D236 Pathophysiology - Set 2 - Part 1

Correct Answer: Metabolic alkalosis

Prolonged vomiting causes loss of stomach acid leading to metabolic alkalosis, which increases neuronal excitability causing confusion and twitching.
Option a is incorrect because metabolic acidosis would result from bicarbonate loss or acid retention, not stomach acid loss described.
Option c is incorrect because respiratory acidosis results from carbon dioxide retention in lungs, not gastrointestinal fluid losses.
Option d is incorrect because respiratory alkalosis comes from hyperventilation and excessive carbon dioxide loss, not vomiting effects.

Correct Answer: Vasoconstriction response

Brief initial vasoconstriction occurs immediately after injury to limit blood loss before vasodilation and inflammation begin properly.
Option a is incorrect because white cell migration happens after vascular changes create conditions for cells to leave vessels.
Option b is incorrect because increased permeability follows initial vasoconstriction and subsequent vasodilation in the inflammatory sequence.
Option d is incorrect because granulation tissue forms days later during proliferative phase, not as the initial response.

Correct Answer: Twenty five percent

As carriers of autosomal recessive cystic fibrosis, each pregnancy has twenty five percent chance of affected child.
Option a is incorrect because carrier parents always have risk of passing both recessive alleles to offspring together.
Option c is incorrect because fifty percent risk applies to autosomal dominant conditions, not recessive inheritance patterns described.
Option d is incorrect because seventy five percent represents unaffected probability, not the risk for disease in offspring.

Correct Answer: Pharmacogenomic testing

Pharmacogenomic testing analyzes genetic variations affecting drug metabolism, allowing personalized medication selection and dosing for safety.
Option a is incorrect because gene therapy treats genetic diseases by replacing defective genes, not predicting drug responses.
Option c is incorrect because stem cell therapy regenerates damaged tissues but doesn't predict medication reactions or metabolism.
Option d is incorrect because chromosome analysis identifies structural abnormalities but not specific drug metabolism gene variants.

Correct Answer: Messenger RNA codons

Messenger RNA codons specify exact amino acid sequences during translation, determining the final protein structure and function.
Option a is incorrect because DNA polymerase replicates DNA during cell division, not involved in protein synthesis translation.
Option c is incorrect because ribosomal RNA provides structural framework for translation but doesn't specify amino acid sequence.
Option d is incorrect because transfer RNA brings amino acids but the sequence is determined by messenger RNA codons.

Correct Answer: Adenomyosis

Adenomyosis involves endometrial tissue invading the myometrium causing heavy bleeding, pain, and uterine enlargement during menstruation.
Option a is incorrect because endometriosis involves endometrial tissue outside the uterus entirely, not within muscle walls.
Option c is incorrect because leiomyomas are benign smooth muscle tumors, not endometrial tissue invasion into myometrium.
Option d is incorrect because cervical dysplasia involves abnormal cervical cells, not endometrial tissue in uterine muscle.

Correct Answer: Osteocyte cells

Osteocytes are mature bone cells trapped in lacunae that sense mechanical forces and coordinate bone remodeling responses.
Option a is incorrect because osteoblasts actively build bone matrix but aren't the trapped cells maintaining bone tissue.
Option b is incorrect because osteoclasts resorb bone tissue and remain mobile, not trapped in bone matrix.
Option d is incorrect because osteoprogenitor cells are stem cells that differentiate into osteoblasts, not trapped maintenance cells.

Correct Answer: Kidney versus lung excretion

Volatile acids like carbonic acid are eliminated through lungs as carbon dioxide while nonvolatile acids require kidney excretion.
Option b is incorrect because the distinction isn't production speed but rather the elimination route for each acid type.
Option c is incorrect because buffering capacity relates to the buffer systems, not the acid classification as volatile versus nonvolatile.
Option d is incorrect because both acid types exist throughout body fluids, distinguished by elimination method not location.

Correct Answer: Multifactorial inheritance

Multifactorial inheritance involves multiple genes interacting with environmental factors to produce complex diseases like diabetes mellitus.
Option a is incorrect because single gene disorders follow Mendelian patterns without the complex environmental interactions described here.
Option c is incorrect because chromosomal abnormalities involve whole chromosome changes, not multiple gene-environment interactions causing disease.
Option d is incorrect because mitochondrial disorders follow maternal inheritance patterns, not complex multifactorial patterns described.

Correct Answer: Neutrophil cells

Neutrophils arrive first during acute inflammation, rapidly phagocytosing bacteria and forming pus at infection sites effectively.
Option a is incorrect because lymphocytes participate in adaptive immunity arriving later, not as first responders to injury.
Option c is incorrect because macrophages arrive after neutrophils to continue phagocytosis and coordinate healing responses over time.
Option d is incorrect because eosinophils respond to parasites and allergic reactions, not typical acute bacterial inflammation.

