INTEGUMENTARY SYSTEM
ANATOMY & PHYSIOLOGY
Mr. Eric Mahinay| 1St Semester | BSN – 1B
S.Y. 2023 – 2024
● Integumentary system - includes the skin 2.) Melanocytes- 8% of the cells
and its accessory structures including hair, - produce the pigment melanin
nails, and glands, as well as blood vessels, - contributes to skin color
muscles, and nerves - absorbs UV light
● Dermatology - a medical specialty of the - protects against damage by
diagnosis and treatment of disorders of the UV radiation
integumentary system. 3.) Langerhan Cells- involved in
immune responses
- arise from red bone marrow
STRUCTURES OF THE SKIN
- constitute a small % portion
● Cutaneous membrane (SKIN) covers the - easily damaged by UV light
body and is the largest organ of the body by 4.) Merker Cells - least in number
surface area and weight - found in the deepest layer of
● Area - 2sqm (22sqft) epidermis
● Weight - 4.5 - kg (10-11lbs) - function in the sensation of
● 16% of body weight touch along with tactile discs
● 0.5 - 4mm thick, thinnest on the eyelids,
thickest on the heels; average thickness is
1-2 mm
LAYERS OF THE SKIN
Epidermis outer, thinner layer
consists of epithelial
tissue
Dermis inner, thicker layer LAYERS OF EPIDERMIS
Hypodermis subcutaneous (subQ ● Stratum basale or stratum germinativum
layer) ➔ deepest layer
beneath the dermis ➔ single row of cuboidal or columnal
attaches the skin to the keratinocytes
underlying tissues and ➔ where new cells are formed
organs ➔ where cell division occurs which
not a major layer produces other layers
● Stratum spinosum
EPIDERMIS ➔ 8-10 layers of keratinocytes
➔ above stratum basale
● composed of keratinized stratified ➔ some cells retain ther ability for cell
squamous epithelium. division
● it contains four principal types of cells: ➔ cells have spine-like projections
1.) Keratinocytes - 90% of the cells (bundles of filaments of the
- produce keratin (a fibrous cytoskeleton)
protein that provides ➔ tightly joins cells to each other
protection + waterproofs the ➔ provides strength and flexibility to
skin) the skin
TRANS BY: ELMIRA SALAZAR 1
, INTEGUMENTARY SYSTEM
ANATOMY & PHYSIOLOGY
Mr. Eric Mahinay| 1St Semester | BSN – 1B
S.Y. 2023 – 2024
● Stratum granulosum Growth
➔ includes keratohyalin and lamellar
granules
➔ above stratum spinosum
➔ 3-5 layers of flattened keratinocytes
undergoing apoptosis
➔ organelles begin to disintegrate
➔ becomes non-living cells - The process takes about 4 weeks
➔ transition between deeper - Rate of cell division in stratum
metabolicaly active strata and the basale increases during injury
dead cells of the superficial strata
➔ secretes lipid reach secretion (acts DERMIS
as water sealant)
● second deepest part of skin
● Stratum Lucidum
● composed of connective tissues (collagen +
➔ only in thick skin (fingertips, palms,
elastic fibers)
and soles)
❖ collagen fibers - 70% of the dermis
➔ 3-5 layers of clear, flat, dead
(gives structural toughness and
keratinocytes
strength)
➔ thick plasma membrane
❖ elastin fibers - loosely arranged in all
● Stratum corneum
directions (gives elasticity)
➔ composed of many sublayers of flat,
● blood vessels, nerves, glands, and hair
dead keratinocytes (corneocytes or
follicles are embedded here
squames)
➔ constant friction can stimulate
formation of callus LAYERS OF DERMIS
➔ 25-30 layers of dead keratinocytes
➔ serves as water, microbe, injury ● Papillary region - outer
barrier - consists of areolar connective tissue
containing thin collagen + elastic
fibers + dermal papillae (including
capillary loops), corpuscles of
touch and free neve endings
- superficial portion of the dermis
- surface area is increased due to
projections called dermal papillae
- contains capillaries or tactile
receptors
- epidermal ridges conforms to the
dermal papillae
● Reticular region - deeper portion
Keratinization - accumulation of more and - provides skin with strength and
more protective keratin, occurs as cells elasticity
move from deepest to the surface layer - consists of dense irregular
Dandruff - excess of keratinized cells shed connective tissue (contains collagen
from the scal & elastic fibers, adipose cells, hair
TRANS BY: ELMIRA SALAZAR 2
