- What tissue is found at the end of the arrow?
- Infundibulum
- Pars tuberalis
- Pars intermedius
- Pars nervosa
- Pars distalis(Answer E.)
- Thyroglobulin is produced from which of the following types of cells?
- A
- B
- C
- D
- None of these cells secrete thyroglobulin.(Answer E. Thyroglobulin is secreted by follicular cells.)
- Which of the following hormones is produced by an acidophilic cell type?
- Prolactin (PRL)
- Follicle Stimulating Hormone (FSH)
- Luteinizing hormone (LH)
- Adrenal corticotropin (ACTH)
- Lipotropin (LPH) (Answer A. Lactotrophs (PRL production) and Somatotrophs (GH production) are both acidophilic cells.)
- A pituitary adenoma secreting somatotropin in a child would cause which of the following conditions?
- Addisons’ Disease
- Congenital adrenal hyperplasia
- Type I DM
- Gigantism
- Acromegaly (Answer D.)
- Pitocin is a synthetic oxytocin injection often used to induce labour. Although it is man-made, the drug works identical to the naturally occurring hormone Oxytocin. Which of the following is a potential side effect of excessive Pitocin?
- Hypertension
- Increased frequency in urination
- Milk synthesis
- Postpartum depression
- Hyperkalemia(Answer A. Oxytocin has a structure extremely similar to ADH therefore it can also play a role in Na+ and water retention. Na+/water retention can lead to hypertension.
- After seeing a patient who has been complaining of diarrhea for several days, you decide to take a stool sample and evaluate the sample microscopically. After using an acid-fast stain, you see an abundance of a large organism in the range of 10 micrometers. What is the most likely organism for you to have found?
- Entamoeba histolytica
- Cyclospora
- Cryptosporidium
- Mycobacterium
- Toxoplasma gondii(Answer B.)
- A patient with a history of AIDS presents to your clinic with a complaint of diarrhea for the last 3 days. Which of these would be most concerning in regards to your patient?
- Giardia lamblia
- Cryptosporidium
- Entamoeba histolytica
- Trypanosoma brucei
- Pediculus humanus(Answer B.)
- A patient in the hospital has been experiencing a recurring fever and hematuria over the past week and imaging shows signs of cerebral hemorrhage. Blood analysis shows a protozoan infection affecting all RBCs. What is a likely specimen that could be causing these clinical presentations?
- P. falciparum
- P. malariae
- P. vivax
- P. ovale
- P. rotundum(Answer A. Falciparum causes cerebral lesions due to “sticky RBCs” and affects all RBCs. Malariae affects older RBCs, and vivax and ovale affect primarily immature RBCs.)
- What is the invading organism in the blood smear shown below?
- Toxoplasma gondii
- Entamoeba histolytica
- Giardia lamblia
- Plasmodium falciparum
- Babesia microti(Answer E. The infected cells have the maltese cross associated with babesia. Giardia would have a characteristic “clown face”. Plasmodium falciparum has the banana-shaped gametocyte.)
- Congenital adrenal hyperplasia is caused by a lack of which hormone?
- Aldosterone
- Cortisol
- Androstenedione
- DHEA
- ACTH(Answer B. This condition will cause low levels of cortisol, which is critical for it’s negative feedback effect on the anterior pituitary. Without this feedback, ACTH levels rise, resulting in hyperplasia of the adrenal glands.)
- A 23 year old female presents with severe hypotension, nausea, irregular heart rhythm, and exhaustion. Blood tests confirm hyperkalemia with low mineralocorticoid and glucocorticoid levels. Physical exam is otherwise unremarkable. Which adrenal enzyme would you expect to be low in a patient with this presentation?
- CYP21A2
- CYP17A1
- Aldosterone synthase
- HSD3B2
- CYP19A1(Answer A. 21 hydroxylase deficiency would present with these symptoms due to low aldosterone and cortisol. If the patient were unable to make progesterone, androgens or estrogens, it would be apparent on clinical presentation. Aldosterone synthase deficiency would still allow for cortisol synthesis.)
