Circulatory System

Question 1

blood flows in – loops

Answer 1

unidirectional

Question 2

one loops is the – which moves blood from the heart, through the body, and back to heart

Answer 2

systemic circuit

Question 3

the loops that moves blood from the heart, to the lungs, and back to the heart

Answer 3

pulmonary circuit

Question 4

– are large blood vessels that leave the heart

Answer 4

arteries

Question 5

arteries have thick walls and are very – to accommodate blood pressure

Answer 5

elastic

Question 6

as arteries leave the heart, they branch into smaller vessels called –

Answer 6

arterioles

Question 7

smallest vessels

Answer 7

capillaries

Question 8

– site of gas exchange within tissues

Answer 8

capillary beds

Question 9

T/F: capillary beds are so small that RBC line up single file to pass through them

Answer 9

true

Question 10

once gas has been exchanged, the capillaries widen and become – that head back to the heart

Answer 10

venules

Question 11

– pushes blood through arteries and arterioles

Answer 11

blood pressure

Question 12

movement of blood in venules and veins is facilitated by muscles that contract to push the blood along and – that close to proven back flow of blood

Answer 12

valves

Question 13

vasoconstriction and vasodilation of arteries serves as a means to regulate blood flow, pressure, and –

Answer 13

temperature

Question 14

arteries of the systemic circuit branch off the – side of the heart and carry oxygenated blood to the capillaries of the body where gas exchange occurs

Answer 14

left

Question 15

as the blood is being moved from the arteries to the capillaries, there is a significant – in velocity

Answer 15

decrease

Question 16

because there are very many capillaries throughout the body, the total cross-sectional area of the capillaries is – than that of the arteries

Answer 16

greater

Question 17

decrease in velocity provides adequate time fro gas exchange between the blood and –

Answer 17

interstitial fluid (fluid that surrounds cells)

Question 18

deoxygenated blood returns to the – side of the heart via systemic veins

Answer 18

right

Question 19

pulmonary circuit involves pulmonary arteries that branch off the – side o the heart and carry deoxygenated blood towards the lungs

Answer 19

right

Question 20

– allow for gas exchange with the alveoli

Answer 20

pulmonary capillaries

Question 21

newly oxygenated blood moves back toward the – side of the heart via pulmonary veins

Answer 21

left

Question 22

capillary bed is a collection of capillaries, all branching off a single – , that serves a specific location in the body

Answer 22

arteriole

Question 23

blood entering the systemic capillary bed is – and high in nutrients

Answer 23

oxygenated

Question 24

as blood moves through the capillary bed, oxygen and nutrients must diffuse out into the – and CO2 and wastes must diffuse in

Answer 24

interstitial fluid

Question 25

in pulmonary circulation, – enters the pulmonary capillary bed, were CO2 diffuses out and oxygen diffuses in causing oxygenation of blood

Answer 25

deoxygenated blood

Question 26

– guard the entrance to capillary beds

Answer 26

precapillary sphincters