স্পেশাল বিসিএস (স্বাস্থ্য)

Thelarche is the development of breast.

Anus below the pectinate line develops from proctoderm

Individual hepatocytes are separated from the leaky sinusoids by the space of Disse, which contains stellate cells that store vitamin A and play an important part in regulating liver blood flow.

Reference: Davidson 23rd; P-464
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Explanation: A delusion is a false belief, Illusions are misperceptions of real stimuli. Hallucinations are sensory perceptions that occur in the absence of external stimuli

Three Sources of Energy for Muscle Contraction

1)      The first source of energy that is used to reconstitute the ATP is the substance phosphocreatine, which carries a high-energy phosphate bond similar to the bonds of ATP.

2)      The second important source of energy, which is used to reconstitute both ATP and phosphocreatine, is a process called glycolysis-the breakdown of glycogen previously stored in the muscle cells.

3)      The third and final source of energy is oxidative metabolism, which means combining oxygen with the end products of glycolysis and with various other cellular foodstuffs to liberate ATP.

More than 95% of all energy used by the muscles for sustained long-term contraction is derived from oxidative metabolism.

Reference: Davidson 23rd; P-133

Explanation: Microalbuminuria is the most sensitive test for detecting early diabetic nephropathy. Davidson explains that albumin excretion increases in the early stages of kidney damage, even before significant declines in GFR or rises in serum creatinine are seen. Harrison emphasises that early detection through microalbuminuria allows for timely interventions to slow disease progression.

Schwann cell is cell of PNS.

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

Nucleic acid vaccines
 COVID-19 (RNA vaccines)  Ebola virus (DNA in clinical trials)

Reference: Davidson 23rd, Page:- 89

Chlamydia is intracellular so can't be seen under microscope. & has flexible thin wall.

Reference: Davidson 23rd; P-357

Lysosomal enzymes:
The most common lysosomal enzymes are acid hydrolases such as
 Proteases
 Nucleases
 Phosphatase
 Lipase
 Phospholipases
 Sulfatases
 ß-glucuronidase

Enzymes of peroxisomes: Catalase, D-and L-amino oxidases, urate oxidase, hydroxyacid oxidase

কোন ব্যাখ্যা যোগ হয় নি।

Answer: C. Collect clothes as evidence under MLC protocols
Justification:
Clothing is property, not part of body → can be collected.
Medical exam on body requires consent.
(Reddy Ch. 20; Legal procedure for evidence handling)

Zones 1, 2, and 3 of Pulmonary Blood Flow
The capillaries in the alveolar walls are distended by the blood pressure inside them but simultaneously are compressed by the alveolar air pressure on their outsides. Therefore, whenever the lung alveolar air pressure becomes greater than the capillary blood pressure, the capillaries close, and there is no blood flow.
Under different normal and pathological lung conditions, one may find any one of three possible zones (patterns) of pulmonary blood flow, as follows:

Zone 1: No blood flow during all portions of the cardiac cycle because the local alveolar capillary pressure in that area of the lung never rises higher than the alveolar air pressure during any part of the cardiac cycle
Zone 2: Intermittent blood flow only during the peaks of pulmonary arterial pressure because the systolic pressure is then greater than the alveolar air pressure, but the diastolic pressure is less than the alveolar air pressure
Zone 3: Continuous blood flow because the alveolar capillary pressure are remains greater than alveolar air pressure during the entire cardiac cycle

Normally, the lungs have only zones 2 and 3 blood flow-zone 2 (intermittent flow) in the apices and zone 3 (continuous flow) in all the lower areas.

Explanation :
Fungi -
Eukaryotes 
Mitochondria and endoplasmic reticulum present
Sterol present in cell membrane 
Chitin present in cell wall
Sexual and asexual spores are present

The three major organs of articulation are the lips,tongue,  and soft palate. 

The resonators include the mouth, the nose and associated nasal sinuses, the pharynx, and even the chest cavity. 

This is a sign of meningitis.

The pivotal investigation is echocardiography, which can confirm the diagnosis and also helps to identify the optimum site for aspiration of the fluid.

Dyspnea but chest is clear—pulmonary embolism, metabolic acidosis (diabeti ketoacidosis, renal failure, lactic acidosis salicylate poisoning), severe anemia, shock, pneumocystis jiroveci pneumonia, psychogenic.

Dyspnea with stridor (indicates upper airway obstruction)—foreign body or tumor, acute epiglottitis, anaphylactic reaction, laryngeal trauma, laryngeal fracture.

Mood disorders Mood or affective disorders include:
 unipolar depression: one or more episodes of low mood and associated symptoms
 bipolar disorder: episodes of elevated mood interspersed with episodes of depression
 dysthymia: chronic low-grade depressed mood without sufcient other symptoms to count as ‘clinically signicant’ or ‘major’ depression.

Reed–Sternberg cells (giant binucleate cells) are pathognomonic for Hodgkin lymphoma.

All occurs in HIV patient. But kaposi sarcoma is most common.

This sensory organ of the hearing is situated on the basilar membrane. It is spread like a ribbon along the entire length of basilar membrane.