- A 57 year old caucasian male presents to the clinic with difficulty swallowing, enlarged lymph nodes, and a hoarse voice. Endoscopy reveals a mass in the distal esophagus. A biopsy is taken and is identified as esophageal adenocarcinoma. The patient has had a long history of gastroesophageal reflux. Which of the following correctly describes the metaplasia of the esophageal epithelium that most likely occurred prior to this patient’s diagnosis?
- Simple Columnar to stratified squamous
- Stratified squamous to simple columnar
- Stratified squamous to simple cuboidal
- Simple cuboidal to stratified squamous
- Stratified squamous to transitional epitheliumAnswer B. Barrett’s esophagus is metaplasia of the esophageal epithelium where SSE → Simple Columnar Epithelium. It is more likely in patients >50 y/o and results from gastroesophageal reflux. It is a common precursor of esophageal adenocarcinoma.
- A 32 year old female presents to the clinic 12 weeks pregnant. Upon further testing, you discover that her total T3/T4 levels are high. Which of the following is TRUE regarding this patient?
- She will have symptoms of hyperthyroidism brought about by the high levels of hCG during pregnancy
- She will have symptoms of hypothyroidism brought about by the high levels of hCG during pregnancy
- She most likely has Graves’ disease
- Iron deficiency anemia associated with pregnancy will cause hyperthyroidism
- If tested, her free levels of thyroid hormones would most likely be normal.(Answer E. While hCG causes an increase in total T3/T4, fT3/fT4 levels will be normal. Therefore, pregnancy is not usually associated with symptoms of hyperthyroidism.)
- Which of the following is a potential symptom of hypothyroidism?
- Heat intolerance
- Weight loss
- Hypercholesterolemia
- Tachycardia
- Palpitations (Answer C. Thyroid hormones (T3) function to increase lipolysis, increase LDL, and decrease plasma cholesterol. Therefore, hypothyroidism can result in hypercholesterolemia. All other answers are symptoms of hyperthyroidism.)
- A 6 month old female patient presents to the clinic with symptoms of iodine deficiency. Urinalysis reveals high levels of MIT and DIT. Which of the following is most likely deficient?
- Selenodeionidase
- TPO
- NIS
- Pendrin
- iodotyrosine deiodinase(Answer E.)
- Selenium deficiency could result in which of the following symptoms?
- Water hammer pulse pressure
- Hyperreflexia
- Cardiomegaly
- Heat intolerance
- Weight loss(Answer C. Selenium deficiency would result in hypothyroidism due to an inability to convert T4 to T3 (dysfunction of D1/D2). Cardiomegaly is the only symptom characteristic of hypothyroidism.)
- You are on rotations in OB-GYN when a a 25 year old woman presents to the clinic 6 weeks pregnant. She reports having recent symptoms of slow reflexes, intolerance to cold, and goiter within the last 6 months. You learn that she has been only consuming himalayan pink salt because it’s “all natural.” What is your main concern regarding this patient?
- Deficient intrauterine T3 can result in mental and growth retardation in her fetus
- Her hCG levels may be low indicating a problem with the pregnancy
- Although her fetus won’t be affected, you recommend that the woman be treated for Iodine deficiency.
- This patient most likely has a congenital hypothyroidism and should be placed on a synthetic thyroid hormone
Overactive TSH from Iodine deficiency would lead to increase T3 and developmental delays in the fetus.(Answer A. The question stem indicates that she has hypothyroidism caused by an Iodine deficiency which would result in an ability to make thyroid hormones. T3 is vital for fetal brain development and growth (T3 stimulates IGF-1 and GH). Therefore, your main concern regarding pregnant women with any type of hypothyroidism should be the effects on the fetus. While low hCG levels can indicate a problem with the pregnancy, it often doesn’t result in hypothyroidism. This woman doesn’t have congenital hypothyroidism or her symptoms would have been present from childhood. While TSH is increased in Iodine deficiency (explains the goiter), an increase in T3 would not lead to developmental delays.)
