Integument (Exam 3)

Question 1

What is the epidermis derived from

Answer 1

surface ectoderm

Question 2

What are the three stages of epidermis development

Answer 2

Stage 1
Stage 2
Stage 3

Question 3

What occurs in the first stage of epidermis development

Answer 3

surface ectoderm and mesoderm form

Question 4

What occurs in the second stage of epidermis development

Answer 4

surface ectoderm proliferates and forms superficial cells

Question 5

What occurs to the superficial cells produced in the first stage of epidermis development

Answer 5

they become keratinized

Question 6

What do the keratinized cells of epidermis form

Answer 6

vernix caseosa

Question 7

What is the function of the vernix caseosa

Answer 7

lubrication and protection

Question 8

What does the original layer of ectoderm remain as

Answer 8

proliferative layer

Question 9

What occurs during the third stage of ectoderm formation

Answer 9

definitive layers are formed

Question 10

What are the definitive layers of the ectoderm

Answer 10

stratum germivatum
stratum spinosum
stratum granulosum
stratum lucidum
stratus corneum

Question 11

What will nerural crest cells give rise to in the skin

Answer 11

melanocytes

Question 12

What will melanocytes secrete

Answer 12

melanin

Question 13

What is the dermis derived from

Answer 13

somatic mesoderm from lateral plate mesoderm

somites

Question 14

How do sebaceous glands develop

Answer 14

buds of ectoderm down into the dermis layer

Question 15

Where do the sebaceous glands form in the dermis layer

Answer 15

near the root of hair follicles

Question 16

What is the function of sebaceous glands in the fetus

Answer 16

contribute to the vernix caseosa

Question 17

What is the vernix caseosa

Answer 17

white thick, cheesy material that protects the skin

Question 18

What is the vernix caseosa composed of

Answer 18

epithelial cells and secretions of glands

Question 19

How are mammary glands formed

Answer 19

buds of ectoderm into the dermis (mammary buds)

follow the ectodermal ridge thickenings (milk lines) down the body

Question 20

What is witch’s milk

Answer 20

clear or milky white fluid that is sometimes expressed from a new born’s breasts due to the influence of maternal hormones

Question 21

What are the only ducts formed at birth

Answer 21

main lactiferous ducts

Question 22

When do the remaining mammary ducts form

Answer 22

at puberty

Question 23

How do hair follicles form

Answer 23

proliferation of the deepest ectoderm layer into the derms.
forms a bulb at the end which contains germinal matrix to produce the hair

as cells proliferate they are pushed to the surface and become keratizines

Question 24

What is the function of the first hairs produced by the embryo

Answer 24

hold the vernix against the skin

Question 25

Later, what occurs to the hair bulbs

Answer 25

melanocytes migrate into the hair bulbs and contribute melanin to the hair

Question 26

How will arrector pili muscles form

Answer 26

mesoderm

Question 27

How do nails form

Answer 27

epidermal thickenings (nail fields) at the tip of the digits. Migrates to the dorsal aspect with time

Question 28

What is ichthyosis

Answer 28

excessive keratinization of the skin, producing dry and scaly skin

Question 29

In a harlequin fetus, what is the skin like

Answer 29

abnormally thick and cracked

Question 30

In a collodion infant what is the skin like

Answer 30

thick membrane that cracks and eventually is shed to reveal normal skin

Question 31

What are angiomas

Answer 31

persistence or surplus of blood or lymphatic vessels

Question 32

What is nevus flammeus

Answer 32

flat pink or red blotch that appears on the psoterior aspect of the neck

Question 33

What is a hemagioma (port wine stain)

Answer 33

red but is found on the face

Question 34

WHat causes albinism

Answer 34

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

Question 35

What are supernumerary nipples

Answer 35

extra nipples or breast tissue can form anywhere along the milk lines and are fairly common

Question 36

What is congenital alopecia

Answer 36

absence of hair

Question 37

What is hypertrichosis

Answer 37

abnormal amount of hair growth on the body

Question 38

In what condition is localized hypertrichosis found

Answer 38

spina bifida occulta

Question 39

What is neurofibromatosis Type 1

Answer 39

NT1-Chromosome 17 GTPase that activates ras common features: plexiform, cafe au lait spots, axillary frecklying