? SURFACE OF THE BODY
? FORMS 15% OF THE TOTAL BODY WEIGHT
? THICKNESS-1.5 to 5.0 mm
? LARGEST ORGAN OF THE BODY
--- Content provided by FirstRanker.com ---
INTEGUMENTARY SYSTEM
--- Content provided by FirstRanker.com ---
Some Facts about Skin? Surface area: 1.5-2.0 sq meters
? Growth rate of nail: 0.1mm per day
? Growth rate of hair: 1.5-2.2 mm per week
--- Content provided by FirstRanker.com ---
? Life span of hair:Eyelashes, axilla- 4 months
Scalp ? 4 years
--- Content provided by FirstRanker.com ---
STRUCTURE OF SKIN? TWO DISTINCT LAYERS
* EPIDERMIS
* DERMIS
--- Content provided by FirstRanker.com ---
? EPIDERMIS : SUPERFICIAL AND AVASCULAR? DERMIS : DEEP AND VASCULAR
TERMS USED FOR MOVEMENTS
--- Content provided by FirstRanker.com ---
TYPES OF SKIN? THICK SKIN - EPIDERMIS VERY THICK
USUALLY HAIRLESS ON
PALMS OF HAND & SOLES
--- Content provided by FirstRanker.com ---
OF FEET? THIN SKIN ? COVERS GREATER PART OF
BODY & IS USUALLY HAIRY
? EXCEPTION ? SCALP : THICK AND HAIRY
--- Content provided by FirstRanker.com ---
Layers Of Skin
Epidermis:
? Composed of keratinized
--- Content provided by FirstRanker.com ---
stratified squamous epithelium.
Dermis:
? Papillary region composed of
--- Content provided by FirstRanker.com ---
loose connective tissue.
? Reticular region composed of
--- Content provided by FirstRanker.com ---
dense irregular connective tissue.Hypodermis:
? Composed of areolar tissue with
--- Content provided by FirstRanker.com ---
abundant adipocytesCells
? Keratinocytes
--- Content provided by FirstRanker.com ---
? Melanocytes-pigment forming cells fromneural crest cells
? Merkel cells-sensory mechanoreceptors
--- Content provided by FirstRanker.com ---
? Langerhans cells-antigen presenting cells frombone marrow
? Free nerve endings
--- Content provided by FirstRanker.com ---
LAYERS OF THE EPIDERMIS
Stratum Basale (Germinal/
--- Content provided by FirstRanker.com ---
Malpighian layer):
? Single layer of cuboidal cells resting on
--- Content provided by FirstRanker.com ---
basement membrane.? High mitotic activity.
Stratum Spinosum:
? Several layers of polygonal cells.
--- Content provided by FirstRanker.com ---
? Cells are held together bydesmosomes.
Stratum Granulosum:
--- Content provided by FirstRanker.com ---
? 3-5 layers of flattened polygonal cells.? Cells contain keratohyaline granules.
contd....
--- Content provided by FirstRanker.com ---
Stratum Lucidum:? Seen only in non-hairy or thick skin.
? Cel s are flattened, translucent,
--- Content provided by FirstRanker.com ---
eosinophilic with indistinct
boundaries & nucleus.
--- Content provided by FirstRanker.com ---
? Contains a product ofkeratohyaline i.e. eleidin.
Stratum Corneum:
--- Content provided by FirstRanker.com ---
? Composed of structureless
dehydrated dead cel s.
--- Content provided by FirstRanker.com ---
? Flattened & scale-like.? Fil ed with keratin.
? Superficial layer is continuosly
--- Content provided by FirstRanker.com ---
sloughed off.
Stratum Basale
--- Content provided by FirstRanker.com ---
Stratum Spinosum
--- Content provided by FirstRanker.com ---
Stratum GranulosumStratum Lucidum
Stratum Corneum
--- Content provided by FirstRanker.com ---
SPECIALIZED CELLS OF THE EPIDERMIS
--- Content provided by FirstRanker.com ---
Keratinocytes:
? Most common cel s of the epidermis.