- The detection of increased levels of 24,25-hydroxycholecalciferol would be accompanied by which of the following?
- Elevated plasma concentration of calcium
- Elevated levels of parathyroid hormone
- Decreased plasma concentration of thyroid hormones
- Decreased plasma concentration of Vitamin D3
- Elevated levels of 25-hydroxycholecalciferol(Answer A.)
- Stimulation of the endocrine function of pancreatic alpha cells can be inhibited by:
- Norepinephrine
- High plasma amino acid concentration
- Epinephrine
- Somatostatin
- Hypoglycemia(Answer D.)
- Which of the following hormones is NOT considered to be ketogenic?
- Glucagon
- Cortisol
- Growth Hormone
- Insulin
- DHEA(Answer D.)
- A common biomarker for pancreatic adenocarcinomas reduces gastric emptying time by binding to Y4 receptors. Which pancreatic cell type secretes this hormone?
- α cells
- β cells
- ε cells
- δ cells
- F cells(Answer E. F cells secrete pancreatic peptide (PP).)
- In a male patient with epispadias, the urethral tract has improperly fused during development. At what point in male embryological development is the full urethral tract completed?
- 4th week
- 7th week
- 9th week
- 11th week
- 12th week(Answer D.)
- During the development of the female reproductive system, it is possible for the superior portion of the paramesonephric ducts to fail to fuse. Which abnormality would arise in this scenario
- Double uterus with double vagina
- Double uterus with single vagina
- Bicornuate uterus
- Unicornuate uterus
- Divided uterus(Answer C.)
- A male patient is born with an external urethral orifice on the ventral surface of the glans, a condition known as?
- Epispadias
- Hypospadias
- Hydrocele
- Cryptorchidism
- Peraspadias(Answer B.)
- Which of the following statements is true concerning the regulation of hormone secretion by GnRH neurons?
- GnRH neuronal activity is increased by activation of sex steroid hormone receptors on the GnRH neurons
- GnRH neuronal activity is decreased by activation of sex steroid hormone receptors on the GnRH neurons
- GnRH neuronal activity is increased by activation of kisspeptin receptors on the GnRH neurons
- GnRH neuronal activity is decreased by activation of neurokinin B receptors on the GnRH neurons
- GnRH neuronal activity is increased by activation of beta endorphin receptors on the GnRH neurons(Answer C. A and B are both incorrect, because GnRH neurons do not have primary receptors for sex hormones such as estrogen, progesterone, or androgens. Neurokinin B increases GnRH and beta endorphin decreases GnRH.)
- A person with a deficiency in 17βHSD type 3 would have a problem with which steroidal reaction?
- Activation of estrogens
- Deactivation of estrogens
- Activation of androgens
- Deactivation of androgens(Answer C.)
- Which of the following is a function of the zona pellucida?
- Prevents polyspermy
- Facilitates fertilization
- Protects zygotes against immunologic rejection
- A & B
- A, B & C(Answer E. This is a pretty simple question but make sure you know these functions! Hef mentioned this multiple times throughout these three lectures so it must be important.)
- Which of the following hormones is DIRECTLY responsible for ovulation?
- LH
- Estradiol
- Progesterone
- FSH
- Estrone(Answer A. The LH surge (caused by high amounts of estrogen) is responsible for ovulation. While estrogen does play a role in initiated the LH surge (high E2/Estradiol → +AVPV → +Kisspeptin → +GnRH → +LH), the most direct hormone in play is LH.)
- Which of the following mechanisms has been hypothesized to cause hormonal atresia?
