10.4 The Vascular Pathways

Question 1

what are the circuits in the circulatory system

Answer 1

• pulmonary circuit (circulates blood through lungs)

- systemic circuit (serves the needs of body tissues)

Question 2

describe the pulmonary circuit

Answer 2

-blood all regions collect in the right atrium to right ventricle pumps to pumonary trunk, divides into left and right pulmonary arteries to arterioles that take blood to pulmonary capillaries for gas exchange. blood then passes through pulmonary venules to four pulmonary veins to left atrium

Question 3

describe the systemic circuit

Answer 3

includes major arteries and veins

Question 4

where does the superior (anterior) and inferior (posterier) vena cava collect blood from

Answer 4

superior anterior: blood from head, chest, arms

inferior posterier: blood from lower regions

Question 5

what is the path of blood to and from the legs

Answer 5

left ventricle, aorta, common iliac artery, femoral artery, leg capillaries, femoral veins, common iliac veins, inferior (posterior) vena cava, right atrium

Question 6

describe coronary arteries

Answer 6

serves the heart muscles itself because heart is not nourished by the blood in its own chambers

• first branches of aorta
• above aortic semilunar valve on exterior of heart dividing into arterioles
• coronary capillary beds join to form venules which converge to form cardiac veins that empty into the right atrium

Question 7

why can coronary arteries become clogged

Answer 7

small diameter

Question 8

describe the portal system

Answer 8

-in blood circulation begins/ends in capillaries

Question 9

describe the hepatic portal system

Answer 9

-capillaries that occur in villi of small intestine pass into venules that join to form hepatic portal vein (vein that carries blood in liver capillaries), hepatic vein leaves liver and enters inferior vena cava

Question 10

define systolic and diastolic pressure

Answer 10

systolic: pressure from blood forced into arteries during ventricular systole (contraction)
diastolic: pressure in arteries during ventricular diastold

Question 11

describe the blood flow in the main blood vessesl

Answer 11

aorta to arteries and arterioles: BP falls, diff between systolic and diastolic pressure diminishes
capillaries: blow flow slow and fairly even (high cross sectional area of capillaries)

Question 12

what is the brachial artery

Answer 12

BP measured on this artery in the upper arm using a sphygmomanometer

Question 13

describe the BP in veins (skeletal musles)

Answer 13

low, inefficient means of moving blood back to the heart, esp from limbs

• when skeletal muscles near veins contract, put pressure on veins and blood they contain
• valves prevent backflow of blood in veins, muscle contraction is suffiicient to move blood toward the heart

Question 14

why is it important to take stretch breaks while sitting down for long periods of time

Answer 14

clots may form in deep veins of legs, can cause serious problems if they break free and become lodged in lungs
-should take frequent stretch breaks