Identify the muscular ridges that are found on the anterior wall of the right atrium and extend into the auricles.

Correct Answer: A

Rationale: Pectinate muscles (A) are ridges in the right atrium and auricles. Trabeculae carneae (B) are in ventricles, coronary sulci (C) are grooves, and papillary muscles (D) anchor valves.

Correct Answer: C

Rationale: Anxiety and fear (C) increase heart rate via sympathetic activation. Pain (A) and cold (B) may slow it via vagal reflexes, grief (D) varies.

Correct Answer: B

Rationale: The ventricles (B) are the lower, pumping chambers. Atria (A) receive, auricles (C) extend atria, coronary sinuses (D) are veins.

Correct Answer: B

Rationale: Systolic pressure (B) is the pressure during ventricular contraction (~120 mmHg). Diastolic (A) is relaxation, pulse (C) is the difference, mean (D) is average.

Correct Answer: D

Rationale: Reticulocytes (D) are immature RBCs post-nucleus loss, entering circulation. Proerythroblasts (A) are early, megakaryocytes (B) form platelets, progenitors (C) are stem cells.