Development of the Integument Flashcards
What occurs soon after fertilisation?
gastrulation
what are the three germ layers?
ectoderm (top)
mesoderm (middle)
endoderm (bottom)
what do the 3 germ layers form?
the trilaminar disc
what eventually makes up all the animal’s tissues and organs?
the three germ layers
the flat layers roll up into a?
tube
the ectoderm on the outside
mesoderm in the middle
endoderm inside lining
1st step of neurulation?
Notochprd forms from mesoderm cells soon after the gastrulation is complete
2nd step of neurulation?
Signals from notochord cause inward folding of ectoderm at the neural plate
3rd step of neurulation?
ends of the neural plate fuse and disconnect to form an autonomous neural tube
during gastrulation, what is defined?
the body axes
ectoderm gives rise to?
integument
endoderm gives rise to?
lining of intestines
neurulation?
formation of neural tube
notochord is embedded in the?
mesoderm
cranial –> caudal direction
specialised mesoderm
neural crest cells
green on diagram slide 4
found boundary between ectoderm and neural plate
what does the ectoderm form?
the epidermal and neural cells
what does the mesoderm form?
muscloskeletal system, connective tissues and organs, (the meat and bones)
what does the endoderm form?
lining of the gut and respiratory system and out-pouchings (liver, pancreas)
which part of the germ layer does the epidermis form from?
from ectoderm
the epidermis (including nails, hair follicles and glands)
the dermis and subcutis?
from mesoderm
melanocytes?
from the neural crest cells (ectoderm)
somites?
blocks of tissue in which the mesoderm has organised itself into
embryo development direction?
cranial to caudal
Where do cutaneous nerves arise from?
they arise from spinal nerves at regular intervals along the body
when do somites form?
at a later embryonic stage
