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C ET 1SKIN APPENDAGES

• PROF. DR. FAUZIAH OTHMAN
• DEPT OF HUMAN ANATOMY

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Contents

• Function of skin
• Epidermis- layer cell of epidermis
• Dermis papillary layer reticular layer
• Subcutaneous tissue
• Blood vessels skin sensorial receptors
• Hairs
• Nails
• Glands of skin sweat gland sebaceous gland.

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Skin layers epidermis, dermis, and subcutis,
showing a hair follicle, sweat gland sebaceous
gland.
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Function of Skin

• Protection
• Sensation
• Heat regulation
• Control of evaporation
• Aesthetics and communication
• Storage and synthesis
• Excretion
• Absorption
• Water resistance

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Epidermis- layer cell of epidermis

• Outermost layer of the skin
• About 90 of the epidermal cells are
  keratinocytes
• Made up of stratified squamous epithelium with an
  underlying basal lamina.

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5 layers

• stratum basale
• stratum spinosum
• stratum granulosum
• stratum lucidum
• stratum corneum

Bottom
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Cell of epidermis

• Three types of specialized cells
• Melanocyte produces pigment (melanin)
• Langerhans' cell frontline defense of the
  immune system in the skin
• Merkel's cell's is not clearly known

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Dermis papillary layer reticular layer

• Layer of skin beneath the epidermis.
• Consists -connective tissue
• - cushions the body from stress and
  strain.
• Tightly connected to the epidermis - basement
  membrane, and harbors many nerve endings that
  provide the sense of touch and heat.

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• It contains the hair follicles, sweat glands,
  sebaceous glands, apocrine glands, and blood
  vessels. The blood vessels in the dermis provide
  nourishment and waste removal to its own cells,
  as well as the Stratum basale of the epidermis.

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superficial area adjacent papillary region

• The dermis

Deep thicker area Reticular region
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Papillary Layer

• Thin arrangement of collagen fibers
• -fingerlike projections
• -composed of loose areolar connective tissue
• Fx supplies nutrients
• regulates temperature
• (Constriction and expansion control the amount of
  blood that flows through the skin and dictate
  whether body heat is dispelled when the skin is
  hot or conserved when it is cold.)

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Reticular Layer

• Thicker and made of thick collagen fibers that
  are arranged in parallel to the surface of the
  skin.
• Denser than the papillary dermis, and it
  strengthens the skin, providing structure and
  elasticity.
• It also supports other components of the skin,
  such as hair follicles, sweat glands, and
  sebaceous glands.

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Subcutaneous Tissue

• Layer of tissue directly underlying the cutis.
• composed of adipose tissue connective tissue
  that houses larger blood vessels and nerves.
• The thickness depends on the amount of fat
  present.Its physiological function includes
  insulation and storage of nutrients

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Blood vessels skin sensorial receptors
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• Heat, cold, touch, texture, pressure, vibration,
  and tissue injury (pain)
• abundant on the face, palms, fingers, soles,
  nipples and genitals.
• relatively few on the back, and joint areas

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sensory receptors in skin
Name Location Function
Hair Follicle Ending Hairy Skin Areas responds to hair displacement
Ruffini Endings Dermis of hairy and glabrous skin responds to pressure on skin
Krause corpuscle Lips, tongue, genitals responds to pressure
Pacinian corpuscle Deep layers of demis in hairy and glabrous skin responds to vibration sensitive at 150-300 Hz range
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Meissner corpuscle Demis of glabrous skin responds to vibration sensitive at 20-40 Hz range
Free nerve endings Throughout your skin different types of free nerve endings respond to mechanical, thermal, or noxious stimulation
Merkel Epidermis of glabrous skin responds to pressure of the skin
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Hairs

• Itself is dead, but it's produced by living
  cells.
• largely made up of a protein called keratin.
• Cells in the hair follicle regularly produce the
  keratin and other proteins that become
  incorporated into the hair shaft.
• Coloration comes from melanocytes which produce
  the brown pigment melanin

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Nails

• made of a tough protein called keratin and have
  many different parts

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• Nail body- visible portion of the nail
• Nail bed cover an area epidermis
• The free edge of the nail-distal portion that
  continues past the nail bed
• Hyponychium an area of thickened stratum
  corneum.

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• Nail root - nail production occurs
• Eponychium/ cuticle - aportion of stratum corneum
  of the nail root extend over the exposed.
• Lunula- near the root, vessels may be obscured,
  leaving pale cresent.

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Glands of skin sweat gland sebaceous gland
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• Skin contains 2 types of exocrine glands
• 1. Sebaceous glands
• ( produce oily lipid that coat hair shafts the
  epidermis)
• 2. Sweat glands
• ( produce watery solution perform other special
  functions.)

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Sebaceous glands

• Holocrine glands that discharge a waxy, oily
  secretion into hair follicles
• Communicate with the single follicle share a duct
  thus classified as simple branched alveolar
  glands

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• Gland cell produce large quantities of lipid-
  mature
• Secretion of lipids sebum
• ( triacylglycerides cholesterol proteins
  electrolyte)

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Sweat gland

• Other nameSudoriferous glands
• Apocrine gland
• Merocrine gland
• Names refer to the mechanism of the secretion