Circulation and Vessels

Question 1

Purpose of circulation

Answer 1

Delivery and exchange of nutrients and waste.

Question 2

Most important single activity

Answer 2

Oxygen delivery.

Question 3

The aorta has lots of ____ tissue and is very _______.

Answer 3

The aorta has lots of elastic tissue, and it is very distensible.

Question 4

The aorta ____ energy during systole, and ____ energy during diastole.

Answer 4

It stores energy during systole, and returns it during diastole.

Question 5

Stopcocks of the vascular system

Answer 5

Arterioles

Question 6

Arterioles are made of _____ muscle, and are controlled by __________.

Answer 6

Arterioles are made up of smooth muscle, and are controlled by sympathetic activity.

Question 7

What do the arterioles control?

Answer 7

They control vascular resistance, blood pressure, and localized flow and delivery according to activity and need.

Question 8

These vessels are complex networks in charge of gas diffusion and fluid osmosis.

Answer 8

Capillaries

Question 9

Transit time in capillaries?

Answer 9

1-3 seconds

Question 10

Surface area of capillaries

Answer 10

500 m2

Question 11

Capillaries are made up of _____ cells.

Answer 11

endothelial.

Question 12

Diameter of a capillary?

Answer 12

8 microns (roughly the size of one RBC)

Question 13

3 mechanisms of venous return

Answer 13

1. muscle pump
2. soleal sinuses
3. one-way valves

Question 14

Venous return is a ___ pressure system, __-__ mmHg.

Answer 14

It is a low pressure system, 0-15 mmHg.

Question 15

Collecting tubes from capillaries

Answer 15

Venules

Question 16

Venules have __ layers: _______ & _______

Answer 16

They have 2 layers: the intima (made up of endothelial cells) and the adventitia. They have no media.

Question 17

These vessels are compliant and their walls are thinner than those of arteries.

Answer 17

Veins

Question 18

Veins hold ____ of all blood, this is called the _________.

Answer 18

The hold 2/3 of the blood in the circulatory system, this is known as the venous reservoir.

Question 19

Veins can expand how many times more than arteries?

Answer 19

4-5x more

Question 20

3 types of veins in LE?

Answer 20

1. Deep
2. Superficial
3. Perforators

Question 21

These types of veins always accompany arteries

Answer 21

Deep veins

Question 22

These veins run along the surface of the skin

Answer 22

Superficial veins

Question 23

These veins are the communication between superficial and deep veins

Answer 23

Perforators

Question 24

Why does the body need the venous reservoir?

Answer 24

It is needed during exercise and hemorrhage. It holds the potential volume you can supply to the body when in need.

Question 25

Venous valves have __ cusps and are made of ____ cells.

Answer 25

They have 2 cusps and are made of endothelial cells.

Question 26

Pro and con of sinuses?

Answer 26

Pro: can help close the valves
Cons: can be an area of potential stasis

Question 27

Flow in perforator veins always flows from ____ to ____.

Answer 27

Superficial to deep

Question 28

Primary mechanism for venous return?

Answer 28

Muscle pump (especially in the leg/calf muscles)

Question 29

The muscle pump overcomes _____ ______.

Answer 29

Hydrostatic pressure.

Question 30

What type of veins lie with in the muscle?

Answer 30

Deep veins

Question 31

Venous valves create _____ ____ to ensure flow goes up. They ____ ____the column of fluid.

Answer 31

They create pressure gradients and break up the column of fluid.

Question 32

The muscle pump is also known as the ____ ____.

Answer 32

Peripheral heart

Question 33

Mechanism of the peripheral heart

Answer 33

Contraction: pushes blood upward
Relaxation: blood goes superficial to deep