৪৮তম বিশেষ বিসিএস [স্বাস্থ্য] ⎯ মডেল টেস্ট [Archived]

The inferior mesenteric vein is not a direct tributary of portal vein. It drains into the splenic vein. 

The uterine artery arises from the anterior division of the internal iliac artery.

It upplies blood to the uterus, as well as parts of the vagina and fallopian tubes.

The absent P wave indicates that the atrium is not depolarizing and, therefore, the pacemaker cannot be in the sinoatrial (SA) node. Because the QRS and
T waves are normal, depolarization and repolarization of the ventricle must be proceeding in the normal sequence. This situation can occur if the pacemaker is located in the
atrioventricular (AV) node. If the pacemaker were located in the bundle of His or in the Purkinje system, the ventricles would activate in an abnormal sequence (depending on
the exact location of the pacemaker) and the QRS wave would have an abnormal configuration. Ventricular muscle does not have pacemaker properties.

B. Chemoreceptors for CO2, H+, and O2 (Table 4-7)

1. Central chemoreceptors in the medulla

■ are sensitive to the pH of the cerebrospinal fluid (CSF). Decreases in the pH of the CSF produce increases in breathing rate (hyperventilation).
■ H+does not cross the blood–brain barrier as well as CO2 does.
a. CO2 diffuses from arterial blood into the CSF because CO2 is lipid-soluble and readily crosses the blood–brain barrier.
b. In the CSF, CO2 combines with H2O to produce H+ and HCO3–. The resulting H+ acts directly on the central chemoreceptors.
c. Thus, increases in PCO2 and [H+] stimulate breathing, and decreases in PCO2 and [H+] inhibit breathing.
d. The resulting hyperventilation or hypoventilation then returns the arterial PCO2 toward normal.

2. Peripheral chemoreceptors in the carotid and aortic bodies

■ The carotid bodies are located at the bifurcation of the common carotid arteries.
■ The aortic bodies are located above and below the aortic arch.

a. Decreases in arterial PO2
■ stimulate the peripheral chemoreceptors and increase breathing rate.
■ PO2 must decrease to low levels (<60 mm Hg) before breathing is stimulated. When PO2 is less than 60 mm Hg, breathing rate is exquisitely sensitive to PO2.

b. Increases in arterial PCO2
■ stimulate peripheral chemoreceptors and increase breathing rate.
■ potentiate the stimulation of breathing caused by hypoxemia.
■ The response of the peripheral chemoreceptors to CO2 is less important than the
response of the central chemoreceptors to CO2 (or H+).

c. Increases in arterial [H+]
■ stimulate the carotid body peripheral chemoreceptors directly, independent of changes in PCO2.
■ In metabolic acidosis, breathing rate is increased (hyperventilation) because arterial [H+] is increased and pH is decreased.

Para-aminohippuric acid (PAH) has the greatest clearance of all of the substances because it is both filtered and secreted. Inulin is only filtered. The other substances are filtered and subsequently reabsorbed; therefore, they will have clearances
that are lower than the inulin clearance.

 Actions of insulin

■ Insulin acts on the liver, adipose tissue, and muscle.
a. Insulin decreases blood glucose concentration by the following mechanisms:
(1) It increases uptake of glucose into target cells by directing the insertion of glucose transporters into cell membranes. As glucose enters the cells, the blood glucose concentration decreases.
(2) It promotes formation of glycogen from glucose in muscle and liver, and simultaneously inhibits glycogenolysis.
(3) It decreases gluconeogenesis. Insulin increases the production of fructose 2,6-bisphosphate, increasing phosphofructokinase activity. In effect, substrate is directed away from glucose formation.

b. Insulin decreases blood fatty acid and ketoacid concentrations.
■ In adipose tissue, insulin stimulates fat deposition and inhibits lipolysis.
■ Insulin inhibits ketoacid formation in the liver because decreased fatty acid degradation provides less acetyl CoA substrate for ketoacid formation.

c. Insulin decreases blood amino acid concentration.
■ Insulin stimulates amino acid uptake into cells, increases protein synthesis, and inhibits protein degradation. Thus, insulin is anabolic.

d. Insulin decreases blood K+ concentration.

■ Insulin increases K+ uptake into cells, thereby decreasing blood [K+].

