THE INTEGUMENTARY
SYSTEM
THE INTEGUMENTARY
SYSTEM
THE INTEGUMENTARY SYSTEM
THE INTEGUMENTARY SYSTEM
The integumentary System
composed of
skin
and
appendages:
hair
nails
sweat glands
sebaceous glands.
SKIN THE
SKIN THE
The skin covers the entire outer
surface of the body and it is the
largest organ of the body
constituting 16% of the body
weight.
SKIN FUNCTIONS
SKIN FUNCTIONS
Protection
Excretion
Absorption.
Regulation of body temperature
THERE ARE TWO TYPES OF SKIN
THERE ARE TWO TYPES OF SKIN
* Thick Skin
* Thin Skin
Skin is classified as thick or thin
according to
1. the thickness of the epidermis.
2. The presence or absence of hair.
3. The presence or absence of certain
epidermal layers.
DIFFERENCE BETWEEN THICK AND THIN
SKIN
DIFFERENCE BETWEEN THICK AND THIN
SKIN
Thick skin
1.Covers the plams
and soles.
2.The epidermis
consists of five layers:
Stratum basale
Stratum spinosum
Stratum granulosum
Stratum lucidum
Stratum corneum.
3. Thick skin has
sweat glands.
Thin skin
1.Covers most the remainder
of the body.
2.The epidermis consists of
four layers:
Stratum basale
Stratum spinosum
Stratum granulosum
Stratum corneum (thin).
3. Thin skin has hair follicles,
arrector pili muscles,
Sebaceous glands, and
sweat glands.
THERE ARE TWO TYPES OF SKIN
THERE ARE TWO TYPES OF SKIN
Thick skin
Thin skin
LAYERS OF SKIN
LAYERS OF SKIN
1. Epidermis
2. Dermis
3. Hypodermis
1. EPIDERMIS
1. EPIDERMIS
Consist of 5 layers
1-
Stratum basale
: deepest single layer columnar
cells with basophilic cytoplasm.
2-
Stratum spinosum:
consist of 6-8 rows of
polyhedral cells become flattened toward the surface.
3-
Stratum granulosum:
consist of 3-5 layers of
flattened cells which filled with basophilic
keratohyalin granules.
4- Stratum lucidum :
cells lack nuclei or organelles
and are packed with keratin filaments this layer is
present only in thick skin.
5- Stratum corneum :
the most superficial layer
consist of flat , dead cells filled with soft keratin.
Epidermis
2. DERMIS
2. DERMIS
Consist of 2 layers
Papillary layer
: It is the superficial layer in dermis and
contains loose irregular connective tissue type III
collagen fibers and elastic fibers. Papillary layer
contains
fibroblasts
macrophages
plasma cells
mast cells.
Reticular layer
:
Is the deeper and thicker layer in
dermis filled with dense irregular Connective tissue
type I collagen fibers and elastic fibers. Reticular layer
contains
fibroblasts
lymphocytes
mast cells.
GLANDS OF THE SKIN
GLANDS OF THE SKIN
Sebaceous glands
: Simple branched alveolar
glands associated with each hair follicle. The
secretory product of the sebaceous glands
sebum.
GLANDS OF THE SKIN
GLANDS OF THE SKIN
Sweat glands:
Widely distributed in skin and
are of two types
1. Apocrine Sweat glands
2. Eccrine Sweat glands : are simple coiled
tubular glands located deep in the dermis or in
the underlying hypodermis
-Secretory Unit: the secretory portion of the
gland a simple cuboidal to low columnar
epithelium.
-Duct : is composed of a stratified cuboidal
epithelium made up of two layers.
Sebaceous gland
Sweat
gland
Secretary unit
HAIR FOLLICLES
HAIR FOLLICLES
The hair follicle: is a tube-shaped sheath that
surrounds the part of the hair that is under the
skin and nourishes the hair.
The hair bulb: The deepest part of the hair
follicles is an oval cavity filled with loose
connective tissue.
Dermal papilla: Is a region rich in capillaries that
supply nutrients and oxygen to cells of hair
follicles.
hair papilla
hair bulb
Sebaceous
gland
Thin skin
