Embryology week 3 Flashcards
The first major event of the third week (about 16 days) is called what?
Gastrulation
Gastrulation starts with the formation of a longitudinal midline structure called what? What end is it near?
Primitive streak
Caudal end of the bilaminar embryonic disc
The cranial end of the primitive streak is expanding and is called what?
primitive node
The primitive streak also contain a circular depression called the ________, and it leads to a trough like depression called _________.
primitive pit
primitive groove
What color is endoderm?
yellow
What color is mesoderm?
red
What color is ectoderm?
blue
True/False: the primitive pit and groove are areas where cells are leaving the primitive streak and entering the interior of the embryonic disc.
True
What does the precordal plate form?
mouth
Cardiogenic mesoderm forms what?
heart
What is the order of migration from cranial to caudal?
Notochord Head mesoderm somites intermediate mesoderm lateral plate mesoderm
What is the future vertebrae?
notochord
What is the origin of notochord? (IMPORTANT)
mesoderm
IN the future head region the mesoderm forms bands of cells that remain ________ as the head mesoderm.
unsegmented
The head mesoderm eventually gives rise to the striated muscles of the _________________.
Face, jaw, and throat
A loosely organized, mainly mesodermal embryonic tissue that develops into connective and skeletal tissues, including blood and lymph.
Mesenchyme
What are block-like condensations of mesoderm?
somites
Th caudal most several somites eventually disappear, why? How many somite pairs are left?
because we don’t have a tail
37 pairs
Is head mesoderm above or below somites?
above, towards cranial end
Somites form what important structures?
vertebral column, occipital bone, voluntary musculature of the neck, body wall, limbs, etc.
What does the lateral plate mesoderm split into?
parietal (somatic) layer with overlying ectoderm
visceral (splanchnic) layer
Formation of the neural tube which is the beginning of the neural system?
Neuralation
Neurulation involves four main events called what:
Formation of the neural plate
shaping of the neural plate
bending of the neural plate
closure of the neural groove
True/False: Notochord is on the surface of the Neural plate.
False, notochord is underneath the neural plate
