PBM Mod 4

2. Allows passage of blood from vena cava to left atrium in fetus

A. Foramen ovale

Removal of proximal segments of the small intestine results in a decrease of: A. Pancreatic enzyme secretion B. Basal acid output C. Maximal acid output D. Gastric emptying of liquids E. Gastric emptying of solids

A. Pancreatic enzyme secretion

Secretin: A. is secreted by the duodenum. B. is secreted in response to an alkaline load. C. induces production of HCl by the pancreas. D. is induced by cholecystokinin. E. is all of the above.

A. is secreted by the duodenum.

Important functions of the gastric mucus neck cells include secretion of: A. mucus. B. alpha-amylase. C. bile. D. trypsinogen. E. water.

A. mucus.

A 25-year-old woman comes to her physician complaining of pain with intercourse and dysmenorrhea that worsens one-two days before her period starts. Ultrasonography reveals unilateral adnexal masses, and laparoscopy shows reddish-brown cysts on the ovaries. This patient is at increased risk for developing which of the following conditions? A. Carcinoma B. Infertility C. Intracranial hemorrhage D. Masculinization E. Obesity

B The correct answer is B. A blood-filled cyst (a so-called chocolate cyst) is characteristic of endometriosis, a condition that results in nonneoplastic endometrial glands/stroma being abnormally located outside the endometrial cavity. The ovary and the pelvic peritoneum are the most common sites. The cysts are formed during cyclic bleeding from the tissue, mimicking menstruation. Severe menstrual related pain (dysmenorrhea), pain during sexual intercourse (dyspareunia), and infertility are possible complications of endometriosis. Answer A is incorrect. Common cancers in the reproductive tract include endometrial carcinoma, which can arise from endometrial hyperplasia caused by excess estrogen stimulation, and cervical carcinoma, associated with human papillomavirus infection. Endometriosis does not progress to cancer. Answer C is incorrect. Autosomal dominant (adult) polycystic kidney disease (ADPKD) is characterized by bilaterally enlarged kidneys with multiple cysts. Cysts can also involve the liver, pancreas, heart, and brain. This disease manifests as renal abnormalities that progresses to end stage renal disease. In patients with ADPKD there is usually a family history, bilateral involvement, and constant pain that does not wax and wane in conjunction with menstrual cycles. Another manifestation of ADPKD is the emergence of intracranial berry aneurysms that can rupture and produce intracranial hemorrhage. Endometriosis is not associated with ADPKD. Answer D is incorrect. Polycystic ovarian syndrome (PCOS or Stein-Leventhal syndrome) has many causes. The main characteristics of PCOS are irregular or anovulation and hyperandrogenism. Features seen in PCOS include ovarian cysts, amenorrhea, infertility, obesity, and hirsutism caused by excess LH and androgens. In some women this is associated with insulin resistance and hyperinsulinemia, which increases androgen production in the ovarian theca cells and, secondarily, LH production. The insulin resistance also leads to hyperglycemia and suppresses hepatic steroid hormone binding globulin (SHBG) synthesis. The decrease in SHBG along with the increase in androgen production leads to a vicious cycle of amenorrhea and infertility. Endometriosis is not associated with masculinization and PCOS. Answer E is incorrect. Endometriosis is not associated with obesity.

5. Keeps work of breathing due to surface tension low

B. FRC

A 70-year-old woman presents to her primary care physician for a check-up after undergoing repair of a broken hip due to a minor fall. Which of the following is the most likely hormonal profile of this woman?

C This patient most likely suffers from osteoporosis, or weakened bones, as a complication of menopause. Estrogen regulates bone resorption, maintaining proper bone mass in women. At menopause, estrogen production ceases due to a decreased number of ovarian follicles. The reduction in estrogen results in increased bone resorption. Along with low estrogen levels, postmenopausal women have high levels of LH, FSH, and GnRH due to the lack of negative feedback of estrogen on the anterior pituitary gland and hypothalamus. Answer A is incorrect. While estrogen levels are indeed low in postmenopausal women, levels of LH and FSH are high due to the lack of negative feedback on the anterior pituitary. This profile suggests that the problem is in the anterior pituitary, which is receiving GnRH stimulation but is unable to produce enough LH and FSH to stimulate the ovaries. Menopause, however, is a primary dysfunction of estrogen production in the ovaries, with a normally functioning anterior pituitary gland. Answer B is incorrect. While estrogen levels are indeed low in postmenopausal women, LH, FSH, and GnRH levels are high due to the lack of negative feedback on the anterior pituitary and hypothalamus. This profile suggests a problem in the hypothalamus, resulting in low GnRH, which leads to suboptimal stimulation of the anterior pituitary causing low FSH and LH. The low FSH and LH levels cause decreased stimulation of the ovaries, resulting in low estrogen levels. Menopause, however, is a primary dysfunction of estrogen production in the ovaries, with a normally functioning anterior pituitary gland. Answer D is incorrect. Menopause is a primary dysfunction of estrogen production in the ovaries. Thus, estrogen levels are low in postmenopausal women. Answer E is incorrect. Menopause is a primary dysfunction of estrogen production in the ovaries. Thus, estrogen levels are low in postmenopausal

