Lecture 3.5 Pulmonary Blood flow Flashcards
Describe the flow of blood flow through the lungs
Deoxygenated blood from the right ventricle comes to the lungs in the pulmonary artery
The blood is then taken through the pulmonary system where gas exchange occurs
The CO2 that is in the blood is removed and O2 is added into the blood.
This blood travels in the pulmonary veins into the left atrium to the left ventricle and out to the body
The alveolar vessels receive blood from the _____ ventricle and the extra-alveolar receives blood from the ______
right
left
Why is the PaO2 higher in the extra-alveolar blood than the alveolar
Because this blood is coming from the left ventricle which has OXYGENATED blood
What is the goal of the extra-alveolar capillary?
Provide nutrients to and remove waste from the airways
The blood in this capillary is referred to as a “venous admixture”
Extra-alveolar capillary
Describe what happens if you stand up and you lock your knees
skeletal muscle pumps are not able to pump the blood that settled because of gravity back to the heart and the brain, so you pass out
Describe the blood flow to the different areas of the lungs
The apex of the lung has the least amount of blood flow and the base has the most
The middle of the lungs is the most “normal” and the values that are found here are typically what are found in the blood that is leaving the pulmonary system
How does where the portion of the lung is in relation to the heart effect blood flow and blood pressure.
For a region that is higher than the heart, the blood flow and pressure will be lower because it has to work harder to get here
For a region that is below the heart, the blood flow will increase and pressure will increase because of the affects of gravity
What is the role of the lymphatic system in the alveoli?
Help to keep everything dry. The lymphatics help to drain the fluids that are filtered from the capillaries out of the lungs so that gas exchange is still able to happen
Describe the renin aldosterone pathway
Renin is made by the kidneys
Angiotensin 1 is made from angiotensinogen
Angiotensin 1 is turned into angiotensin 2 by ACE in the lungs
What are the other effects of ACE?
Inhibits bradykinin: people can develop a chronic cough when placed on ACE inhibitors to lower blood pressure
What are the forces that favor filtration out of the capillary into the alveolus?
Pc
Oncotic pressure of the tissue
Pressure of the tissue
