogen,
- Eloise’s child shows signs of retarded bone growth, and mental retardation in early childhood and reduced thyroid function is detected. Production of which factor that might contribute to the poor growth is likely to be reduced as a result of the reduced thyroid function? → Growth hormone
The exogenous cortisol inhibits ACTH production, and the adrenal cortex becomes atrophic.
The correct answer is: Atrophy of the cortex
Ataxia is an irregularity in muscular function, Alexithymia is the impaired ability to understand, process, or describing emotions, Alogia is a deficiency in the amount or content of speech, Agnosia is an inability to recognize and name objects.
The correct answer is: Anhedonia
An increased plasma potassium concentration and increased ACTH also trigger the secretion of aldosterone but a decrease in intravascular blood volume is the primary stimulus.
The correct answer is: A decrease in effective intravascular blood volume
This is due to negative feedback of T3 and T4 to reduce TRH release and in-turn to reduce TSH release. The feedback would also directly inhibit the release of TSH and thyroid hormones. Goitre occurs when the thyroid is overstimulated.
The correct answer is: The secretion rate of TRH declines
Cortisol produces immunosuppression and will cause the organs of the immune system (e.g. thymus) to shrink. Negative feedback will cause the release of CRH to decrease but the cell bodies reside in the hypothalamus, not the anterior pituitary. ACTH release from the anterior pituitary will be reduced through negative feedback. Cortisol promotes breakdown of fat and proteins and will cause body mass to decrease.
The correct answer is: The person develops a decrease in thymus mass
The elevated T4 and T3 show a hyperthyroid state. Opposite effects on TSH (lowered levels) indicate the problem is at the thyroid itself, since the elevated T4 and T3 are still feeding back to the hypothalamus and pituitary to reduce the output of TSH. When levels of T3, T4 and TSH are all affected similarly (i.e. all elevated or all lowered), then this is usually a problem at the hypothalamus or pituitary and thus a secondary form of hypo- or hyperthyroidism. If the lady’s TBG and TSH were elevated, she could be euthyroid and pregnant, but this does not result in an enlarged thyroid gland. The thyroid hormone level profile and the enlarged thyroid gland in this case could point to Grave’s autoimmune disease.
The correct answer is: Hyperthyroid, primary cause at the level of the thyroid
Your answer is incorrect.
The inferior cervical ganglion contains cell bodies of postganglionic sympathetic neurons that innervate the head and neck, and also that contribute to the cardiopulmonary plexuses.
The correct answer is: Reduced sympathetic innervation to the head and neck
Your answer is incorrect.
Spinal nerves leave from all spinal cord segments and all of them carry somatic motor and sensory information. Spinal nerves innervate all somatic areas from the neck down. Cranial nerves innervate somatic structures in the head (and also the neck too). All spinal nerves also carry sympathetic innervation to get to the muscles and sweat glands for a sympathetic response - this is to the limbs but also the trunk. Parasympathetic innervation is only to the trunk, these do not need to travel with spinal nerves.
The correct answer is: Somatic motor and sensory information and sympathetic innervation, to the neck down
Vasopressin (otherwise known as antidiuretic hormone) is a hypothalamic neuro-hormone released from the posterior pituitary in response to osmoreceptor activation it activates ADH receptors to reabsorb and retain water in the body. Dopamine is a hypothalamic neuro-hormonel which is released into the hypothalamic-pituitary portal system and acts on receptors in the anterior piruitary unconnected with fluid retention. The other substances are produced peripherally.
The correct answer is: Antidiuretic hormone
Renal sympathetic nerve stimulation releases norepinephrine which acts on the beta-adrenoreceptors on the juxtaglomerular cells of the renal afferent arterioles stimulating secretion of renin. Angiotensin II reduces renin secretion by feedback inhibition. ANP acts to inhibit reabsorption of sodium and water, thus counteracting the response to renin but has no effect on renin secretion. Increased glomerular filtration has no direct effect on renin secretion. Increasing mean blood pressure will stimulate baroreceptor reflexes and reduce sympathetic nervous activity. It will also increase pressure in the renal afferent arterioles and inhibit renin release.
