Sec 30.4: Blood Vessels and Transport

Question 1

What are the 3 types of blood vessels and what is their role?

Answer 1

Arteries, Veins, and Capillaries; they act as transportation networks for the blood

Question 2

What do arteries do?

Answer 2

They carry oxygenated blood away from the heart to body cells

Question 3

Why do arteries need to be strong and flexible?

Answer 3

Because the blood carried is under great pressure

Question 4

What are the 3 layers that compose the arteries’ thick walls?

Answer 4

The innermost layer consists of endothelium coated with a protein that prevents blood from clotting
The middle layer is a thick band of smooth muscle and elastic fibers
The outer layer consists of connective tissue and elastic fibers

Question 5

What is the function of elastic fibers?

Answer 5

They allow the arterial wall to expand and contract to help move blood through the arteries

Question 6

What are arterioles?

Answer 6

They are smaller arteries that contain the same 3 layers but with thinner outer and middle layers.

Question 7

What do veins do?

Answer 7

They carry deoxygenated blood from the body cells to the heart

Question 8

What does their structure reflect?

Answer 8

That blood is under less pressure when returning to the heart

Question 9

How are veins structured?

Answer 9

• have larger diameters and thinner walls than arteries
• contain valves that prevent blood from flowing backwards
• their walls are thinner than arteries and do not expand and contract

Question 10

How do skeletal muscles help maintain circulation?

Answer 10

They push against veins so valves open and blood moves toward the heart

Question 11

What are venules?

Answer 11

They are small veins that join larger veins to capillaries

Question 12

What do capillaries do?

Answer 12

They carry blood between blood cells

Question 13

What are their walls made of?

Answer 13

Epithelium

Question 14

How are they strctured?

Answer 14

• They do not contain muscle cells or elastic fibers
• Their one-cell-thick walls allow materials to diffuse into and out of the blood quickly and easily

Question 15

What happens as a result of high metabolic activity in the lungs, kidneys, liver,etc.?

Answer 15

Capillaries form dense networks called capillary beds that move a great deal of blood into and out of organs

Question 16

What is blood presure?

Answer 16

It is the force with which blood pushes against the wall of an artery. A healthy blood pressure is 120/70 mm Hg

Question 17

What is systolic pressure?

Answer 17

It is the top and higher #, and it is the amount of pressure on the walls of an artery when the left ventricle contracts to pump blood through the body.

Question 18

What is diastolic pressure?

Answer 18

It is the bottom and lower #, and it is the pressure in the artery when the left ventricle relaxes

Question 19

What does blood pressure depend on?

Answer 19

It depends on how elastic and unblocked the arteries are and on the strength of the heart’s contractions

Question 20

What happens when the arteries become less elastic or more blocked?

Answer 20

Blood flow is reduced; the heart must pump harder, and blood pressure rises

Question 21

How does blood pressure rise naturally?

Answer 21

With activity, stress, and strong emotions

Question 22

What is hypertension?

Answer 22

It is a condition where people have permanently high blood pressure, which can lead to a heart attack or a stroke

Question 23

When does a heart attack occur?

Answer 23

When the arteries to the heart muscle are damaged or blocked

Question 24

When does a stroke occur?

Answer 24

It occurs when blood flow to the brain is interrupted

Question 25

How can you lower blood pressure and reduce the risk of circulatory disease?

Answer 25

By weight loss, proper diet, and exercise, or medications in the extreme condition

Question 26

What increases the risk of developing circulatory diseases?

Answer 26

Smoking, lack of exercise, excessive weight, long-term stress, and a diet low in fruits/vegetables (high in saturated fats)

Question 27

What is arteriosclerosis?

Answer 27

It is a circulatory disease where the artery walls become thick and inflexible

Question 28

What is atherosclerosis?

Answer 28

It is a circulatory disease where blood flow is partially/fully blocked by plaque

Question 29

What is plaque?

Answer 29

It is a sticky material that collects on the walls of arteries

Question 30

What can arteriosclerosis and atherosclerosis lead to if untreated?

Answer 30

They can lead to heart attack, stroke, or disease, and they are warning signs of high blood pressure

Question 31

What is balloon angioplasty?

Answer 31

It is a surgical technique where blocked arteries supplying the heart muscles can be opened by a device threaded into the artery and then inflated to squeeze the obstruction against the wall.

Question 32

If balloon angioplasty does not work, what can be done then?

Answer 32

Bypass surgery

Question 33

What is bypass surgery?

Answer 33

It is an operation where a healthy blood vessel from another part of the body (usually the leg) is attached to the artery on either side of the blockage so blood can bypass it.