video thumbnail

Pulmonary Vascular Circuit Changes Under Varying Conditions

Duration: 24:36

Write A New Comment

0 Comments

This video will present: Properties of the pulmonary vasculature. Division and the filtration function of the pulmonary vasculature. Metabolic functions of the pulmonary vasculature. Comparison of the pulmonary and systemic vasulatures. Change in the pressures with breathing and valsalva's manuver. Clinical points of the pulmonary vasculature.

 

STUDY NOTES:

PROPERTIES OF PULMONARY VASCULATURE

The heart pumps a volume of blood into the lungs which after getting oxygenated is transported back to heart. This oxygenated blood is then pumped out of the heart and into the aorta and subsequently into the systemic circulation. As a consequence, at any given time the lungs (pulmonary vasculature) contain around 500ml of blood, thereby allowing them to function as a reservoir of the blood. This reservoir volume is increased by another 500 ml when the person is in the supine or lying down position. This is because in supine position there's an increased venous return (due to the effect of gravity) to the right heart from the peripheries and therefore more blood accumulates in the central parts of body. Upon standing up, this extra 500ml of blood gets redistributed under the effect of gravity, to the now more dependent parts of the body which includes the peripheral tissues and the lower extremities.

The division of vasculature in the pulmonary circuit is somewhat different from that in the systemic circulation. The arteries in the pulmonary circuit divide in a binary fashion, thereby following the pattern of division of the airways. The veins too exhibit a pattern similar to the arterioles and the bronchioles, thereby finally converging into forming one large pulmonary vein. These pulmonary veins transport the oxygenated blood back to the heart.

Apart from the primary function of lungs to deliver oxygenated blood to the heart, it has several secondary functions as well:

1) Filtration: Pulmonary vascular bed acts as a filter for the blood received by the right side of the heart andbefore this blood leaves the left side of the heart to enter the systemic circulation. Blood arriving from the right side of the heart to the lungs may contain an embolus or a thrombus or any foreign particle that may result in obstruction of the vessels. The pulmonary artery divides into numerous small capillaries with diameters too small to allow passage of any dislodged particles into the pulmonary artery and subsequently in to the left side of the heart. Therefore, the pulmonary vascular bed acts as a filtration barrier that prevents introduction of any particles into the systemic circulation.

 

2) Metabolic Functions: The pulmonary vasculature also has some metabolic functions:

 

a) The endothelium of the pulmonary vessels is lined by fibrinolytic enzymes that cause lysis of the fibrin clots which get stuck in the pulmonary vasculature.

 

b) The pulmonary capillary endothelium is lined by another enzyme as well. This enzyme is called the Angiotensin Converting Enzyme (ACE). ACE functions to convert Angiotensin I to Angiotensin II. ACE is also present in the endothelium of other vascular beds and the plasma, however, the amount present in the pulmonary vascular bed is the highest.  ACE within the pulmonary vascular bed is responsible for more than 70% of the total conversion of Angiotensin I to Angiotensin II in the body.

In this video we will discuss:

1. Changes in pulmonary vasculature during exercise.

2. Changes during hemorrhage.

3. Changes during valsalva maneuver.

4. Changes during breathing.

5. Changes during swan gatz catheterization.

6. Different factors responsible for these changes. 

Following answers are created by ChatGPT. Occasionally the answer may be harmful, incorrect, false, misleading, incomplete, or limited in knowledge of world. Please contact your doctor for all healthcare decisions. Also, double check the answer provided by the AI below.

Faculty

In addition to the presenter, following authors may have helped with the content writing, review, or approval:

  • Dr. Mobeen Syed

CME, CE, CEU and Other Credit Types:

ACCME Accreditation Statement
The DrBeen Corp is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

AMA Credit Designation Statement
The DrBeen Corp designates this enduring material for a maximum of 0.5 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.


Disclosure Information

In accordance with the disclosure policies of DrBeen Corp and the ACCME (Accreditation Council for Continuing Medical Education), we are committed to upholding principles of balance, independence, objectivity, and scientific rigor in all of our Continuing Medical Education (CME) and Continuing Education (CE) activities. These policies include the careful management and mitigation of any relevant financial relationships with organizations that are not eligible.
All members of the Activity Planning Committee and presenters have disclosed their relevant financial relationships. The DrBeen Corp CE Committee has thoroughly reviewed these disclosures and determined that these relationships are not deemed inappropriate in the context of their respective presentations. Additionally, they are found to be consistent with the educational objectives and the integrity of the activity.

Faculty Disclosures
Dr. Mobeen Syed Author declares no conflict of interest.

Please login to access this content.

Don't have an account?

Start Your Free trial

No credit card information needed.

Instructors

Dr. Mobeen Syed

Dr. Mobeen Syed

MD., MSc., MSc., BSc

Mobeen Syed is the CEO of DrBeen Corp, a modern online medical education marketplace. Mobeen is a medical doctor and a software engineer. He graduated from the prestigious King Edward Medical University Lahore. He has been teaching medicine since 1994. Mobeen is also a software engineer and engineering leader. In this role, Mobeen has run teams consisting of hundreds of engineers and millions of dollars of budgets. Mobeen loves music, teaching, and doing business. He lives in Cupertino CA.

Family Medicine - Cardiology Concentration

Related Videos