A 48 year old diabetic man who has been on a weight loss program comes to the ER complaining of right upper quadrant pain that radiates to his shoulder. He lost 40 lb in 3 months by cutting fatty foods and minimizing caloric intake. His pain began 4 hours ago and has gotten progressively worse. His body temp is mildly elevated. Murphy sign is positive. Blood test AST-25U/l (Normal 8-20 U/L) ALT-21U/l (Normal 8-20 U/L) GGT- elevated Bilirubin - elevated Blood glucose -140 mg/dl (N 70-110 mg/dl) What is the most likely cause of this patient's symptoms? A. Liver cirrhosis B. Constipation C. Cholecystitis D. Uncontrolled hyperglycemia E. Kidney stone

C. Cholecystitis

8.Makes first breath difficult

C. Surface tension

About 75% of the blood flowing through the liver is from the portal vein, and the remainder is from the hepatic artery during resting conditions. Which of the following best describes the liver circulation in terms of resistance, pressure, and flow?

D

A 60-year-old man has a 2-month history of dysphagia, or swallowing difficulties. Barium swallow studies reveal a stricture at the gastroesophageal junction. Esophageal manometric studies showed an increased resting gastroesophageal sphincter pressure and a failure of the sphincter to relax with swallowing. What diagnosis do these results suggest? A. Hirschsprung's disease B. Secondary peristaltic waves C. GERD D. Achalasia E. Water brash

D. Achalasia

A physiological experiment was carried out with the intent to investigate what happens to gastrointestinal secretions after neuronal stimulation. A bilateral vagotomy was carried out to be able to artificially stimulate the vagus nerve. Plasma hormone levels, enzyme secretion, pH, and volume secreted were measured. Upon stimulation of the vagal nerve endings, what happens? A. Gastrin release is inhibited. B. Enzyme secretion from the pancreas is decreased. C. Pepsinogen secretion is inhibited. D. Gastric pH is decreased. E. Bicarbonate secretion from the pancreas is decreased.

D. Gastric pH is decreased.

4. Fluid storage at this site could compromise gas exchange

D. Perimicrovascular interstitial space

A 63-year-old woman has undergone a total gastrectomy for a prior gastric carcinoma. After surgery, because of being underinsured, she received no nutritional supplementation or counseling. Four years later she appears at your office severely anemic and extremely fatigued. What is the most likely cause of her symptoms? A. Recurrence of the gastric carcinoma B. Previously undetected metastatic growth in the pancreas C. Lack of nutrient absorption D. Vitamin B12 deficiency E. Constipation

D. Vitamin B12 deficiency

3. Temporary storage site of alveolar fluid after birth

E. Peribronchovascular interstitial space

Receptive relaxation is a phenomenon which is best described as: A. peristaltic contractions that occur in the stomach as a result of the release of motilin. B. defined by the electrical activity of the gastrointestinal tract after ingestion of a meal. C. limited increases in esophageal pressure as food is propelled through the esophagus. D. unlimited increases in stomach wall tension and intragastric pressure as food enters. E. limited increases in stomach wall tension and intragastric pressure as food enters.

E. limited increases in stomach wall tension and intragastric pressure as food enters.

Stimulation of the sympathetic nervous system causes: A. the stomach to release secretin. B. the stomach to secrete HCl. C. the pancreas to secrete bicarbonate and enzymes. D. the pancreas to secrete insulin into the lumen of duodenum. E. the intestinal epithelium to absorb water in the meal.

E. the intestinal epithelium to absorb water in the meal.

7. Responsible for fluid-filled alveoli in fetus

F. Chloride pump

6. Promotes water reabsorption from alveoli before and after birth

G. Sodium pump

What is goiter? Explain why it occurs.

