UWorld 4/15

(Choice A) Damage to the corpus callosum can result in the

"split-brain" syndrome. Although these patients may appear normal in general social situations, further evaluation can demonstrate lack of interhemispheric transfer of information (eg, patient unable use one hand to retrieve an object palpated with the other hand).

This preterm infant with increased work of breathing and hypoxia has diffuse ground-glass opacities and air bronchograms on imaging. These findings are consistent with neonatal respiratory distress syndrome (RDS). RDS is caused by immaturity of type 2 pneumocytes, which normally produce alveolar surfactant. Lack of surfactant causes decreased compliance and increased surface tension of alveoli, leading to alveolar collapse at the end of expiration. This diffuse atelectasis results in the characteristic reticular or ground-glass opacities on chest x-ray. Unlike alveoli, larger airways remain patent and filled with air due to their cartilaginous walls, making them visible (air bronchograms) against the reticular background. Management of RDS is respiratory support (to maintain alveolar pressure and prevent collapse) and surfactant (to reduce surface tension). During the first week of life, type 2 pneumocytes begin to release endogenous surfactant, and respiratory distress typically begins to improve C. Diffuse atelectasis (%)

4-hour-old girl is evaluated in the neonatal intensive care unit. The patient was born at 30 weeks gestation via spontaneous vaginal delivery after 3 hours of labor. Membranes ruptured at the onset of labor and amniotic fluid appeared clear. Immediately after birth, the child was placed on continuous positive airway pressure by nasal prongs due to signs of breathing difficulty. Temperature is 36.7 C (98 F), pulse is 158/min, and respirations are 54/min. Pulse oximetry is 92% on 60% oxygen. Examination shows audible grunting and subcostal chest wall retractions. Cardiac examination shows no murmurs. A chest x-ray is obtained: The radiographic findings in this patient most likely represent which of the following? A. Air leakage into pleural space (%) B. Decreased alveolar and capillary development (%) C. Diffuse atelectasis (%) D. Fibrosis of the interstitium (%) E. Occlusion of the bronchioles (%) F. Retained extracellular fluid (%)

The depletion of ATP in critical cellular areas and the accumulation of toxins result in loss of contractility within about

60 seconds of total myocardial ischemia (Choice A).

B. Alpha and beta-adrenergic agonist (%) =

A medical student is observing a pharmacology experiment where drug A is being intravenously administered to a pregnant dog. Some parameters that are being recorded during the experiment include heart rate, blood pressure, pupil size, and uterine contractions. The following diagrams illustrate the measured parameters and observed changes after infusing drug A. Which of the following best characterizes drug A? A. Beta-adrenergic agonist (%) B. Alpha and beta-adrenergic agonist (%) C. Alpha-adrenergic agonist (%) D. Beta-adrenergic antagonist (%) E. Alpha-adrenergic antagonist and beta-adrenergic agonist (%)

A 62-year-old woman comes to the emergency department due to acute eye pain. She has a history of seasonal allergies and developed itchy, watery, red eyes after working outdoors in her garden. The patient used over-the-counter eye drops to treat her allergy symptoms, and several hours later, she began experiencing severe right eye pain and headache. On examination, the right eye appears red with a hazy cornea and dilated pupil that responds poorly to light. Palpation of the globes reveals notable firmness on the right compared to the left. Visual acuity in the affected eye is severely diminished. Tonometry reveals elevated intraocular pressure. Which of the following medications was most likely used by this patient? A. Alpha-adrenergic agonist (%) B. Beta blocker (%) C. Mast cell stabilizer (%) D. Nonsteroidal anti-inflammatory drug (%) E. Prostaglandin analogue (%)

