Heart development

Heart development US Medical PG Question 1: A 2-day-old boy is examined on day of discharge from the newborn nursery. He was born at 39 weeks by vaginal delivery to a primigravid mother. The pregnancy and delivery were uncomplicated, and the baby has been stooling, urinating, and feeding normally. Both the patient’s mother and father have no known past medical history and are found to have normal hemoglobin electrophoresis results. Compared to adult hemoglobin, the infant’s predominant hemoglobin is most likely to exhibit which of the following properties?

• A. Decreased affinity for 2,3-bisphosphoglycerate (Correct Answer)
• B. More likely to form hexagonal crystals
• C. More likely to cause red blood cell sickling
• D. Lower affinity for binding oxygen
• E. Increased affinity for 2,3-bisphosphoglycerate

Heart development Explanation: ***Decreased affinity for 2,3-bisphosphoglycerate*** - The baby's predominant hemoglobin is **hemoglobin F (HbF)**, which has a **gamma globin subunit** instead of the beta globin subunit found in adult hemoglobin (HbA). - The gamma subunit of HbF results in a **reduced binding affinity to 2,3-bisphosphoglycerate (2,3-BPG)**, which in turn leads to a **higher affinity for oxygen** and more efficient oxygen transfer from the mother to the fetus. *More likely to form hexagonal crystals* - The formation of **hexagonal crystals** is characteristic of **hemoglobin C (HbC)** disease, a variant of adult hemoglobin, which is not predominant in a newborn. - The parents have normal hemoglobin electrophoresis, ruling out the inheritance of significant hemoglobinopathies like HbC in a homozygous or compound heterozygous state. *More likely to cause red blood cell sickling* - **Red blood cell sickling** is a hallmark of **sickle cell anemia**, caused by hemoglobin S (HbS) which is an abnormal adult hemoglobin, not fetal hemoglobin. - The parents have normal hemoglobin electrophoresis, meaning they are unlikely to carry the sickle cell trait, and the newborn's predominant HbF actually protects against sickling. *Lower affinity for binding oxygen* - HbF in newborns has a **higher affinity for oxygen** than adult hemoglobin (HbA) to facilitate efficient oxygen extraction from maternal blood across the placenta. - A lower affinity for oxygen would be detrimental for a newborn as it would impair proper tissue oxygenation. *Increased affinity for 2,3-bisphosphoglycerate* - HbF has a **decreased affinity for 2,3-BPG**. An increased affinity for 2,3-BPG would lead to a reduction in oxygen binding affinity, which is the opposite of the physiological need in a newborn.

Heart development US Medical PG Question 2: An 8-year-old girl is brought to the physician by her parents for the evaluation of an episode of unconsciousness while at the playground that morning. She was unconscious for about 15 seconds and did not shake, bite her tongue, or lose bowel or bladder control. Her grandfather died suddenly at the age of 29 of an unknown heart condition; her parents are both healthy. An ECG shows sinus rhythm and a QT interval corrected for heart rate (QTc) of 470 milliseconds. Laboratory studies are within normal limits. Which of the following is the most likely additional finding in this patient?

• A. Oblique palpebral fissures
• B. Subvalvular ventricular outflow obstruction murmur
• C. Sensorineural hearing loss (Correct Answer)
• D. Brachial-femoral pulse delay
• E. Skin folds between the mastoid process and acromion

