Integumentary Flashcards
epidermis is derived from
surface ectoderm
dermis is derived from
mesoderm
periderm becomes
vernix caseosa
replaces periderm and forms layers of skin
basal layer
fingerprints are formed at week ___ from this layer of skin
10
stratum germinativum
where can you find thick skin
palms of hands and soles of feet
5 layers of epidermis
stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
layer that is only present in thick skin
stratum lucidum
layer that contains keratin granules
stratum granulosum
four kinds of cells found in skin
keratinocytes
Langerhans cells
Merkle cells
Melanocytes
derived from monocytes, present in stratum spinosum and contribute to immune function
Langerhans cells
derived from NCC, mechanoreceptor cells in skin
Merkle cells
derived from NCC, produce melanin before birth, protecting against UV radiation
Melanocytes
what causes albinism
what causes vitiligo
melanocytes don’t produce melanin (but are alive)
progressive loss of melanin as melanocytes die
what are the 2 regions of the dermis
papillary region (superficial)
reticular region (deep)
where would you find Meissner corpuscles, and what are they?
mechanoreceptors found in papillary region of dermis
where would you find Pacinian corpuscles, and what are they?
pressure and vibration receptors found in the reticular region of the dermis
which region of dermis has blood vessels, nerves, and lymphatics?
papillary
which region of dermis has accessory structures and arrector pili muscles?
reticular
what is the hypodermis?
layer of loose connective tissue and adipose tissue between dermis and fascia
There are ___ layers of epidermis and ____ regions of dermis
5
2
excessive keratinization – dryness and fish-skin like scales
ichthyosis
benign tumors or endothelial cells that contain blood, giving a port wine stain
hemangiomas
glands that grow down and coil to form secretory part
sweat glands
glands that grow into dermis off of the hair follicles and along the epidermis
sebaceous glands
direction of hair follicle formation
from epidermis down to dermis
hair follicle contains (2)
hair bud - forms hair bulb
hair matrix - in hair bulb and forms hair shaft
first hair to develop
lanugo
where is hair first visible (3), and when?
eyebrow, upper lip, chin
week 12
two types of hair and what they’re used for
vellus hair - tactile sensations (human hair)
terminal hair - thermal insulation (other primates)
basal lamina that separates dermis from follicular epithelium in hair follicle
glassy membrane
two parts of the hair bulb
dermal papilla
hair root
outer layers of follicular epithelium (hair follicle): ______
inner layers: ______
external root sheath
internal root sheath
three layers of hair shaft (xs)
medulla - core
cortex - layer outside medulla
cuticle - outside dense glossy layer
when do nails develop
10 weeks
Nail development:
_______ migrate onto dorsal surface and get covered by _______ (epidermis)
_______ keratinized to form _______, which grows _______ (direction)
nail fields
nail folds
nail fields
nail plate
proximally
another name for cuticle
eponychium
region of nail root beneath proximal nail fold
nail matrix
mammary glands are modified _________
sweat glands
thickened strips of ectoderm that extend from axillary to inguinal region and are the basis for supernumerary nipples
mammary crest
mammary gland becomes depressed to form _________, which forms nipples after birth
mammary pit
lactiferous ducts develop from ______ that are a down growth of epidermis at the crest
mammary buds
how many lactiferous ducts are there by birth?
10 to 15
excessive male mammary tissue:______
extra breasts: _______
extra nipples: ________
gynecomastia
polymastia
polythelia
U-shaped bands deep in tissue that develops 10 centers of proliferation for tooth buds
dental lamina
describe odontogenesis
NCC induce changes in ectoderm. In week 6 epithelium thickens to form dental lamina
fills dental papilla and forms internal part of tooth
tooth bud
produces enamel
ectoderm of developing tooth
hardest substance in the body
enamel
surrounding mesenchyme of tooth forms _______, which forms________ (CT covering root) and __________ (vascular CT around root that helps anchor tooth in alveolus)
dental sac
cement
periodontal ligament
_________ differentiates into ondontoblasts
dental papilla
odontoblasts produce ________ to deposit epithelium below enamel, which calcifies and becomes _______
predentine
dentin