Goiter is abnormal enlargement (hypertrophy) of the thyroid gland. Goiter usually results from dietary deficiency of iodine which leads to insufficient synthesis and secretion of thyroid hormone. The lack of normal negative feedback to the adenohypophysis by the thyroid hormone results in excess TSH secretion, which leads to hypertrophy (goiter) of the thyroid gland.

Explain how Graves' disease, an autoimmune disease, leads to hyperthyroidism.

Graves' disease results from an autoantibody that is directed against the TSH receptor of thyroid follicle cells. Binding of the antibody to the TSH receptor results in prolonged, excessive trophic stimulation of the thyroid gland, which leads to excessive thyroid growth (goiter) and thyroid hormone secretion (=hyperthyroidism).

1. Allows passage of blood from pulmonary artery to aorta in fetus

H. Ductus arteriosus

A young couple is trying to conceive their first child. The woman speaks to her mother, who tells her that she should take her temperature to determine when she ovulates. The action of which of the following hormones is responsible for this change in body temperature? A. Estrogen B. Human chorionic gonadotropin C. Luteinizing hormone D. Progesterone E. Prolactin

The correct answer is D. Progesterone is produced by the corpus luteum shortly after ovulation. One of its locations of action is the hypothalamic thermoregulatory center, leading to a slightly elevated basal body temperature (up to 1°F). Therefore, it is possible to assess when ovulation has occurred by checking one's basal body temperature on a daily basis. Answer A is incorrect. Estrogen does have some effect at the hypothalamic thermoregulatory center during menopause, contributing to "hot flashes," but it does not affect body temperature during the normal menstrual cycle. Answer B is incorrect. Human chorionic gonadotropin has no effect on body temperature following ovulation. It is present during pregnancy and is the hormone detected during a pregnancy test. Answer C is incorrect. LH surge causes ovulation to occur but has no physiologic effects on body temperature. Answer E is incorrect. Prolactin has no effect on body temperature following ovulation. It is responsible for the production of breast milk, and high levels of prolactin cause anovulation

After fertilization of the ovum, implantation occurs in the endometrium. At this time the developing placenta begins to produce a hormone necessary for embryonic viability. Which of the following best describes this hormone's action? A. Increases the production of milk by the mammary glands B. Increases the threshold for uterine contraction C. Initiates parturition at the end of pregnancy D. Stimulates the corpus luteum to produce estriol and progesterone E. Stimulates the placenta to produce estriol and progesterone

The correct answer is D. b-hCG is produced by the placenta immediately after implantation in the endometrium of the uterus. b-hCG acts on the corpus luteum to rescue it from regression. It stimulates the corpus luteum to produce estriol and progesterone to maintain the pregnancy until the placenta takes over this role in the second and third trimesters. bhCG levels peak at week nine of gestation and then begin to decline until reaching a steady state around week 25. Answer A is incorrect. Prolactin, not b-hCG, is responsible for stimulating production of milk by the mammary glands. Answer B is incorrect. Progesterone, not bhCG, raises the threshold for uterine contraction. This helps prevent spontaneous abortion of the fetus. Answer C is incorrect. b-hCG does not initiate parturition at the end of pregnancy. The actual initiating event is unknown. Answer E is incorrect. Estrogen and progesterone are produced by the corpus luteum in the first trimester and by the placenta in the second and third trimesters. The developing placenta starts producing b-hCG after implantation, which stimulates the corpus luteum to produce estrogen and progesterone until the placenta takes over.

A 14-year-old boy is brought to the clinic by his parents who are concerned because he has not yet begun puberty. Laboratory results indicate hypogonadism secondary to failure of the hypothalamic-pituitary-gonadal axis. Which of the following are possible adverse effects of the treatment for this patient's condition? A. Anemia B. Decreased serum LDL cholesterol levels C. Increased spermatogenesis D. Leukocytosis E. Premature closing of the epiphyseal plates

The correct answer is E. Androgenic steroids are used to treat hypogonadism either due to failure of the hypothalamic-pituitary-gonadal axis (secondary hypogonadism) or due to Leydig cell dysfunction (primary hypogonadism). Patients should be warned that androgens cause premature closing of the epiphyseal plates by promoting calcium deposition in the bones. Answer A is incorrect. Androgenic steroids can cause polycythemia rather than anemia. This adverse effect is another risk factor for premature coronary artery disease and thrombosis. Answer B is incorrect. Some androgenic steroids increase, rather than decrease, LDL cholesterol levels. The lipid profile disturbance increases the possibility of atherosclerotic change and raises the risk of early coronary artery disease. Answer C is incorrect. Excess androgens can cause decreased spermatogenesis by downregulating GnRH. Decreased GnRH causes decreased release of LH and FSH, which are necessary for spermatogenesis. Answer D is incorrect. A serious adverse reaction to some androgens is not leukocytosis, but rather leukopenia because of decreased marrow production or decreased WBC survival.

