15 Circulatory System Histology Flashcards
What 2 systems constitute the circulatory system?
cardiovascular and lymphatic
What is the innermost aspect of the heart wall?
Endocardium
What portion/layer of the endocardium is made of simple squamous epithelial cells?
endothelium
What types of cells make up the sub endothelium?
Loose Irregular CT, elastic fibers and smooth muscle cells
What layer of endocardium contains veins, arteries, and purkinje cells?
subendocardium— loose irregular CT connecting endocardium to myocardium
What is the thickest region of the heart wall?
myocardium
Where is the cardiac muscle the thickest?
left ventricle
Outer layer of the heart wall after opening pericardial sac?
epicardium
What type of tissue makes up the epicardium?
Adipose and loose irregular CT
Purpose of epicardium?
- support/cushion to heart as it beats in pericardial sac
- contains coronary vessels
What is the purpose of pericardial cavity?
contains lubricating fluid and reduces friction/heat
What layer of the heart secretes pericardial fluid into cavity?
parietal layer and visceral layers of the serous pericardium
what tissue type makes up the fibrous pericardium?
thick layer of dense irregular CT
What layer of the great vessels is the fibrous pericardium continuous with superiorly?
tunica adventitia
What layer of pericardium serves as an anchor to the diaphragm and the sternum?
Fibrous pericardium
What tissue type makes up the four fibrous rings surrounding the the heart valves?
Dense irregular CT– attachment for valve leaflets
What connects and holds together the 4 fibrous rings of the heart valves?
2 Fibrous trigones
What portion of the heart is made of dense irregular CT, is devoid of cardiac muscle, and contains branches of the conducting system?
membranous septa