Heart development Explanation: ***Sensorineural hearing loss*** - This patient presents with an episode of syncope, a **prolonged QTc interval** (470 ms; normal <450 ms in prepubertal females, diagnostic threshold >460 ms), and a family history of **sudden cardiac death**, highly suggestive of **Long QT syndrome (LQTS)**. - **Jervell and Lange-Nielsen syndrome** is a specific form of LQTS (autosomal recessive) characterized by both **prolonged QT interval** and **congenital sensorineural hearing loss**, making this the most likely additional finding. *Oblique palpebral fissures* - **Oblique palpebral fissures**, along with epicanthal folds and a flat facial profile, are characteristic features of **Down syndrome (Trisomy 21)**. - These features are not typically associated with cardiac arrhythmias or Long QT syndrome, and there is no other information to suggest a chromosomal abnormality. *Subvalvular ventricular outflow obstruction murmur* - A **subvalvular ventricular outflow obstruction murmur** is indicative of conditions like **hypertrophic obstructive cardiomyopathy (HOCM)**. - While HOCM can cause syncope and sudden cardiac death, the primary finding in this patient is a **prolonged QTc interval**, which is characteristic of LQTS, not HOCM. *Brachial-femoral pulse delay* - A **brachial-femoral pulse delay** is the classic physical exam finding for **coarctation of the aorta**, a congenital narrowing of the aorta. - There is no clinical information to suggest coarctation, and it does not explain the prolonged QTc interval and family history of sudden cardiac death. *Skin folds between the mastoid process and acromion* - **Skin folds between the mastoid process and acromion** (webbed neck or pterygium colli) are a classic sign of **Turner syndrome (XO)** or **Noonan syndrome**. - These conditions are not primarily associated with a prolonged QTc interval and exert their cardiac effects through structural defects like coarctation or pulmonary stenosis, not typically primary arrhythmias.

Heart development US Medical PG Question 3: A 38-year-old woman, gravida 2, para 1, at 24 weeks' gestation comes to the physician for a routine prenatal evaluation. She has no history of major medical illness and takes no medications. Fetal ultrasonography shows a cardiac defect resulting from abnormal development of the endocardial cushions. This defect is most likely to result in which of the following?

• A. Transposition of the great vessels
• B. Atrioventricular septal defect (Correct Answer)
• C. Dextrocardia
• D. Patent foramen ovale
• E. Sinus venosus defect

Heart development Explanation: ***Atrioventricular septal defect*** - **Endocardial cushion defects** are a hallmark of atrioventricular septal defects, leading to a common atrioventricular valve and an interatrial and/or interventricular communication. - This defect commonly presents in individuals with **Down syndrome (Trisomy 21)**, though it can occur in isolation. *Transposition of the great vessels* - This defect results from abnormal **spiraling of the conotruncal septum**, not from endocardial cushion malformation. - It leads to the **aorta arising from the right ventricle** and the **pulmonary artery from the left ventricle**, a circulation incompatible with life without a shunt. *Dextrocardia* - **Dextrocardia** is a condition where the heart is located on the right side of the chest, usually due to abnormal embryonic folding, and is not directly caused by endocardial cushion defects. - It can occur as an isolated finding or as part of a more complex syndrome like **Kartagener syndrome**. *Patent foramen ovale* - A **patent foramen ovale** is a common remnant of fetal circulation, occurring when the foramen ovale fails to close after birth. - It is a defect of the **atrial septum secondary to incomplete fusion between the septum primum and septum secundum**, not an endocardial cushion defect. *Sinus venosus defect* - A **sinus venosus defect** is a type of atrial septal defect occurring near the entrance of the superior or inferior vena cava. - It is caused by **abnormal development of the sinus venosus** and is not directly related to endocardial cushion malformation.

Heart development US Medical PG Question 4: An investigator is studying the relationship between fetal blood oxygen saturation and intrauterine growth restriction using MRI studies. The magnetic resonance transverse relaxation time (T2) is inversely related to the concentration of deoxyhemoglobin so that high concentrations of deoxyhemoglobin produce a low signal intensity on T2-weighted MRI. In a normal fetus, the T2 signal is most likely to be the highest in which of the following vessels?

