T3 Flashcards
What occurs during the first differentiation of pluripotent stem cells?
Cells on the outer layer differentiate into trophectoderm, forming extraembryonic structures like the placenta, while inner cells form the inner cell mass
The inner cell mass consists of pluripotent cells that can give rise to the entire embryo.
What is the preimplantation stage?
The embryo implants in the uterus around 3–4 days after fertilization in mice and 5–7 days in humans.
What are the three germ layers formed during gastrulation?
- Ectoderm: Forms skin, brain, nerve cells, etc.
- Endoderm: Forms lining of gastrointestinal and respiratory tracts, liver, pancreas, etc.
- Mesoderm: Develops into skeletal muscles, heart, blood vessels, etc.
What is a morphogen?
A signaling molecule that induces different responses based on its concentration.
What role does Nodal play in embryogenesis?
Nodal forms a gradient influencing cell differentiation and positioning during gastrulation.
What are neural crest cells (NCCs) often referred to as?
The ‘fourth germ layer’ due to their significance in organ formation.
What do neural crest cells give rise to?
Multiple cell types from all three germ layers.
What is the process of cardiac development?
The heart forms through cardiogenic plates differentiating into cardiomyocytes and endocardial cells.
What occurs during looping and chamber formation of the heart?
The straight heart tube undergoes changes to form a four-chambered heart.
What are the two main processes involved in blood vessel development?
- Vasculogenesis: Creation of new vessels.
- Angiogenesis: Growth from existing vessels.
What is the role of endothelial cells (ECs) in blood vessels?
They line the vessels.
What stabilizes blood vessel walls?
Recruitment of smooth muscle cells (SMCs) and pericytes.
What is the origin of peripheral nerve tissue?
Derived from neuroectoderm or neural crest cells.
What does the nerve sheath comprise?
- Epineurium
- Perineurium
- Endoneurium
What does the ectoderm give rise to in skin development?
The epidermis (both follicular and interfollicular).