Glucose-dependent insulinotropic peptide (GIP) is the only gastrointestinal (GI) hormone that is released in response to all three categories of nutrients—fat, protein, and carbohydrate. Oral glucose releases GIP, which, in turn, causes the release of insulin from the endocrine pancreas. This action of GIP explains why oral glucose is more effective than intravenous glucose in releasing insulin.

Taste

1. Taste pathways
a. Taste receptor cells line the taste buds that are located on specialized papillae. The receptor cells are covered with microvilli, which increase the surface area for binding taste chemicals. In contrast to olfactory receptor cells, taste receptors are not neurons.

b. The anterior two-thirds of the tongue
■ has fungiform papillae.
■ detects salty, sweet, and umami sensations.
■ is innervated by CN VII (chorda tympani).

c. The posterior one-third of the tongue
■ has circumvallate and foliate papillae.
■ detects sour and bitter sensations.
■ is innervated by CN IX (glossopharyngeal).
■ The back of the throat and the epiglottis are innervated by CN X.

d. CN VII, CN IX, and CN X enter the medulla, ascend in the solitary tract, and terminate on second-order taste neurons in the solitary nucleus. They project, primarily ipsilaterally, to the ventral posteromedial nucleus of the thalamus and, finally, to the taste cortex.

2. Steps in taste transduction
■ Taste chemicals (sour, sweet, salty, bitter, and umami) bind to taste receptors on the microvilli and produce a depolarizing receptor potential in the receptor cell.

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ECF volume is 20% of total body weight . 

so, 20% of 80 kg is = 16 L

Biotransformation is the molecular alteration of a drug within the biological system. Drugs usually get ready for metabolism by biotransformation.

Among the options, only atropine as the antagonist of muscarinic Ach receptor

Potency and drug safety are not directly linked to half life. Frequent dosing will help to reach steady state concentration.

Extensive anti microbial coverage is not essential after normal vaginal delivery. A single broad spectrum antibiotic (e.g. Cephradine) may provide highest protection.

Explanation:
• A person with XY chromosomes but external female genitalia is termed a male pseudohermaphrodite.
• True hermaphrodites have both ovarian and testicular tissues.

Explanation:
• In hanging, the ligature mark is high, oblique, and usually incomplete.
• This distinguishes it from strangulation, where the mark is low and horizontal.

Explanation:
• Emasculation, or loss of masculine functions, is listed under grievous hurt in BPC 320.

Explanation:
• Unethical practice for financial gain, such as unnecessary surgeries, is termed infamous conduct by MCI.

Explanation:
• MLR should be contemporaneous, written in ink, signed with date and time, and kept as legal documentation.

Explanation:
• OPV may rarely cause VAPP, especially in immunocompromised individuals.
• IPV does not cause VAPP but is costlier and injectable.

Explanation:
• Emergency contraception with levonorgestrel is most effective when taken within 72 hours of unprotected intercourse.

Explanation:
• Incidence and relative risk (RR) can be calculated in cohort studies as subjects are followed over time.

Explanation:
• Exposure to sound above 85 decibels (dB) for prolonged periods may result in noise-induced hearing loss

Explanation:
• The SDG agenda was launched in 2015, with the goal of achieving all 17 goals by 2030.

Contraindications of live vaccines (names only):
Immunodeficiency (congenital or acquired)
HIV infection with severe immunosuppression
Pregnancy
Recent administration of immunosuppressive therapy (e.g., chemotherapy, high-dose steroids)
History of severe allergic reaction to vaccine components

Explanation:
Parasitic infections like hookworm typically cause eosinophilia due to immune response against helminths

Explanation:
Levothyroxine, synthetic T4, is the standard treatment for hypothyroidism.

Explanation:
Psoriatic arthritis commonly affects DIP joints, which helps differentiate it from rheumatoid arthritis.

Explannation :
Complications of Gonorrhoea Infection :
Pelvic Inflammatory Disease (PID)
Ectopic pregnancy
Infertility (both male and female)
Chronic pelvic pain
Epididymitis
Prostatitis
Disseminated Gonococcal Infection (DGI)
Septic arthritis

Explanation:
• Giardia is transmitted by ingestion of cysts in contaminated water.
• It’s a major cause of traveler’s diarrhea.

Explanation:
• Iron overload occurs with multiple transfusions due to accumulation.
• Managed with chelation therapy (e.g., deferoxamine).

Explanation:
• Low C3 complement is common in AGN (especially post-infectious types).