• A. Descending aorta
• B. Superior vena cava
• C. Ductus venosus (Correct Answer)
• D. Pulmonary veins
• E. Right atrium

Heart development Explanation: ***Ductus venosus*** - The **ductus venosus** shunts highly oxygenated blood directly from the **umbilical vein** to the inferior vena cava, bypassing the liver. - This vessel carries the most oxygen-rich blood in the fetal circulation (lowest deoxyhemoglobin concentration), resulting in the **highest T2 signal intensity**. *Descending aorta* - The descending aorta receives a mixture of oxygenated blood from the left ventricle and deoxygenated blood from the **pulmonary artery** via the **ductus arteriosus**. - This mixing reduces its overall oxygen saturation compared to the umbilical vein and ductus venosus. *Superior vena cava* - The superior vena cava carries **deoxygenated blood** from the upper body and head back to the right atrium. - This vessel has a low oxygen saturation and high deoxyhemoglobin concentration, leading to a **low T2 signal**. *Pulmonary veins* - In a normal fetal circulation, the **lungs are not fully functional**, and pulmonary blood flow is relatively low. - The pulmonary veins carry only a small amount of moderately oxygenated blood returning from the developing lungs, which is significantly less oxygenated than blood in the ductus venosus. *Right atrium* - The right atrium receives **mixed blood** from both the superior and inferior vena cava. - While it receives some oxygenated blood from the inferior vena cava via the ductus venosus, this is diluted by deoxygenated blood, resulting in lower oxygen saturation than the blood within the ductus venosus itself.

Heart development US Medical PG Question 5: Shortly after delivery, a female newborn develops bluish discoloration of the lips, fingers, and toes. She was born at term to a 38-year-old primigravid woman. Pregnancy was complicated by maternal diabetes mellitus. Pulse oximetry on room air shows an oxygen saturation of 81%. Echocardiography shows immediate bifurcation of the vessel arising from the left ventricle; the vessel emerging from the right ventricle gives out coronary, head, and neck vessels. An abnormality in which of the following developmental processes most likely accounts for this patient's condition?

• A. Alignment of infundibular septum
• B. Fusion of endocardial cushion
• C. Spiraling of aorticopulmonary septum (Correct Answer)
• D. Separation of tricuspid valve tissue from myocardium
• E. Division of aorta and pulmonary artery

Heart development Explanation: ***Spiraling of aorticopulmonary septum*** - The description of a vessel arising from the left ventricle that immediately bifurcates (pulmonary artery) and a vessel from the right ventricle that gives off coronary, head, and neck vessels (aorta) is characteristic of **transposition of the great arteries (TGA)**. - TGA results from a failure of the **aorticopulmonary septum** to spiral during embryological development, leading to the aorta originating from the right ventricle and the pulmonary artery from the left ventricle. *Alignment of infundibular septum* - Abnormal alignment of the infundibular septum is associated with conditions like **tetralogy of Fallot**, which involves a maligned interventricular septum and a shifted aorta, presenting with a different set of echocardiographic findings. - While also a **cyanotic heart defect**, tetralogy of Fallot's anatomy (e.g., interventricular septal defect, pulmonary stenosis) differs from the described TGA. *Fusion of endocardial cushion* - Failure of fusion of the **endocardial cushions** leads to **atrioventricular septal defects**, which involve defects in both the atria and ventricular septa, and often affect the mitral and tricuspid valves. - These defects typically present with heart failure symptoms and different echocardiographic findings than those described for TGA. *Separation of tricuspid valve tissue from myocardium* - An abnormality in the separation of tricuspid valve tissue from the myocardium is the cause of **Ebstein anomaly**, where the tricuspid valve leaflets are displaced downwards into the right ventricle, leading to tricuspid regurgitation. - Ebstein anomaly is characterized by right atrial enlargement and a largely functional right ventricle, leading to issues with right heart output but not the great artery transposition described. *Division of aorta and pulmonary artery* - The division of the truncus arteriosus into the aorta and pulmonary artery is a normal developmental process, which when complete usually produces the correct great artery connections. However, the exact arrangement of these vessels is determined by the **spiraling of the aorticopulmonary septum**, not just the division itself. - Failure of this division, resulting in a **persistent truncus arteriosus**, would present as a single great artery arising from both ventricles, which is distinct from the two separate but transposed vessels seen in TGA.

