Flashcards in Embryology of the Integument Deck (36)
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1
up to how many weeks of development is the embryonic skin consist of only a single layer of surface ectoderm
5 weeks
2
stage one of epidermis/dermis development
surface ectoderm and mesoderm
3
stage two of epidermis/dermis development
surface ectoderm proliferates and forms a layer of superficial cells
4
periderm
superficial cells that become keratinized cells
5
vernix caseosa
functions as a protection and lubricant
6
the original layer of ectoderm remains as
a proliferative layer
7
stage three of epidermis/dermis development
there are now identifiable layers of the skin
8
what happens by 8 weeks by involvement of neural crest cells
migrate into the skin and give rise to melanocytes-these produce and secrete pigment melanin
9
dermis is derive from
mesoderm underlying ectoderm mostly from lateral plate mesoderm
10
most sebaceous glands develop as invaginations of the
epidermis related to the root of hair follicles
11
what contribute to the vernix caseosa
sebaceous glands
12
how to sweat glands develop
invaginations of the epidermis and grow into the dermis
13
peripheral cells of the sweat glands develop into
secretory and myoepithelial cells
14
mammary glands are modified
sweat glands
15
mammary glands form along
thickened ectodermal ridges that extends from the axilla to the pubic region
16
connective tissue and adipose associated with mammary glands derives from
mesoderm
17
what is the function of the first hairs
they hold the vernix against the skin
18
the arrector pili muscles form from
mesoderm
19
nails begin to develop at the very tip of the digits as
epidermal thickenings called the nail fields
20
teeth are derived from what sources
oral ectoderm, mesoderm and neural crest cells
21
mandiublar teeth develop before or after maxillary teeth
mandibular teeth
22
what sex's teeth develop first
female
23
What are the three stages of tooth development
bud stage, cap stage, and bell stage
24
what part of the teeth are formed from oral ectoderm
enamel
25
the dental sac forms
periodontal ligament and cementum
26
ichthyosis
excessive keratinization of the skin
27
angiomas
from the persistence or surplus of blood or lymphatic vessels
28
nevus flammeus
flat pink or red blotck that appears on the posterior aspect of the neck
29
hemangioma
port wine stain found on the face
30
albinism
melanocytes fail to produce melanin and the skin, hair, and retina lack pigament
31
supernumery nipples
extranipples or even breast form anywhere along the milk lines and are fairly common
32
congenital alopecia
absence of loss of hair
33
hypotrichosis
excessive hairiness
34
amelogenesis inperfecta
enamel is improperly formed and is soft and friable and the teeth are yellow or brown because of exposed dentin
35
dentinogenesis imperfecta
common condition where the odontoblasts fail to differentiate and dentin is NOT calcified
36
