Histology Flashcards
(53 cards)
order the layers of the heart from top to bottom:
1) visceral pericardium/epicardium
3) myocardium
4) endocardium
the endocardium contain conductive cells called
Purkinje fibers in subendocardial layer
purkinje fibers are present between which 2 layers of the heart?
between myocardium and endocardium
which layer of the valve absorbs the shock and contains proteoglycans?
sponginosa
Heart valves are composed of connective tissue with overlying ………….
endocardium (deepest)
which layer of the valves is covered with endothelium and continues into the chordae tendineae, then attach to muscular projections called papillary muscles?
ventricularis
………… are avascular, they are made of connective tissue proper and are
thin enough to allow
nutrients and oxygen to
diffuse from the blood
valve cusps
………… are bundles of impulse-conducting cardiac fibers extending from the atrioventricular node. thye can be found beneath the endocardium lining
purkinje fibers
the pulmonary and aortic valves are called …………….., and they form …..vein/artery….?
semilunar valves
they form arteries
which cell junctions connect to pacemakers and allow for passage of ions, resulting in depolarization/repolarization
gap junctions
Myofibrils of cardiac muscle separate to pass around the nucleus, thus outlining a
…………….region in which the cell organelles are concentrated, it is a region rich in mitochondria and contains the Golgi apparatus, lipofuscin pigment granules, and glycogen.
biconical juxtanuclear region
which cells are the sinoatrial and atrioventricular nodes made up of? and what do they lack?
The nodal cardiac muscle cells in both the SA and AV nodes.
They lack intercalated discs.
why do purkinje fibers stain positive for periodic acid-Schiff (PAS) staining and are more resistant to hypoxia than are
ventricular muscle cells ?
due to the large amount of glycogen
do purkinje fibers have intercalated discs?
yes
the lining of the pericardium/epicardium consists of
mesothelial cells
All of the extracellular components of the tunica media are produced by …………
vascular smooth muscle cells (and NOT FIBROBLAST)
which layer of the artery is made up of fibroblast?
tunica adventitia
………….. serve as flow regulators for the capillary beds.
Arterioles
The slight thickening of the smooth muscle at the origin of a capillary
bed from an arteriole is called the ……………… : contraction of the smooth muscle in the wall of an arteriole increases
the vascular resistance and reduces or shuts off the blood going to the
capillaries.
precapillary sphincter.
…………..consist of a single layer of endothelial cells and their basal lamina, which is a part of tunica intima. they don’t have tunica media or adventitia
capillaries (only has tunica intima)
which type of capillary is found in connective tissue; cardiac, skeletal, and smooth
muscles; skin; lungs; and the CNS?
continuous capillaries(uninterrupted vascular endothelium.)
which type of capillary is found in endocrine glands and sites of fluid or metabolite absorption, such as the gallbladder, kidney, pancreas, and intestinal tract.
Fenestrated capillaries (contain circular openings known as fenestrations)
In many tissues, there are direct routes between the arteries and veins
that divert blood from the capillaries.
It creates a backup pathway b/w veins and arteries for blood flow if a blood vessel becomes blocked.
they play an important role in temperature regulation in humans in their thermoneutral zone
–>These routes are called ………….
arteriovenous
(AV) anastomoses or AV shunts.
the Proximal segment before entering into the capillary bed is called a
……………., also allow some
blood to pass more directly from
artery to vein.
metarteriole