Heart development US Medical PG Question 6: A 3-year-old boy is brought to his pediatrician by his parents for a follow-up visit. Several concerning traits were observed at his last physical, 6 months ago. He had developmental delay, a delay in meeting gross and fine motor control benchmarks, and repetitive behaviors. At birth, he was noted to have flat feet, poor muscle tone, an elongated face with large, prominent ears, and enlarged testicles. He takes a chewable multivitamin every morning. There is one other member of the family, on the mother’s side, with a similar condition. Today, his blood pressure is 110/65 mm Hg, heart rate is 90/min, respiratory rate is 22/min, and temperature of 37.0°C (98.6°F). On physical exam, the boy repetitively rocks back and forth and has difficulty following commands. His heart has a mid-systolic click, followed by a late systolic murmur and his lungs are clear to auscultation bilaterally. Several vials of whole blood are collected for analysis. Which of the following studies should be conducted as part of the diagnostic screening protocol?

• A. Northern blot with RNA probes
• B. Two-dimensional gel electrophoresis
• C. Southern blot with DNA probes (Correct Answer)
• D. Western blot
• E. PCR followed by northern blot with RNA probes

Heart development Explanation: ***Southern blot with DNA probes*** - The patient's presentation with developmental delay, repetitive behaviors, flat feet, hypotonia, elongated face, prominent ears, and macroorchidism (*enlarged testicles*) is highly suggestive of **Fragile X syndrome**. - **Fragile X syndrome** is caused by an abnormal expansion of a **CGG trinucleotide repeat** in the *FMR1* gene on the X chromosome, which leads to hypermethylation and silencing of the gene. **Southern blot analysis with DNA probes** is the gold standard for detecting these expansions, as it can measure the size of the *CGG* repeat and the methylation status of the gene. *Northern blot with RNA probes* - **Northern blot analysis** is used to detect and quantify specific **RNA molecules**. - While the *FMR1* gene's mRNA expression is affected in Fragile X syndrome, northern blot is not the primary diagnostic test for detecting the underlying **DNA repeat expansion** and methylation. *Two-dimensional gel electrophoresis* - **Two-dimensional gel electrophoresis** is a technique used to separate **proteins** based on their **isoelectric point** and then by **molecular weight**. - This method is used for proteomic studies and is not relevant for diagnosing a genetic disorder caused by a DNA repeat expansion. *Western blot* - **Western blot analysis** is used to detect specific **proteins** in a sample. - In Fragile X syndrome, the *FMR1* gene product, **FMRP (Fragile X Mental Retardation Protein)**, is absent or reduced, which could be theoretically detected by Western blot. However, the definitive diagnosis relies on identifying the genetic mutation (CGG expansion and methylation) in the DNA, for which Southern blot is superior. *PCR followed by northern blot with RNA probes* - **PCR (Polymerase Chain Reaction)** is used to amplify specific **DNA sequences**. While *PCR* can detect smaller *CGG* expansions, it often fails to accurately size the full mutations found in Fragile X syndrome due to the large repeat numbers. - Combining *PCR* with **northern blot (RNA detection)** would still not be the primary diagnostic approach for the DNA-based *CGG* repeat expansion and methylation status, which is essential for diagnosing Fragile X.

Heart development US Medical PG Question 7: A 70-year-old woman presents with substernal chest pain. She says that the symptoms began 2 hours ago and have not improved. She describes the pain as severe, episodic, and worse with exertion. She reports that she has had multiple similar episodes that have worsened and increased in frequency over the previous 4 months. Past medical history is significant for diabetes and hypertension, both managed medically. The vital signs include temperature 37.0°C (98.6°F), blood pressure 150/100 mm Hg, pulse 80/min, and respiratory rate 15/min. Her serum total cholesterol is 280 mg/dL and high-density lipoprotein (HDL) is 30 mg/dL. The electrocardiogram (ECG) shows ST-segment depression on multiple chest leads. Coronary angiography reveals 75% narrowing of her left main coronary artery. In which of the following anatomical locations is a mural thrombus most likely to form in this patient?