Correct Answer: Variable expressivity

Variable expressivity causes different phenotypes from identical genotypes, explaining varying disease severity in genetically identical twins.
Option a is incorrect because penetrance refers to whether disease appears at all, not severity differences when present.
Option c is incorrect because genetic drift affects population genetics over generations, not individual twin differences observed.
Option d is incorrect because mosaicism involves different cell populations, but identical twins start with same genetics.

Correct Answer: Renal system

The kidneys produce and regulate bicarbonate levels while excreting acids, critical for metabolic acid base balance maintenance.
Option a is incorrect because lungs regulate carbon dioxide and respiratory acids, not bicarbonate production for metabolic balance.
Option c is incorrect because while liver affects metabolism, kidneys specifically regulate bicarbonate and acid excretion described.
Option d is incorrect because cardiovascular system transports buffers but doesn't produce bicarbonate or excrete acids directly.

Correct Answer: Messenger RNA

Messenger RNA undergoes splicing to remove introns and join exons, creating mature transcripts for protein translation.
Option a is incorrect because transfer RNA molecules are already mature and don't undergo splicing before functioning.
Option b is incorrect because ribosomal RNA forms ribosome structure without requiring intron removal through splicing processes.
Option d is incorrect because micro RNA regulates gene expression but doesn't undergo splicing for protein coding purposes.

Correct Answer: Blood components

Blood from damaged vessels forms the hematoma containing platelets, growth factors, and cells initiating fracture healing cascade.
Option a is incorrect because lymphatic fluid drains tissues but doesn't form the primary hematoma at fracture sites.
Option c is incorrect because synovial fluid lubricates joints but isn't involved in fracture hematoma formation described.
Option d is incorrect because interstitial fluid bathes tissues but blood specifically forms the organizing hematoma structure.

Correct Answer: Mother only

Mitochondrial disorders are maternally inherited because only egg cells contribute mitochondria to offspring during fertilization process.
Option a is incorrect because sperm contribute nuclear DNA but mitochondria are destroyed after fertilization, preventing paternal transmission.
Option c is incorrect because mitochondrial inheritance is exclusively maternal, not biparental like nuclear genetic inheritance patterns.
Option d is incorrect because while new mutations occur, most mitochondrial disorders show clear maternal inheritance patterns described.

Correct Answer: Lysosomes

Lysosomes contain digestive enzymes that fuse with phagosomes to destroy engulfed pathogens within phagocytic immune cells.
Option a is incorrect because mitochondria produce energy through cellular respiration, not digestive enzymes for pathogen destruction.
Option c is incorrect because ribosomes synthesize proteins but don't contain the digestive enzymes for breaking down pathogens.
Option d is incorrect because peroxisomes metabolize fatty acids and detoxify substances but aren't primary pathogen digesters.

Correct Answer: Rheumatoid arthritis

Rheumatoid arthritis involves autoimmune inflammation of synovial membranes causing joint destruction, unlike mechanical wear in osteoarthritis.
Option a is incorrect because osteoarthritis results from mechanical stress and cartilage wear, not autoimmune synovial attack.
Option c is incorrect because septic arthritis involves bacterial infection of joints, not autoimmune inflammation of synovium.
Option d is incorrect because gouty arthritis results from uric acid crystal deposition, not autoimmune synovial membrane attack.

Correct Answer: Silencer regions

Silencer regions bind repressor proteins that decrease gene transcription rates, providing negative regulation of gene expression.
Option a is incorrect because promoters are where transcription initiates, not regions that specifically decrease transcription when bound.
Option b is incorrect because enhancers increase transcription rates when activated, opposite of the decreasing effect described.
Option d is incorrect because terminators signal transcription ending but don't regulate transcription rates through repressor binding.

Correct Answer: Heterozygote advantage

Heterozygote advantage occurs when carriers have selective benefit, like malaria resistance in sickle cell trait carriers.
Option b is incorrect because genetic drift involves random allele frequency changes, not the selective advantage described here.
Option c is incorrect because founder effect involves population bottlenecks, not the balanced selection maintaining disease alleles.
Option d is incorrect because gene flow involves allele movement between populations, not selective advantage within populations.

Correct Answer: Bisphosphonate drugs

Bisphosphonates inhibit osteoclast activity reducing bone resorption, helping prevent fractures in conditions with excessive bone breakdown.
Option a is incorrect because calcium supplements alone won't stop excessive osteoclast activity if intake is already normal.
Option c is incorrect because antibiotics treat infections, not the excessive osteoclast activity causing bone loss described.
Option d is incorrect because steroids can actually worsen bone loss rather than inhibiting osteoclast activity effectively.