- Lack of sufficient aromatase receptors in non-dominant follicles lead to a build up of androgens and production of Estrogen leading to atresia
- Lack of sufficient aromatase receptors in non-dominant follicles leads to a build up of FSH causing the death signal associated with atresia
- The LH surge in the non-dominant follicles causes atresia
- Lack of progesterone in the non-dominant follicle causes atresia
- Lack of sufficient aromatase receptors in non-dominant follicles lead to a build up of androgens and production of DHT leading to atresia(Answer E.)
- The menstrual phase of the uterine cycle is closely correlated with which of the following?
- Low progesterone and high estrogen
- Low progesterone and low estrogen
- High progesterone and low estrogen
- High progesterone and high estrogen
- Presence of the corpus luteum(Answer B. The menstrual phase of the uterine cycle is closely correlated with low levels of estradiol and progesterone due to the degeneration of the corpus luteum into the corpus albicans.)
- Which of the following hormones is responsible for the onset of the secretory phase of the uterine cycle?
- Estradiol
- Estrone
- Progesterone
- FSH
- LH(Answer C. Progesterone is responsible for converting the endometrium into a highly vascularized, glycogen filled tissue. Recall that this glycogen supplies the nutrients to the zygote prior to implantation in a process known a decidualization.)
- Which of the following hormones is responsible for the slight increase in body temperature associated with early pregnancy?
- Estradiol
- Estrone
- Progesterone
- FSH
- LH(Answer C.)
- It is not uncommon for women suffering from malnutrition to become infertile. Which of the following best explains the mechanisms for how this infertility arises?
- Hunger stimulates both CRH and ACTH which act to induce beta-endorphin and inhibit GnRH secretion
- Hunger stimulates CRH and ACTH which act on Arcuate Kisspeptin to inhibit GnRH secretion
- Increased cortisol directly inhibits GnRH secretion
- Increased cortisol directly inhibits LH secretion
- Increased cortisol directly inhibits FSH secretion(Answer A.)
- Which of the following best describes the mechanism for progesterone-only contraceptive pills?
- It causes the cervical mucus to become thin and watery
- It causes a ferning effect on the cervical mucus
- Prevents the LH surge
- Increase the thickness of the cervical mucus
- Increase uterine contractions and causing miscarriage(Answer D. Estrogen causes the cervical mucus to become thin and watery (known as the ferning effect). Answer choice C explains how birth control pills using estrogen mimics work to prevent ovulation. Uterine contractions is usually associated with estrogen and inhibited by progesterone. Answer choice E explains how many emergency contraceptive pills work. They use a progesterone antagonist to inhibition progesterone’s inhibition on uterine contractions and cause miscarriage.)
- Which of the following is NOT associated with menopause?
- Higher risk for osteoporosis
- Higher risk for cardiovascular disease
- Low Estrogen
- Elevated Gonadotropins
- High progesterone(Answer E.)
- Which of the following is TRUE regarding estrogen?
- E1 (estrone) is the most active form
- E2 (estradiol) is most closely associated with pregnancy
- Estrogens bind to albumin with high affinity
- More Estrogens are bound to albumin than SHBG
- E3 (estriol) is the main estrogen produced during menopause(Answer D.)
- hCG is produced by which of the following?
- Chorionic villi
- Corpus luteum
- Corpus albicans
- Granulosa cells
- Theca interna cells(Answer A.)
- You are on rotations in the OB-GYN when a 24 year old female presents for her first prenatal appointment following a positive home pregnancy test. You are performing follow up bloodwork and urinalysis to confirm pregnancy. Assuming the patient is otherwise healthy, what would be a normal substance to find in excess in her urine?
- Potassium
- Bicarbonate
- Calcium
- Sodium
- Testosterone(Answer B. Progesterone increases the respiratory center in pregnant women. This is beneficial because it increase maternal blood affinity for CO2 and allows for easier fetal CO2 extraction. It is common for pregnant women to acquire mild respiratory alkalosis with increased respiration. Respiratory alkalosis will result in HCO3- in the urine.)