? Provides protection and
--- Content provided by FirstRanker.com ---
waterproofing sealant.Melanocytes:
? Rounded cel s with dendrite-like
--- Content provided by FirstRanker.com ---
branches.? Present in Stratum basale.
? Produces melanin pigment
--- Content provided by FirstRanker.com ---
responsible for the colour of skin.? Melanin is a brown/black pigment
that absorbs UV-light.
--- Content provided by FirstRanker.com ---
SPECIALIZED CELLS OF THE EPIDERMIS
Langerhans Cells (antigen presenting
--- Content provided by FirstRanker.com ---
cells):? Non-pigmented granular dendrocytes.
? Present in Stratum spinosum.
--- Content provided by FirstRanker.com ---
? Nucleus is indented at many places &
cytoplasm contains rod-shaped
--- Content provided by FirstRanker.com ---
granules.? They participate in immune responses
against bacteria and viruses.
--- Content provided by FirstRanker.com ---
Merkel Cells:
? Found in Stratum basale.
--- Content provided by FirstRanker.com ---
? Sensory cells innervated by sensorynerves.
? Abundant in fingertips, oral mucosa &
--- Content provided by FirstRanker.com ---
hair follicles.
? Function as mechanoreceptors.
--- Content provided by FirstRanker.com ---
PIGMENTATION OF SKIN
The colour of skin depends upon fol owing factors:
--- Content provided by FirstRanker.com ---
? Carotene: yellow-orange pigment (precursor of vitamin A)found in stratum corneum & dermis.
? Melanin: produced in epidermis by melanocytes
--- Content provided by FirstRanker.com ---
gives black colour to the skin.
? Hemoglobin (in blood vessels of dermis): gives pink colour
--- Content provided by FirstRanker.com ---
to the skin.LAYERS OF THE DERMIS
?
--- Content provided by FirstRanker.com ---
Papil ary layer:
-Narrow band of loose connective tissue.
--- Content provided by FirstRanker.com ---
-In contact with basement membrane ofstratum basale.
-Dermal papil ae (finger- like processes)
--- Content provided by FirstRanker.com ---
- provide mechanical anchorage and supply
nerves and blood vessels
--- Content provided by FirstRanker.com ---
?
Reticular layer:
--- Content provided by FirstRanker.com ---
-
4
--- Content provided by FirstRanker.com ---
Dense irregular connective tissue.Dermal
papil a
--- Content provided by FirstRanker.com ---
-Thick elastic fibres.
-may be involved in development of skin lines
--- Content provided by FirstRanker.com ---
31
2
--- Content provided by FirstRanker.com ---
TYPES OF SKIN
Th
--- Content provided by FirstRanker.com ---
Thin Skinin Skin
Th
--- Content provided by FirstRanker.com ---
Thick i
Skck
--- Content provided by FirstRanker.com ---
in SkinLayers of epidermis
St. corneum &
--- Content provided by FirstRanker.com ---
St. corneum & spinosum are
spinosum are thin while thick while lucidum is
--- Content provided by FirstRanker.com ---
lucidum is absent.present.
Thickness of epidermis
--- Content provided by FirstRanker.com ---
0.10-0.15 mm
0.6-4.5 mm
--- Content provided by FirstRanker.com ---
Epidermal ridgesAbsent
Present (well developed
--- Content provided by FirstRanker.com ---
dermal paplillae)
Hair fol icles, arrector pili Present
--- Content provided by FirstRanker.com ---
Absentmuscle & sebaceous
gland
--- Content provided by FirstRanker.com ---
Sweat glandsFew
Many
--- Content provided by FirstRanker.com ---
Sensory receptors
Less
--- Content provided by FirstRanker.com ---
MoreDistribution
Covers all parts of body Present in palms, palmar
--- Content provided by FirstRanker.com ---
except palms & soles
surface of digits & soles
--- Content provided by FirstRanker.com ---
APPENDAGES OF THE SKIN
HAIRS:
--- Content provided by FirstRanker.com ---
? Keratinized filaments derived from
invagination of the basal layer of
--- Content provided by FirstRanker.com ---
epidermis into the dermis.? Parts-
a) Root: enclosed by hair follicle.
--- Content provided by FirstRanker.com ---
b) Shaft: projects above the surface.