ANATOMY & PHYSIOLOGY
Mr. Eric Mahinay| 1St Semester | BSN – 1B
S.Y. 2023 – 2024
● Integumentary system - includes the skin 2.) Melanocytes- 8% of the cells
and its accessory structures including hair, - produce the pigment melanin
nails, and glands, as well as blood vessels, - contributes to skin color
muscles, and nerves - absorbs UV light
● Dermatology - a medical specialty of the - protects against damage by
diagnosis and treatment of disorders of the UV radiation
integumentary system. 3.) Langerhan Cells- involved in
immune responses
- arise from red bone marrow
STRUCTURES OF THE SKIN
- constitute a small % portion
● Cutaneous membrane (SKIN) covers the - easily damaged by UV light
body and is the largest organ of the body by 4.) Merker Cells - least in number
surface area and weight - found in the deepest layer of
● Area - 2sqm (22sqft) epidermis
● Weight - 4.5 - kg (10-11lbs) - function in the sensation of
● 16% of body weight touch along with tactile discs
● 0.5 - 4mm thick, thinnest on the eyelids,
thickest on the heels; average thickness is
1-2 mm
LAYERS OF THE SKIN
Epidermis outer, thinner layer
consists of epithelial
tissue
Dermis inner, thicker layer LAYERS OF EPIDERMIS
Hypodermis subcutaneous (subQ ● Stratum basale or stratum germinativum
layer) ➔ deepest layer
beneath the dermis ➔ single row of cuboidal or columnal
attaches the skin to the keratinocytes
underlying tissues and ➔ where new cells are formed
organs ➔ where cell division occurs which
not a major layer produces other layers
● Stratum spinosum
EPIDERMIS ➔ 8-10 layers of keratinocytes
➔ above stratum basale
● composed of keratinized stratified ➔ some cells retain ther ability for cell
squamous epithelium. division
● it contains four principal types of cells: ➔ cells have spine-like projections
1.) Keratinocytes - 90% of the cells (bundles of filaments of the
- produce keratin (a fibrous cytoskeleton)
protein that provides ➔ tightly joins cells to each other
protection + waterproofs the ➔ provides strength and flexibility to
skin) the skin
TRANS BY: ELMIRA SALAZAR 1
, INTEGUMENTARY SYSTEM
ANATOMY & PHYSIOLOGY
Mr. Eric Mahinay| 1St Semester | BSN – 1B
S.Y. 2023 – 2024
● Stratum granulosum Growth
➔ includes keratohyalin and lamellar
granules
➔ above stratum spinosum
➔ 3-5 layers of flattened keratinocytes
undergoing apoptosis
➔ organelles begin to disintegrate
➔ becomes non-living cells - The process takes about 4 weeks
➔ transition between deeper - Rate of cell division in stratum
metabolicaly active strata and the basale increases during injury
dead cells of the superficial strata
➔ secretes lipid reach secretion (acts DERMIS
as water sealant)
● second deepest part of skin
● Stratum Lucidum
● composed of connective tissues (collagen +
➔ only in thick skin (fingertips, palms,
elastic fibers)
and soles)
❖ collagen fibers - 70% of the dermis
➔ 3-5 layers of clear, flat, dead
(gives structural toughness and
keratinocytes
strength)
➔ thick plasma membrane
❖ elastin fibers - loosely arranged in all
● Stratum corneum
directions (gives elasticity)
➔ composed of many sublayers of flat,
● blood vessels, nerves, glands, and hair
dead keratinocytes (corneocytes or
follicles are embedded here
squames)
➔ constant friction can stimulate
formation of callus LAYERS OF DERMIS
➔ 25-30 layers of dead keratinocytes
➔ serves as water, microbe, injury ● Papillary region - outer
barrier - consists of areolar connective tissue
containing thin collagen + elastic
fibers + dermal papillae (including
capillary loops), corpuscles of
touch and free neve endings
- superficial portion of the dermis
- surface area is increased due to
projections called dermal papillae
- contains capillaries or tactile
receptors
- epidermal ridges conforms to the
dermal papillae
● Reticular region - deeper portion
Keratinization - accumulation of more and - provides skin with strength and
more protective keratin, occurs as cells elasticity
move from deepest to the surface layer - consists of dense irregular
Dandruff - excess of keratinized cells shed connective tissue (contains collagen
from the scal & elastic fibers, adipose cells, hair
TRANS BY: ELMIRA SALAZAR 2
