Final Exam 2

Question 1

What is the embryonic origin of the mesoduodenum?

Answer 1

Dorsal mesentery

Question 2

The intraembryonic coelom forms where?

Answer 2

between somatic and splanchnic mesoderm

Question 3

Which feature do the parietal pleura, parietal pericardium and parietal peritoneum share in common?

Answer 3

derive from somatic mesoderm

Question 4

Which structure does not contribute to diaphragm development?

Answer 4

pleuropericardial folds

Question 5

Delayed/failed closure by which structure typically accounts for diaphragmatic hernia formation?

Answer 5

pleuroperitoneal membranes

Question 6

An organ that develops in the peritoneal cavity and is then displaced outside of the parietal peritoneum is referred to as?

Answer 6

secondary retroperitoneal

Question 7

Which two chick embryo “extraembryonic” membranes derive from somatopleure?

Answer 7

amnion and chorion

Question 8

Which term best describes the human placenta?

Answer 8

hemochorial

Question 9

The maternal portion of the placenta develops in which area?

Answer 9

decidua basalis

Question 10

Which extraembryonic membrane actually covers the umbilical cord?

Answer 10

amnion

Question 11

The somatopleure is a membrane comprised of which two tissues?

Answer 11

ectoderm and somatic mesoderm

Question 12

The placental barrier “thins” during gestation to improve exchange. How does this occur?

Answer 12

loss of mesenchyme and cytotrophoblast within the placental villi

Question 13

What is the primary source of amniotic fluid after 12 weeks of gestation?

Answer 13

fetal urine production

Question 14

Where does the allantois originate?

Answer 14

embryonic endoderm

Question 15

Why is the allantois important?

Answer 15

umbilical cord blood vessel formation

Question 16

Which layer disappears during gestation?

Answer 16

decidua capsularis

Question 17

Based on amnion/chorian arrangement, which situation would most likely produce conjoined twins?

Answer 17

monochorionic, monoamniotic twins

Question 18

Splitting of the embryo at the inner cell mass stage would result in which membrane arrangement?

Answer 18

monochorionic, diamniotic twins

Question 19

Differentiation of mesoderm-derived angioblasts into endothelial cells is an example of which process?

Answer 19

vasculogenesis

Question 20

Where is the first site of intraembryonic blood cell formation?

Answer 20

AGM (aorta-genial-mesonephric region)

Question 21

The “fetal” hemoglobin contains which two pairs of globin molecules?

Answer 21

2 alpha, 2 gamma

Question 22

Which cell is the immediate precursor to erythrocytes?

Answer 22

reticulocyte

Question 23

The Rh-incompatibility syndrome (hemolytic disease of the newborn) occurs when?

Answer 23

Rh- mother has a Rh+ fetus

Question 24

What is the source of the mesothelium that makes up the parietal pericardium?

Answer 24

lateral somatic mesoderm

Question 25

What is the source of the mesothelium that makes up the visceral pericardium?

Answer 25

proepicardial primordium

Question 26

The mesenchyme of the pleuropericardial folds gives rise to which layer?

Answer 26

fibrous pericardium

Question 27

The smooth part of the definitive left atrium derives from which structure?

Answer 27

pulmonary veins

Question 28

The sinus venarium derives from which structure?

Answer 28

right sinus venosus

Question 29

The coronary sinus predominately derives from which structure?

Answer 29

left sinus venosus

Question 30

The crista terminalis marks the separation between which two structures?

Answer 30

primitive and definitive right atrium

Question 31

Where would you expect to find the "moderator band"?

Answer 31

right ventricle

Question 32

Atrial septation and foramen ovale formation requires closure of which passageway?

Answer 32

osteum primum

Question 33

Atrial septal and membranous interventricular septal defects could occur due to failed development where?

Answer 33

endocardial cushion

Question 34

The definitive right ventricle derives primarily from which are of the embryonic heart tube?

Answer 34

bulbus cordis

Question 35

Which fetal shunt directs blood from the pulmonary trunk to the aorta?

Answer 35

ductus arteriosus

Question 36

A majority of the blood in the fetal left atrium enters from which source?

Answer 36

right atrium

Question 37

The definitive left ventricle derives primarily from which area of the embryonic heart tube?

Answer 37

primitive ventricle

Question 38

What is the source of the cardiac endothelium and myocardium?

Answer 38

lateral splanchnic mesoderm

Question 39

The ventricular papillary muscles derive from which source?