--- Content provided by FirstRanker.com ---
? Hair fol icle: tubular invagination,
partly epidermal and partly dermal in
--- Content provided by FirstRanker.com ---
origin.contd.....
--- Content provided by FirstRanker.com ---
Structure of shaft and root:
? Medul a
? Cortex
? Cuticle
--- Content provided by FirstRanker.com ---
Hair fol icle:? Tubular invagination of epidermis
& dermis in which hair root
--- Content provided by FirstRanker.com ---
resides.? Layers: 3 (inner root sheath, outer
root sheath, connective tissue
--- Content provided by FirstRanker.com ---
sheath).
contd.....
--- Content provided by FirstRanker.com ---
? Hair bulb: lower expandedend of hair follicle.
? Hair papil a: the
--- Content provided by FirstRanker.com ---
indentation at the base of
hair bulb by part of the
dermis.
--- Content provided by FirstRanker.com ---
contd.....Arrector Pilorum Muscle:
? Smooth muscle innervated
--- Content provided by FirstRanker.com ---
by sympathetic nerves.
? Extends from papil ary
--- Content provided by FirstRanker.com ---
layer of dermis to theconnective tissue sheath of
a hair fol icle.
--- Content provided by FirstRanker.com ---
? Contraction of muscle
presses the sebaceous
--- Content provided by FirstRanker.com ---
gland which squeezes outsebum.
? Formation of "goose flesh".
--- Content provided by FirstRanker.com ---
APPENDAGES OF THE SKIN
--- Content provided by FirstRanker.com ---
NAILS:
? Hardened keratin plates on
--- Content provided by FirstRanker.com ---
the dorsal surface of thetips of fingers & toes.
? Parts:
--- Content provided by FirstRanker.com ---
a) Root
b) Free border
--- Content provided by FirstRanker.com ---
c) Body? Nail bed: tissue on which
the nail rests. Made up of
--- Content provided by FirstRanker.com ---
stratum basale & spinosum.
APPENDAGES OF THE SKIN
--- Content provided by FirstRanker.com ---
SEBACEOUS GLANDS:? Distributed all over the
dermis of the skin, except
--- Content provided by FirstRanker.com ---
for the palms & soles.
? Abundant in the scalp,
--- Content provided by FirstRanker.com ---
face, around theapertures of the ear, nose,
mouth & anus.
--- Content provided by FirstRanker.com ---
APPENDAGES OF THE SKIN
SEBACEOUS GLANDS:
--- Content provided by FirstRanker.com ---
? Holocrine in nature.? Number of alveoli
connected to broad duct
--- Content provided by FirstRanker.com ---
that opens into hair
follicle.
--- Content provided by FirstRanker.com ---
? Produces an oilysecretion called sebum.
--- Content provided by FirstRanker.com ---
SWEAT GLANDS (SUDORIFEROUS GLANDS)? Absent from lips, glans & nail bed.
? Mode of secretion: merocrine
--- Content provided by FirstRanker.com ---
? Simple tubular gland
? 2 parts:
--- Content provided by FirstRanker.com ---
(a) Secretory portion(b) Excretory duct
Secretory portion:
--- Content provided by FirstRanker.com ---
? Twisted coil like structure with simple
cuboidal epithelium.
--- Content provided by FirstRanker.com ---
? 3 types of cel s: clear cel s, dark cel s,myoepithelial cel s.
Excretory duct:
--- Content provided by FirstRanker.com ---
? Long & extends from secretory portion to
surface of epidermis.
--- Content provided by FirstRanker.com ---
contd....2 types:
Eccrine:
? Most numerous in the soles &
--- Content provided by FirstRanker.com ---
palms.
? Produces thin watery secretion.
Apocrine:
--- Content provided by FirstRanker.com ---
? Confined to axil a, eyelids (Moll'sglands), nipple & areola of breast,
perianal region, and the external
--- Content provided by FirstRanker.com ---
genitalia.
? Produces thick odourous secretion.
? Ceruminous glands & lactating
--- Content provided by FirstRanker.com ---
mammary glands are modified
apocrine sweat glands.