A. Alpha-adrenergic agonist (%) This patient is presenting with angle-closure glaucoma (ACG) that was precipitated by use of over-the-counter eye drops. ACG typically occurs in patients with a predisposing narrow chamber angle and develops when the normal drainage pathway of aqueous humor becomes blocked. Aqueous humor is produced by the ciliary body and flows from the posterior chamber of the eye through the pupil into the anterior chamber and out of the eye via the trabecular network. In susceptible individuals, dilation of the pupil causes the iris to press against the anterior surface of the lens. This limits flow of aqueous humor through the pupil, causing the iris to bulge forward. The corresponding reduction (closing) of the iridocorneal angle blocks drainage of aqueous humor through the trabecular meshwork. Acute ACG may be precipitated by topical and systemic medications that cause pupillary dilation, such as alpha-adrenergic agonists (eg, naphazoline) and drugs with strong anticholinergic effects (eg, tricyclic antidepressants, antihistamines). Acute blockage results in a rapid rise in intraocular pressure that typically causes severe eye pain, conjunctival injection, and corneal edema (haziness). If not corrected, the elevated pressure can damage the optic nerve and cause permanent vision impairment

A 67-year-old man is brought to the emergency department by his son after a syncopal episode. The son was helping his father clean out the garage when the father said he felt dizzy. As the son was helping him into a chair, the patient lost consciousness. He woke up spontaneously about a minute later without any disorientation or confusion. ECG demonstrates bradycardia with a regular rhythm and narrow QRS complexes. There is complete desynchronization between the P waves and QRS complexes. Which of the following locations is most likely pacing this patient's ventricles? A. His bundle (%) B. Left bundle branch (%) C. Left ventricular muscle (%) D. Purkinje system (%) E. Sinoatrial node (%)

A. His bundle (%) The electrical impulses in the myocardial conduction system are normally initiated by the sinoatrial (SA) node at a rate of 60-100/min. These impulses are then transmitted through the atria to the atrioventricular (AV) node, then on to the His bundle, bundle branches, Purkinje fibers, and ventricular myocardium. Most of the conduction system has its own intrinsic pacemaker, which is normally suppressed by the more rapid SA node pacemaker but triggers when a signal from further up the conduction system is not received. This patient's ECG shows complete dissociation of P waves and QRS complexes consistent with third-degree (complete) AV block. In third-degree AV block, electrical impulses coming from the SA node are blocked before being transmitted to the ventricles; the point of blockade usually is within the AV node or His bundle. The cells located immediately distal to the blockade (eg, in the His bundle) never receive the impulse from the SA node and therefore begin generating their own pacemaker impulse that is transmitted to the ventricles. On ECG, the SA node impulses continue to march out as P waves, and the His bundle impulses generate QRS complexes (an escape rhythm) at the intrinsic rate of the His bundle pacemaker (eg, 40-60/min). Because the atria and the ventricles are not communicating, the P waves and QRS complexes have no relation to one anothe

A 42-year-old woman, gravida 4 para 4, comes to the office due to heavy and painful menstrual bleeding over the past 3 months. The patient's last menstrual period was 3 weeks ago. Menarche was at age 10, and menstrual periods last for 3-5 days and occur every 30 days. She is sexually active with her husband and does not have pain with intercourse. The patient had a bilateral tubal ligation 3 years ago after the birth of her last child. She takes no medications and has no allergies. BMI is 24 kg/m2. Vital signs are normal. On bimanual examination, the uterus is uniformly enlarged and tender. Urine β-hCG is negative. Which of the following is the most likely cause of this patient's symptoms? A. Benign myometrial smooth muscle cell proliferation (%) B. Blastocyst implantation in the fallopian tube (%) C. Endometrial glands and stroma within the myometrium (%) D. Localized overgrowth of endometrium into the uterine cavity (%) E. Unregulated endometrial proliferation with increased gland-to-stroma ratio (%)

C. Endometrial glands and stroma within the myometrium (%) This patient has adenomyosis, a disorder caused by an abnormal collection of endometrial glands and stroma within the uterine myometrium. Adenomyosis is common in multiparous women, and prior uterine surgery (eg, cesarean delivery) is a risk factor. Although the exact pathogenesis is unclear, adenomyosis may occur due to endometrial invagination into the myometrium during periods of myometrial weakening or changes in vascularity at the endomyometrial interface (eg, pregnancy, uterine surgery). The clinical features of adenomyosis reflect its pathophysiology: endometrial gland proliferation and cyclic bleeding within the myometrium leads to dysmenorrhea and uterine tenderness abnormal myometrial hyperplasia and hypertrophy results in a concentric, uniformly enlarged uterus uterine enlargement and subsequently increased endometrial surface area causes regular, heavy menstrual bleeding Definitive therapy is with hysterectomy, which allows for histologic diagnosis.