• A. Left ventricle (Correct Answer)
• B. Left atrium
• C. Aorta
• D. Right atrium
• E. Right ventricle

Heart development Explanation: ***Left ventricle*** - The patient presents with symptoms and ECG findings consistent with **unstable angina** or **non-ST elevation myocardial infarction (NSTEMI)**, indicating myocardial ischemia. - With **75% left main coronary artery stenosis**, there is high risk of progression to **transmural myocardial infarction (STEMI)**, particularly affecting the anterior wall and septum. - Mural thrombi in the left ventricle typically form **3-7 days post-infarction** in areas of **dyskinetic or akinetic myocardium** due to blood stasis, endocardial injury, and hypercoagulability (Virchow's triad). - Left main disease affecting such a large territory makes the **left ventricle the most likely site** for mural thrombus formation. *Left atrium* - Mural thrombi in the left atrium are most commonly associated with **atrial fibrillation** due to blood stasis in the **left atrial appendage**. - This patient's symptoms are characteristic of coronary artery disease affecting the left ventricle, not an atrial arrhythmia. *Aorta* - While thrombi can form in the aorta (e.g., in the setting of **atherosclerosis** or **aneurysms**), they are typically mural thrombi associated with specific vascular pathologies. - The symptoms of **chest pain, ST depression**, and **coronary artery narrowing** point toward a myocardial event, making the left ventricle the most likely site for mural thrombus in this clinical context. *Right atrium* - Thrombi in the right atrium are usually associated with conditions leading to **venous stasis, such as deep vein thrombosis**, **central venous catheters**, or **right-sided heart failure**. - The patient's presentation with exertional chest pain and left main coronary artery narrowing is unrelated to right atrial thrombosis. *Right ventricle* - The right ventricle is **much less commonly** affected by ischemic events leading to mural thrombi compared to the left ventricle, due to its **lower oxygen demand** and **different blood supply** (right coronary artery). - While right ventricular infarction can occur (usually with inferior MI), the **left main coronary artery** supplies the left ventricle, making it the primary concern for mural thrombus formation in this patient.

Heart development US Medical PG Question 8: A 3175-g (7-lb) male newborn is delivered at 39 weeks' gestation to a 29-year-old primigravid woman following a spontaneous vaginal delivery. Apgar scores are 8 and 9 at 1 and 5 minutes, respectively. Cardiac examination in the delivery room shows a continuous machine-like murmur. An echocardiogram shows a structure with blood flow between the pulmonary artery and the aorta. This structure is most likely a derivate of which of the following?

• A. 4th aortic arch
• B. 1st aortic arch
• C. 6th aortic arch (Correct Answer)
• D. 2nd aortic arch
• E. 3rd aortic arch

Heart development Explanation: ***6th aortic arch*** - The description of a "continuous machine-like murmur" and a structure with blood flow between the pulmonary artery and the aorta is characteristic of a **patent ductus arteriosus (PDA)**. - The **ductus arteriosus** is a remnant of the **6th aortic arch**, connecting the pulmonary artery to the aorta in fetal life. *4th aortic arch* - The **4th aortic arch** contributes to the formation of the **aortic arch** itself on the left side and the proximal **right subclavian artery** on the right. - Abnormalities of the 4th arch can lead to conditions like **coarctation of the aorta** or **vascular rings**, which do not typically present as a PDA. *1st aortic arch* - The **1st aortic arch** largely disappears, but its remnants contribute to the formation of the **maxillary artery** and the **external carotid artery**. - It is not involved in developmental anomalies of the major vessels between the pulmonary artery and aorta. *2nd aortic arch* - The **2nd aortic arch** also largely regresses, but its remnants contribute to the **stapedial artery** and part of the **hyoid artery**. - It does not play a role in the formation of the ductus arteriosus or other major arteries of the heart. *3rd aortic arch* - The **3rd aortic arch** develops into the common carotid arteries and the proximal internal carotid arteries. - Genetic disorders and malformations involving this arch typically affect the carotid system, not the connection between the pulmonary artery and aorta.

