Lecture 23 10/17/23 Flashcards
What is the function of the CV system?
circulate blood at rates that meet metabolic demand while maintaining adequate perfusion and low filling pressures
What does blood contain?
-nutrients/waste
-gases
-electrolytes
How is oxygen bound to hemoglobin conveyed?
from the lungs to the metabolizing tissues
How is CO2 conveyed?
from the metabolizing tissues to the lungs
How do gases, nutrients, and wastes move?
via diffusion
What are the characteristics of blood flow?
-pulsatile
-established by cyclic mechanical activity of heart
What are the two “pumps” of the heart?
-pumping blood through the systemic vascular bed
-pumping blood through the pulmonary vascular bed
What is the stroke volume?
the volume of blood that the ventricle ejects each systole
What is cardiac output?
the volume of blood that leaves one side of the heart in one minute
Why is it important that the cardiac output of the left and right heart are equal over time?
don’t want one side of the heart to fall behind
What are the different structures in the heart?
atria
-valves
-ventricles
What are AV valves?
valves guarding the entrances to the ventricles
What are semilunar valves?
valves guarding the entrances to the great arteries
When are AV valves open and closed?
open: during filling/diastole
closed: contraction/systole
When are the semilunar valves open and closed?
open: during contraction/systole
closed: filling/diastole
What is the function of ventricles, in general?
propel the stroke volume into the respective vascular bed
What are the characteristics of the right ventricle?
-thin-walled
-pyrimidal
-“volume pump”
-geometrically suited for low resistance/low pressure
What are the characteristics of the left ventricle?
-cylindrical
-“pressure pump”
-generates high pressures
What is the vasculature?
branching system of vessels that conveys blood and provides a site for metabolite exchange
What is the role of veins/venules?
convey blood to the heart