Histology- Cardiovascular
Terms
undefined, object
copy deck
- What is an intercalated disk?
- Consists of fascia adherens, desmosomes, and gap jxns.
- Continuous Capillaries:
-
Most frequent
present in skeletal muscle, connectice tissue, lung, brain
Uninterrupted barrier to macromolecules - Describe Cardiac Myocytes
-
1)Contract through intrinsic action potentials that are passed to neighbors via GAP JXN
2)Contain a Diad which is a T-tubule flanked by one terminal cisterna
3) Intercalated disks
- Describe the adventitia (3)
-
1) Fibroblasts
2) Type I collagen
3) Some elastic fibers
- What does epicardium consist of?
- Connective tissue and a layer of mesothelium. (Visceral layer of the pericardial sac)
- Arterioles are different in tunica media why?
-
1)The tunica media consists of only 1 -2 layers of smooth muscle cell.
2)Plays a major role in reg. blood pressure. - Are purkinje myocytes neurons?
-
NO, they arejust modified myocytes
- Describe the intima. (4)
-
1)Consists of endothelium,
2)basal lamina,
3)loose connective tissue,
4)internal elastic membrane - What is endocardium lined with?
-
Endothelium on top of subendocardial layer that is continuous with the tunica intima of blood vessels
- What makes muscular arteries different?
- Tunica intima with a PROMINENT internal elastic lamina and a tunica media with a PROMINENT smooth muscle cell component
- Can cardiac muscle be repaired?
- No, the muscles cannot regenerate, but the injury is usually replaced with connective tissue.
- Lymphatic Vessels:
-
Lymph capillaries are blind ended and resemble sinusoids.
They may show three distinct TUNICS.
Have many closely spaced valves. - What is in the subendocardial later?
- Blood vessels, nerves and purkinje fibers.
- Capillaries
-
Tubes of endothelium reinforced by a basal lamina. Cross sectional area is 800 times that of aorta. Site of exchange of nutrients.
1) continuous
2) fenestrated
3) sinusoidal - What are the three tunics of blood vessels (b.v)?
-
Tunica intima
Tunica media
Tunica adventitia - Describe the media (4)
-
1)smooth muscle cells
2)Type III collagen
3)Elastic fibers
4)external elastic lamina - Large Veins:
-
SUPERIOR/INFERIOR VC
I: thicker with scattered bundles of longitudinal SM (Internal elastic membrane?)
M: Thin lacks SM
A: THICKEST with connective tissue and longitudinal SM - Venules:
-
Intima: only an endothelium
Media: Thin (1-2 layers of muscle, few elastic fibers
Adventitia: Slightly thicker than media and made of longitudinally arranged collage fibers
- Sinusoidal Capillaries:
-
Gaps are present between endothelial cells allowing passage of large molecules and cells
LIVER, SPLEEN - What makes Elastic Arteries so great?
- Have tunica media with a prominent elastic fiber component that responds to the high systolic pressure
- Fenestrated capillaries:
- Endothelial cells are perforated by pores. These holes allow very large molecules to cross the endothelium
- Small to medium veins:
-
Intima: endo alone, or together with elastic fibers and bundles of longitudinal smooth muscle
Media: Thin --alternating plates of SM and networks of collagen and elastic fibers
Adventitia: well developed fibroelastic coat - How do you identify a vein?
- It is with an accompanying artery.