Histology Flashcards
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
which one has a thicker wall, veins or arteries?
veins. cz they need to carry blood to the heart against high resistnace
which layer is thicker in medium and large VEINS?
tunica adventitia
which layer is thicker in arteries?
tunica media
……….represent venous channels in the cranial cavity. and they don’t have valves
Dural venous sinuses
Which vessels is most
responsible for maintaining blood pressure?
arterioles
A cardiologist places a stent in a vessel
commonly known as “the widow maker:’ What region of the heart is perfused by the branches of this vessel?
Anterior wall of the heart
The vessel of the heart commonly known as the “widow maker” is the anterior descending
branch of the left coronary artery and it supplies the entire anterior wall of the heart.
A particular medication prescribed to a
patient cannot cross the blood-brain barrier
because capillaries in the CNS have which of
the following characteristics?
Fasciae occludentes
Vasa vasorum function in a way that is
similar to
coronary arteries.
Vasa vasorum are small blood vessels that supply the walls of elastic and muscular arteries
with oxygen and nutrients just as the coronary arteries provide for the walls of the heart.
vitelline veins :
return poorly oxygenated blood from the umbilical vesicle
umbilical veins:
veins in embryo carry oxygenated blood TO embryo
carry well-oxygenated blood from the chorionic sac ,which (functions in nourishment of embryo)
common carotid veins:
return poorly oxygenated blood from the body of the embryo to the heart
where do the vitelline, umbilical, and common cardinal veins drain into?
senous venousus of the heart
The superior vena cava (SVC) forms from what?
forms from cardinal vein
right supracardinal vein
becomes the inferior part of the ……………
inferior vena cava
which arteries supply the umbilical vesicle and, later, the primordial gut?
vitelline
vitelline arteries forms:
the celiac arterial trunk to the …………..,
the superior mesenteric artery to the …………..,
the inferior mesenteric artery to the …………..
foregut
midgut
hindgut
The umbilical arteries:
arteries in embryo carry poorly oxygenated blood AWAY from embryo
carry poorly oxygenated fetal blood to the placenta.
external layer of the embryonal heart is made from which layer?
splanchnic mesoderm surrounding the pericardial cavity
the epicardium is derived from …………
second heart field
- common carotid vein connects with ……….
- vitelline vein connect with ……….
- umbilical veins connect with ……….
- extremities
- umbilical vesicle
- placenta
……………..:
Ascending aorta and pulmonary trunk
………………..:
Smooth portions of right and left ventricle
………………:
Trabeculated right and left ventricle
…………….:
Anterior (trabeculated) portions of right and left atria
……………..:
Posterior portion of right atrium and coronary sinus
…………………:
Aortic, pulmonary, tricuspid, mitral valves
Truncus arteriosus Bulbus cordis Primitive ventricle Primitive atrium Sinus venosus Endocardial cushions
Blood enters the sinus venosus from the Embryo through the ………….
common cardinal veins
Blood enters the sinus venosus from the umbilical vesicle through the ………..
vitelline veins
Blood enters the sinus venosus from the developing placenta through the …………..
umbilical veins
the common cardinal veins drain into what?
sinuous venosus
the sinuous venosus drain into what?
priative atria
*the right vitelline vein(that extends from yolk sac) circulation spreads to
hepatic portal system and hepatic portion of inferior vena cava
*the left umbilical vein(that extends from placenta) will become the adult remnant as ……………
ligamentum teres
any blood from the placenta that goes through the inferior vena cava must pass through :
left umbilical vein–> ductus arteriosus–>inferior vena cava
