What vessel has the lowest pressure?
Where does the systemic circulation come from in the heart?
left side of heart ventricle
where does pulmonary circuit come from?
What is the function of endocardium?
integrity, impulse conduction
what is the function of epicardium
What is another name for visceral pericardium?
what do mesothelial cells look like
flattened pavement like
use wright stain
What are intercalated disks?
in between cardiac cells- adhering junction and gap junctions
What is the annuli fibrosi?
the 4 fibrous rings from which the valve leaflets originate
provide anchor for valve leaflets
What is the trigona fibrosa?
the 2 structures that join annuli fibrosi
What is an os cordis?
bones of the heart from animals like cattle
What are the layers of the heart valve
spongiosa (loose collagenous and elastic)
Fibrosa- fibrous extensions, collagenous support
Ventricularis- dense CT
What are the fibrous threadlike cords in the free edge of the AV node?
What is the order of autorhythmicity?
SA, AV, Bundle of His, Bundle branches, purkinje fibers
what is unique about the node muscle of the heart?
no intercalated discs
do purkinje fibers conduct things faster or slower than muscle cells?
What do purkinje fibers contain lots of?
Where is internal elastic lamina found?
evident in arteries and some arterioles
What is the inner layer of vessels?
What is in the tunica media?
helically arranged layers of smooth muscle, elastin fibers, collagen, proteoglycans to external elastic lamina
What is the outer most layer of vessels?
longitudinally arranged connective tissue
What is the vasa vasorum
the network of blood vessels that supplies oxygen and nutrients to the outer portions of large vessels
What is the function of the tunica media?
regulates vessel compliance with number of elastic fibers, contractile state of smooth muscles
What does the venule lack that the other veins have?
What are the elastic arteries? 6
aorta, pulmonary artery, common iliac, brachiocephalic, common carotid, subclavain
What are examples of medium/muscluar arteries?
brachial, anterior tibial, coronary
what stain can help differentiate muscular arteries from elastic arteries?
orcein, van giosen, Verhoeff
do arterioles have internal elastic lamina? adventitia?
What is the thickest part of a large vein?
the tunica adventita
How do continuous capillaries transport substances?
through pinocytotic vesicles and caveolae
Where are fenestrated capillaries present?
Kidney glomerulus, intestinal villi, chorid plexus
Where are sinusoidal capillaries present?
liver, bone marrow, spleen
What is a portal system
vein or arteriole interposed between two capillary networks
where do lymphatic vessels drain?
into large veins eventually lymph nodes
What do lymphatic capillaries lack?
tight junctions, makes them more permeable