A45-year-old man comes to the emergency department due to 2 weeks of chest pain and cough. He has a history of advanced HIV and has taken his antiretroviral medications inconsistently over the past few months. Temperature is 38.1 C (100.6 F). Crackles are heard on pulmonary examination. CD4 cell count is 98/mm3. Chest x-ray reveals nodules and hilar lymphadenopathy. A bronchoscopy is performed. Mucicarmine staining of the patient's bronchoalveolar fluid shows budding yeast forms with thick capsules. Symptomatic infection with the organism causing this patient's condition most commonly manifests as which of the following? A. Esophagitis (%) B. Interstitial pneumonia (%) C. Meningoencephalitis (%) D. Oral plaques (%) E. Sinusitis (%) F. Skin infection (%)

C. Meningoencephalitis (%) Budding yeasts with thick capsules are characteristic of Cryptococcus neoformans, which typically affects only immunocompromised patients (opportunistic pathogen). C neoformans is present in soil and pigeon droppings; it is transmitted by the respiratory route but not acquired via person-to-person contact. Inhaled yeast forms enter the lungs. In immunocompetent persons, they are cleared by macrophages and T cells. In individuals with an impaired cellular immune response, C neoformans can cause symptomatic disease, most commonly meningoencephalitis. Cryptococcal meningoencephalitis is typically seen in patients with HIV, sarcoidosis, or leukemia and in those on high-dose corticosteroid therapy. Headache, nausea, vomiting, and confusion are common symptoms. Diagnosis is made by examining cerebrospinal fluid (CSF) stained with India ink. The round budding yeasts have peripheral clearings or "halos," due to their thick polysaccharide capsules. Serologic testing (latex agglutination) is used to detect the C neoformans capsular antigen in CSF. Although lung infection occurs first, it is usually asymptomatic. In some patients, pulmonary cryptococcosis may manifest as cough with scant sputum production, dyspnea, or pleuritic chest pain; it can be diagnosed by microscopic examination of bronchopulmonary washings and lung tissue (red yeast on mucicarmine stain)

73-year-old woman comes to the physician complaining of progressive, severe pain and discharge from her left ear for the past 2 days. She has had type 2 diabetes for many years and has been noncompliant with her medications and follow-up appointments. On examination, moving or touching the pinna produces extreme pain. Otoscopic examination shows granulation tissue in the left ear canal with a scant amount of discharge. The tympanic membrane is clear, and there is no middle ear effusion. Initial cultures from the ear show a Gram-negative rod. Which of the following microbiological characteristics best describes the infecting organism? A. Comma-shaped and grows well in high pH (%) B. Fast lactose fermenter (%) C. Motile and oxidase positive (%) D. Nonmotile and a lactose nonfermenter (%) E. Requires factors V and X for growth (%)

C. Motile and oxidase positive (%) This patient's presentation is consistent with malignant otitis externa (MOE), a severe infection most commonly seen in elderly diabetic patients. It is most frequently caused by Pseudomonas aeruginosa, a nonlactose-fermenting, oxidase-positive, motile Gram-negative rod. Patients typically present with exquisite ear pain and drainage. The granulation tissue seen within the ear canal is an important characteristic finding of MOE, and the tympanic membrane is usually intact. Progression of this infection can lead to osteomyelitis of the skull base and cranial nerve damage. Treatment consists of systemic antibiotics such as ciprofloxacin that are effective against P aeruginosa

A 14-year-old boy experiences severe, prolonged bleeding following a tooth extraction. He also has a history of multiple episodes of painful joint swelling following minor trauma. His parents have no bleeding problems. Evaluation shows that the patient has an inherited disorder and that one of his parents is a genetic carrier. His older sister, who does not have this condition, is pregnant. She does not know the sex of her child. She asks about the risk that her child will be affected. Which of the following is the best estimate that this child will have the disease? A. Near 0 (%) B. 1/2 (%) C. 1/4 (%) D. 1/8 (%) E. 1/16 (%) F. 1/32 (%)