The correct answer is: Increasing sympathetic nerve activity
a) By inhibiting the stimulatory effect of aldosterone on Na+ reabsorption an aldosterone antagonist will indirectly increase renin secretion and hence increase Ang II.
b) Angiotensin AT1 receptor antagonists will inhibit the negative feedback of Ang II on renin secretion, which will increase and hence increase Ang II.
c) Arterioloar vasodilators will increase flow through the renal artery and stimulate renin secretion and hence increase Ang II.
d) Beta blockers are antagonists of the actions of epinephrine and norepinephrine at beta-adrenoreceptors. Beta adrenoreceptors mediate the stimulatory effects of the sympathetic nervous system on renin release from the juxtaglomerular cells of the kidney afferent arterioles. Beta-blockers will reduce the stimulus for renin release from the juxtaglomerular cells, decrease renin secretion and hence decrease Ang II.
e) Loop diuretics will reduce reabsorption of Na+ and reduce swelling of the macula densa cells, thereby increasing renin secretion and hence increase Ang II.
The correct answer is: Beta-blocker
ACh acting at muscarinic receptors, noradrenaline released from sympathetic nerves causes relaxation of the detrusor muscle, ATP is co-released with acetylcholine but from parasympathetic nerves.
The correct answer is: acetylcholine released from parasympathetic nerves acting at muscarinic M3 receptors.
During bladder filling, the sympathetic innervation of the bladder dome keeps the detrusor muscle relaxed, allowing the bladder to expand at low pressure.
The correct answer is: Bladder filling occurs at low intravesical pressure.
- Contraction of detrusor muscle occurs through release of acetylcholine from the parasympathetic nerve afferents contained within the pelvic nerve
- The external urethral sphincter contraction is maintained during bladder filling by acetylcholine released from the pudendal nerve acting on nicotinic receptors
The correct answer is: 1. Initiates contraction of the detrusor muscle during voiding → Pelvic nerve, 2. Maintains contraction of the external urethral sphincter during bladder filling → Pudendal nerve, 3. Integrates signals from the brain and bladder to determine when an appropriate time to void would be → Pontine micturition centre
Urea is the major nitrogen waste product excreted in the urine which also contains uric acid, creatinine & ammonium ions but in smaller amounts than urea.
The correct answer is: Urea
The correct answer is: Cortex
The left renal vein is crossed by the superior mesenteric. This vessels leaves the aorta at a sharp descending angle and can press of the left renal vein which is longer since it has to cross the aorta and the midline to the IVC.
The correct answer is: In the left renal vein because it is crossed by the superior mesenteric artery which may occlude it
Aldosterone is the primary regulator of water balance through its effects on the kidney to retain sodium and excrete potassium, which increases water retention (as sodium is the predominant osmotically active ion in the ECF) and increases blood volume.
The correct answer is: Regulate Na+ and water balance in the ECF
The hypothalamus is the endocrine centre which responds to external factors such as stress to stimulate the release of CRH, which in turn stimulates the release of ACTH by the anterior pituitary, then glucocorticoid production is triggered in the adrenal cortex.
The correct answer is: Hypothalamus
Plasma hydrostatic pressure of 55mm Hg is OUT of the glomerulus, whereas both the other pressures (plasma colloid pressure of 20 mm Hg and Bowman’s fluid pressure of 25 mm Hg) are of a direction of fluid movement INTO the glomerulus, since the proteins are in the fluid within the glomerulus and thus want to draw water in that way. Therefore, the balance is 55 – (20 +25) = 10mm Hg in the direction of the balance which is OUT of the glomerulus, i.e. the pressure favours fluid to pass into the capsule.
The correct answer is: 10mm Hg into Bowman’s capsule
The descending limb of the loop of Henle is water permeable while the ascending limb is water impermeable. The fluid in the loop of Henle goes from isotonic when it enters the medulla, to hypertonic deep in the medulla, and ends up hypotonic when it leaves the medulla due to the active pumping out of ions in the thick ascending limb, along with water impermeability here, which means water does not also leave the tubule.
