DA4 Flashcards
What system is first to become functional in developing embryo?
Cardiovascular system
Cardiovascular system begins as paired condensations of splanchnic mesoderm called ______.
Cardiogenic fields
After cardiogenic fields develop, cells proliferate and differentiate into _______.
Angiogenic cell clusturs
Cells organize into cords then into paired ______.
Endocardial tubes
Inductive influences of _______ is essential for the development of the cardiovascular system.
Endoderm
Without the influence of the endoderm, what happens to the cardiovascular system?
Acardia - no heart develops
Body folding tubes fust to form single median ______.
Endocardial tube
Cardia bifida
Double heart, lethal conditions because none of the two hearts are functionally competent
The endocardial tube is temporarily connected to the dorsal wall by ______.
Dorsal mesocardium which will degenerate - it is only a temporary structure
The heart differentiates into four parts after the formation of the endocardial tube. List them from cranial to caudal.
- Bulbus cordis 2. Ventricle 3. Atrium 4. Sinus venosus
Formation of cardiac loop is determined by:
- Elongation of tube within restricted pericardium 2. degeneration of dorsal mesocardium 3. Anchorage of tube at both ends
The endocardial tube folds on itself to form the…..
Cardiac loop
The cardiac loop is formed by the cranial portion folding _________ and the caudal portion folding ________.
Cranial portion folds ventrocaudally and to the right. Caudal portion folds dorsocranially and to the left.
Formation of cardiac chambers are indicated by _____.
Local expansions
Formation of cardiac chambers is induced by _____.
Direction of blood flow; blood becomes shifted to the right
Formation of cardiac chambers is accomplished by the formation of _______.
Cardiac septa
Endocardium between two chambers proliferates to form ______
Endocardial cushions which divide AV canal into right and left canals
Endocardial cushions are remodeled by ______ of internal walls
Selective escavations
Partitioning of common atrium starts with the formation of ______, which is a ridge from the roof of the atrium extending towards cushions.
Septum Primum
The septum primum leaves temporary communication between atria, called _______.
Ostium primum
Before the septum primum fuses with cushions, its dorsal part degenerates to form _______.
Ostium secundum
During the formation of the septum secundum, the dosral part extends from the ______, and the ventral part extends from the ______.
Dorsal part extends from the roo of the atrium.
Ventral part extends from the cushions.
The dorsal and ventral parts of the septum secundum do not fuse before birth, so the two atria communicate via ______.
Foramen ovale
When does the complete separatino of the two atria occur? And what structure forms as a result?
Complete separation of two atria occurs after birth by fusion of the two septa.
Fossa ovalis
The partitioning of the common ventricle is accomplished by a myocardial ridge between ventricle and bublus cordis extending towards cushions called _____
Muscular septum
Complete separation of ventricles occurs by formation of _______ from the ______.
Membranous septum from the cushions
Paritioning of bulbus cordis consists of two parts:
Dilated part and narrow part (called conus cordis)
The major dilated part of the bulbus cordis is incorportated into RV as the origin of _______. In the adult, this portion is called the ________.
Pulmonary trunk arteries
Conus arteriosus
Partitioning of conus cordis maintains communication with ____
Both ventricles
Partitioning of conus cordis is divided by paired ______ into two main channels _____ and ____.
Divided by paired conotruncal ridges into two main channels: aortic and pulmonary
Formation of blood vessels form contemporaneously with the ______.
Heart
Angiogenic cells _____ to heart form its cranial and caudal connections.
Lateral
Angiogenic cells in _____ and _____ form extraembryonic vessels.
Yolk sac and allantois
Proccesses involved in formation of blood vessels: vasculogenesis
Formation of vascular plexuses. Hemangioblasts of splanchnic mesoderm form blood islands. Blood islands connect to form the vascular plexuses.
Vascular plexuses in the yolk sac are called:
Extraembryonic plexuses
Vascular plexuses around forming organs are called _______.
Intraemryonic plexuses
Cells of plexuses differentiate to _____ and ______.
Blood cells and vascular endothelium
Proccesses involved in formation of blood vessels: Angiogenesis
Sprouting of blood vessels and remodeling of vascular plexuses
Several organs produce _________ for vessel formation
Angiogenesis factors
Arterial and venous differentiation is dependent on:
The amount and direction of blood flow (pressure differences)
Arterial system is represented by paired:
- Aortic arches
- Dorsal aorta
- Vitelline artery
- umbilical artery
Venous system represnted by paired:q
- Cranial cardinal V
- Caudal cardinal V
- Vitelline V
- Umbilical V
Vitelline veins
- Convey blood from yolk sac to heart
- Within liver form hepatic sinusoids
- Cranial patent portions form hepatic veins
- Caudal patent portions form portal vein
Vitelline arteries
- Distribute blood from dorsal aortae to yolk sac
- In adult - right ones form ventral, unpaired branches of aorta: bronchoesophageal artery, celiac artery, carnial and caudal mesenteric arteries
Umbical veins convey oxygengated blood from placenta. The right umbilical vein obliterates and persists as the _______.
Round ligament of the liver
Umbilical arteries return fetal blood to placenta. If they remain patent they will form ______, and if they collapse, they form _______.
Cranial vessicle arteries; round ligament of the bladder
Aortic arches
- Represent the arterial components of pharyngeal arches
- Are formed in serial order
Aortic arches: six pairs develop in vertebrate embryo but only which ones are retained?
3, 4, and 6
The transofrmation of aortic arches accounts for establishment of definitive ________
arterial system
Transformation of dosral aortae
- Caudal to arch VI fuse to form adult aorta
- In area of arches remain paired - extend to form internal carotid arteries
Transformation of ventral aortae
- They fuse near the heart
- Their cranial extensions form external carotid arteries
- between arches III and IV become common carotid arteries
First two pairs of aortic arches ______.
Degenerate
The fifth aortic arch …..
never forms or rapidly degenerates
Transformation of arch III
Retained as connections between ventral aortae and internal carotid Aa.
Transformation of arch IV
- Left - forms adult aortic arch
- Right - forms brachiocephalic trunk
Transformation of arch VI
- Poximal parts - form roots of pulmonary arteries
- distal parts - right is lost, left becomes ductus arteriosus and in the adult the duct collapes to become fibrous tissue called ligamentus arteriosus