D. 1/8 (%) This patient is a boy with excessive bleeding and hemarthroses, suggesting a diagnosis of hemophilia A or B. Both diseases are X-linked recessive coagulation factor deficiencies. The probability that his sister will give birth to an affected child can be calculated by multiplying the following probabilities: The probability (p1) that the sister is a carrier = 0.5. The patient's father does not carry the mutation on his X chromosome because he would be affected by the disease if he did. That means the mother carries the mutation on 1 of her 2 X chromosomes. This gives the daughter a 50% chance of having inherited the mutated X chromosome and therefore being a carrier. The probability (p2) that the offspring of a female carrier will inherit the X chromosome with the hemophilia gene = 0.5. Assuming the daughter is a carrier, the probability of passing on the mutant allele is 50% as only 1 of her 2 X chromosomes is passed to her offspring. The probability (p3) that his sister will have a boy = 0.5. If the sister's child is female, the child could be a carrier of the disease but would not be affected by it. If a male child inherits the mutated X chromosome, he will have the disease. The probability that the sister will have an affected son is the probability that all 3 of the above events will take place (ie, the product of their individual probabilities): p1 x p2 x p3 = 1/2 x 1/2 x 1/2 = 1/8.

A 68-year-old man comes to the emergency department due to abdominal pain and nausea for the past 2 days. He has a history of atherosclerotic cardiovascular disease and underwent coronary artery bypass surgery 2 years ago. Blood pressure is 105/65 mm Hg and heart rate is 120/min and irregular. Abdominal examination reveals mild diffuse tenderness and decreased bowel sounds. Laboratory studies are as follows: Serum chemistry Sodium 142 mEq/L Chloride 104 mEq/L Bicarbonate 12 mEq/L Creatinine 0.8 mg/dL Arterial blood gases pH 7.25 PaCO2 29 mm Hg Lactic acid, venous blood 5.6 mmol/L (normal: 0.5 - 2.0 mmol/L) ECG shows absent P waves and an irregular rate and rhythm. CT scan of the abdomen reveals colonic wall thickening and no enhancement with intravenous contrast. Urinalysis shows acidic urine. Renal metabolism of which of the following amino acids is most important for maximizing acid excretion in this patient? A. Alanine (%) B. Arginine (%) C. Aspartate (%) D. Glutamine (%) E. Histidine (%)

D. Glutamine (%) This patient has acute ischemic colitis, which is most likely due to embolic disease related to his atrial fibrillation. The ischemic bowel undergoes anaerobic metabolism, causing lactate accumulation in the blood that leads to an anion gap metabolic acidosis. Acidosis stimulates renal ammoniagenesis, a process by which renal epithelial cells metabolize glutamine, generating ammonium and bicarbonate. Ammonium ions are transported into the tubular fluid and excreted in the urine while peritubular capillaries absorb bicarbonate, which functions to buffer acids in the blood. Under normal physiologic conditions, about half of the total amount of acid secreted in the urine is in the form of ammonium, and the remainder is excreted primarily as titratable acids, particularly inorganic phosphate. However, increased ammonium production is almost entirely responsible for the increase in renal acid excretion seen with chronic acidosis

A 21-year-old man undergoes a routine pre-employment physical examination. During testicular examination, he is found to have only 1 testis in his scrotum. Further evaluation reveals an elevated serum FSH level and a normal serum LH level. Production of which of the following substances is likely to be impaired in this patient? A. Testosterone (%) B. Dihydrotestosterone (%) C. DHEA (%) D. Inhibin B (%) E. Cortisol (%)

D. Inhibin B (%) Pulsatile secretion of gonadotrophin-releasing hormone (GnRH) from the hypothalamus stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Both FSH and LH are produced by the gonadotroph cells of the anterior pituitary. LH stimulates the release of testosterone from the Leydig cells of the testes; FSH stimulates the release of inhibin B from the Sertoli cells of the testes. Testosterone has a negative feedback effect on LH and GnRH secretion, and inhibin B suppresses FSH secretion. Sertoli cells are present within the seminiferous tubules of the testes. In patients with 1 testicle, the mass of Sertoli cells is significantly reduced. Therefore, the circulating levels of inhibin B are likely to be low in these patients. Low inhibin B levels will not provide adequate negative feedback on FSH secretion, thus FSH levels will tend to be elevated in males who only have 1 testicle. A male patient of any age who has only 1 testicle requires further evaluation. Since there is an increased cancer risk in men with an undescended testicle, most of these "abdominal testicles" are either removed (orchiectomy) or receive surgery that allows descent into the scrotum (orchiopexy

