3. There is an anatomical abnormality, usually congenital in origin, known as an
ID: 3476672 • Letter: 3
Question
3. There is an anatomical abnormality, usually congenital in origin, known as an arteriovenous fistula (fistula mean an abnormal passageway). This consists of a tangled mass of arteries and veins, typically in or near the brain, in which a direct connection between an artery and a vein can form Aside from the detrimental effect this has on blood supply to the nearby regions of the brain, such an opening, when it involves a large vein and artery, dramatically changes the operation of the circulatory system. In anatomical and physiological terms and referring to specific equation(s). explain the major effects the opening of such a fistula has on TPR and CO, and the longer-term effects on the development of hyper- or hypotrophic states of the heart. (Three sentences or less.,)Explanation / Answer
It leads to the decrease in TPR( total peripheral resistance).This is because the blood bypasses the arterioles which results in a decrease in the total peripheral resistance (TPR).
This lowered peripheral resistance causes the heart to increase cardiac output in order to maintain blood flow to all tissues.Heart rate and stroke volume increases to increase the cardiac output.Cardiac output is also increased due to increased venous return to the heart.
Pulmonary artery pressure did not correlate with blood flow rate of Atriovenous fistula and duration after Atriovenous fistula creation . In hemodialysis patients, a surgically created Atriovenous fistula has no significant effect on the development of pulmonary arterial hypertension within a long-term period. Similarly, blood flow rate of Atriovenous fistula also did not affect remarkably systolic pulmonary artery pressure within the long-term period.The risk of cardiac failure significantly increases when the Qa (AVFflow) of AVF is more than 2.0 L/min with much higher Cardac output and lower peripheral vascular resistance .
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.