Embryology 2 Flashcards
Before the placenta is formed and can take over, what provides nutrition and gas exchange between the mother and the developing embryos the fetus to move freely within the walls of theuterus?
the yolk sac
What does the primitive streak consist of?
- groove- primitive groove
- depression- primitive pit
- mound- primitive node
What does the Ectoderm become?
Epidermis and CNS
What does Mesoderm become?
Musculoskeletal; Cardiovascular and Urogenital Systems
What does Endoderm become?
Lining of GI and Respiratory tract
What is theembryonicprecursor to thecentral nervous system, which is made up of thebrainandspinal cord?
The neural tube
What is Sclerotome?
results in bone or other skeletal tissue
What is Myotome?
group of muscles which a single spinal nerve innervates
What is dermatome?
area of skin mainly supplied by a single spinal nerve
The embryoblast differentiates into two layers called?
Epiblast and Hypoblast
What is the name of membrane inbetween the epiblast and hypoblast?
bilaminar germ disc
What is the epiblast?
cell layer of the embryonic disc that forms three primary germ layers, amniotic ectoderm and extraembryonic mesoderm.
What is the hypoblast?
second layer of the embryonic disc that forms the yolk sac
What does the epiblast become when the intraembryonic mesoderm and endoderm have formed?
Ectoderm
What does the hypoblast become as it matures?
Endoderm
What is the definition of mesoderm?
One of the three germ layers of bilaterally symmetrical animals, found in the early embryo between the ectoderm and endoderm
What is the definition of Mesenchyme?
Is an undifferentiated tissue found in embryonic true mesoderm.
What does the central neural tube become?
Spinal chord
As the mesoderm matures, they form cylindrical structures, what are they?
paraxial - will form axial skeleton, voluntary muscle and portion of the dermis
intermediate - forms urinary tract and parts of the genital system
lateral mesodermal condensations - these form into 2 portions on day 17
What is neurolation?
Formation of the neural tube
What does the neural crest differentiate into?
Cranial nerves
Somites lead to the segmental organisation of the body - true or false?
True
What do somites differentiate into?
Dermatome, Myotome, Scleratome
What do somites 1-4 differentiate into?
Occipital bone, bones around the eyes, nose and inner ears, extrinsic ocular muscles, muscles of the tongue