A 65-year-old woman is enrolled in a clinical trial to test a new medication for rheumatoid arthritis. The patient's condition has been poorly controlled despite prolonged treatment with multiple disease-modifying antirheumatic drugs. The new medication is a CTLA4-Ig fusion protein that prevents CD28 from binding to CD80/86 on antigen-presenting cells. A month after treatment begins, the patient reports a significant reduction in joint pain and stiffness. Laboratory results reveal reduced levels of C-reactive protein and IL-2. Which of the following is the most likely underlying cause of this patient's treatment response? A. Complement inhibition (%) B. Immune complex clearance (%) C. Negative selection (%) D. Peripheral tolerance (%) E. Sensitization (%)

D. Peripheral tolerance (%) Abatacept, a disease-modifying antirheumatic drug, is a fusion of CTLA4 with the Fc portion of IgG (CTLA4-Ig). CTLA4 is a naturally occurring immune checkpoint receptor that is upregulated on the surface of active T cells. It acts as a brake for the adaptive immune response by preventing the conversion of antigen-specific naive T cells into effector T cells. The activation of cytotoxic T cells requires 2 stimulatory signals. First, the T cell must bind to a specific antigen on the class I major histocompatibility complex (MHC) of an antigen-presenting cell (APC); then, the bound T cell must be costimulated by an interaction between the T cell surface receptor CD28 and the APC cell surface ligand CD80/86. T cells that bind an antigen on an APC but are not costimulated undergo anergy, a form of peripheral immune tolerance marked by a lack of T-cell response to cytokine, ligand, or antigen stimulation (T-cell inactivation). Because CTLA4 binds to CD80/86 with greater affinity than CD28, administration of exogenous CTLA4 (eg, abatacept) reduces the availability of ligands necessary for T cell costimulation, which dramatically increases T cell anergy in areas of active inflammation

A 71-year-old man comes to the emergency department due to sudden-onset vision loss in his left eye for one hour. He has a history of coronary artery disease, hypertension, and type 2 diabetes mellitus. Blood pressure is 145/80 mm Hg and pulse is 72/min. On examination, the patient can see only hand motions through the left eye. Funduscopic evaluation of the eye shows a cherry-red spot in the macula with surrounding retinal whitening. Cranial nerve examination is otherwise unremarkable. There is a left-sided neck bruit on cardiovascular examination. Which of the following is the most likely path of the embolus causing this patient's symptoms? A. External carotid artery, facial artery, ophthalmic artery, retinal artery (%) B. External carotid artery, ophthalmic artery, retinal artery (%) C. External carotid artery, temporal artery, retinal artery (%) D. Internal carotid artery, anterior cerebral artery, retinal artery (%) E. Internal carotid artery, ophthalmic artery, retinal artery (%)

E. Internal carotid artery, ophthalmic artery, retinal artery (%)

A 68-year-old woman is evaluated for right lower extremity weakness while hospitalized. The patient was admitted after sustaining a right femoral neck fracture and underwent total hip arthroplasty. Her operative course was uncomplicated, but the patient experienced right leg weakness postoperatively. Since the surgery, she has had difficulty with physical therapy and reports numbness of the right leg. The patient's other medical conditions include hypertension, type 2 diabetes mellitus, a prior transient ischemic attack, and osteoarthritis. Right lower extremity examination shows weakness in dorsiflexion, plantar flexion, and knee flexion. Hip flexion and knee extension are normal. Sensation to light touch is decreased on the dorsum of the right foot and posterolateral aspect of the right calf. Ankle reflex is absent on the right. Which of the following is the most likely cause of this patient's current findings? A. Diabetic neuropathy (%) B. L5 radiculopathy (%) C. Lacunar stroke (%) D. Peroneal nerve compression (%) E. Sciatic nerve injury (%)

