Histology-Arteries, Veins and Capillaries Flashcards
What types of cells make up the areas indicated by the red arrows?
In the heart, cardiac myocytes. In the artery, smooth muscle. In valves, elastic fibers.
What cells are indicated by the arrow?
Purkinje fibers. Note lighter staining fibers adjacent to endocardium.
What is are major differences between the histology of arteries and veins?
Arteries have a more robust tunica media and may have elastic fibers. Veins may have smooth muscle in their tunica adventitia.
What cells make elastic fibers in the aorta?
Smooth muscle cells
What is a major difference between elastic and muscular arteries?
Muscular arteries have an inner elastic lamella and possibly an outer elastic lamella where elastic arteries have elastic fibers throughout the tunica media.
How do you know the blood vessel on the left is a venule and not a lymphatic vessel?
Although the venule looks like a lymphatic vessel with very thin walls and no muscle layers, it is transporting RBCs.
What blood vessel do you see here?
An arteriole. Note it has 1-2 layers of smooth muscle in the vascular wall.
If you are a physician interested in controlling smooth muscle contraction in your patient, what control points can you use to do so?
Target the influx and sensitivity of calcium in the smooth muscle cell.
How is it that histamine can cause vasodilation and vasoconstriction on the same blood vessel?
If it binds to the endothelial cell, it induces NO production which relaxes smooth muscle. If it binds to the smooth muscle, it makes it contract.
What is the difference between fenestrated and discontinuous capillaries?
Fenestrated = small holes or diaphragms between endothelial cells. Discontinuous = holes between endothelial cells.
What are the initial cells that begin forming new blood vessels in angiogenesis? Where are they mainly found?
Pericytes. They are mainly found on the basal lamina of venules.
What growth factors play a role in angiogenesis?
VEGF and FGF
What are the three layers of the heart?
Epicardium, myocardium and endocardium
What type of cardiac layers are found in this sample of the interventricular septum?
Myocardium and endocardium
What layer of the heart is this?
Note fat and blood vessels (coronary arteries and veins) that exist in the epicardium
If this is the aorta, where do you expect to find elastic tissue? What cells make this elastin?
2, the tunica media. Smooth muscle cells make the elastin
What is this?
Vena cava. Note sparse bits of circular smooth muscle in the tunica media and longitudinal smooth muscle in the tunica adventitia (it looks like bacon).
Which is the artery and the vein?
Note #1 has rippled tunica intima. When you fix the cells, the cells realize there is no pressure and they contract to form the ripples. Also note the thick muscular layer in #1. This is the artery. #2 is they vein.
What are the labeled structures?
1) muscular artery a) tunica intima b) tunica media c) tunica adventitia #2) arteriole #3) venule #4) capillary #5) lymphatic
What are the labeled structures?
1) arterioles 2) venules 3) capillary
Where are the discontinuous capillaries found in this image?
This is a spleen. They are found in the red pulp.
What are the labeled structures?
1) artery 2) vein 3) vein 4) lymphatic 5) valve 6) capillary
