স্পেশাল বিসিএস (স্বাস্থ্য)

Reference: Davidson 23rd; P-584

Structure seen through opthalmoscope:
1.Optic Disc
2.Retina
3.Blood vessels
4.Macula

Snell 8th-349

Mitochondria are membrane enclosed organelles with arrays of enzymes specialized for aerobic respiration and production of ATPs. Hence it is called the power house of cell.

- Size: 0.5-1 um in diameter & up to 10 um in length

- Shape: Elongated/rod shaped

- Number: The number of mitochondria is related to the cell's energy needs: cells with a high- energy metabolism (eg, cardiac muscle, cells of some kidney tubules, hepatocytes etc.) have abundant mitochondria, whereas cells with a low-energy metabolism have few mitochondria.

- Mitochondria are absent in RBCs and terminal keratinocytes of skin.

- Mitochondrial matrix contains a small circular chromosome of DNA, ribosomes, mRNA, and tRNA, all with similarities to the corresponding bacterial components.

- Mitochondrial DNA is a small circular double helix DNA that contains 37 genes.
- Mitochondrial DNA is inherited from mother (ovum), as cytoplasm of sperm do not contribute to zygote.
- Due to mitochondrial DNA, mitochondria are self replicating.

- Mitochondria are highly plastic, rapidly changing shape, fusing with one another and dividing, and are moved through the cytoplasm along microtubules.

Reference: Davidson 23rd; P-814

Anti-dsDNA antibodies are highly specific (100%) for diagnosis of SLE. Its level correlates with lupus activity.

Stem Breakdown:

Chronic non-productive cough and exertional dyspnoea: These are common symptoms of interstitial lung diseases, such as idiopathic pulmonary fibrosis (IPF).
Bilateral inspiratory crackles and digital clubbing: Inspiratory crackles ("Velcro crackles") are a hallmark of IPF, and clubbing is a common associated finding.
Reticular opacities on chest X-ray, especially in the lower lobes: This is characteristic of interstitial lung diseases like IPF.
Option Analysis:

A) Idiopathic pulmonary fibrosis: This is the correct diagnosis. Davidson and Harrison describe idiopathic pulmonary fibrosis (IPF) as a chronic progressive fibrosing interstitial lung disease. It primarily affects the lower lobes of the lungs and presents with exertional dyspnoea, a non-productive cough, and bilateral inspiratory crackles. Clubbing is also commonly seen in these patients.
B) Chronic obstructive pulmonary disease (COPD): COPD is characterised by airflow limitation due to chronic bronchitis or emphysema. It usually presents with a productive cough, wheezing, and hyperinflation on chest X-ray, not the reticular opacities seen in IPF.
C) Congestive heart failure: While heart failure can cause dyspnoea and bilateral crackles due to pulmonary ooedema, it usually presents with signs of fluid overload (e.g., leg ooedema, elevated jugular venous pressure). Additionally, the chest X-ray would show pulmonary congestion rather than reticular opacities.
D) Bronchiectasis: Bronchiectasis causes a chronic productive cough with copious sputum production and recurrent infections. It would show airway dilation (bronchial thickening) on imaging rather than reticular interstitial opacities.

Explanation: The World Health Organisation (WHO) guideline value for arsenic content in tube well water is 10 μg/L

Explanation :
Causes of CKD -
Diabetes malitus (20-40%)
Interstitial disease (20-30%)
Glomerular disease
Hypertension 
SLE
PCOD
Renal artery stenosis
Unknown (5-20%)

Reference: Davidson 23rd; P-793

Explanation : Schwann cells Provide myelination (insulation) around the nerve fibers in PNS , Play important role in nerve regeneration , Remove cellular debris during regeneration by their phagocytic activity. Satellite cells Provide physical support to the PNS neurons , help in regulation of chemical environment of ECF around the PNS neurons.
Ref : Sembulingam 6th Edition (Page- 774)

TB is most common cause of Bronchiectasis

Severe dengue is characterized by plasma leakage, leading to hemoconcentration, pleural effusions, or ascites. This is the hallmark of dengue hemorrhagic fever and dengue shock syndrome. Warning signs include persistent vomiting, abdominal pain, mucosal bleeding, and evidence of plasma leakage (e.g., rising hematocrit). Early recognition is critical for fluid management to prevent shock.

Reference: Davidson 23rd; P-857
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Ref: Davidson 23rd; P- 938

Explanation :
Features of innocent or benign murmur -
Soft
Mid- systolic
Heard at left sternal edge
No radiation 
No other cardiac abnormalities 
Present in anaemia,Thyrotoxicosis,Pregnancy. 

