Transcript INTEGUMENT - University of Kansas

INTEGUMENT
Surface Anatomy
Palpation
 Bony landmarks
 Dermatomes

Neural assessment
Integument Histology

Epidermis:
Stratified squamous epithelium
Resting on:

Basement membrane
Resting on:

Dermis:
Dense irregular connective tissue
Epidermis
The epidermis is a stratified squamous
epithelium.
 It is made up of many layers of cells.
 The stratum germinativum is the deepest
layer:

Area of high mitotic activity.
Epidermis

The stratum corneum is the most
superficial layer:
The cells in this layer are dead and
keratinized.

Between the stratum germinativum and
the stratum corneum are several
transitional layers represented by cells
from the stratum germinativum that are
transforming into dead, keratinized cells.
Epidermis
The epidermis is innervated.
 The epidermis is avascular.

Dermis
The dermis is the deepest region of the
integument.
 The dermis is classified as dense irregular
connective tissue
 The dermis has an abundance of collagen
fibers
 There may also be some elastic fibers:

Decrease with age.
Dermis
The dermis is vascularized.
 Refer to Figure 1 in your course packet.

Thick Skin vs. Thin Skin
Classification into thin and thick skin
depends on the structure of the epidermis.
 Layers of epidermis are well-formed in
thick skin.
 Layers of epidermis are not as well-formed
or thick in thin skin.

Thick Skin
Thick skin is found only on the palms of
the hands and the soles of the feet.
 The epidermis of thick skin is 0.4 – 0.6 mm
thick
 Thick skin has no hair follicles.

Thin Skin
Thin skin is found over the rest of the
body.
 The epidermis of thin skin is 0.075 – 0.150
mm thick.
 Total skin thickness is 0.5 – 3 mm thick.

Skin Thickness
Thickest skin found on back (= thin skin)
 Thinnest skin found on eyelids (= thin skin)
 Thicker on extensor surfaces than flexor
surfaces.

Superficial Fascia: Synonyms
Subcutaneous fascia
 Superficial fascia
 Hypodermis
 SubQ

Superficial Fascia
Consists of loose bundles of collagen and
elastic fibers with variably sized
aggregations of lipocytes (fat cells)
 May be loosely or tightly attached
 Supports cutaneous nerves and blood
vessels

Deep Fascia

Synonyms:
Membranous fascia
Investing fascia
Usually several thin layers of tough
collagen material
 Tightly adherent to muscles, bones,
tendons, etc.

Cutaneous Derivatives
Glands.
 Hairs.
 Nails.

Glands
Glands are epithelial structures
 Glands are classified according to the
presence or absence of a secretory duct:
Exocrine
Endocrine

Epidermal Glands
Sudoriferous glands
 Sebaceous glands
 Ceruminous glands
 Mammary glands

Sudoriferous Glands

Are long, simple, tubular glands.

Their method of secretion is merocrine .
Sebaceous Glands

Are holocrine .

Sebaceous glands are associated with
hair follicles.
Ceruminous Glands


Are located in the external auditory canal.
Secrete ear wax.
Mammary Glands

Are modified sweat glands

Method of secretion is apocrine
Hairs

Hairs develop during 3rd month of
gestation.

The earliest fine embryonic hair = lanugo.

Lanugo is Shed before birth except around
eyebrows, scalp, and eyelids.
Hairs
A new downy coat of hair appears a few
months after birth.
 This new coat is called vellus.
 Vellus is converted to terminal hair at
puberty:

Vellus represents 95% of the hair coverage
in males.
Vellus represents 35% of the hair coverage
in females.
Parts of a Hair

Shaft:
Made up of dead cornified epidermal cells.

Follicle:
Derived from both epidermis and dermis.

Dermal papilla with matrix.
Parts of a Hair
Arrector pili muscle.
 Sebaceous glands.
 Hair bulb and connective tissue papilla.

Hair Growth

Anlagen
Active growth:
Scalp hair = 2-3 years
Eyebrow hair = 3-4 months
Hair Function and Location

Hair follicles are innervated, and hairs
serve as sensory receptors.

Hairs are found everywhere except palms,
soles, dorsal distal phalanges, anal and
urogenital apertures
Nails

Ungis:
Modified stratum corneum
Flattened
Avascular and not innervated
Travels over a nail bed guided by lateral nail
grooves

Matrix:
Stratum germinativum produces ungis

Subungis
Melanocytes
Found in deep layers of epidermis
 Derived from nervous system components
 Form:

Melanosomes:
Passed off to keratinocytes (cells of
epidermis).
Phagocytized by keratinocytes.
Melanocytes
All individuals produce same number of
melanosomes.
 Skin color depends on number of
remaining melanosomes.

Langer’s Lines
Represent tension lines created by
orientation of collagen fibers in the dermis
of the skin.
 Used by surgeons as guides for incisions:

Incisions normally made parallel to Langer’s
lines
Dermatomes

Specific region of skin innervated by a
specific spinal cord level.

Refer in syllabus to figure 3