Chapter 20 - The Heart - PART 1 Flashcards
Does the heart ever rest?
no
Blood flows through a network of blood vessels that extend between the ___ and ____ ____
between the heart and peripheral tissues
What is a pulmonary circuit?
The blood vessels that carry blood to and from the gas exchange surfaces of the lungs
what is a systemic circuit?
transports blood to and from the rest of the body
Each circuit begins and ends where?
at the heart
Blood returning to the heart from the systemic circuit must complete the ——– before returning to the systemic circuit
(blood travels through circuits in ____)
must complete the pulmonary circuit
(blood travels through circuits in SEQUENCE)
Arteries could also be called….
efferent vessels
veins could also be called….
afferent vessels
efferent vessels carry blood…
away from the heart
afferent vessels carry blood….
towards the heart
(they return blood to the heart)
What are microscopic, thin-walled vessels?
capillaries
What do capillaries interconnect?
the smallest arteries and the smallest veins
capillaries could also be called…..
exchange vessels
Why could capillaries also be called exchange vessels?
because their thin walls permit the exchange of nutrients, dissolved gasses, and waste products between the blood and surrounding tissues
Each day the heart pumps about _____ liters of blood
8000
Is the heart a relatively large or small organ?
small - roughly the size of a clenched fist
Is the heart a relatively large or small organ?
small - roughly the size of a clenched fist
How many muscular chambers does the heart have?
4
List the 4 muscular chambers of the heart
right atrium
right ventricle
left atrium
left ventricle
Explain the function of the right atrium
the right atrium RECEIVES blood from the SYSTEMIC CIRCUIT and passes it to the RIGHT VENTRICLE
The right ventricle receives blood from —– and pumps blood into the—–
the right ventricle receives blood from the RIGHT ATRIUM and pumps blood into the PULMONARY CIRCUIT
The left atrium collects blood from —— and empties it into ——-
the left atrium collects blood from the PULMONARY CIRCUIT and empties it into the LEFT VENTRICLE
The left ventricle receives blood from —– and pumps it into——
the left ventricle receives blood from the LEFT ATRIUM and pumps it into the SYSTEMIC CIRCULATION
When the heart beats fast - which contracts first: the atria or the ventricles?
the atria contract first