Chapter 15

Question 1

What layer of the blood vessel wall is responsible for vasoconstriction/dilation?

Answer 1

The tunica media

Question 2

What layer of the blood vessel wall is responsible for preventing or allowing blood clotting?

Answer 2

Tunica Intima

Question 3

What layer of the blood vessel wall is responsible for resistance to high blood pressure by providing structure?

Answer 3

Tunica Media

Question 4

What layer of the blood vessel wall is responsible for formation of new blood vessels?

Answer 4

Tunica Intima

Question 5

Which is more elastic, veins or arteries? WHY???

Answer 5

Arteries are because they need to withstand the high pressure of blood pumped directly from the heart. THEY ARE ALWAYS UNDER CONSTANT PRESSURE.

Veins are less elastic so they can hold a very high percentage of the blood in circulation

Question 6

Explain elastic rebound in the large arteries

Answer 6

When the ventricle pushes the blood out the artery walls stretch because of the pressure (cushions the pressure during ventricular systole). Then when the ventricle relaxes (ventricular diastole) and there is no more pressure. Then it causes the artery walls to snap back (un stretch) and it sends a huge force in the artery to get the blood to the rest of the body.

Question 7

How does elastic rebound affect systolic blood pressure?

Answer 7

It lowers systolic blood pressure

Question 8

How does elastic rebound affect diastolic blood pressure?

Answer 8

It raises diastolic pressure

Question 9

What type of vessel carries the highest percentage of blood at rest?

Answer 9

Veins and venules

Question 10

What are the 2 things allow venous blood to return to the heart REAGARDLESS of low blood pressure?

Answer 10

1. The skeletal muscle pump
2. Respiratory pump

Question 11

What causes varicose veins? (4) And what is it?

Answer 11

Sitting and standing in one place for long periods of time, pregnancy, obesity pressures or it is heredity

It is where blood pools in the leg veins stretching the walls and the valves no longer work

Question 12

What are continuous capillaries and their functions?

Answer 12

They are endothelium complete lining capillaries connected by tight junctions

Functions: Prevent blood loss, keep plasma in the blood, allows passage of water, solutes, and lipid-soluble materials

Question 13

What are fenestrated capillaries and their functions?

Answer 13

They help with quicker filtration (#2 fastest). They contain pores to do that and are located in the choroid plexus, endocrine organs, and kidneys

Question 14

What are sinusoids capillaries and their functions?

Answer 14

They are capillaries that are larger and more permeable that allow blood cells and huge substances to go through by gaps between adjacent cells.

Question 15

Where are continuous, fenestrated, and sinusoid capillaries located?

Answer 15

Continuous: in tissues EXCEPT cartilage and epithelia
Fenestrated: choroid plexus, endocrine organs, and kidneys
Sinusoids: Liver, bone marrow, spleen

Question 16

How do you calculate pulse pressure?

Answer 16

systolic pressure MINUS the diastolic pressure

systolic pressure - diastolic pressure

Question 17

What is a normal pulse pressure for a heart at rest?

Answer 17

40mmHg or lower

Question 18

Explain what vascular resistance is.

Answer 18

It is the friction caused by the blood and the wall of the vessel. The opposition of blood flow as it goes through the vessel

Question 19

What blood vessels are most responsible for vascular resistance? WHY?

Answer 19

Arterioles, because they are so small

Question 20

How does vascular resistance affect blood pressure in the largest arteries?

Answer 20

Basically arteries are wide, then the blood flows to the distribution arteries which are narrower and slow down (back pressure increases, and resistance), and then you get to the arterioles which are even narrower and increases back pressure and resistance.

More resistance = higher blood pressure

Question 21

Where is blood velocity highest in the body?

Answer 21

Arteries

Question 22

Where is blood velocity lowest in the body?

Answer 22

Capillary beds

Question 23

Why is fast/high blood velocity in the arteries and slow/low blood velocity in the capillaries super important?

