Bio Exam 1 - Cardio and respiratory Flashcards
single circulation
blood leaves the heart and passes through two capillary beds before going back to the heart. Fish, rays, and sharks
double circulation
oxygen poor and oxygen rich blood are pumped separately from the right and left sides of the heart
how is blood circulated through double circulation?
Oxygen-poor blood comes into the right atrium to the right ventricle and goes to the lungs through the pulmonary artery, then back into the veins to the left atrium and left ventricle and then to the body
pulmonary circuit
carries blood to the lungs
systemic circuit
carries blood to everywhere in the body except the lungs
How does blood enter the heart
blood enters through an atrium and is pumped out through a ventricle
cardiac output
Volume of blood pumped into systemic circulation per minute and depends on both the heart rate and stroke volume
stroke volume
amount of blood pumped in a single contraction of the heart
capillary beds
sites of chemical exchange between blood and interstitial fluid
venules
Converge into veins and return blood from capillaries to the heart
arteries
branch into arterioles and carry blood away from the heart to capillaries
blood pressure
Pressure that blood exerts as it is pressed against the wall of a vessel
rigid vessels
vessel walls are stiff and pressure is maintained as in arteries
less rigid vessels
vessel walls are flexible and blood pressure is lost
systolic pressure
pressure in the arteries during ventricular systole or contraction - this is the highest pressure
diastolic pressure
pressure in the arteries during ventricular diastole or relaxation - lower than systolic
When is blood flow slow?
In the capillary beds - good for exchange of nutrients and waste
blood pressure is determined by…
cardiac output and total peripheral resistance or resistance of arteries to blood flow
vasoconstriction
contraction of smooth muscle in arteriole walls which increases blood pressure and reduces blood flow
vasodilation
Relaxation of smooth muscle in the arterioles which causes blood pressure to to fall and increases blood flow
What are the three anatomic components of the mammalian circulatory system?
Blood, blood vessels, and the heart
cardiac construction system
A network of specialized muscle cells in the heart walls send signals to the rest of the heart muscle, causing a contraction
open circulatory system
No distinction between blood and interstitial fluid and the blood bathes the organs directly. Within insects, mollusks, and arthropods
closed circulatory system
blood is confined to vessels and is distinct from interstitial fluid. These are more efficient at transporting circulatory fluids to tissues and cells. Found in annelids, cephalopods, and vertebrates