TBL 1
Why is gray matter gray?
Nissl bodies and absence of myelin
Disruption of the bicuspid/mitral valve will affect blood flow from this place to the next.
L atrium to L ventricle
What does the dorsal mesenchymal protrusion form?
4 pulmonary veins
Where do the R vagus and R phrenic nerves travel with respect to the root of the R lung?
R vagus travels posteriorly to root of R lung
R phrenic travels anterior to root of R lung
Why does permanent disability result from CNS injury?
Injured axons in the CNS don’t recover/regenerate due to astrocyte proliferation at the injury site; therefore, these neurons and their connections degenerate and die.
Disruption in the formation of the neuroectoderm would affect which structures?
Neural tube
CNS
Neural crest cells
T or F: Ventricular systole comes before atrial systole.
F: atrial systole occurs first to make sure the ventricles are full of blood before they contract
If the organization of the epiblast derived cardiac progenitor cells was interrupted, what structure would not be formed correctly?
What are the 3 hiatuses and where are they?
IVC at T8
Esophagus at T10
Descending aorta at T12
Why does the inner cell mass have clinical potential?
The inner cell mass produces embryonic stem cells. These cells are pluripotent and can form almost any cell or tissue; therefore, they have the potential to cure various diseases.
Compare the lengths of the presynaptic axons of the sympathetic and parasympathetic nervous systems.
- presynatpic axons of parasympathetic: long
What are trabeculae carneae?
Large beams of cardiac muscle which line the walls of the ventricles
Allow for ventricles to contract like the wringing of a towel.
What does the 6th right aortic arch develop into?
right pulmonary artery
What are the three branches on the aorta from right to left?
brachiocephalic trunk, left common carotid artery, left subclavian artery
Why can dysphagia result from mitral valve stenosis?
The bicuspid valve narrows, the left atrium swells and the esophagus is behind the left atrium so the enlargement of the atrium pressing on the esophagus interferes with swallowing.
What major axes will not be defined if there are issues with the formation of the primitive streak?
Left and right
What is the difference between the systemic and pulmonary circuits?
Systemic circuit brings oxygenated blood to the body’s tissues and returns deoxygenated blood to the heart
Pulmonary circuit brings deoxygenated blood to the lungs and oxygenated blood back to the heart
Which septal malformation causes transposition of the great vessels?
The conotruncal septum develops straight down instead of in a spiral. This causes the aorta to form from the right ventricle instead of the left ventricle and then the pulmonary artery originates from the left ventricle instead of the right. It is also associated with defects in the membranous portion of the interventricular septum, usually an open ductus arteriosus.
Describe the pathway taken by the azygous vein.
arises from posterior side of IVC
passes through aortic hiatus to enter thoracic cavity
runs on R side of vertebral bodies
arches over root of R lung to open into SVC
What are the two principal causes of the ostium secundum defect?
There is either (1) excessive cell death/resorption of the septum primum or (2) there is inadequate development of the septum secundum.
What structures does endoderm form?
Epithelial tissue lining gut tube, respiratory tract, bladder, urethra
Parenchyma of thyroid, parathyroid, liver, pancreas
What causes pleural adhesion and why is it marked by sharp, stabbing pain, especially on exertion?
Inflamed parietal and visceral pleura may adhere to each due to friction as the inflammation allows them to touch across the serous fluid that is supposed to lubricate them. There is pain during breathing due to the frictional rubbing of the pleura which is intensified during exertion when the rate and depth of inspiration increases.
What do the subcardinal veins give rise to?
left renal vein
renal segment of IVC
From anterior to posterior, identify the structures found in the mediastinum
thymus, brachiocephalic veins, arch of aorta, trachea, esophagus
What causes Tetralogy of Fallot, and what are the four characteristic cardiovascular alterations?
Tetralogy of Fallot is caused by an unequal division of the conus resulting from anterior displacement.
Interventricular septum defect
Hypertrophy of the right ventricular wall due to elevated pressure in the right ventricle
Overriding aorta: displacement of aorta over ventricular septal defect
Pulmonary stenosis: narrow right ventricular outflow region, causing elevated pressure in R ventricle