Answer 23

Arteries: it ensures efficient delivery of oxygen and nutrients to tissues throughout the body by rapidly transporting blood from the heart to the smaller blood vessels

Capillaries: Because allows time for the exchange of gases and nutrients

Question 24

Explain what blood colloid osmotic pressure (BCOP) is.

Answer 24

An attracting pressure caused by Albumin in the capillaries that attracts Na+ ions and water back into the capillary REABSORBS (-25mmHg)

Question 25

Explain what capillary hydrostatic pressure (CHP) is.

Answer 25

Water and small solutes forced out of the capillary value is 35-40mmHg

Question 26

Explain what net filtration pressure (NFP) is.

Answer 26

It is the difference between CHP and BCOP CHP - BCOP

Question 27

What values are normal for blood colloid osmotic pressure (BCOP), capillary hydrostatic pressure (CHP), and net filtration pressure (NFP)?

Answer 27

blood colloid osmotic pressure (BCOP)- (-25mmHg) capillary hydrostatic pressure (CHP)- 35-40mmHg net filtration pressure (NFP)- -7mmHg

Question 28

What is the role of albumin with regards to net filtration pressure?

Answer 28

It attracts Na+ ions which attracts water and reabsorbs it back into the capillaries

Question 29

What is pulmonary blood pressure?

Answer 29

the pressure within the arteries of the lungs

Question 30

Why is pulmonary blood pressure levels so low?

Answer 30

To prevent fluid filtration into the lungs

Question 31

Explain what autoregulation of blood flow is.

Answer 31

ability of an organ to maintain blood flow at a nearly constant rate despite changes in arterial perfusion pressure

Question 32

What role does nitric oxide have in autoregulation of blood flow?

Answer 32

It dilates the blood vessels

Question 33

How does aldosterone affect blood pressure?

Answer 33

INCREASES BLOOD PRESSURE by keeping sodium in the kidneys and constricts arterioles

Question 34

How does ADH hormone affect blood pressure?

Answer 34

It does vasoconstriction by reabsorbing water from the kidneys and INCREASES BLOOD PRESSURE

Question 35

How does natriuretic peptide affect blood pressure?

Answer 35

It gets rid of sodium in the kidneys which causes water to get excreted as well and it decreases the blood pressure

Question 36

How does erythropoietin affect blood pressure?

Answer 36

It causes vasoconstriction and production of red blood cells and it causes an INCREASES BLOOD PRESSURE

Question 37

How does epinephrine and norepinephrine affect blood pressure?

Answer 37

Epinephrine: Vasoconstricts organs that don't need blood during flight of fight INCREASES BLOOD PRESSURE Norepinephrine: Vasodilates in places in the body that need blood during flight or fight INCREASES BLOOD PRESSURE

Question 38

What would happen to the systolic and diastolic pressure if there was less elastic rebound in the arteries? (the walls are stiffer)

Answer 38

Systolic pressure would be increased and the diastolic pressure would be decreased

Question 39

How do the skeletal muscle pump and the respiratory pump work?

Answer 39

Skeletal muscle pump: you push blood up to the heart when your muscle contracts. Then when it is relaxed the blood comes back down but the valves in the veins close so it doesn't go down farther and negate the work it made getting it up to the heart. So it goes from valve to valve every time a muscle contracts and relaxes until it reaches the heart. (same thing with respiratory pump) Respiratory pump: Same thing as the skeletal muscle pump but when you inhale and exhale

Question 40

What are the 4 things that resist blood flow?

Answer 40

Three things that resist blood flow 1. Radius of the blood vessels (diameter, smaller diameter = more resistance, large diameter = less resistance) EFFECTS IT THE MOST 2. Length of the vessel (longer vessel it is hard/more resistance, shorter = less resistance) 3. Viscosity of blood (thickness of blood, thicker = more resistance, thinner = less resistance) 4. Turbulence (flow of the blood is disturbed by the plaque in the blood vessels and even the flow is disturbed after going past the plaque in the blood vessels)