Heart development US Medical PG Question 9: A 55-year-old man visits the clinic with his wife. He has had difficulty swallowing solid foods for the past 2 months. His wife adds that his voice is getting hoarse but they thought it was due to his recent flu. His medical history is significant for type 2 diabetes mellitus for which he is on metformin. He suffered from many childhood diseases due to lack of medical care and poverty. His blood pressure is 125/87 mm Hg, pulse 95/min, respiratory rate 14/min, and temperature 37.1°C (98.7°F). On examination, an opening snap is heard over the cardiac apex. An echocardiogram shows an enlarged cardiac chamber pressing into his esophagus. Changes in which of the following structures is most likely responsible for this patient’s symptoms?

• A. Patent ductus arteriosus
• B. Right ventricle
• C. Left ventricle
• D. Left atrium (Correct Answer)
• E. Right atrium

Heart development Explanation: ***Left atrium*** - The patient's symptoms of **dysphagia (difficulty swallowing)** and **hoarseness** suggest compression of anatomical structures by an enlarged cardiac chamber, which the echocardiogram confirms. - An enlarged **left atrium**, typically due to **mitral stenosis**, can compress the esophagus (leading to dysphagia) and the **recurrent laryngeal nerve** (leading to hoarseness, known as Ortner's syndrome). The **opening snap** at the apex is also highly characteristic of mitral stenosis. *Patent ductus arteriosus* - A **patent ductus arteriosus (PDA)** is a congenital heart defect that typically causes a **continuous murmur** and may lead to pulmonary hypertension or heart failure, but not direct compression of the esophagus or recurrent laryngeal nerve. - The symptoms of PDA are usually present earlier in life, though uncorrected large PDAs can cause symptoms in adulthood, they do not cause dysphagia or hoarseness through direct esophageal compression. *Right ventricle* - An enlarged **right ventricle** usually causes symptoms related to right heart failure like **peripheral edema** or **dyspnea** due to pulmonary hypertension. - It is not anatomically positioned to compress the esophagus or recurrent laryngeal nerve in a way that would cause dysphagia or hoarseness. *Left ventricle* - An enlarged **left ventricle** (e.g., due to hypertension or aortic stenosis) primarily causes symptoms like **dyspnea on exertion** or **angina**. - While a severely dilated left ventricle can displace other structures, it does not typically cause direct esophageal compression leading to dysphagia or recurrent laryngeal nerve compression leading to hoarseness. *Right atrium* - An enlarged **right atrium** might be seen in conditions like tricuspid regurgitation or right heart failure but can manifest as **edema** or **jugular venous distention**. - It is not anatomically positioned to cause dysphagia or hoarseness from esophageal or recurrent laryngeal nerve compression.

Heart development US Medical PG Question 10: A 28-year-old man comes to the physician because of a persistent tingling sensation in the right side of his face. The sensation began after he underwent an extraction of an impacted molar 2 weeks ago. Examination shows decreased sensation of the skin over the right side of the mandible, chin, and the anterior portion of the tongue. Taste sensation is preserved. The affected nerve exits the skull through which of the following openings?