E. Sciatic nerve injury (%) This patient underwent total hip replacement following a right femoral neck fracture and developed right lower extremity neurological deficits across the sciatic nerve (L4-S3) and its main branches: Sciatic nerve: weakness in knee flexion Common peroneal nerve: weakness in dorsiflexion, numbness on dorsal foot and posterolateral calf Tibial nerve: weakness in plantar flexion and inversion, absent ankle reflex These deficits are characteristic of a proximal sciatic nerve injury. The sciatic nerve is particularly susceptible to injury in patients with femoral head dislocation, hip fracture, and/or arthroplasty due to its proximity to the hip joint and femur. Injury to the nerve can be caused by direct mechanical trauma (caused by the surgery or initial fracture), compression of the nerve (due to hematoma or swelling), or local inflammation

A 39-year-old right-handed man is brought to the office by his wife due to concerns about his behavior. Two months ago, the patient was robbed and hit in the head and knees with a baseball bat when he resisted. He initially had difficulty walking, but his injuries have since healed. His wife and other family members say that his overall demeanor has changed significantly since the attack. Prior to the assault, the patient was kind, considerate, and extremely polite. However, since the attack, he has been very irritable and rude, and was recently fired from his job for insulting customers and making socially insensitive comments to coworkers. Damage to which anatomical region of the brain is the most likely explanation for this patient's symptoms? A. Corpus callosum (%) B. Dominant parietal cortex (%) C. Dominant temporal cortex (%) D. Lateral prefrontal cortex (%) E. Nondominant parietal cortex (%) F. Nondominant temporal cortex (%) G. Orbitofrontal cortex (%)

G. Orbitofrontal cortex (%) This patient's personality change, disinhibition, and irritability are most likely due to damage affecting the orbitofrontal cortex (OFC). The OFC is located in the frontal lobe and has strong modulatory connections to the limbic system (ie, the brain's primary emotional system); it is involved in behavioral and emotional regulation. Pathological behavioral and emotional changes are more commonly seen with bilateral, rather than unilateral, injury to the OFC. Disinhibition may be associated with significant impulsivity and loss of social etiquette, whereas increased irritability in the context of disinhibition may lead to frank, aggressive behavior. Diagnostic workup includes obtaining information from family and friends about personality changes, neuropsychological testing, and structural brain imaging.

Equilibrium potentials of cellular ions reflect how they affect the membrane potential if the membrane were permeable solely for that ion. The resting membrane potential shown in the graph is negative, indicating that at rest, the membrane is permeable to an ion with a negative equilibrium potential (potassium or chloride). Opening of ligand-gated ion channels in response to neurotransmitter binding (black arrow) causes an increase in membrane potential to above zero. This indicates that the membrane has become permeable for an ion with a positive equilibrium potential (sodium or calcium). Opening of voltage-gated ion channels in response to the change in membrane potential (red arrow) causes a drop in membrane potential, indicating that the membrane becomes permeable to an ion with a negative equilibrium potential (potassium or chloride) RMP: potassium Ligand gated: sodium Voltage gated: chloride

Researchers are studying how the membrane potential of a postsynaptic neuron changes in response to neurotransmitter stimulation. Baseline measurements determine that the resting membrane potential is generated by high membrane permeability for a particular ion. When neurotransmitter stimulation begins, ligand-gated ion channels open (black arrow) and increase the membrane permeability for a different ion, causing a change in membrane potential. This triggers the delayed opening of voltage-gated ion channels (red arrow), which increase the membrane permeability for a third type of ion. The results of the experiment are shown in the graph below. The equilibrium potentials of different ions under physiologic conditions are as follows: The equilibrium potentials of different ions under physiologic conditions are as follows: ENa=+60 mVE K=−90 mVE Cl=−75 mVE Ca=+125 mV Which of the following options would best explain the changes in this neuron's membrane potential during the experiment Resting membrane, black arrow, red arrow

(Choice D) Damage to the lateral prefrontal cortex may result in

The lateral prefrontal cortex is involved in executive functioning, which includes motivation, organization, planning, and purposeful action. dysexecutive syndrome, a syndrome characterized by significant difficulties performing these functions.