--- Content provided by FirstRanker.com ---
Sweat GlandSURFACE IRREGULARITIES
--- Content provided by FirstRanker.com ---
? FLEXURE LINES - Permanent lines alongwhich
the skin folds during habitual
--- Content provided by FirstRanker.com ---
movements of joints
? CLEAVAGE LINES - According to arrangement
--- Content provided by FirstRanker.com ---
of fibres in deep fascia, horizontal intrunk, in old age fibres atrophy and skin
wrinkles
--- Content provided by FirstRanker.com ---
PAPILLARY RIDGES
PAPILLARY RIDGES
? Palms and soles and digits
--- Content provided by FirstRanker.com ---
? Form narrow ridges separatedby fine paral el grooves,
? corrospond to dermal papil ae
--- Content provided by FirstRanker.com ---
? Study is cal ed dermatoglypics? Pattern of finger prints- loops ,
whorls and arches and
--- Content provided by FirstRanker.com ---
compositeLanger's lines(Cleavage lines)
? Langer lines of skin tension, or
--- Content provided by FirstRanker.com ---
sometimes called cleavage lines
? Correspond to the natural orientation
--- Content provided by FirstRanker.com ---
of collagen fibers in the dermis,? Are generally parallel to the orientation of
the underlying muscle fibers.
--- Content provided by FirstRanker.com ---
? Langer's lines have relevance to forensic
science and the development of surgical
--- Content provided by FirstRanker.com ---
techniquesLanger's lines
? Langer lines of skin tension, or
--- Content provided by FirstRanker.com ---
sometimes cal ed cleavage
lines
--- Content provided by FirstRanker.com ---
? Correspond to the naturalorientation of collagen fibers
in the dermis,
--- Content provided by FirstRanker.com ---
? Are general y paral el to the
orientation of the underlying
--- Content provided by FirstRanker.com ---
muscle fibers.? Langer's lines have relevance
to forensic science and the
--- Content provided by FirstRanker.com ---
development of surgical
techniques
Applications of Langer Lines
--- Content provided by FirstRanker.com ---
? Incisions made parallel to Langer's lines may
heal better and produce less scarring than
--- Content provided by FirstRanker.com ---
those that cut across. Conversely, incisionsperpendicular to Langer's lines have a
tendency to pucker and remain obvious,
--- Content provided by FirstRanker.com ---
although sometimes this is unavoidable
? In old age, elastic fibres atrophy and skin
--- Content provided by FirstRanker.com ---
becomes wrinkledLinea gravidarum
? Rupture of fibre bundles
--- Content provided by FirstRanker.com ---
of dermis due to
excessive stretching
--- Content provided by FirstRanker.com ---
result in prominentwhite lines.
? Seen in anterior
--- Content provided by FirstRanker.com ---
abdominal wall in
pregnancy.
--- Content provided by FirstRanker.com ---
Rule of Nine: To estimatethe extent of damaged skin
in burn injuries.
--- Content provided by FirstRanker.com ---
? First degree burn-
only epidermis.
--- Content provided by FirstRanker.com ---
? Second degree burn-epidermis + upper region of
dermis.
--- Content provided by FirstRanker.com ---
? Third degree burn-
entire thickness of skin.
--- Content provided by FirstRanker.com ---
Dermatomes? The strip of skin
supplied by a single
--- Content provided by FirstRanker.com ---
spinal nerve is called
dermatome.
