WGU D027 Practice Exam | Study
Questions and Answers with Rationale |
Verified and Graded A+ | Latest
2024/2025
Which complex (wave) represents the sum of all ventricular
muscle cell depolarizations?
- Correct Answer - QRS -
The QRS wave of an electrocardiogram (ECG or EKG) represents
the largest spike in electrical activity of the heart, as ventricular
muscle cells perform the highest burden of work to pump blood
volume out of the heart in that instance.
What effect does atherosclerosis have on the development of an
aneurysm?
- Correct Answer - Erodes the vessel wall -
Atherosclerosis, also known as the process of "hardening of the
arteries" and secondary to plaque formation, weakens the
flexibility of a blood vessel wall. Without vascular compliance, the
,vessel wall becomes more rigid and susceptible to rupture (i.e.,
an aneurysm).
What is the effect of oxidized low-density lipoproteins (LDLs) in
atherosclerosis?
- Correct Answer - LDLs cause smooth muscle proliferation -
Within the arterial wall subintima, oxidized LDLs stimulate
macrophage foam cell formation and proinflammatory pathways,
which lead to smooth muscle proliferation, fatty streak creation,
and eventual fibrous plaque overlays (McCance, p. 699 & 1072).
Which factor is responsible for the hypertrophy of the myocardium
associated with hypertension?
- Correct Answer - Angiotensin II -
Angiotensin II leads to myocardial hypertrophy, poor myocardial
compliance, and ventricular dilation through stimulating increased
cardiac preload and afterload and direct toxicity to myocardial
cells. It causes sarcomere death, abnormal collagen matrices,
and interstitial fibrosis (McCance, p. 1099).
,Most cardiovascular developments occur between which weeks of
gestation?
- Correct Answer - Fourth and seventh weeks -
During weeks four to seven, the primitive heart tube progresses
through numerous stages of development leading to a developed
heart with distinct atria, ventricles, and cardiac vessels.
Which compensatory mechanism is spontaneously used by
children diagnosed with tetralogy of Fallot (TOF) to relieve
hypoxic spells?
- Correct Answer - Squatting -
Spontaneous squatting helps relieve hypercyanotic events in
older children through increasing systemic vascular resistance,
decreasing venous blood return. This provides a larger amount of
oxygenated blood for the body and leads to the temporary
reversal of blood through the ventricular septal defect (VSD),
which results in increased pulmonary flow. Squatting is rarely
seen clinically because most TOF defects are diagnosed and
surgically repaired in infancy (McCance, p. 1127).
, Which condition is consistent with the cardiac defect of
transposition of the great vessels?
- Correct Answer - The aorta arises from the right ventricle -
In transposition of the great vessels, opposite of a normal heart,
the aorta arises from the right ventricle, and the pulmonary artery
arises from the left ventricle.
What produces ADH?
- Correct Answer - Posterior pituitary -
The anterior pituitary gland produces a wide variety of hormones
such as the adrenocorticotropic hormone (ACTH), thyroid-
stimulating hormone (TSH), luteinising hormone (LH), follicle-
stimulating hormone (FSH), prolactin (PRL), growth hormone
(GH), and melanocyte-stimulating hormone (MSH). The
hypothalamus also produces a number of hormones such as the
thyrotropin-releasing hormone (TRH), growth hormone-releasing
and growth inhibiting hormones (GHRH and GHIH), gonadotropin-
releasing hormone (GnRH), corticotropin-releasing hormone
(CRH), and oxytocin. The posterior pituitary stores oxytocin and
the antidiuretic hormone (ADH) from the hypothalamus for later
use. The complex interaction of feedback and influence that the
