Flashcards in CVS Session 1- Histology Of The CVS Deck (17)
Where does the aorta arise from and what does it bifurcate into (L-R)?
Arises from the left ventricle.
Bifurcated into the left subclavian, common carotid and brachiocephalic arteries.
What does the pulmonary trunk arise from and what does it bifurcate into?
It arises from the R ventricle.
Bifurcated into the L and R pulmonary arteries.
What is the course of blood flow, from the heart, in terms of vessels?
Heart, arteries, arterioles, metarterioles, capillaries, post-capillary venules, venules, veins, heart
Why can metarterioles act as pre-capillary sphincters?
Because their muscle layer isn't continuous.
What is the advantage of slow blood flow in the capillaries?
Allows maximum gas exchange via diffusion between capillaries and tissues.
What structure in vessels means that blood return to the heart is aided?
Valves- prevent retrograde blood flow.
How do veins structurally differ from arteries? (2)
-they have larger lumen
-they have thinner walls
What are the four layers of vessels (in to out)?
What are vasa vasorum and where are they found?
They are a blood supply to large vessels.
They are necessary as large vessels have such thick walls that they require their own blood supply to ensure that they receive adequate nutrients.
What are venae comitantes and what do they do?
They are deep paired veins either side of a small artery.
The three vessels are wrapped together in the same sheath.
Pulsing of the artery aids venous return to the heart.
What are end arteries?
What happens if they are occluded?
They are a terminal/sole arterial supply to a tissue/organ.
If they are occluded, there is an insufficient blood supply to the dependant tissue.
Give an example of an end artery and what it supplies.
The coronary arteries.
Supply to the heart.
What are sinusoids?
Where are they found?
Capillaries with a larger diameter and therefore slower blood flow than normal capillaries.
Liver, spleen and bone marrow.
What are pericytes, where are they found, and what are they capable of doing?
They are cells that are found on the outer surface of capillaries.
They are capable of dividing into muscle cells/fibroblasts during angiogenesis, tumour growth and wound healing.
Where does the right atrium receive blood from? (3)
Superior and inferior vena cavae
Which two valves are located posterior to the sternum?
Which intercostal spaces are they found in?
Tricuspid valve- 4th and 5th
Mitral valve- 4th costal cartilage