Cardiology Flashcards
What separates the tunica media and adventitia?
external elastic membrane
Why are the largest arteries e.g. aorta termed elastic arteries?
contain many sheets of elastic fibres in tunica media to provide elastic recoil
Why do large arteries have their own vascular supply?
only inner half of wall can obtain nutrients from lumen.
What is the vascular supply large arteries called?
Called Vaso vasorum
True or false: arterioles have many layers of smooth muscle in tunica media?
False - only have 1 or 2, and have almost no adventita
What are capillaries composed of?
basal lamina and endothelial cells, may contain pericytes
What are pericytes?
Connective tissue cells with contractile properties
What are the 3 types of capillaries?
continuous, fenestrated and sinusoidal (discontinuous)
Which type of capillary is most common?
continuous
Where are continuous capillaries found?
skin, nerves, connective tissue, muscle, lungs
Where are fenestrated capillaries found?
glomeruli of kidney, gut, endocrine glands
Where are sinusoidal capillaries found?
liver, spleen, bone marrow
What does the endocardium line?
entire inner surface of heart and its valves
What is endocardium?
endothelium, basal lamina, thin layer of collagen fibres
What is the myocardium?
Thick middle layer. Bundles and layers of contractile cardiac muscle fibres.
What is the epithelium?
Outer layer of the heart. On the surface, this is a single layer of flattened epithelium called mesothelium. This contains a basal lamina and fibroelastic connective tissue and, in some places, adipose tissue.
What are the 2 parts of the pericardium and what do they consist of?
Fibrous pericardium is a sac of tough fibrocollagenous connective tissue, while Serous pericardium is made up of a layer of simple squamous epithelium (termed mesothelium), backed by a basal lamina and connective tissue.
What are the 3 types of cardiac muscle cells?
contractile, pacemaker and conducting
Do pacemaker cells appear dark or pale histologically?
pale
What has the important job of electrically isolating the atria from the ventricles
fibrous skeleton
Are Purkinje fibres larger or smaller than normal cardiac cells?
larger
Where are Purkinje fibres found?
in the subendocardial layer just deep to the endocardium
What do lymphatic capillaries begin as?
blind sacs
Do lymphatic vessels have a central pump?
No