• A. Foramen rotundum
• B. Hypoglossal canal
• C. Foramen magnum
• D. Foramen ovale (Correct Answer)
• E. Stylomastoid foramen

Heart development Explanation: ***Foramen ovale*** - This patient presents with **paresthesia** in the distribution of branches of the **mandibular nerve (V3)** following molar extraction. The affected areas (mandible, chin, and anterior tongue sensation) indicate injury to the **inferior alveolar nerve** (lower teeth, chin, lower lip) and/or **lingual nerve** (general sensation to anterior 2/3 of tongue). - Both the **inferior alveolar nerve** and **lingual nerve** are branches of the **mandibular nerve (V3)**, which exits the skull through the **foramen ovale**. These nerves run in close proximity during molar extraction and are commonly injured together. - Taste sensation is preserved because the **chorda tympani** (taste fibers from CN VII) travels with the lingual nerve but does not exit through foramen ovale. *Foramen rotundum* - The **foramen rotundum** transmits the **maxillary nerve (V2)**, which innervates the midface, upper teeth, and palate. - Injury to this nerve would cause sensory deficits in the upper lip and cheek, not the mandible or chin. *Hypoglossal canal* - The **hypoglossal canal** transmits the **hypoglossal nerve (CN XII)**, which is a motor nerve to the intrinsic and extrinsic muscles of the tongue. - Damage to this nerve would result in **tongue weakness** or **atrophy**, not sensory changes to the face or tongue. *Foramen magnum* - The **foramen magnum** is the largest opening in the skull, transmitting the **spinal cord**, vertebral arteries, and accessory nerve (CN XI). - Damage here would likely involve severe neurological deficits, not isolated sensory loss to the lower face. *Stylomastoid foramen* - The **stylomastoid foramen** transmits the **facial nerve (CN VII)**, which is primarily responsible for facial expression and taste sensation to the anterior two-thirds of the tongue via the chorda tympani. - While CN VII provides taste to the tongue, it does not provide general sensory innervation to the skin of the mandible or chin, and taste is preserved in this patient.

Heart development Flashcard 1 of 10

Question: The embryonic _____ gives rise to the AV and semilunar valves

Answer: endocardial cushion

Heart development Flashcard 2 of 10

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

Answer: heart

Heart development Flashcard 3 of 10

Question: In the third step of ventricular partioning, growth of _____ separates atria from ventricles

Answer: endocardial cushions

Heart development Flashcard 4 of 10

Question: The 6th aortic arch forms the _____ artery and _____.

Answer: pulmonary

Heart development Flashcard 5 of 10

Question: The 4th aortic arch forms the _____ artery.

Answer: adult aortic arch and subclavian

Heart development Flashcard 6 of 10

Question: aorticopulmonary septum

Answer: neural crest

Heart development Flashcard 7 of 10

Question: cardiovascular structures

Answer: mesoderm

Heart development Flashcard 8 of 10

Question: The embryonic _____ gives rise to the ascending aorta and pulmonary trunk

Answer: truncus arteriosus

Extra Information: Watch associated Bootcamp video [https://app.bootcamp.com/med-school/cardiology/videos/embryology?index=2] https://onlinemeded.org/spa/cardiac/cyanotic-congenital-heart-disease/acquire?ref=anki 

Heart development Flashcard 9 of 10

Question: TAPVR causes a dilated _____ atrium and ventricle

Answer: right

Extra Information:  Watch Right to Left Shunts [https://dashboard.sketchy.com/study/medical/courses/medical-pathophysiology/units/medical-pathophysiology-cardiac/videos/medical-pathophysiology-cardiac-congenital-heart-disease-right-to-left-shunts?utm_source=anki&utm_medium=partnership&utm_campaign=february_update&utm_content=medical]Watch associated Bootcamp video [https://app.bootcamp.com/med-school/cardiology/videos/cyanotic-congenital-heart-defects?index=7] https://onlinemeded.org/spa/cardiac?ref=anki 

Heart development Flashcard 10 of 10

Question: In the second step of atrial partitioning, the _____ forms in place of the ostium primum

Answer: ostium secundum

Extra Information: Watch associated Bootcamp video [https://app.bootcamp.com/med-school/embryology/videos/thoracic-systems-respiratory-and-cardiovascular?index=7] https://onlinemeded.org?ref=anki