Embryology of the Integument

Question 1

up to how many weeks of development is the embryonic skin consist of only a single layer of surface ectoderm

Answer 1

5 weeks

Question 2

stage one of epidermis/dermis development

Answer 2

surface ectoderm and mesoderm

Question 3

stage two of epidermis/dermis development

Answer 3

surface ectoderm proliferates and forms a layer of superficial cells

Question 4

periderm

Answer 4

superficial cells that become keratinized cells

Question 5

vernix caseosa

Answer 5

functions as a protection and lubricant

Question 6

the original layer of ectoderm remains as

Answer 6

a proliferative layer

Question 7

stage three of epidermis/dermis development

Answer 7

there are now identifiable layers of the skin

Question 8

what happens by 8 weeks by involvement of neural crest cells

Answer 8

migrate into the skin and give rise to melanocytes-these produce and secrete pigment melanin

Question 9

dermis is derive from

Answer 9

mesoderm underlying ectoderm mostly from lateral plate mesoderm

Question 10

most sebaceous glands develop as invaginations of the

Answer 10

epidermis related to the root of hair follicles

Question 11

what contribute to the vernix caseosa

Answer 11

sebaceous glands

Question 12

how to sweat glands develop

Answer 12

invaginations of the epidermis and grow into the dermis

Question 13

peripheral cells of the sweat glands develop into

Answer 13

secretory and myoepithelial cells

Question 14

mammary glands are modified

Answer 14

sweat glands

Question 15

mammary glands form along

Answer 15

thickened ectodermal ridges that extends from the axilla to the pubic region

Question 16

connective tissue and adipose associated with mammary glands derives from

Answer 16

mesoderm

Question 17

what is the function of the first hairs

Answer 17

they hold the vernix against the skin

Question 18

the arrector pili muscles form from

Answer 18

mesoderm

Question 19

nails begin to develop at the very tip of the digits as

Answer 19

epidermal thickenings called the nail fields

Question 20

teeth are derived from what sources

Answer 20

oral ectoderm, mesoderm and neural crest cells

Question 21

mandiublar teeth develop before or after maxillary teeth

Answer 21

mandibular teeth

Question 22

what sex’s teeth develop first

Answer 22

female

Question 23

What are the three stages of tooth development

Answer 23

bud stage, cap stage, and bell stage

Question 24

what part of the teeth are formed from oral ectoderm

Answer 24

enamel

Question 25

the dental sac forms

Answer 25

periodontal ligament and cementum

Question 26

ichthyosis

Answer 26

excessive keratinization of the skin

Question 27

angiomas

Answer 27

from the persistence or surplus of blood or lymphatic vessels

Question 28

nevus flammeus

Answer 28

flat pink or red blotck that appears on the posterior aspect of the neck

Question 29

hemangioma

Answer 29

port wine stain found on the face

Question 30

albinism

Answer 30

melanocytes fail to produce melanin and the skin, hair, and retina lack pigament

Question 31

supernumery nipples

Answer 31

extranipples or even breast form anywhere along the milk lines and are fairly common

Question 32

congenital alopecia

Answer 32

absence of loss of hair

Question 33

hypotrichosis

Answer 33

excessive hairiness

Question 34

amelogenesis inperfecta

Answer 34

enamel is improperly formed and is soft and friable and the teeth are yellow or brown because of exposed dentin

Question 35

dentinogenesis imperfecta

Answer 35

common condition where the odontoblasts fail to differentiate and dentin is NOT calcified

Question 36

discolored teeth

Answer 36

tetracycline can cause teeth to yellow brown