- Gestational diabetes is a condition in which a woman without diabetes develops high blood sugar levels during pregnancy. It increase the risk of pre-eclampsia, depression, and requiring a Caesarean section. Which of the following hormones is most likely associated with gestational diabetes?
- Relaxin
- Human chorionic Gonadotropin
- Growth Hormone
- Progesterone
- Human chorionic somatomammotropin(Answer E.)
- Organophosphates are toxic agents used in insecticides, medications, and nerve agents. The underlying mechanism involves the inhibition of acetylcholinesterase, leading to the buildup of acetylcholine (ACh) in the body. Which of the following is a likely effect of Organophosphate poisoning on the GI system?
- Increased excitability of smooth muscle and diarrhea
- Increased excitability of smooth muscle and constipation
- Decreased excitability of smooth muscle and diarrhea
- Decreased excitability of smooth muscle and constipation
- Increased excitability of skeletal muscle and diarrhea (Answer A. Increased ACh would cause depolarization and increase the excitability of smooth muscle fibers. This would in turn lead to increase GI motility and diarrhea. Recall the mnemonic “SLUDGE” for a cholinergic crisis from past lectures and that the “D” stands for Defecation and the “G” stands for GI distress due to increased motility and, thus, cramping.)
- Diltiazem is a medication used to prevent chest pain by blocking L-type calcium channels Which of the following is a likely side effect of a patient taking Diltiazem?
- Hypertension
- Tachycardia
- Diarrhea
- Constipation
- Psychosis(Answer D. L-type calcium channels are also involved in GI depolarization. When blocked, GI motility will be decreased and thus this medication can often have the side effect of constipation.)
- You are on rotations in the Emergency Department when a 19 year old male presents following a heroine overdose. Your attending administers Naloxone (Narcan) to reverse the overdose. When the patient finally becomes conscious, the attending asks you to inform the patient of the side effects of this drug. Which of the following is a potential GI side effect from Naloxone?
- Constipation
- Bloating
- Diarrhea
- Hematochezia
- Melena(Answer C. Naloxone blocks opioid receptors leading to diarrhea.)
- Vagotomy is a surgical procedure that involves removing part of the vagus nerve. This procedure is done typically to reduce the rate of gastric secretion (e.g. in treating peptic ulcers). Which of the following structures would NOT be affected in a patient that has undergone a vagotomy
- Small intestine
- Upper colon
- Pancreas
- Esophagus
- Sigmoid colonAnswer E. The Vagus nerve is responsible for Parasympathetic innervation to the proximal ⅔ of the GI system. Sacral parasympathetics innervate the distal half of the large intestine.
- It has been hypothesized that irritable bowel syndrome (IBS) is caused by the overreaction of the colon stimulated by the act of eating or drinking. This can subsequently lead to abdominal pain, diarrhea, or constipation. Which GI reflex is most likely involved in this hypothesis concerning IBS?
- Peristalsis
- Vagovagal
- Gastrocolic
- Enterogastric
- ColonoilealAnswer C. The gastrocolic reflex is responsible for the urge to defecate following the consumption of a meal.
- A patient presents to the clinic 2 days post appendectomy complaining of constipation. The patient is a recovering alcoholic, and therefore declined use of narcotics to manage pain. Which of the following is a potential mechanism for this patient’s recent onset of constipation?
- Without opioids, the GI motility will be decreased
- Stress from surgery can increase sympathetic activation and decrease GI motility
- Stress from surgery can increase parasympathetic activation and decrease GI motility
- The patient is most likely using illicit drugs which has led to decreased GI motility
- Stress from surgery can decrease parasympathetic activation and decrease GI motility Answer B. Sympathetic innervation leads to reduced motility, discharge and blood flow. This explains the reasoning behind paralytic ileus following surgery.
- Angel S. is a competitive eater. She can consume exactly 50 Chick-fil-a nuggets in 2 min. Which of the following reflexes is most likely responsible for her ability to consume this massive quantity of food?
