Heart development — Flashcards

Flashcard 31: Atrial septal defect may be distinguished from a patent foramen ovale in that the septa are _____ rather than unfused

Answer: missing tissue

Flashcard 32: During heart development, the right horn of the sinus venosus is incorporated into the right atrium to form the smooth-walled portion known as the _____

Answer: Sinus venarum

Extra: The right atrium has two main parts with different embryological origins: - **Sinus venarum**: The smooth-walled posterior part derived from the **right horn of the sinus venosus**. - **Pectinate muscles**: The rough-walled anterior part derived from the **primitive atrium**. The **crista terminalis** is the internal ridge that separates these two parts (derived from the right venous valve).

Flashcard 33: The _____ is the first functional organ to develop in vertebrate embryos

Answer: heart

Flashcard 34: The primary heart tube _____ to establish left-right polarity beginning in week 4 of gestation

Answer: loops

Flashcard 35: What is the embryonic origin of the aorticopulmonary septum? _____

Answer: neural crest cells

Flashcard 36: Symptomatic aortic stenosis may present in patients around age 50 with a _____ aortic valve

Answer: bicuspid

Flashcard 37: During heart development, growth of the _____ separates the atria from the ventricles.

Answer: Endocardial cushions

Flashcard 38: D-transposition of great vessels is due to failure of the _____ to spiral

Answer: aorticopulmonary septum

Flashcard 39: Most of the highly oxygenated blood reaching the heart via the fetal IVC is directed from the RA to the LA via the _____ and pumped into the aorta to supply the head and body

Answer: foramen ovale

Flashcard 40: In which week of embryogenesis does the heart begin to beat? _____

Answer: Week 4 (4 weeks = 4 heart chambers)