Explanation:
• G6PD deficiency causes haemolysis after oxidative stress (e.g., drugs, infection).
• Bite cells and Heinz bodies are characteristic.

Explanation:
• Light’s criteria are used to classify pleural fluid as transudate or exudate.

Explanation:
• Facial plethora, bruising, and proximal muscle weakness point toward Cushing’s syndrome.

Explanation:
• Microfilariae show nocturnal periodicity; hence, blood is collected around midnight.

Explanation:
• Viral encephalitis typically shows lymphocytic CSF, normal glucose, and mildly raised protein.

Explanation:
• Type 1 respiratory failure: PaO₂ < 60 mmHg, PaCO₂ normal or low.
• Seen in pneumonia, ARDS, and PE.

Explanation:
• Functional dyspepsia (non-ulcer) is diagnosed when no structural cause is found on endoscopy.

Explanation:
• In women, the cervix is most commonly affected, followed by urethra and rectum.

Explanation:
• Morbilliform rash is the most common presentation of drug-induced hypersensitivity.

Explanation:
• ATN from ischemia or nephrotoxins is the most common cause of hospital-acquired AKI.

Explanation:
• Ranson’s criteria include age, WBC, glucose, AST, LDH etc. to assess severity/mortality in acute pancreatitis.

Explanation:
• Biological symptoms include early waking, appetite loss, weight loss, libido loss.

Explanation:
• Most cases of acute pericarditis are due to viral infections (Coxsackie, echovirus).

Explanation:
• Streptococcus pneumoniae is the leading cause of CAP.
• Mycoplasma is more common in young adults with atypical symptoms.

USG is the first line imaging in hepatobiliary pathology. 

The half life of PTH is only 3-5 minutes.

In case of inadvertent removal of parathuroid glands during thyroidectomy or disruption of the blood supply of the parathyroid glands can cause hypoparathyroidism and hypocalcemic tetany during the immediate post-operative period. 

T4 has a longer half life (about 7 days) and remains in blood for some time even after total thyroidectomy. 

Explanation:
Normal amniotic fluid is clear or colourless in early pregnancy and  slightly straw-colored in term.
Green fluid indicates meconium staining; brown suggests old blood or intrauterine death.

Explanation:
Fibroids have a characteristic whorled, firm, gray-white cut surface.

Explanation:
Complete (or total) placenta previa occurs when the placenta entirely covers the cervical os, requiring cesarean delivery.

Explanation:
TAH involves the surgical removal of the entire uterus including the cervix through an abdominal (laparotomy) incision.

Explanation:
IgG antibodies cross the placenta and attack Rh-positive fetal red blood cells, causing hemolysis.

Explanation:
CA-125 is elevated in most epithelial ovarian cancers, especially serous types, and is used for diagnosis, prognosis, and monitoring treatment response.

Explanation:
To reduce maternal complications while ensuring uteroplacental perfusion, BP is maintained <140/90 in non-severe cases.

Explanation:
Maternal blood glucose is not routinely recorded on the partograph. The partograph tracks labor-related parameters such as cervical dilation, fetal descent, contractions, fetal heart rate, and maternal vitals like pulse and blood pressure.

Explanation:
The 75g OGTT is the standard screening and diagnostic test for GDM.

Explanation:
While Pap smear and HPV DNA testing are screening tools, colposcopy with directed biopsy remains the gold standard for diagnosing and grading premalignant cervical lesions.
It allows direct visualization of abnormal epithelium and histological confirmation.

Explanation: The classical CRS triad includes:
Cataracts,
Sensorineural deafness,
Congenital heart disease (commonly PDA or pulmonary artery stenosis).

Explanation:
Topical azole antifungals like clotrimazole are first-line for uncomplicated cases; oral fluconazole is also effective in complicated ones

Explanation:
The main aim of antenatal care is to monitor maternal and fetal health, detect complications early, and ensure a safe pregnancy outcome
To delivery a healthy baby from healthy mother

Explanation:
Estrogen from the ovaries stimulates ductal growth and fat deposition in the breasts, leading to thelarche.

Explanation:
True labor begins with regular, painful contractions leading to progressive cervical changes (effacement and dilation).

Explanation:
Neonates typically present with nonspecific signs such as:
Poor feeding
Lethargy or irritability
Hypo- or hyperthermia
Respiratory distress or apnea associated with jaundice

These signs warrant prompt evaluation for sepsis, as symptoms can progress rapidly.