The correct answer is: The water impermeability of the thick ascending loop and urine that is hypotonic at the end of the Loop of Henle
The perinephric fat surround the kidney and its capsule, but is contained by the renal fascia. The renal fascia of one kidney extends over across the large vessels (abdominal aorta and IVC) and surrounds the contralateral kidney and perinephric fascia.
The correct answer is: It is contained in the area where the perinephric fat lies and could physically affect the large vessels and ipsilateral kidney
- Contraction of detrusor muscle occurs through release of acetylcholine from the parasympathetic nerve afferents contained within the pelvic nerve
- The external urethral sphincter contraction is maintained during bladder filling by acetylcholine released from the pudendal nerve acting on nicotinic receptors
The correct answer is: 1. Initiates contraction of the detrusor muscle during voiding → Pelvic nerve, 2. Maintains contraction of the external urethral sphincter during bladder filling → Pudendal nerve, 3. Integrates signals from the brain and bladder to determine when an appropriate time to void would be → Pontine micturition centre
ACh acting at muscarinic receptors, noradrenaline released from sympathetic nerves causes relaxation of the detrusor muscle, ATP is co-released with acetylcholine but from parasympathetic nerves.
The correct answer is: acetylcholine released from parasympathetic nerves acting at muscarinic M3 receptors.
During bladder filling, the sympathetic innervation of the bladder dome keeps the detrusor muscle relaxed, allowing the bladder to expand at low pressure.
The correct answer is: Bladder filling occurs at low intravesical pressure.
Urea is the major nitrogen waste product excreted in the urine which also contains uric acid, creatinine & ammonium ions but in smaller amounts than urea.
The correct answer is: Urea
Ascending infection via a refluxing vesicoureteric junction is by far the most likely for a faecal organism like E. coli. Haematogenous renal infection does occur, but generally in conditions such as tuberculosis and infective endocarditis. The other routes of infection would be exceptionally rare for any organism.
The correct answer is: ascending infection from the bladder
A greater anion gap indicates that acid has been added to the system. An acid = H+ plus an anion (A-), e.g. lactic acid = hydrogen cation plus lactate anion. When extra acid is in plasma, bicarbonate ions will be used to buffer the extra H+, therefore the measurable plasma level of bicarbonate (HCO3) will be decreased. Because the unmeasurable anion(s) from this acid are making up the total anions, and the usually measurable HCO3 anions are lower, any increase in the anion gap is directly proportional to a decrease in the amount of measured HCO3 anions.
The correct answer is: A decrease in bicarbonate levels
- As Candida is a yeast, it does not respond to antibiotic therapy.
The correct answer is: 1. Mary describes symptoms of urinary frequency and burning when voiding. You suspect she has a urinary tract infection. The most likely causative organism is? → Escherichia coli, 2. You prescribe ampicillin antibiotics for Mary which she takes for 5 days. On completion of her antibiotics she develops diarrhoea. The most likely causative organism is? → Clostridium dificile, 3. Antibiotics are an ineffective treatment and Mary’s symptoms persist. You do a urine dipstick test and see high level pyuria but negative for nitrates. What organism do you now suspect? → Candida albicans
Because creatinine is freely filtered by the glomerulus, but not secreted or reabsorbed to a significant extent, the renal clearance of creatinine is approximately equal to the glomerular filtration rate. In fact, creatinine clearance is commonly used to assess renal function in the clinical setting. When a kidney is removed, the total glomerular filtration rate decreases because 50% of the nephrons have been removed, which causes the creatinine clearance to decrease. In turn, the plasma creatinine concentration (choice D) increases until the rate of creatinine excretion by the kidneys (choice E) is equal to the rate of creatinine production by the body. Recall that creatinine excretion = GFR x plasma creatinine concentration. Therefore, creatinine excretion is normal when GFR is decreased following removal of a kidney because the plasma concentration of creatinine is elevated. Creatinine is a waste product of metabolism. Creatinine production (choice B) is directly related to the muscle mass of an individual, but is independent of renal function. The daily excretion of sodium (choice C) is unaffected by the removal of a kidney. The amount of sodium excreted each day by the remaining kidney exactly matches the amount of sodium entering the body in the diet.