Hypoparathyroidism leads to hypocalcemia, by decreasing the resorption of calcium from bones. Hypocalcemia causes neuromuscular hyperexcitability, resulting in hypocalcemic tetany. Normally, tetany occurs when plasma calcium level falls below 6 mg/dL from its normal value of 9.4 mg/dL.

Molecular layer (plexiform layer). This is the most superficial layer; It consists mainly of a dense network of tangentially oriented nerve fibres. These fibres are derived from the apical dendrites of the pyramidal cells and fusiform cells, the axons of the stellate cells, and the cells of Martinelli.

• Patient feeling feverish with excessive sweating—Thyrotoxicosis.

Explanations:
In the usual Na+ gradient, the [Na+] is higher in extracellular than in intracellular fluid (maintained by the Na+–K+ pump). Two forms of transport are energized by this Na+ gradient cotransport and countertransport. Because glucose is moving in the same direction as Na+, one can conclude that it is cotransport.

Explanation: Infarct (85%), Haemorrhage (15%), venous (1%)

Stem Breakdown:

Fever, weight loss, and a new systolic murmur: These symptoms are concerning for a systemic infection affecting the heart valves, raising suspicion for infective endocarditis. Murmurs are common in endocarditis due to the vegetation forming on heart valves.
Blood cultures grow gramme-positive cocci. This is typical for organisms like Streptococcus viridans and Staphylococcus aureus, both of which commonly cause infective endocarditis.
Option Analysis:

A) Infective endocarditis: This is the correct diagnosis. Endocarditis is characterised by infection of the heart valves or endocardium, often due to gramme-positive organisms. Davidson and Harrison explain that fever, new murmurs, and positive blood cultures are hallmarks of the disease. Risk factors include valve disease, intravenous drug use, or recent dental procedures.
B) Rheumatic heart disease: While this condition can cause valvular damage, it usually arises as a sequela of untreated streptococcal pharyngitis and does not typically present with acute infection or gramme-positive bacteremia. Rheumatic disease causes chronic changes in valve function, not an acute systemic infection.
C) Pericarditis: Pericarditis often presents with sharp chest pain that improves when sitting up and has different auscultatory findings (pericardial friction rub) compared to a systolic murmur. Blood cultures in pericarditis are typically sterile unless there is a coexisting infection.
D) Myocarditis: Myocarditis primarily involves inflammation of the heart muscle, often due to viral infections. It may cause heart failure symptoms or arrhythmias but typically does not cause systolic murmurs or gramme-positive bacteremia.

[Robbins 9th 33]

T lymphocyte is involved in cell mediated immunity

Untreated malaria caused by P. falciparum is potentially life-threatening as a result of extensive brain (cerebral malaria) and kidney (blackwater fever) damage.

Reference: Davidson 23rd; P-556

The fluid in the lumen of the seminiferous tubules is quite different from plasma; it contains very little protein and glucose but is rich in androgens, estrogens, K+, inositol, and glutamic and aspartic acids.
Maintenance of its composition depends on the blood-testis barrier. The barrier also protects the germ cells from bloodborne noxious agents, prevents antigenic products of germ cell division and maturation from entering the circulation and generating an autoimmune response, and may help establish an osmotic gradient that facilitates movement of fluid into the tubular lumen.

Explanation: pleural fluid accumulates as a result of either increased hydrostatic pressure or decreased osmotic pressure (‘transudative’ effusion, as seen in cardiac, liver or renal failure), or from increased microvascular pressure due to disease of the pleura or injury in the adjacent lung (‘exudative’ effusion).

Inlet of inguinal canal is an oval gap in fascia transversalis.

Gametes are derived from Primordial germ cells

Explanation: GIT secretions contain seceretory immunoglobulin A

Line of zahn are marked in thrombi formed within aorta

• The depth of invasion and the extent of nodal and distant metastases at the time of diagnosis remain the most powerful prognostic indicators in gastric cancer.
• Local invasion into the duodenum, pancreas, and retroperitoneum is common.

Reference: Davidson 23rd, Box-18.11

Explanation : Acetylcholine is the transmitter substance at the neuromuscular junction and synapse. It is also released by the following nerve endings:
1. Preganglionic parasympathetic nerve
2. Postganglionic parasympathetic nerve
3. Preganglionic sympathetic nerve
4. Postganglionic sympathetic cholinergic nerves:
  i. Nerves supplying eccrine sweat glands
  ii. Sympathetic vasodilator nerves in skeletal muscle
5. Nerves in amacrine cells of retina
6. Many regions of brain.

Ref : Sembulingam 6th edition (Page- 789)

Explanation : Presynaptic inhibition is mediated by axoaxonal synapses. It is prominent in spinal cord. Negative feedback inhibition is the type of synaptic inhibition, which is caused by Renshaw cells in spinal cord. Feedforward synaptic inhibition occurs in cerebellum and it controls the neuronal activity in cerebellum. Inhibition of antagonistic muscles when a group of muscles are activated is called reciprocal inhibition. It is because of reciprocal innervation.
Ref : Sembulingam 6th edition (Page- 783, 784)

Staphylococcus aureus is the most common cause of septic arthritis in all age groups, especially in those with joint prostheses or IV drug use.