A 63-year-old woman comes to the office for evaluation of chronic constipation. For the past 8 months, the patient has had increased straining with bowel movements but no abdominal pain or rectal bleeding. She has 2 children, both delivered via forceps-assisted vaginal delivery. BMI is 31 kg/m2. On digital rectal examination, there are no masses and rectal tone is normal; pelvic examination shows a visible bulge into the vagina with straining. Sensation around the perineum is intact. Fecal occult blood testing is negative. Which of the following is the most likely cause of this patient's symptoms? A. Absence of colonic intramural ganglion cells (2%) B. Colonic sensitivity with chronic irregular contractions (3%) C. Damage to the levator ani muscle complex (78%) D. Defect in the external anal sphincter (7%) E. Increased internal anal sphincter parasympathetic tone (7%)

This patient's chronic constipation is caused by pelvic organ prolapse, the herniation of pelvic organs (eg, bladder, rectum) into the vaginal wall due to levator ani muscle complex damage. The levator ani muscle complex forms most of the pelvic floor and functions to hold the pelvic organs in a stable position; when this complex is damaged, such as with increased intraabdominal pressure (eg, pregnancy, obesity) or obstetric trauma (eg, forceps-assisted vaginal delivery), there is increased pelvic floor laxity, resulting in decreased pelvic organ support. The decreased pelvic floor support causes an anatomic change to normal pelvic organ positions; for the rectum, this leads to a change in rectal angle during defecation, which can cause incomplete defecation and constipation. With accumulation of fecal material, the rectum expands and herniates through the rectovaginal septum, causing prolapse of the rectum into the posterior vaginal wall (ie, rectocele). The prolapse is exacerbated by Valsalva maneuvers (eg, vaginal bulge while straining), which cause further difficulty with defecation; therefore, some patients apply digital pressure against the prolapse (ie, splinting) to help improve bowel movements.

C. Interalveolar septal destruction with bronchial wall inflammation (%) emphysema!! Emphysema consists of alveolar destruction and enlargement that results from a combination of inflammation and leukocyte infiltration, increased protease activity, and oxidative stress, usually in response to exposure to cigarette smoke. In severe disease, large air spaces known as subpleural blebs can form in the lung apices.

Which of the following underlying histopathological changes are expected in this patient? A. Ferruginous bodies embedded within interstitial fibrous tissue (%) B. Hemosiderin-laden macrophages within congested airways (%) C. Interalveolar septal destruction with bronchial wall inflammation (%) D. Multinucleated giant cells surrounding caseating granulomas (%) E. Necrotizing arteritis with adjacent palisading epithelioid histiocytes (%) F. Patchy interstitial fibrosis with the presence of fibroblastic foci (%)

post partum depression timline

develops usually within 4-6 weeks of giving birth >2 weeks of moderate to severe depression depression suffered by a mother following childbirth, typically arising from the combination of hormonal changes, psychological adjustment to motherhood, and fatigue.

(Choices B and E) Parietal cortex (dominant and non dominant hemispheres!) damage results in

difficulties with spatial and visual perception. Dominant lesions (>95% of right-handed and >50% of left-handed patients are left hemisphere dominant) result in Gerstmann syndrome with right-left confusion and difficulty with writing and mathematics. Nondominant parietal cortex lesions (most commonly right-sided) can result in hemi-neglect, constructional apraxia, and denial of the problem. The parietal cortex processes and interprets visual, auditory, and motor signals received from other brain areas.

The posterior surface of the heart is mostly formed by the left atrium, which lies directly over the

esophagus. Longstanding mitral stenosis/regurgitation can lead to progressive left atrial enlargement, further displacing the left atrium posteriorly and causing external compression of the mid-esophagus with dysphagia

(Choices C and F) Temporal cortex injury can cause disturbances in

language, sensory interpretation, and impaired memory. These patients can also exhibit behavioral changes, such as apathy, hyperorality, hypersexuality, and visual agnosia as seen in Klüver-Bucy syndrome. Nondominant (usually right-sided) lesions can affect nonverbal memory, including musical ability; dominant left-sided lesions can affect verbal memory, such as word recognition. This patient's symptoms are most characteristic of an OFC injury.