Blood Vessels

Question 0

Layer which contains muscles and retains the shape of the blood vessels

Answer 0

Middle layer

Question 1

What is in the medial layer of blood vessels that makes blood circulation possible?

Answer 1

Muscles (elastic fibers)

Question 2

What keeps the arteries round?

Answer 2

Attachment to surrounding tissues and presence of muscles

Why is the vein collapsed? (If the volume is low. Does it need attachment to surrounding tissues?)

Question 3

Which type of blood vessel has no internal elastic membrane?

Hint: Type of artery

Answer 3

Elastic artery

Question 4

Type of artery

Makes sure that the pressure gradient at point B will become less
Can absorb the pressure sustained during the systolic phase (in the heart)

Answer 4

Elastic artery

Question 5

T or F

During the recoil mode, the flow continues

Answer 5

True

Question: What is the physiology behind this?

Question 6

What happens during the state of tonic contraction (tonic state)?

Answer 6

There is blood in the heart

Related to the question: Why in diastole, pressure is not 0?

Question 7

What happens to the blood vessels?

Diameter decreases
Active input is required

vs

Diameter increases
Related to muscle relaxation

Answer 7

Vasoconstriction

vs

Vasodilation
Another nerve is stimulated to counterract the signals of the constrictor nerves

Question 8

True or False

As collective diameter increases, pressure increases
For example, in capillaries

Answer 8

False
Decreases
Diameter and pressure are inversely proportional

Question 9

True or False

There is constant of blood going to the brain

Answer 9

True

Not an excuse to be sleepy after meals

Question 10

Can’t be seen
Not anatomical
But functional
Stops the flow of blood in the capillaries

Answer 10

Precapillary sphincter

Leads to arteriovenous shunt (blood goes to the area of lesser pressure)

Capillaries don’t close all at once

Question 11

What happens to the pressure?

Arterioles to capillaries

Why?

Answer 11

Decreases

Collective diameter gets bigger
Dilation of arterioles (vasodilation, decrease in pressure)

RBCs fold to pass through the capillaries (8 microns vs 4-5 microns)
Example, in diabetes, RBC unable to fold

Question 12

Valves of veins

Answer 12

Makes sure that flow goes in one direction
Flow will continue to go upwards
The pressure (P1) down is not enough to push blood upwards

Question 13

What drives flow in the venous system?

Answer 13

Relaxation of heart

Question 14

How many milliseconds does the heart contract?

Which is longer: relaxation or contraction phase?

Answer 14

1/3 of a second, so it gets 60-70 ml (SV) in 2/3 of a second. HOW? By having extra pumps to refill the blood.

Relaxation phase

Question 15

When valves in the veins fail, blood goes somewhere

Answer 15

Varicose veins

Question 16

Bakit dalawa ang puso natin?

If the heart is a pump…

Answer 16

1 Heart

2 Calf muscle pump! Pump in the veins (venous return) to return the blood

3 Respiratory pump: Pressure decreases in thoracic cavity; Pressure increases in abdominal cavity

Question 17

Why is it that when you are tired, then you take a bath, the veins become visible?

Answer 17

Tired: Engorged/dilated veins
Cold: Thins epidermis/dermis

= Visible veins

Question 18

Korotkoff Sounds

Answer 18

Blood Pressure sounds

Question 19

T or F

The higher the blood volume, the lower the blood pressure

Answer 19

F

Higher

Question 20

Vagus nerve

Relax or contract?

Answer 20

Relax

Question 21

Body’s largest organ
One cell thick
1-2 trillion endothelial cells
Surface area of 400 sq.m. / 6 tennis courts

Answer 21

Vascular endothelium

Heterogenous (many different functions)
-can promote action opposite to the first function (that was stopped)

Question 22

Functions of the endothelium

Answer 22

Barrier and transducing functions
Hemostatic functions
Control of vascular wall functions
Leukocyte / Endothelial cell adhesive functions