Sympathetic Nerve supply of appendix arise from T10

Reference: Davidson 23rd; P-825

The average blood volume of adults is about 7% of body weight, or about 5 litres. About 60% of the blood is plasma and 40% is red blood cells, but these percentages can vary considerably in different people, depending on sex, weight, and other factors.

Explanation -
Arterial thrombi :
are frequently occlusive; the most common sites in decreasing order of frequency are the coronary, cerebral, and femoral arteries. They typically consist of a friable meshwork of platelets, fibrin, red cells, and degenerating leukocytes. Although these are usually superimposed on a ruptured atherosclerotic plaque, other vascular injuries (vasculitis, trauma) may be the underlying cause.

Venous thrombosis (phlebothrombosis)- is almost invariably occlusive, with the thrombus forming a long luminal cast. Because these thrombi form in the sluggish venous circulation, they tend to contain more enmeshed red cells (and relatively few platelets) and are therefore known as red thrombi or stasis thrombi. Venous thrombi are firm, are focally attached to the vessel wall. 

Barr body:
- Tightly coiled clump of chromatin mass (heterochromatin), genetically inactive
- It represents inactivated X chromosome.**
- During cell division Barr body disappears
- Number of Barr body is always 1 less than the number of X chromosome
- Female has 1 Barr body, male has no Barr body normally.
- Klinefilter syndrome : 47,XXY ; 1 Barr body

Explanation: Malar rash in SLE: Fixed erythema, flat or raised, sparing the nasolabial folds

*** There is no male to male transmission in X-linked disorders, because in male the X chromosome comes from the mother. 

Criteria of X-linked recessive disorders:
1. Affected cases are usually males carrying the gene.
2. Homozygous females can be affected, but this is rare. 
3. Heterozygous females usually do not express the full phenotypic changes because of the paired normal allele.
4. Only females are carriers.
5. If a female has the allele (female carrier)- with a normal male, off-springs will be-
    - 50% daughters carrier, 50% normal
    - 50% sons affected, 50% normal
6. If a male has the allele (affected male)- with a normal male the off-springs will be-
    - All daughters carrier
    - All sons normal (no male to male transmission)
7. Affected cases have affected brothers and maternal uncles.
8. Since females have two copies of X-chromosomes and males have only one, X-linked recessive disease are much more common among males than in females.

Reddy and Nandy recommend saturated salt solution for viscera in poisoning cases; formalin destroys toxins.

Explanation:

Explanation :
Lesion of left optic nerve: Total blindness of left eye.
Lesion of right optic nerve: Total blindness of right eye.
Lesion of lateral fibers in left side of optic chiasma: Left nasal hemianopia.
Lesion of lateral fibers in right side of optic chiasma: Right nasal hemianopia C + D.
Lesion of lateral fibers in both sides of optic chiasma: Binasal hemianopia.
Lesion of medial fibers in optic chiasma: Bitemporal hemianopia.
Lesion of left optic radiation: Right homonymous hemianopia.
Lesion of right optic radiation: Left homonymous hemianopia.nknown.

Ref : Sembulingam 6th edition (Figure-168.5)

কোন ব্যাখ্যা যোগ হয় নি।

Periosteum is a layer of dense connective tissue on the outer surface of bone, bound to bone matrix by bundles of type I collagen called perforating (or Sharpey) fibers.

Explanation: Although most clinical syndromes are caused by zoonotic transmission of parasites from animals to humans through phlebotomine sandfly vectors

Leishmania is a hemoflagellete

Confidentiality is breached when shared without medical or legal necessity. (Reddy, Ch. 2; BMDC Code of Ethics)

Explanation :

Ref : Sembulingam 6th edition (Table-144.3)

It is the innermost part of the adrenal gland, consisting of chromaffin cells that secrete catecholamines, including epinephrine (adrenaline), norepinephrine (noradrenaline), and a small amount of dopamine, in response to stimulation by sympathetic preganglionic neurons.