A 6-year-old child whose family arrived in the United States from Asia last week is brought to the pediatrician for a checkup. On physical examination, the patient is found to be short, potbellied, and pale with a puffy face, a protruding umbilicus, and a protuberant tongue. The child shows clear signs of significant mental retardation. Upon questioning, the mother reveals that she did not suspect any abnormality because many children in their village share the same appearance. The physician suspects thyroid abnormalities and orders a thyroid function test. Which are the most likely results of thyroid-stimulating hormone (TSH) and thyroid hormone levels relative to normal baseline values for this patient?

The correct answer is High TSH; low T4 and T3. This patient is likely suffering from endemic cretinism due to a deficiency in dietary iodine, a disorder that is still common in parts of the world. Lack of dietary iodine leads to deficient thyroid hormone production and thus hypothyroidism. Thyroid hormone is critical during development and thus children who grow up in iodine-deficient areas may manifest skeletal and central nervous system abnormalities, including short stature and mental retardation. Unfortunately for this child, once the syndrome is clinically apparent, it cannot be reversed. Thyroid function tests detect the presence of TSH secreted by the pituitary gland, as well as circulating levels of total serum triiodothyronine (T3) and thyroxine (T4). In primary hypothyroidism, T3 and T4 levels will both be low, and a compensatory increase in pituitary activity will increase TSH.

A 40-year-old woman with a history of pernicious anemia comes to the physician complaining of increased anxiety, heart palpitations, heat intolerance, unexplained weight loss, and multiple daily bowel movements. On physical examination, the patient is found to have a goiter, a thyroid bruit, and mild exophthalmos. Laboratory studies show elevated T3 and T4 levels, and an undetectable TSH. What is the most likely etiology of this patient's disease?

The correct answer is: Autoimmune stimulation of TSH receptors. This patient presents as a classic case of Graves' disease. In Graves' disease, thyroid-stimulating IgG antibodies bind to TSH receptors and lead to thyroid hormone production. This causes glandular hyperplasia and enlargement characteristic of the goiter associated with Graves' disease. Graves' disease is the most common cause of thyrotoxicosis. Patients with this condition may have other autoimmune diseases, such as pernicious anemia or type 1 diabetes mellitus, and frequently present with anxiety, irritability, tremor, heat intolerance with sweaty skin, tachycardia and cardiac palpitations, weight loss, increased appetite, fine hair, diarrhea, and amenorrhea or oligomenorrhea. Signs include diffuse goiter, proptosis, periorbital edema. Laboratory values reveal increased thyroid hormone levels and decreased TSH levels.

A 65-year-old woman comes to her primary care physician complaining of progressive weakness and fatigue. On further questioning, she notes a recent weight gain and constipation as well as constant subjective chills. Physical examination shows a moderate nontender goiter. A biopsy shows a lymphocytic infiltrate. What are the most likely results of thyroid-stimulating hormone (TSH) and thyroid hormone levels relative to normal baseline values for this patient?

The correct answer is: High TSH; low total T4 and free T4. The vignette d scribes a classic history for hypothyroidism caused by Hashimoto's thyroiditis. This primary hypothyroidism is characterized by reduced secretion of thyroid hormone, resulting in decreased levels of free and total T4 and increased levels of TSH due to the absence of negative feedback by T4.

List the three possible defects responsible for hypothyroidism.

There are three (3) possible types of defects responsible for hypothyroidism: primary hypothyroid - thyroid response to TSH is low, but pituitary response to TRH is high (circulating TRH and TSH elevated). secondary hypothyroid -thyroid response to TSH is normal, but pituitary response to TRH is low (circulating TSH is low). tertiary hypothyroid - thyroid response to TSH is normal, pituitary response to TRH is normal (circulating TRH is low).