Circulation, Pressure, Flow, and Resistance

Question 1

Systemic circulation

• Serves?
• Blood volume
• AKA

Answer 1

Serves all tissues except lungs
Contains 84% blood volume
Peripheral circulation

Question 2

Pulmonary circulation
-Serves?
-Blood volume
`

Answer 2

Lungs

9% of blood volume and 7% heart

Question 3

Arteries

Answer 3

Arteries- transport blood under high pressure to tissues and have strong vascular walls. Blood flows at high velocity in arteries

Question 4

Arterioles

Answer 4

Small branches of arterial system. Releases blood into the capillaries. Has strong vascular walls.

Question 5

Capillaries

Answer 5

Exchange fluid, nutrients, electrolytes, hormones, and other things between blood and interstitial fluid. Walls are very thin and filled with pores.

Question 6

Venules

Answer 6

Collect blood from capillaries and progress into larger veins.

Question 7

Veins

Answer 7

Transport blood from venules back to the heart and are a major reservoir of blood. Venous walls are thin due to low venous system pressure.

Question 8

Relation between cross-section of pulmonary/peripheral circulation structures?

Answer 8

Capillaries have largest area of cross section so blood travels slower through capillaries. Aorta has smallest cross section and blood travels fastest. The lower the cross section, the faster the blood travels. The bigger the cross section, the slower blood travels. Think of water flowing fast through a stream (aorta) and then going slow once it flows into an open lake (capillaries).

Question 9

Normal arterial systolic and diastolic pressure

Answer 9

Systolic-120mmHg

Diastolic-80mmHg

Question 10

As blood flows through system circulation, arterial pressure?

Answer 10

0 mmHg

Question 11

Systemic capillary pressure

Answer 11

Varies.
At arteriolar ends-35mmHg
At venous ends-10mmHg

Question 12

Pulmonary artery systemic/diastolic pressure

Answer 12

25/8 mmHg

Question 13

T/F Total blood flow through lungs each minute is same as through the systemic circulation

Answer 13

True-because systemic and pulmonary circulation are in SERIES. Right heart pumps same amount as left heart.

Arteries, arterioles, capillaries, venules, and veins are in series.

Question 14

Organs in systemic circulation are in parallel or series?

Answer 14

Parallel. Rate of blood flow to each tissue can be regulated independently of each tissue.

Question 15

Pathway blood flows

Answer 15

START SYSTOLIC CIRCULATION:Aorta (100mmHg)–>arteries(100)–>arterioles(slowly drops)–>capillaries(35)–>veins(7)–>vena cava–> END SYSTOLIC CIRCULATION–>BEGIN PULMONARY–>vena cava–>Pulmonary arteries(25)–>arterioles(drops)–capillaries(drops)–>venules–>pulmonary veins START SYSTOLIC

Question 16

What are some things that would happen if arterial pressure dropped below 100mmHg?

Answer 16

• Increase the force of heart pumping
• Cause contractions of veins to push more blood to the heart
• Constriction of most arterioles throughout the body so blood can go to arteries to increase arterial pressure.

Question 17

Ohms law

Answer 17

Blood flow= change in pressure of 2 ends of vessel (aterial-venous pressure)/ resistance

Question 18

Laminar flow vs turbulent blood flow

Answer 18

Blood flows in layers going in one direction. Blood flow is silent. Turbulent blood flow happens when their is bloodflow in opposite directions (due to stenosis or some abnormality) and you can hear noises (murmur).

Question 19

Blood pressure

Answer 19

The force exerted by the blood against area of vessel wall.

Question 20

The rate of bloodflow through the circulatory system is equal to the rate of blood pumping by the heart

AKA

Answer 20

The rate of bloodflow through the circulatory system is equal to cardiac output.

Question 21

Flow is proportional to what power of the radius? This means???

Answer 21

4th power. This means that small changes in radius of blood vessel can cause dramatic changes in blood flow through a tissue.

Question 22

Besides pressure and resistance, what else can affect blood flow?

Answer 22

Viscosity (n) and length of vessel (l) demonstrated in Poiseuille’s Law.
blood flow=change in vessel pressureXradius^4/viscosityXlength