Cardio phys Flashcards
Blood enters the fetus through…
Umbilical vein
enters the IVC via the ductus venosus bypassing hepatic flow.
How is most of the fetal blood delivered to the heart?
Foramen ovale via the IVC/ductus venosus.
How does the ductus arteriosis work?
Sends deoxygenated blood from the right atrium/pulmonary artery into the aorta where it is delivered via the descending aorta/umbilical arteries to the mother.
What closes the ductus arteriosis in a newborn?
Following increased O2 from respiration and a DECREASE IN PROSTAGLANDINS.
How can indomethacin be used in infants?
Helps to close the ductus arteriosis by decreasing prostaglandins.
Results in ligamentum arteriosum.
What does the urachus/Allantois become in the adult?
Median umbilical ligament.
What does the ductus arteriosis become in the adult?
Ligamentum arteriosum
What does the ductus venosus become in the adult?
Ligamentum venosum.
What do the umbilical arteries become in the adult?
These become the medial umbilical ligament.
Dont confuse this with the urachus that becomes the median umbilical ligament.
What does the umbiical vein become in the adult?
Ligamentum Teres hepatic.
This is contained IN THE FALCIFORM LIGAMENT!!!
Which coronary artery supply the SA and AV nodes?
The right coronary artery.
Note that an infarct would cause nodal dysfunction!!!
A right dominant heart would denote….
That the posterior descending coronary artery comes from the right coronary.
Where is a coronary artery occlusion most commonly found?
Most commonly found in the left anterior descending artery that upplies the anterior 2/3 of interventricular septum.
When does coronary blood flow peak?
During diastole
What makes up the most posterior side of the heart and what problems can occur if it becomes enlarged?
The left atrium is the most posterior, enlargement can cause dysphagia by compressing the esophagus or hoarsness due to compressing the left recurrent laryngeal nerve (branch of vegas)
How can one calculate the mean arterial pressure?
MAP = Cardiac output x total peripheral resistance.
How is cardiac output maintained early on during exercise?
Mostly through increased HR and stroke volume.
How is cardiac output maintained late into exercise?
It is maintained mostly by HR as Stroke volume tops out.
The heart can only pump out so much at a time and HR comprimises end diastolic volume.
What is pulse pressure?
Systolic Pressure - Diastolic pressure
It is porportional to stroke volume!
What is ejection fraction?
Stroke volume / End diastolic volume.
How can pressure be calculated?
Pressure = Flow x Resistance
What effects resistance most?
The radius of the vessel.
As it increases, resistance is greatly decreased!