Human Development Lecture 16 – Cardiovascular System
Blood flow through heart (post-natal);
Right atrium → right ventricle → pulmonary arteries (longslagader) → lungs →
pulmonary veins (longader) → left atrium → left ventricle → aorta
Arteries (zuurstofrijk) → capillaries → veins (zuurstofarm)
LET OP;
• In lungs; pulmonary arteries (=deoxygenated) pulmonary veins (=oxygenated)
• In prenatal life; 2 umbilical arteries (=deoxygenated from fetus to placenta) 1
umbilical vein (=oxygenated blood from placenta to fetus)
Beter; vein = to heart, artery = from heart
Formation of the heart;
Heart progenitor cells migrate from day 16. First organ that
develop.
Placenta;
Placenta formation from embryonic chorion + maternal
uterine tissue
Placenta formation; vaculoses form (trophoblastic lacuna) in the synchtiotrophoblast.
Maternal cappilaries form maternal sinusoids. Cytotrophoblast grow into
synchiotorophoblast. Newly formed extraembryonic
mesoderm is formed → primary chorionic stem villi
Extraembryonic mesoderm does the same → secondary
chorionic stem villi
They become tertiary chorionic stem villi containing
differentiated blood vessels,
The gasses, nutrients and wastes have to pass 4 tissue layers to
become into the synchiotrophoblast.
1. The endothelium of the villus capillaries
2. The loos connective tissue of the extaembryonic mesoderm
3. Layer of cytotrophoblast
4. Layer of sythriotrophoblast
After 4th month cytotrophoblast layer disappears from tertiary
villi, now they have to pass 3 layers.
The cytotrophoblast invades the maternal vessels and destroy
the smooth muscle tissue. → reduction blood vessel elasticity &
increased blood flow. Now called endovascular cytotrophoblast.
Placenta composed of;
• Chorionic plate (fetal tissue)
• Basal plate (maternal & fetal tissue) = decidua basalis
Epithelial transformations;
• Basal plate = decidua basalis → bij placenta
• Decidua capsularis → om embryo heen
, • Decidua parientalis → aan andere kant baarmoeder dan placenta
Placenta Development;
Passive transport;
• Simple diffusion; concentration difference
• Osmosis; water crosses placenta through
specialized pores, water channels/aquaporins,
proteins localized in plasma membrane
• Simplified transport; concentration difference with
help of transport molecules (e.g. glucose)
Active transport; transport against concentration gradient
Vesicular transport; Endocytosis/Exocytosis of
macromolecules
Trophoblast secrete hCG which signals corpus luteum
keeps progesterone and estrogen concentration high.
The heart;
Cephalocaudal folding (in pre-somite embryo).
Folding around the formed axis (neural tube, notochord,
somites).
Mesoderm generates cardiac progenitors and move to cranial
region. The 2 progenitor regions form the cardiac cresence. 2 thin
walled endocardial tubes.
Pericardiac cavity (cardiac cresence) bent over the cardiogenetic
plate
Yolk sac become part of the gut and formed vitelline duct.
Allantois forms within connecting stalk
Beginning;
Start as 2 thin-walled endocardial tube.
You have 2 endocardial tubes (blood to the heart) and 2
dorsal aorta (blood away from the heart)
The endocardial tubes will become one and is now
called the heart.
Blood flow through heart (post-natal);
Right atrium → right ventricle → pulmonary arteries (longslagader) → lungs →
pulmonary veins (longader) → left atrium → left ventricle → aorta
Arteries (zuurstofrijk) → capillaries → veins (zuurstofarm)
LET OP;
• In lungs; pulmonary arteries (=deoxygenated) pulmonary veins (=oxygenated)
• In prenatal life; 2 umbilical arteries (=deoxygenated from fetus to placenta) 1
umbilical vein (=oxygenated blood from placenta to fetus)
Beter; vein = to heart, artery = from heart
Formation of the heart;
Heart progenitor cells migrate from day 16. First organ that
develop.
Placenta;
Placenta formation from embryonic chorion + maternal
uterine tissue
Placenta formation; vaculoses form (trophoblastic lacuna) in the synchtiotrophoblast.
Maternal cappilaries form maternal sinusoids. Cytotrophoblast grow into
synchiotorophoblast. Newly formed extraembryonic
mesoderm is formed → primary chorionic stem villi
Extraembryonic mesoderm does the same → secondary
chorionic stem villi
They become tertiary chorionic stem villi containing
differentiated blood vessels,
The gasses, nutrients and wastes have to pass 4 tissue layers to
become into the synchiotrophoblast.
1. The endothelium of the villus capillaries
2. The loos connective tissue of the extaembryonic mesoderm
3. Layer of cytotrophoblast
4. Layer of sythriotrophoblast
After 4th month cytotrophoblast layer disappears from tertiary
villi, now they have to pass 3 layers.
The cytotrophoblast invades the maternal vessels and destroy
the smooth muscle tissue. → reduction blood vessel elasticity &
increased blood flow. Now called endovascular cytotrophoblast.
Placenta composed of;
• Chorionic plate (fetal tissue)
• Basal plate (maternal & fetal tissue) = decidua basalis
Epithelial transformations;
• Basal plate = decidua basalis → bij placenta
• Decidua capsularis → om embryo heen
, • Decidua parientalis → aan andere kant baarmoeder dan placenta
Placenta Development;
Passive transport;
• Simple diffusion; concentration difference
• Osmosis; water crosses placenta through
specialized pores, water channels/aquaporins,
proteins localized in plasma membrane
• Simplified transport; concentration difference with
help of transport molecules (e.g. glucose)
Active transport; transport against concentration gradient
Vesicular transport; Endocytosis/Exocytosis of
macromolecules
Trophoblast secrete hCG which signals corpus luteum
keeps progesterone and estrogen concentration high.
The heart;
Cephalocaudal folding (in pre-somite embryo).
Folding around the formed axis (neural tube, notochord,
somites).
Mesoderm generates cardiac progenitors and move to cranial
region. The 2 progenitor regions form the cardiac cresence. 2 thin
walled endocardial tubes.
Pericardiac cavity (cardiac cresence) bent over the cardiogenetic
plate
Yolk sac become part of the gut and formed vitelline duct.
Allantois forms within connecting stalk
Beginning;
Start as 2 thin-walled endocardial tube.
You have 2 endocardial tubes (blood to the heart) and 2
dorsal aorta (blood away from the heart)
The endocardial tubes will become one and is now
called the heart.