- Enterocolic
- Gastrocolic
- Vagovagal
- Colonoileal
- PeristalsisAnswer C. The Vagovagal reflex controls the contraction in GI muscle s in response to food stimuli. The stomach will distend in response to swallowing food. It allows for the accommodation of large amounts of food in the digestive tracts.
- Which of the following is TRUE regarding the Enteric Nervous System?
- S-type neurons constitute the largest portion of auerbach’s plexus
- S-type neurons fulfill the role of interneurons
- AH-type neurons respond to tetrodotoxin (Na+ channel blocker)
- The Myenteric plexus is located in the submucosa
- The Meissner’s plexus is responsible for secretion(Answer E. AH-type neurons constitute the largest portion of Auerbach’s plexus and fulfill the role of interneurons. S-type neurons respond to tetrodotoxin and are highly excitable, with all of them containing nicotinic fast EPSPs. The Myenteric (Auerbach’s) plexus is located between the circular and longitudinal smooth muscle layers of the muscularis externa.)
- Which of the following evokes a fast EPSP?
- Opioid peptides
- NE
- Galanin
- Adenosine
- Substance P(Answer E. Serotonin, Substance P, ACh, Histamine, Gastrin and CCK can all induce fast EPSPs.)
- You are taking the history of a 58 year old male patient during an annual health exam. Upon inquiring about bowel movements the patient states, “well, doc, I have a cup of coffee every morning and it seems to move right through me after that!” Which of the following most accurately describes the mechanism by how caffeine can lead to bowel movements?
- Caffeine binds to the NE receptor and prevents slow IPSPs
- Caffeine directly leads to fast EPSPs
- Caffeine directly induces slow EPSPs
- Caffeine binds the Adenosine receptor and prevents slow IPSPs
- Caffeine directly induced slow IPSPs(Answer D.)
- Famotidine is a H2 receptor antagonist that is used to treat ulcers, gastroesophageal reflux disease (GERD), and conditions that cause excess stomach acid. Which of the following best explains the mechanisms of action through which this medication works?
- It prevents histamine from inducing a slow EPSP
- It prevents histamine from inducing a fast EPSP
- It prevents histamine from inducing a slow IPSP
- It prevents histamine from inducing presynaptic inhibition
- It prevents histamine from inducing presynaptic facilitation(Answer A. Histamine binding to H2 receptors will induce a slow EPSP. Thus, Famotidine will block this action from occurring. Histamine is also associated with inducing presynaptic inhibition. However, it acts on H3 (not H2) presynaptic receptors to accomplish this.)
- Which of the following is TRUE regarding the mechanism of peristalsis?
- The longitudinal layer contracts ahead of the bolus and relaxes behind the bolus
- The longitudinal layer relaxes ahead of the bolus and contracts behind the nolus
- The circular layer contracts ahead of the bolus and behind the bolus
- The longitudinal layer contracts ahead and behind of the bolus
- The circular layer contracts behind the bolus and ahead of the bolus (Answer D. During peristalsis the longitudinal layer contracts ahead of the bolus to expand the lumen (receiving segment dilation) and behind the bolus both the circular and longitudinal layers contract simultaneously (propulsive segment).)
- A prokinetic agent, is a type of drug which enhances gastrointestinal motility by increasing the frequency or strength of contractions, but without disrupting their rhythm. Which of the following correctly describes the mechanisms by which these drugs work?
- The lead to presynaptic inhibition and decrease the probability of gate opening, enhancing propulsion
- They lead to presynaptic facilitation and increase the probability of gate opening, enhancing propulsion
- They lead to fast EPSPs and increase the probability of gate opening, enhancing propulsion
- They lead to slow EPSPs and increase the probability of gate opening, enhancing propulsion
- The lead to slow IPSPs and decrease the probability of gate opening, enhancing propulsion(Answer B.)