Answer 39

myocardium

Question 40

Which cells are essential to artrioventricular valve development?

Answer 40

epicardial cells & | endothelial derived endocardial cushion cells

Question 41

What is the origin of the left subclavian artery?

Answer 41

left 7th intersegmental artery

Question 42

Which structure derives from or is contributed to by the 3rd aortic arch?

Answer 42

common carotid arteries

Question 43

Which structure derives from or is contributed to by the left 6th aortic arch?

Answer 43

ductus arteriosus

Question 44

Which structure derives from or is contributed to by the right 4th aortic arch?

Answer 44

right subclavian

Question 45

The brachiocephalic artery primarily derives from which structure?

Answer 45

aortic sac

Question 46

The yolk stalk (and therefore the mindgut) is most closely associated with which artery?

Answer 46

superior mesenteric

Question 47

A lateral anastomosis of the first 6 cervical intersegmental arteries is the basis for which major adult artery?

Answer 47

vertebral

Question 48

Relative to the paired dorsal aortas, how are the syndromes of double aortic arch and right aortic arch similar?

Answer 48

the right dorsal aorta is retained in both

Question 49

Which cardiac defect always accompanies failed conotruncal septation?

Answer 49

interventricular septal defect

Question 50

The cardiac malformation "transposition of the great vessels" primarily reflects failed development in the?

Answer 50

conotruncus

Question 51

The definitive adrenal and gonadal arteries derive from?

Answer 51

lateral intersegmental arteries

Question 52

List four primary defects characterizing Tetralogy of Fallot

Answer 52

pulmonary trunk stenosis rightward displacement of aorta ventricular septal defect right ventricular hypertrophy

Question 53

List the four mechanisms that can explain atrial septal defects (ASDs)

Answer 53

osteum secundum defects osteum primum defects sinus venosus related defects failed endocardial cushion defects

Question 54

List 3 cell types that comprise the midgestation human "placental membrane"

Answer 54

syncytiotrophoblast cytotrophoblast fetal endothelium

Question 55

Name the 3 primary routes fro blood circulation in the 4th week human embryo

Answer 55

cardinal-aorta vitelline-yolk sac umbilical

Question 56

Use abbreviation RV=Right ventricle PT=Pulmonary trunk, etc A.Trace the path a red blood cell would follow from the adult superior vena cava to the right internal carotid artery. Include all valves.

Answer 56

A. The red blood cell (RBC) will travel from the superior vena cava (SVC) to the right atrium (RA) – tricuspid valve (TV) – right ventricle (RV) – pulmonary semilunar valve (PSV) – pulmonary trunk (PT) – pulmonary arteries (PA) - Lungs – pulmonary veins (PV) – left atrium (LA) – bicuspid (mitral) valve (BV) – left ventricle (LV) – aortic semilunar valve (ASV) - aortic arch (AA) – brachiocephalic (BRA) – right common carotid (CC) – right internal carotid (IC).

Question 57

B.A red blood cell in the fetal superior vena cava craves oxygen. Trace the shortest route the cell would follow to reach the placental villi.

Answer 57

B) The red blood cell (RBC) will travel from the SVC to the RA - TV – RV – PSV – PT – DA – AO – common iliac (CI) – intenal iliac (II) – umbilical arteries (UA) – placenta

Question 58

What are the fundamental differences between persistent truncus arteriosus and transposition of the great vessels?

Answer 58

In persistent truncus arteriosus the conotruncal ridges fail to form in the truncus arteriosus so there is a large common overriding outflow tract for right and left ventricular output. Always includes a ventricular septal defect. In transposition of the great vessels the conotruncal ridges form and partition the truncus but fail to spiral. The right ventricle pumps blood into the aorta and the left ventricle pumps blood into the pulmonary trunk. Accompanied by patent ductus arteriosus and atrial and/or ventricular defects.

Question 59

A large dissecting needle has been passed through the outermost layer of the pericardium to the left ventricular chamber. Name the layers the pin passes through.

Answer 59

``` Fibrous pericardium Parietal (serous) pericardium Pericardial cavity Visceral (serous) pericardium (epicardium) Myocardium Endocardium (endothelium) ```

Question 60

Outline the cardiac conduction system and describe its function.

Answer 60

SA node – atrial pathways – AV node – Bundle of His – bundle branches, left and right – Purkinje fibers The SA node serves as the pacemaker to initiate cardiac contraction and the conduction system serves to coordinate atrial and ventricular contraction.