Reference: Langman’s 13th; P-32

Stem Breakdown:

Acute-onset left leg pain and coldness: This suggests a sudden loss of blood flow, which is concerning for an acute arterial occlusion.
Pale and pulseless leg: These findings confirm that the limb is ischemic due to an arterial blockage.
History of chronic atrial fibrillation: Atrial fibrillation increases the risk of thromboembolism, which can lead to arterial embolism.
Option Analysis:

A) Deep vein thrombosis: Deep vein thrombosis (DVT) affects the veins, not arteries, and typically causes swelling, pain, and warmth in the affected limb, not coldness or pulselessness.
B) Acute arterial embolism: This is the correct diagnosis. Davidson and Harrison explain that acute arterial embolism is a sudden blockage of an artery, often due to an embolus originating from the heart (e.g., in atrial fibrillation). The "5 Ps" of acute arterial occlusion are Pain, Pallor, Pulselessness, Paresthesia, and Paralysis.
C) Chronic venous insufficiency: Chronic venous insufficiency causes leg swelling, varicose veins, and skin changes, but it does not cause sudden limb ischemia or a pulseless leg.
D) Peripheral neuropathy: Peripheral neuropathy causes numbness, tingling, and weakness, but it does not cause acute pain or loss of pulses.

Reference: Davidson 23rd; P-841

Explanation :
Acute phase proteins :
CRP,Ceruloplasmin,Cryoglobulin
Serum amyloid A protein 
Fibrinogen
Ceruloplasmin
Heptoglobin
Ferritin
Lactoferrin

The kidneys synthesize glucose from amino acids and other precursors during prolonged fasting, a process referred to as gluconeogenesis. The kidneys’ capacity to add glucose to the blood during prolonged periods of fasting rivals that of the liver.

[Robbins 9th 278]

Explanation: Endoscopy is the preferred investigation for diagnosis of peptic ulcer disease

The genetic code is a series of codons by which DNA directs transcription of RNA and its translation into proteins

Properties of genetic code:
 Specificity
 Universality
 Redundant (degenerate)
 Non-overlapping
 Comma less

Explanation : Three areas are present in visual cortex:
i. Primary visual area (area 17), which is concerned with the perception of visual impulses.
ii. Secondary visual area or visual association area (area 18), which is concerned with the interpretation of visual impulses.
iii. Occipital eye field (area 19), which is concerned with the movement of eyes (Chapter 152). Pretectal nucleus is concerned with light reflexes.

Ref : Sembulingam 6th edition (Page- 991)

Submucosal coat forms floor of bacillary ulcer

ANP is called Hypervolemia hormone. It secretion increased during hypervolemia and decreased secretion during dehydration and volume depletion.

Reference: Davidson 23rd, Fig. 21.7 (39 BCS Question)

CCK causes contraction of gallbladder & relaxation of sphincter of Oddi.

Reference: Practical Manual in Clinical Medicine by Professor ABM Abdullah; P-165

Explanation :
Coagulative necrosis is a form of necrosis in which the architecture of dead tissue is preserved for a span of at least some days .
The affected tissue has a firm texture. Presumably, the injury denatures not only structural proteins but also enzymes and so blocks the proteolysis of the dead cells; as a result, intensely eosinophilic cells with indistinct or reddish nuclei may persist for days or weeks.
Ultimately, the necrotic cells are broken down by the action of lysosomal enzymes derived from infiltrating leukocytes, which also remove the debris of the dead cells by phagocytosis. Ischemia caused by obstruction in a vessel may lead to coagulative necrosis of the supplied tissue in all organs except the brain (see next paragraph for explanation).
A localized area of coagulative necrosis is called an infarct.

Reference: Junqueira’s Basic Histology; 14th Edition; Page-438

Median nerve is injured above the level of the elbow in supracondylar fracture of the humerus. As a result, Ape or monkey thumb deformity is present due to paralysis of the thenar muscles.

Dengue Shock Syndrome
Clinical Signs of Dengue Shock Syndrome:
• Cool extremities, delayed capillary refill time
• Lethargy or restlessness (which may be a sign of reduced brain perfusion)
• Tachypnoea or Kussmaul's breathing
• Tachycardia, weak pulse
• Narrow pulse pressure: Pulse pressure ≤20 mmHg with increased diastolic pressure, e.g. 100/80 mmHg •
Hypotension by age, defined as systolic pressure <80 mmHg for those aged <5 years or 80 to 90 mmHg for older children and adults

Reference: Davidson 23rd; P-482
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Reference: Davidson 23rd; P- 1150 (Box-26.1)

Chronic kidney disease (CKD) is the most common cause of secondary hyperparathyroidism. Davidson explains that in CKD, impaired phosphate excretion and decreased production of active vitamin D (calcitriol) lead to hypocalcemia, which stimulates parathyroid hormone (PTH) release. Harrison adds that secondary hyperparathyroidism is an adaptive response to maintain normal calcium levels but can lead to renal osteodystrophy if left untreated.