The correct answer is: Creatinine clearance
The perirenal and pararenal fat support the kidney. The kidneys are surrounded by fascia that attaches the kidneys to the diaphragm and across the aorta and IVC to the contralateral kidney. While detachment of the renal fascia at the diaphragm can contribute to nephroptosis, this is not consistent with the description. The septum between the kidney and the adrenal gland is not really supportive, it is quite weak and would not cause displacement of the kidney. Nephroptosis results in kinking of the ureter.
The correct answer is: Loss of pararenal and/or perirenal fat
Adrenergic receptor agonists directly inhibit pancreatic insulin secretion. Antidiuretic hormone is associated with diabetes insipidus a disease characterized by excretion of large amounts of severely diluted urine and excessive thirst due to an inability of the kidney to reabsorb water rather than due to increased glucose excretion Cholecystokinin is a hormone that not only causes gallbladder contraction, but also causes insulin secretion from the pancreas. Pancreatic glucagon release acts as a paracrine stimulus for insulin secretion. Ingestion of high-sugar meals is a stimulus for the secretion of insulin from the pancreas. Muscarinic activity in the GI tract enhances secretion of insulin from the pancreas.
The correct answer is: Adrenergic agonist
Before you started analyzing all of the answer choices you should have reminded yourself that glucagon increases serum glucose. So an enzyme stimulated by glucagon might be involved in either the breakdown of glycogen to glucose (glycogenolysis) or in the creation of glucose from noncarbohydrate precursors (gluconeogenesis). Glycogen phosphorylase catalyzes the first step in glycogenolysis; it makes sense that it would be stimulated by glucagon. Glucokinase catalyzes the conversion of glucose to glucose-6-phosphate which helps lock glucose inside the cell. As its name implies, glycogen synthase is involved in the synthesis of glycogen. Glucagon (and epinephrine) stimulates the phosphorylation and inactivation of glycogen synthase. HMG-CoA reductase is the key enzyme involved in the synthesis of cholesterol. Since this is an anabolic process that occurs in the well-fed state, you would expect it to be stimulated by insulin and inhibited by glucagon (which it is). Pyruvate kinase catalyzes the last reaction of glycolysis. You would expect it to be inhibited by glucagon (thus decreasing the amount of glucose consumption). Glucagon promotes the phosphorylation of pyruvate kinase, which renders it inactive.
The correct answer is: Glycogen phosphorylase
Select one:
a.
Glucagon
b.
Insulin
c.
Pancreatic polypeptide
d.
Proinsulin
e.
Somatostatin
The region circled is the centre of a pancreatic islet. The pancreatic B-cells are localized to the centre of the islet. These cells secrete Insulin, C peptide, amylin and a small amount of proinsulin. Glucagon is secreted by the A cells which are located more peripherally. Scattered throughout the islet are the D cells and the F cells which secrete somatostatin and pancreatic polypeptide respectively.
The correct answer is: Insulin
Lack of insulin would result in a metabolic setting that resembles ‘starvation’, which means that processes that are normally activated by insulin are NOT active (i.e., glycogen synthesis). In contrast, those processes, which are normally blocked by insulin, are now active (i.e., lipolysis stimulated by hormone-sensitive lipase in adipose tissue [NOT in the liver]). Ketone body formation (e.g. β-hydroxybutyrate) is activated
The correct answer is: Increased gluconeogenesis from lactate
Lipoprotein lipase is important for the extraction of triacyl glycerols from both chylomicrons and VLDLs; therefore answer B is correct.
The correct answer is: Elevation of both plasma chylomicrons and very low-density lipoproteins.
Chylomicrons are normally synthesised in the intestinal epithelial cells after a meal. They serve to transport the dietary fatty acid into the lymphatic system and eventually into the blood. Synthesis of apolipoproteins is necessary for their assembly. Defects result in the accumulation of fats in these epithelial cells.
The correct answer is: Decreased synthesis of an apolipoprotein.