Vascuar Structure And Function

Question 1

Describe the Tunica Intima.

Answer 1

Single endothelial layer lining blood vessels

Question 2

Describe the Tunica Media

Answer 2

• Layers of vascular smooth muscle which modify diameter
• Contain Elastic fibers high in Elastin with outer covering of microfibrils composed of glycoproteins
• Contain some collagen to resist stretching and lit expansion

Question 3

Describe the tunica adventitia

Answer 3

• This outer layer of CT which maintains integrity and shape

Question 4

How is Mean arterial pressure calculated?

Answer 4

MAP = (CO x SVR) + CVP

SVR = Systemic vascular resistance

CVP = Central Venous pressure

CO = Cardia output

Question 5

How is Pulse pressure calculated?

Answer 5

PP = SBP - DBP

Question 6

How is the change in pulse pressure calculated?

Answer 6

Delta P = Delta V / C

C = Compliance

Question 7

What is the principle force of capillary filtration?

Answer 7

Hydrostatic pressure

Question 8

What s the reflection coefficient?

Answer 8

Measures the relative stop of passing of substance through capillaries

Question 9

What is the Gibs-Donnan effect?

Answer 9

movement of charged particles that fail to distribute evenly on each side of membrane. Explains activity of albumn as its negative charge at normal blood pH and the attraction + retention of cations, principally Na+, in vascular compartment.

Question 10

What are Starling Forces?

Answer 10

The forces which determine the movement of fluid in/out of the capillary

Question 11

At the Arterial End, what are the Starling forces?

Answer 11

Outward:

• Vessel Hydrostatic fluid pressure
• Interstitial Oncotic Pressure

Inward:

• Intersitial hydrostatic pressure
• Vessel oncotic pressure

Question 12

What are the vessels involved in coronary circulation?

Answer 12

• Right/left Coronary arteries: Blood supply to myocardium
• Arteriosinusoidal channels: Penetrate chamber wall; lose structure and become irregular; anastomose with other sinuses/channels, etc
• Arterioluminal vessels - Open Directly into atria/ventricles
• Thebesian vessels: connect capillary beds directly with cardiac chambers

Question 13

What is supplied by the Left coronary artery?

What is the structure of the artery?

Answer 13

• Left ventricle
• Left atrium
• Divides into left anterior descending (widow maker) + Circumflex branches
• Left ANT/DESC supplies 2/3 interventrcular septum, anterolateral papillary muscles, and anterior surface of left ventricle

Question 14

What is the structure of the right coronary artery, and what does it supply?

Answer 14

Supplies right ventricle + atrium, SA node

Divides into Posterior descending branch and right marginal artery

• POS DES supplies AV Node, POS 1/3 interventricular septum, post 1/3 wall of ventricles and posteriomedial pappilary muscles
• Righ marginal supplies right ventricle

Question 15

What are the primary factors which affect coronary blood flow?

Answer 15

• Physical factor: Aortic pressure, adjustment to resistance
• Baroreceptors reflex
• Extravascular compression: Squeezing of myocardium
• Coronary perfusion: Difference in aortic diastolic pressure + Left ventricular end diastolic pressure
• Vessel Tone
• Flow Pattern
• Hypotension, occlusion, and stenosis
• Tachycardia and bradycardia

Question 16

What are compounds which change coronary vascular resistance?

Answer 16

H2O2 —> Increase in Cardiac work; Hyper polarization fo muscle membrane, relaxation of vascular smooth muscle

NO + Adenosine —> Dilatse arterioles and adjusts O2 supply to demand

Adenosine (low Conc) —> Activates endothelial K/ATP channels an enhances NO release; reduces vasodilator substances

Question 17

What is the crystal dividens?

Answer 17

• In fetus, Streams of blood which maintain characteristic IVC divided into two unequal streams by edge of the interatrial septum