9: Cardiac Histo And Lymphatics Flashcards
Where are lymphatic capillaries?
Found among capillary beds
Two characteristics of lymphatic capillaries
- 1 way valves for collecting lymph
2. Incomplete basal lamina and openings between endothelial cells -> increased permeability
What are initial lymphatic vessels called after lymphatic capillaries?
Collecting lymphatic vessels
Walls of lymphatic vessels
Contain vascular tunics and valves; increase in thickness as vessels increase in size
What do the right lymphatic duct and thoracic duct drain?
R lymphatic: R side of head, neck, RUE, and R thorax
Thoracic duct: everything else
Where do R lymphatic duct and thoracic duct dump into?
R lymphatic duct: junction of R subclavian + RIJ
Thoracic duct: junction of L subclavian + LIJ
Outermost layer of heart wall
Epicardium
Thickest layer of the heart
Myocardium
3 functions of intercalated discs
Binds cells, transmits force of contraction, allows spread of excitation
Where are diad T-tubule systems found?
Z lines
What does the T tubule system permit?
Uniform contraction of myofibrils within a single cardiocyte
What are Purkinje fibers higher in compared to cardiocytes?
Glycogen
T tubules in Purkinje fibers
Mostly lacking
Cardiac skeleton histo
Dense irregular CT
Where is cardiac skeleton found in heart?
Endocardium; in interventricular and interatrial septa
