anaphy integumentary system Flashcards
which means inward
integumentare
meaning to cover
tegere
Composed of skin, hair,
glands, nails and sensory
receptors.
INTEGUMENTARY SYSTEM
The skin acts as a barrier against physical damage, UV radiation, and pathogens
PROTECTion
The skin synthesizes vitamin D when exposed to sunlight.
Vitamin D Production
The skin excretes some waste products through sweat,
Excretion
The skin contains numerous nerve endings that detect touch
Sensation
by controlling blood flow near the surface
Temperature regulation
aka_____ or
integument covers the external
surface of the body.
Skin/cutaneous membrane
in both surface area and weight
(16% of total body weight).
❑ Thickest:
❑ Thinnest:
❑ 2 parts:
Largest organ of the body
heels
eyelids
epidermis and dermis
It consists mainly of a stratified squamous keratinized
epithelium
Epidermis
Keratin synthesis
Keratinocytes
Pigment production;
PROTECTS THE DNA
Melanocytes
Antigen presenting cell (a
type of macrophage)
Langerhans cells
Tactile epithelial cells
Merkel cells
Stratum basale (basal layer) and the thicker stratum spinosum (spinous layer) are collectively called
Malpighian layer
Layers of Epidermis:
Outermost layer
Absent in thin skin
Granular layer
Thickest layer
Mitotic division
Stratum Corneum
Stratum Lucidum
Stratum Granulosum
Stratum Spinosum
Stratum Basale
germ cell where mitosis
occur / stem cells
Basal Layer/ Germinativum
Cells are arranged as a single layer of
cuboidal or low columnar cells
Keratinocyte stem cells undergo mitotic divisions approximately every
19 days
with their associated Merkel discs are scattered among the keratinocytes of the basal layer.
Melanocytes and Merkel cells
Thickest and still the thickest even in
thin skin
Stratum Spinosum
Aka Prickle cell layer/ Spinous layer
Stratum Spinosum
Composed of polyhedral keratinocytes
with active protein synthetic function
KERATIN SYNTHESIS
Connected by desmosomes
Stratum Spinosum
where langerhan cells are located
Stratum Spinosum
Organelles begin to degenerate
Stratum Granulosum/Granular Layer
Three to five rows of flattened
keratinocytes
Stratum Granulosum/Granular Layer
thin, transparent/clear zone that consists of several layers
of dead cells (3-5 layers)
Stratum Lucidum
Stratum Lucidum Present in thick skin:
fingertips, palms, and soles.
Made of dead cells without
nucleus aka
Stratum Corneum/ Cornified layer
second, deeper part of the skin
Dermis
composed of a strong connective tissue containing collagen
and elastic fibers FOR TENSILE STRENGTH
Dermis
Small, fingerlike structures
Papillary layer
Made of loose connective tissue
Papillary layer
consists of dense irregular connective
tissue
Reticular layer
Detect pain, temperature
and touch
Free nerve endings
high frequency
receptors
Pacinian corpuscles
vibration low frequency
Meissner’s corpuscles
hot sensation
Ruffini endings
coldn sensation
Krause end bulb
the least abundant cell of the skin
Langerhans cell
are present on
most skin surfaces except
the palms
Hairs, or pili
protection and
light touch sensation
Hairs, or pili
Most keratinized
❑Provides strength and
helps keep the inner
layers tightly compacted
Cuticle
Surrounds the medulla
Cortex
Consist of large cell and
air spaces
Medulla
Only part of the hair that
contains soft keratin,
absent in fine hairs Medulla
Medulla
penetrates into the dermis
Hair root
❑ Surrounds the hair root
❑ Produce the hair shafts
Hair follicles
❑ Smooth muscle cells
❑ Pulls hairs upright when cold or
frightened
Arrector pili muscle
contractions force force sebum out
Arrector pili muscle
ANagen (Growth) CAtagen (Regression) TElogen (Resting)
ANagen (Growth) CAtagen (Regression) TElogen (Resting)
Fine long hairs in the body covering
the fetus
Lanugo hairs
Fine short unmedullated hairs
covering the body
Vellus hairs
Long coarse medullated hairs in the
scalp and pubic region influenced by
sex hormone
Terminal hairs
3 TYPES OF SECRETION
merocrine secretion
apocrine secretion
holocrine secretion
vesicle fuse with the cell membrane to secrete the product of the gland
merocrine secretion
parts of the cell is pinched off
apocrine secretion
a mature cell dies completely to secrete the product
holocrine secretion
❑ Produce sweat
❑ Widely distributed in skin except nipples and parts of external genitalia
Sweat or Sudoriferous Glands
❑ produce a thick secretion rich in organic substances (odorless)
❑ open into follicles but only in axilla and genitalia
❑ no dark cells
❑ surrounded by myoepithelial cells
❑ produces PHEROMONES
Apocrine
❑ clear cells - produces sweat
❑ dark cells – fight bacteria
❑ myoepithelial cells that can contract to push sweat
❑ coiled tubular discharge directly to
skin surface
❑ distributed to palms and soles
Merocrine/ Eccrine
large, lipid- producing cells filled with
small fat droplets
Sebocytes
produce a mixture of lipids
sebum
Modified apocrine glands found in
the lining of the external ear canal
Ceruminous Glands
Secretion mixes with sebum to
produce cerumen or ear wax.
Ceruminous Glands
Hard, flexible plates of keratin on the dorsal surface of each distal phalanx
nails
dense keratinized plate
Nail Body/
plate
formed by the epidermal
stratum corneum extending from
the proximal nail fold
Cuticle or eponychium
proximal part covered by the
proximal skin fold which is thin
and lacks both hair and glands
Nail root
stratified squamous epithelium
where the plate rests
Nail bed
a permanent coloration of the skin
tattooing
is deposited with a needle into the dermis
foreign pigment
three pigments that impart a wide variety of colors to skin
Melanin, hemoglobin, and carotene
2 FORMS OF MELANIN
❑ pheomelanin (yellow to red)
❑ eumelanin (brown to black)
