Blood Vessels and Circulation

Question 1

Arteries

Answer 1

Carry blood away from the heart. They do not have valves. The inner layer consists of perforated sheets of elastic tissue, alternating with thin layers of smooth muscle, collagen, and elastic fibers. They expand during systole, recoil during diastole. They lessen the fluctuation of blood pressure

Question 2

Veins

Answer 2

Carry blood too heart. They have valves and sinuses. They have low blood pressure with little fluctuation. They have thinner walls, less muscular and elastic tissue, expand easily. Since veins are elastic, blood pools in them easily. We have to move to keep our blood moving.

Question 3

Capillaries

Answer 3

Where delivery of nutrients or oxygen happens

Question 4

What are the largest arteries?

Answer 4

Conducting (elastic) arteries

Question 5

Conducting (elastic) arteries

Answer 5

The inner layer consists of perforated sheets of elastic tissue, alternating with thin layers of smooth muscle, collagen, and elastic fibers. They expand during systole, recoil during diastole. They lessen the fluctuation of blood pressure

Question 6

Resistance (small) arteries / Arterioles?

Answer 6

Arterioles control amount of blood to various organs

Question 7

Metarterioles

Answer 7

Short vessels that connect arterioles to capillarties. Muscle cells form a precapillary sphincter about entrance to capillary.

Question 8

Throughfare channel

Answer 8

Metarteriole continues through capillary bed to venule.

Question 9

Precapillary sphincters

Answer 9

Muscles that control which beds are well perfused (that get the blood). Only 25% of capillaries are open at a given time

Question 10

Venules

Answer 10

Proximal venule is quite porous, exchanges fluid with tissues, like a capillary, at this point only.

Question 11

Venous sinuses

Answer 11

Veins with thin walls, large lumens, no smooth muscle

Question 12

Where is blood pressure measured?

Answer 12

The brachial artery of the arm

Question 13

What is the normal blood pressure for a young adult?

Answer 13

120/80

Question 14

Mean arterial pressure

Answer 14

The average between the two BP numbers (120/80)

Question 15

Pulse pressure

Answer 15

Difference between the two BP numbers (120/80)

Question 16

Hypertension

Answer 16

140/90. Can weaken small arteries and cause aneurysms (when a vessel bulges and can burst).

Question 17

Hypotension

Answer 17

Abnormally low BP. 90/60

Question 18

Why is it important that arteries are elastic?

Answer 18

Expansion and recoil maintains steady flow of blood throughout the cardiac cycle, smooths out pressure fluctuation and lowers stress on small arteries.

Question 19

Why does BP rise with age?

Answer 19

Because the arteries are less distensible (stretchy)

Question 20

Blood viscosity

Answer 20

It’s determined by the RBC’s and albumin. (the thickness and stickiness of blood. It is a direct measure of the ability of blood to flow through the vessels.)

Question 21

Vessel radius

Answer 21

It has a very powerful influence over the flow. It is the most adjustable variable, controls resistance quickly. (The vessels can change their size because of the muscles in them)

Question 22

Vasoconstriction

Answer 22

Shrinks vessels

Question 23

Vasodilation

Answer 23

Opens the vessels up bigger

Question 24

Local control of BP

Answer 24

It opens more capillary beds to decrease BP, close more to increase BP

Question 25

Neural control of BP

Answer 25

Vasomotor center (keeps BP normal) is in Medulla oblangata. It controls the baroreflexes, chemoreflexes, medullary ischemic reflex.

Question 26

Baroreflexes

Answer 26

Are pressure receptors

Question 27

Chemoreflexes

Answer 27

Are chemical receptors

Question 28

Medullary ischemic reflex

Answer 28

Are oxygen receptors

Question 29

Capillary exchange

Answer 29

Only occurs across capillary walls between blood and surrounding tissues. Exchanging substances in and out of the blood stream

Question 30

Venous return

Answer 30

When blood comes back to the heart. Pressure is very low in the veins. Gravity drains the blood from head to neck.

Question 31

Skeletal muscle pump

Answer 31

Not an actual pump. Helps push blood back to the heart. Since blood in a vein can only move one way the muscles around the bones help squeeze the blood out

Question 32

Thoracic pump

Answer 32

When inhalation occurs, the thoracic cavity expands abdominal pressure, forcing the blood upwards.

Question 33

How many ways are there to get blood to the brain?

Answer 33

4

Question 34

Pulmonary system

Answer 34

Right side pumps that pump to the lungs

Question 35

Systemic system

Answer 35

Left side pumps that pump to the body

Question 36

The pulmonary trunk

Answer 36

Where the vessel splits and the left one goes to the left lung and the right one goes to the right lung.

Question 37

Alveoli

Answer 37

Gas exchange occurs here. There are basket like capillary beds that surround the alveoli. Also, inside the alveoli there is air from the outside. (ps these things are inside our lungs)