ANATOMY
THE INTEGUMENTARY SYSTEM
stethodiaries
,FUNCTIONS OF INTEGUMENTARY SYSTEM
1.PROTECTION
protective, stretchable covering
prevents entry of micro-organisms, foreign materials
2.TEMPERATURE REGULATION
IN HOT SURROUNDINGS IN COLD ENVIRONMENT
excessive production of sweat inhibition of sweating to prevent heat loss
(evaporation of sweat = cooling effect) hair on the skin (minor role)
3.EXCRETION
Removes waste materials such as urea (through perspiration)
4.SYNTHESIS
Produces vitamin D3 (cholecalciferol) from 7-dehydrocholesterol (under UV rays from sun)
necessary for normal growth of bones and teeth
5.SENSORY PERCEPTION
important sensory organ
DERMIS contains receptors for heat, cold, touch, pressure, and pain.
, SKIN
epidermis dermis
superficial
stratum basale papillary layer
stratum spinosum
stratum granulosum deep reticular
layer
stratum lucidum
stratum corneum
,STRUCTURE OF SKIN
, EPIDERMIS
stratified squamous epithelium
contains five layers
Avascular (has no blood vessels)
Nourished by diffusion from blood vessels of dermis.
most superficial layers consist of dead cells (bcz they are away from blood
deep epidermal layers (living and active) vessels)
CELLS
Keratinocytes Melanocytes
Keratinocytes make up 90% of all The deeper layers of epidermis
skin cells. They are found in contain special type of cells called
epidermis. melanocytes .
they secrete a brownish-black
they secrete keratin
pigment called melanin.
present in stratum basale.
, STRATUM CORNEUM
exposed surface of epithelium
composed of dead cells
cytoplasm packed with filaments of special protein keratin
referred to as stratified squamous epithelium
the keratinized cells offer resistance to passage of fluid and to
friction.
its superficial cells are shed off and replaced by new cells
these cells move outward from the deepest layer i.e.,stratum basale
also known as stratum germinativum.
mitotic activity maintains necessary rate of regeneration of epidermis
Keratin is a tough, fibrous protein. Keratin makes the skin strong, waterproof and
resistant to damage. Keratinocytes release cytokines and help in immune defense.
, DERMIS OR CORIUM
lies beneath the epidermis
thick layer of dense connective tissue
contains two layers
the PAPILLARY LAYER forms blunt conical (cone shaped) expressions called
dermal papillae .
they fit into reciprocal depressions on undersurface of epithelium
the RETICULAR LAYER consists chiefly of interlacing bundles of connective
tissue fibers.
contains : blood vessels, nerves, and nerves endings.
it also lodges hair follicles, sebaceous glands, and sweat glands
(these are epidermal derivatives)
, DERMIS OR CORIUM
the dermal papillae binds epidermis to dermis
they contain capillaries ; supply nutrients to epidermis.
under the skin superficial fascia is present also known as subcutaneous tissue or
HYPODERMIS. Located below the dermis. Made up of loose connective tissue and
fat(adipose tissue)
THE INTEGUMENTARY SYSTEM
stethodiaries
,FUNCTIONS OF INTEGUMENTARY SYSTEM
1.PROTECTION
protective, stretchable covering
prevents entry of micro-organisms, foreign materials
2.TEMPERATURE REGULATION
IN HOT SURROUNDINGS IN COLD ENVIRONMENT
excessive production of sweat inhibition of sweating to prevent heat loss
(evaporation of sweat = cooling effect) hair on the skin (minor role)
3.EXCRETION
Removes waste materials such as urea (through perspiration)
4.SYNTHESIS
Produces vitamin D3 (cholecalciferol) from 7-dehydrocholesterol (under UV rays from sun)
necessary for normal growth of bones and teeth
5.SENSORY PERCEPTION
important sensory organ
DERMIS contains receptors for heat, cold, touch, pressure, and pain.
, SKIN
epidermis dermis
superficial
stratum basale papillary layer
stratum spinosum
stratum granulosum deep reticular
layer
stratum lucidum
stratum corneum
,STRUCTURE OF SKIN
, EPIDERMIS
stratified squamous epithelium
contains five layers
Avascular (has no blood vessels)
Nourished by diffusion from blood vessels of dermis.
most superficial layers consist of dead cells (bcz they are away from blood
deep epidermal layers (living and active) vessels)
CELLS
Keratinocytes Melanocytes
Keratinocytes make up 90% of all The deeper layers of epidermis
skin cells. They are found in contain special type of cells called
epidermis. melanocytes .
they secrete a brownish-black
they secrete keratin
pigment called melanin.
present in stratum basale.
, STRATUM CORNEUM
exposed surface of epithelium
composed of dead cells
cytoplasm packed with filaments of special protein keratin
referred to as stratified squamous epithelium
the keratinized cells offer resistance to passage of fluid and to
friction.
its superficial cells are shed off and replaced by new cells
these cells move outward from the deepest layer i.e.,stratum basale
also known as stratum germinativum.
mitotic activity maintains necessary rate of regeneration of epidermis
Keratin is a tough, fibrous protein. Keratin makes the skin strong, waterproof and
resistant to damage. Keratinocytes release cytokines and help in immune defense.
, DERMIS OR CORIUM
lies beneath the epidermis
thick layer of dense connective tissue
contains two layers
the PAPILLARY LAYER forms blunt conical (cone shaped) expressions called
dermal papillae .
they fit into reciprocal depressions on undersurface of epithelium
the RETICULAR LAYER consists chiefly of interlacing bundles of connective
tissue fibers.
contains : blood vessels, nerves, and nerves endings.
it also lodges hair follicles, sebaceous glands, and sweat glands
(these are epidermal derivatives)
, DERMIS OR CORIUM
the dermal papillae binds epidermis to dermis
they contain capillaries ; supply nutrients to epidermis.
under the skin superficial fascia is present also known as subcutaneous tissue or
HYPODERMIS. Located below the dermis. Made up of loose connective tissue and
fat(adipose tissue)