- Which of the following is NOT associated with incompetence of the lower esophageal sphincter (LES)?
- GERD
- Acid reflux
- Esophageal achalasia
- Barrett’s esophagus
- Esophageal Adenocarcinoma(Answer C. Esophageal achalasia results from loss of LES inhibition which causes difficulty in swallowing. Other fyi information about GI sphincter incompetence → Gastritis and bile reflux are associated with incompetence of the pyloric sphincter. Bacterial overgrowth in the small intestine (leading to bloating and pain) are associated with the ileocecal incompetence. Incompetence of the internal anal sphincter will lead to fecal incontinence.)
- Which of the following is TRUE regarding the behavior of the antral (pyloric) pump?
- The pacemaker frequency is 11-12/min
- The leading contraction is responsible for contraction of the pyloric sphincter
- The trailing contraction is caused by the rapid uptroe of the AP
- Stomach emptying decreases at particles decrease in size
- The leading contraction is mainly responsible for the mechanical breakdown of food(Answer B. The pacemaker frequency is only 3/min in the stomach. The leading contraction is responsible for contraction of the pyloric sphincter but has negligible impact on the actual breakdown of food. The trailing contraction is caused by the plateau phase of the AP. Stomach emptying increases as particles decrease in size.)
- Which of the following is associated with bacterial overgrowth in the small intestine?
- Ileocecal sphincter incompetence
- Decreased MMC
- Vagotomy
- A & B
- A, B & C(Answer D.)
- Which of the following correctly describes the purpose behind the production of haustration in the large intestine?
- Allows for the mixing of digestion enzymes
- Allows for the accommodation of large amounts of chyme
- Increases the surface area for the absorption of water
- Provide power propulsion
- Increases the surface area for the absorption of nutrients(Answer C.)
- Sjögren syndrome is an autoimmune disease that affects the body’s moisture-producing glands. Primary symptoms are a dry mouth and dry eyes. Which of the following is likely an additional outcome from an individual with this disease?
- Hypertension
- Tooth Decay
- Bradycardia
- HyperhidrosisAnswer B. Lecture #126 GI Secretion.
- Mineralocorticoids such as aldosterone act in various areas and their effects are not just limited to the kidney tubules. Which of the following best describes Aldosterone’s effect on
- Which of the following is TRUE regarding sympathetic and parasympathetic innervation to the salivary glands?
- Sympathetic inhibits salivary production while parasympathetic stimulates it
- Parasympathetic inhibits salivary production while sympathetic stimulates it
- Both parasympathetic and sympathetic will inhibit salivary production
- Both parasympathetic and sympathetic will stimulate salivary production
- Salivation is stimulated by the ENS and neither sympathetic or parasympathetic innervation have an effect on itAnswer D.
- The conversion of pepsinogen to pepsin is facilitated by which of the following?
- HCl
- Pepsin
- Intrinsic factor
- A & B
- A & C(Answer D.
- What is the most likely outcome for an individual who is deficiency in Antitrypsin enzyme?
- Gastritis
- Acid Reflux
- Pancreatitis
- Inability to digest proteins
- Paralytic ileus(Answer C.)
- Some suggest that hypothyroidism can lead to increased chance of the formation of gallstones. Which of the following best explains the reasoning behind how hypothyroidism contributes to the formation of gallstones?
- Hypothyroidism can lead to hypercholesterolemia
- Hypothyroidism can lead to liver disease
- Hypothyroidism can lead to obesity
- Hypothyroidism leads to bile salt deficiency
- None of the above (Answer A.)
- Crohn’s disease is an inflammatory bowel disease. It causes inflammation of your digestive tract, which can lead to abdominal pain, severe diarrhea, fatigue, weight loss and malnutrition. One of the treatment options for Crohn’s disease is the resection of the distal ileum. Which of the following would NOT likely be a potential consequence of this surgical procedure?
