Embryogenesis and Development Flashcards
Senescence
The process of deterioration that happens with age.. like less cell division rounds… Occurs with telomer shortening
Anencephaly
Skull does not fully develop and the brain is left open and exposed.
Folate (vitamin B9)
Folate is essential for reducing the risk of neural tube defects, including anencephaly, a condition in which the brain fails to develop and the skull is left open.
Induction
Signaling a tissue to grow into something…. determining the fate of something in a sense (determination).
Prostaglandins
These, along with oxytocin, coordinates uterine contractions during parturition and act as inflammatory markers
Morphogen
These promote development down a specific cell line in a competent cell during determination.
Growth Factors
These peptides that promote differentiation and mitosis in certain tissues.
Teratogen
These interfere with development, causing defects or even death of the developing embryo, like those seen in FAS.
How does this affect Hb-O2 affinity?
- Increased 2,3-bisphosphoglycerate
- Decreased blood PaCO2
- Decreased blood pH
- Decrease
- Increase
- Decrease
Germ Layers:
- Skin
- Adrenal Gland
- Small Intestines
- Central Nervous System
- Ectoderm - epidermis AND Mesoderm - dermis
- Mesoderm - adrenal cortex AND Neural Crest (ectoderm) adrenal medulla
- Endoderm - epithelium AND Mesoderm - muscular layer
- Ectoderm only
Compaction
Compaction is an increase in cell-cell adhesion molecules that keep the embryo together
Gastrulation
Gastrulation is the process of developing three distinct cell layers
Bastulation
Making a hollow ball that’s a fluid filled caity (blastocoel) and outer surrounding known as trophoblast
This also is the step where the implantation into the endomertrial lining occurs.
Cleavage
early mitotic cell division with NO GROWTH
Fetal Circulation is necessary to:
- Move blood away from Liver because it cannot handle high blood pressure
- Avoiding Lungs allows more blood to flow upward to brain and arms
- Ductus Venosus allows heart to recieve oxygenated blood to come from placenta
ductus arteriosus
shunt leftover blood from pulmonary artery to aorta
The Ductus Arteriosus shunts leftover blood from _____ to aorta
Pulmonary Artery
ductus venosus
shunts blood returning from the placenta via the umbilical vein directly to the inferior vena cava
foramen ovale
is a one-way valve that connects the right atrium to the left atrium
The Purpose of Fetal Circulation:
Shunts blood to foramen ovale, which shunts from R atria to L atria to bypass lungs –> increases oxygenated blood to brain and arms AND avoid lungs which are underdeveloped (lungs to do not develop until just before birth)
Shunts blood from placenta to Infererior Vena Cava –> get oxygenated blood to heart AND avoid liver which is underdeveloped (fetal liver is sensitive to blood pressure)
Selective Transcription
The process of cells selectively up regulating and down regulating the expression of genes based on their cell type.
Trophoblast differentiation steps:
trophoblast –> chorionic villi –> placenta
Amnion
Shock absorber during pregnancy.. filled with amniotic fluid
Yolk Sac
Site of Early Blood Development
Allantois
Early fluid exchange between the embryo and yolk sac
Paracrine Signaling
diffuses to local cells and stimulates cell response.
Endocrine
Release of some factor (hormone, steroid, etc.) that can be uptaken and act on some other tissue in the body (i.e. adrenal on heart or brain).
Autocrine Signaling
Responding to factors that have been released by the same cell.
Totipotent
Cells that exsit before gatrulation (pre germ layers), and thus can have the highest rate of possible diffeerentiation
Pluripotent
Cells that come after gastrulation, and can differentiate into ANYthing in their respective germ layer.
Multipotent
Semi-specialized cells that can differentiate into a paticular class of cells (i.e. Hematopoteic Stem Cells can turn into different types of blood cells only).
Nonpotent
Very specific cell with no more differentiation possible
Necrosis
A type of cell death found only in “injury”
Apoptosis
Regulation or Programming of cell death.. like dissolving a tissue inorder to make it anew (like the endometrial lining).
Also note, there is no dramatic body response (like in an infection) as seen in Necrosis.
Blastocyst
Hollowed out embryo that has implanted into the endometrial lining
Morula
Embryo which starts as 2 cells turns into a 16 cell mass, but does not grow in size because it undergos cleavage - rapid mitotic cell division with no growth in size (the cells are actually all smaller than the original cell).
Note that Morulation occurs before the embryo has had a chance to implant into the endometrial lining
Zygote
Single cell (egg + sperm) that exist well before implantation in the endometrial lining
