Test Bank for Pathophysiology: A Practical Approach 5th Edition by Lachel Story

TEST BANK FOR PATHOPHYSIOLOGY
PRACTICAL APPROACH 5TH EDITION BY LACHEL
STORY QUESTIONS & 100% VERIFIED ANSWERS
GRADED A+LATEST UPDATE

,CHAPTER 1 — CELLULAR FUNCTION


Question 1 — (energy production)
Which organelle is the primary site of aerobic ATP production via oxidative
phosphorylation?
A. Smooth endoplasmic reticulum
B. Mitochondrion
C. Ribosome
D. Lysosome
Correct answer: B. Mitochondrion
Rationale:
Mitochondria generate the majority of cellular ATP by oxidative phosphorylation
(electron transport chain + chemiosmosis) in the presence of oxygen.
 A is incorrect — smooth ER is involved in lipid synthesis and
detoxification, not major ATP production.
 C is incorrect — ribosomes synthesize proteins.
 D is incorrect — lysosomes digest macromolecules and damaged organelles
but do not produce ATP.


Question 2 — Membrane transport
A patient receives an IV drug that must enter cells against a concentration gradient.
Which transport mechanism is most likely responsible?
A. Simple diffusion through the lipid bilayer
B. Facilitated diffusion through a channel protein
C. Primary active transport using ATP (e.g., Na⁺/K⁺-ATPase)
D. Osmosis
Correct answer: C. Primary active transport using ATP (e.g., Na⁺/K⁺-ATPase)
Rationale:
Movement against a concentration gradient requires energy input; primary active
transport directly uses ATP (or an ATPase) to pump ions or molecules.
 A and B are passive (do not move substances uphill).

,  D (osmosis) is passive movement of water across a semipermeable
membrane down its gradient.


Question 3 — Facilitated diffusion example
Glucose entry into skeletal muscle during resting conditions (no insulin present)
predominantly occurs by:
A. Simple diffusion through the membrane
B. Facilitated diffusion via GLUT transporters (down its concentration gradient)
C. Active transport by Na⁺/glucose cotransporter requiring ATP
D. Endocytosis
Correct answer: B. Facilitated diffusion via GLUT transporters
Rationale:
Glucose crosses membranes via GLUT transporters (carrier proteins) by facilitated
diffusion when no energy is required and transport follows the concentration
gradient.
 A is incorrect — glucose is polar and cannot pass by simple diffusion.
 C (Na⁺/glucose cotransport) is used in some epithelia (e.g., intestinal/renal)
and is secondary active, not the predominant mechanism in resting muscle.
 D is incorrect — endocytosis is not the routine mechanism for glucose
uptake.


Question 4 — Osmotic effects on red blood cells
A patient’s red blood cells placed in a hypertonic IV solution will:
A. Swell and potentially lyse (hemolysis)
B. Shrink (crenate) as water leaves the cell
C. Remain unchanged because RBC membranes are impermeable to water
D. Gain sodium via active transport and maintain size
Correct answer: B. Shrink (crenate) as water leaves the cell
Rationale:
In a hypertonic environment, extracellular osmolarity is higher than intracellular;
water moves out of the cell by osmosis, causing cell shrinkage (crenation).

,  A is what happens in hypotonic solutions (water moves in).
 C is false — water crosses membranes rapidly (aquaporins).
 D is incorrect — acute sodium pumping cannot prevent osmotic water shifts.


Question 5 — Cellular adaptation (definitions)
Which term best describes an increase in cell size (e.g., cardiac myocytes enlarging
from chronic pressure overload)?
A. Hyperplasia
B. Atrophy
C. Hypertrophy
D. Metaplasia
Correct answer: C. Hypertrophy
Rationale:
Hypertrophy = increase in cell size (often with increased functional capacity). For
example, cardiac myocyte hypertrophy occurs with chronic increased workload.
 A (hyperplasia) = increase in cell number.
 B (atrophy) = decrease in cell size and/or number.
 D (metaplasia) = replacement of one adult cell type with another (adaptive
change).


Question 6 — Apoptosis vs necrosis
Which statement correctly distinguishes apoptosis from necrosis?
A. Apoptosis is an inflammatory, uncontrolled cell death; necrosis is programmed
and energy-dependent.
B. Apoptosis is energy-dependent, orderly, and typically non-inflammatory;
necrosis causes membrane rupture and inflammation.
C. Apoptosis only occurs in response to infection; necrosis only occurs with
ischemia.
D. Apoptosis always leads to tissue scarring; necrosis never does.
Correct answer: B. Apoptosis is energy-dependent, orderly, and typically non-
inflammatory; necrosis causes membrane rupture and inflammation.