embryonic development of cardiovascular system Flashcards
fetal cardiac development: the cardiogenic plate it formed by a collection of__ cells in the most anterior part of the embryo.
-The CVS is derived from the ____ tissue (mesenchymal cell) -aggregation of cells derived from mesoderm.
mesoderm cells
Angioblastic tissue
this is a horseshaped tube and is first composed only of endothelial cells
endocardial heart tube
The caudal portion fuses and becomes surrounded by myoblasts to form the myocardium formation of the ____ tube
cardiac tube
this part of the fetal heart allows bypass of the pulmonary system from the right ventricle into the aorta
truncus arteriosus
this part of the heart lies ventral from the primitive ventricle to give rise to both ventricles of the heart
bulbus cordis
this is the hole that allows blood from the right atrium to flow into the left atrium during pulmonary development (pulmonary bypass)
foramen ovale
This is a depression in the right atrium of the heart at the level of interatrial septum . This is what is the thin fibrous sheet that covered the foramen ovale during development
fossa ovalis
in early development the___ of the fetus are not developed., this causes a limited capacitance in the pulmonary vessels from the heart resulting in high resistance
lungs
to accomadate the previous problem there is a direct connection between right and left____. in that the blood from the right flows directly into the left via the _____ _____ and bypasses the pulmoary circuation system
-This shunt allows for normal development of the left atrium and ventricle , training muscles for hard workload to come.
atrium!
FORAMEN OVALE
There are small amounts of blood that flows through the right side, ootherwise there wouldnt be normal development in the right side. However after blood reaches the right ventricle the blood will go through the truncus pulmonalis to bypass into the aorta via the _____ ____
DUCTUS ARTERIOSUS
the _____ ___ allows for the blood to bypass the liver
DUCTUS VENOSUS
the blood in the fetus is highly ____ due to the oxygenated blood from the placenta and the ___ blood from the fetus, making the color __
oxygenated, deoxygenated, purple
this is where the forament ovale is closed up in development
-formation of the primary septum serves as a valve for the foramen ovale
-there will be a first foramen that allows the initial passage of blood from the left to the right heart
- The foramen primum will close & be replaced by a second forament
-the formation of the 2nd septum prevents return of blood into the right atrium
-
process of atrial partioning
After birth the first breath creates sudden decrease in vascular resistance to the ___ , allowing for closure of the ___ ____ to occur
lungs, foramen ovale
- The bypass that allows the blood from the right ventricle to bypass the pulmonary system by going into the aorta
- 2 ridges fuse together to form the aorti -pulmonar septum which stops the flow of ____ blood to the body and ___ blood to the lungs (this isnt compatible with life)
closure of the ductus arteriosus
deoxygenated to body and oxygenated to lungs
congenital anomalies:
- This is the hole that allows the blood of the right ventricle to bypass the pulmonary system during fetal development.
- This portion is supposed to close once the lungs have formed, deoxygenated blood will be circulated into the aorta to the organs and tissue
patent ductus arteriosus
This congenital anomalies can lead to megaesophagus . and is when the aorta comes to the right of the esophagus
Persistant right aortic arch (PRAA)
There are 7 types of vessels what are thet
elastic and muscular arteries , arterioles, capillaries, veins, venules, and lymphatics
What are the three layers of vessels?
innermost layer:tunica intima(endothelium)
middle layer: tunica media
outer layer: tunica adventitia /externa
This layer plays a role in homeostasis - arrests bleeding by physiological properties of vasoconstriction and coagulation
- modulates perfusion through nitric oxide (vasodialation) and endothelium (vasoconstriction)
- plays a role in inflammation
tunica intima(endothelium)
Morphology of arteries : this layer is composed of endothelium and subendothelial layer, internal elastic lamina is seen here
tunica intima
smooth muscle producing elastic , reticular and collagenous fibers is seen in this layer of the arteries
tunica media
This layer of the arteries is composed of loose CT, blood vessels , lymphatics and nerves
tunica adventitia
morphology of veins: in this layer THERE IS NO DISTINCT INTERNAL ELASTIC LAMINA , there is a subendothelial layer and endothelium
tunica intima
in this layer of veins there is loose CT with few nerve fibers . in large veins vasa vasorum penetrate the tunica media
-valves are also noticed projecting into the lumen of the tunica intima
tunica adventitia
this layer of veins is muscular but thinner than the arteries . smooth muscle fibers have an irregular oreintaion , approximately circular
tunica media of veins
morphology of elastic artery : this layer has endothelium and loose CT
tunica intima
elastic artery: contains vasa vasorum to assist in supplying nutritional needs to thick tunica media
tunica adventitia
elastic artery: this layer consists largely of repeating elastic lamellae
tunica media
muscular artery: this layer is primary smooth muscle and is the thickest tunic
tunica media
vascular smooth muscle cells: smooth muscle cells are circumferentially arranged within the tunica___
-regulates diameter and tone(vasodialation and vaso constriction_
tunica media
These vessels have 1-3 layers of smooth muscle
- greatest effect of blood pressure
- nuclei buldge into lumen
- round appearance of vessel
- no internal elastic membrane
morphology of arterioles
these are thin walled tubules , in cross section they are made of only one endoithelial cell rolled into the tube
capillaries
these are very “leaky” vessels
have NO SMOOTH MUSCLE
called the postcapillary venules
venules
what are the 3 different capillaries?
continuous, fenestrated, sinusoidal/discontinuous
These types of capillaries are found in muscle, ___, bone and lungs
-contain pinocytotic vesicles (mesenchymal contractile cells that wrap around capillaries and venules and communicate with endothelial cells by physical contact and paracrine signaling)
brain- Theses are continuous capillaries
these capillaries are found in tissues with substantial fluid exchange- ex. renal corpuscle (glomerulus)-responsible for filtration of plasma
- podocytes are found in these capillaries!- cells responsible for lining the blood vessel , creating gaps that are big enough for small molecules and water to pass through , the proteins stay behind.
fenestrated capillaries
these capillaries have hepatic and splenic sinusoids which allow large molecules to exit.
- The lumen is enlarged and regular
- lining endothelium is discontinuous and fenestrated
- basal lamina may be absent
discontinuous or sinusoidal capillaries