FUNCTIONS OF SKIN
--- Content provided by FirstRanker.com ---
? Protective shield for the body
? Barrier to water
? Thermoregulation
? Important sense organ (pain, touch,
--- Content provided by FirstRanker.com ---
temperature & pressure)
? Absorption of ultraviolet radiation from sun
--- Content provided by FirstRanker.com ---
for the production of vitamin DAPPLIED ANATOMY
? Skin is pale in anemia, yel ow in
--- Content provided by FirstRanker.com ---
jaundice and blue in cyanosis? Skin incisions should be made paral el to
lines of cleavage to have the smal est scar
--- Content provided by FirstRanker.com ---
? Sebaceous cyst is common in scalp
due to obstruction to sebaceous
duct
--- Content provided by FirstRanker.com ---
SUPERFICIAL FASCIASUPERFICIAL FASCIA
? DEFINITION- General coating of the body
--- Content provided by FirstRanker.com ---
beneath the skin made up of loose
areolar tissue and fat
--- Content provided by FirstRanker.com ---
? ABUNDANCE OF FAT- Front of thigh andanterior abdominal wal
? ABSENCE OF FAT- Eyelids & external ear
--- Content provided by FirstRanker.com ---
? In females there is more fat and it is
evenly distributed
--- Content provided by FirstRanker.com ---
TERMS USED FOR MOVEMENTSIMPORTANT FEATURES
? Most distinct in lower part of
--- Content provided by FirstRanker.com ---
anterior abdominal wal & limbs? Very thin on dorsal aspect of hands &
feet, sides of neck, face.
--- Content provided by FirstRanker.com ---
? Very dense in scalp, palms and soles.IMPORTANT FEATURES
--- Content provided by FirstRanker.com ---
? IT CONTAINS1. Cutaneous nerves &
vessels
--- Content provided by FirstRanker.com ---
2. Groups of lymph nodes3. Subcutaneous muscle in
neck
FUNCTIONS
--- Content provided by FirstRanker.com ---
? Helps in movements of skin
? Allows for the passage of the vessels &
nerves to the skin
--- Content provided by FirstRanker.com ---
? Conserves body heat as fat is a bad
conductor of heat
? Fat fills hollow spaces like axilla &
orbits
--- Content provided by FirstRanker.com ---
DEEP FASCIA
? Deep fascia is a fibrous sheet which
--- Content provided by FirstRanker.com ---
covers the body beneath the superficialfascia.
? It is devoid of fat, and is usual y inelastic
--- Content provided by FirstRanker.com ---
and toughDISTRIBUTION OF DEEP FASCIA
--- Content provided by FirstRanker.com ---
? Best seen in limbs where it forms tough andtight sleeves
? Well defined in the neck where it
--- Content provided by FirstRanker.com ---
? forms a collar? Not well formed on the trunk and face
? Blends with periosteum of a subcutaneous
bone
--- Content provided by FirstRanker.com ---
MODIFICATIONS OF DEEP FASCIA
? Inter muscular septa which divides limbs
--- Content provided by FirstRanker.com ---
into compartments? Thickenings form retinacula around joints
like wrist and ankle
--- Content provided by FirstRanker.com ---
? Forms sheath around large arteries
? In palms & soles form aponeurosis
? Form investing layer of fascia in region of
--- Content provided by FirstRanker.com ---
neck giving it shape.INTERMUSCULAR SEPTA
RETINACULA
--- Content provided by FirstRanker.com ---
INVESTING LAYER OF FASCIA
FUNCTIONS
--- Content provided by FirstRanker.com ---
? Keeps underlying structures in position
? Provides extra surface for muscle
attachment
? Helps in venous return
--- Content provided by FirstRanker.com ---
? Helps muscles in action by applying tensionand pressure
? Retinacula keep tendons in position
--- Content provided by FirstRanker.com ---
MCQ
Q1. Which layer is present only in thick skin:
--- Content provided by FirstRanker.com ---
a. Stratum basaleb. Stratum spinosum
c. Stratum granulosum
d. Stratum lucidum
--- Content provided by FirstRanker.com ---
MCQQ2. The characteristic feature of reticular layer of
dermis is:
--- Content provided by FirstRanker.com ---
a. High mitotic activityb. Contains keratin granules
c. Dense irregular connective tissue
d. Finger like processes
MCQ
--- Content provided by FirstRanker.com ---
Q3. Secretion of sebaceous glands is aided by
contraction of:
a. Arrector pilorum muscle
--- Content provided by FirstRanker.com ---
b. Myoepithelial cellsc. Papillary layer of dermis
d. Reticular layer of dermis
MCQ
--- Content provided by FirstRanker.com ---
Q4. Langerhans cells are present in:
a. Stratum basale
b. Stratum spinosum
--- Content provided by FirstRanker.com ---
c. Stratum granulosumd. Stratum lucidum