- Deficiency in fat soluble vitamins
- Scurvy
- Pernicious anemia
- Beri-beri
- Steatorrhea(Answer D. The ileum is involved in the absorption of Vitamin C and B12 and the reabsorption of bile salts. Thus, an individual undergoing a resection of the distal ileum could acquire a deficiency in bile salts, vitamin C, and B12. Deficiency in bile/bile salts will lead to a decreased ability to absorb fats. This can cause deficiency in fat-soluble vitamins and excess fat in the stool (steatorrhea). Vitamin C deficiency can lead to Scurvy and vitamin B12 deficiency can lead to pernicious anemia. Beri-Beri is caused by a B1 (Thiamine) deficiency. Since B1 is absorbed in the jejunum, Beri-Beri would not be a potential consequence of this surgical procedure.)
- A 56 year old male patient presents to the clinic with hypercholesterolemia. Which of the following would be a potential treatment option for this individual?
- Suggest a low fiber diet to increase his excretion of cholesterol
- Prescribe Ezetimibe to decrease the intestinal absorption of cholesterol
- Prescribe Lipitor to decrease the intestinal absorption of cholesterol
- Suggest a diet high in tannic acid to increase excretion of cholesterol
- Suggest a distal ileum resection. (Answer B. Potential treatment options would include a high fiber diet to increase the excretion of cholesterol, Ezetimibe to decrease the intestinal absorption of cholesterol, and Lipitor to decrease the cholesterol synthesis. While Lipitor may be prescribed in this case, the answer choice did not correctly identify the mechanism of action by which it works. Tannic acid is a substance found in various drinks (including tea/coffee) and can decrease iron absorption. A distal ileum resection would not be indicated here, hopefully for obvious reasons.)
- You are on a pediatrics rotation when a 3 month old female patient presents with failure to thrive, steatorrhea, and various developmental delays. Liver biopsy is performed and the histological specimen collected is shown below. A deficiency in which of the following is the most likely the cause of this infant’s symptoms?
- Intrinsic factor
- Sucrase
- Pancreatic cholesterol esterase
- Phospholipase A2
- Microsomal triglyceride transfer protein (MTTP) (Answer E. Abetalipoproteinemia (no aApo B) causes an inability to make chylomicrons and vLDLs. Consequently, this leads to an accumulation of lipid droplets in the cytoplasm of the enterocytes. A deficiency in MTTP is what causes this lack of apo B.)
- In the small intestine, the absorption of various nutrients in dependent on the absorption of Na+ following its concentration gradient. Which of the following is NOT cotransported with Na+?
- Amino Acids
- Glucose
- Fructose
- Galactose(Answer C. Fructose is absorbed via facilitated carrier-mediated transport and is NOT Na+ dependent.)
- A deficiency in which of the following would be most concerning an adult patient?
- Lingual lipase
- Salivary alpha-amylase
- Acid lipase
- Pancreatic lipase
- Pepsin(Answer D. Lingual lipase and salivary alpha-amylase are primarily responsible for taste of fats and starch, respectively. Acid lipase is critical for infants and prefers TAG containing medium chain FAs in milk. Infants have insufficient pancreatic lipase and are dependent on this enzyme. However, it is not critical following infancy. Pancreatic lipase is critical for the digestion of fats in adults. Pepsin is an endopeptidase involved in hydrolyzing proteins but is not critical for sustaining life.)
- Which of the following is an example of a pancreatic exopeptidase?
- Trypsin
- Chymotrypsin
- Elastase
- Pepsin
- Carboxypeptidase A(Answer E. Answers A-C are pancreatic ENDOpeptidases. Pepsin is in an endopeptidase produced in the stomach. Carboxypeptidase A/B are the only pancreatic exopeptidases.)
- Electrolyte modification in the salivary ducts takes place mainly in which structure?
- Acinus
- Intercalated duct
- Intercalated disc
- Striated duct
- Excretory duct(Answer D.)