Histo Skin

Epidermis

From Ectoderm

Epidermis

Made up of Keratinized Stratified Squamous Epithelium

Stratum corneum

Flat cornified Keratinized cells (no nuclei) or Dead Keratinocytes

Stratum lucidum

Only on thick skin like palms and soles

Stratum lucidum

Clear eleidin to be converted to keratin in SC

Stratum lucidum

Desmosomes between cells

Stratum granulosum

3-5 polygonal cells

Stratum granulosum

Central nuclei

Stratum granulosum

Make tonofibrils tighter

Stratum granulosum

Dark basophilic keratohyalin granules

Stratum granulosum

Lamellar granules

Stratum spinosum

Cuboidal or polygonal/ slightly flattened

Stratum spinosum

Less basophilic cytoplasm filled w/ filaments

Stratum granulosum

Tonofibrils or budles of keratin

Stratum granulosum

Keratinocytes

Stratum spinosum

Langerhans

Keratinocytes

Undergoes Cytomo

Langerhans

APC w/ dark nucleus and pale cytoplasm; Has birbeck/ veriform granules

Stratum germinativum/ basale

Has Melanocytes and Merkel Cells

Melanocytes

Small cells with unstained cytoplasm; Transfers melanin to Keratinocytes via melanosomes; Has tyrosinase for melanin synthesis

Merkel Cells

Deeply invaginated nucleus; Dense cored vesicles in cytoplasm; Paraneurons for sensory

Stratum corneum

A

Stratum granulosum

B

Stratum spinosum

C

Stratum germinativum/ basale

D

Epidermis

A

Dermis

B

Hypodermis

C

Stratum corneum

A

Stratum lucidum

B

Stratum granulosum

C

Stratum spinosum

D

Stratum germinativum/ basale

D

Dermis

F

Dermis

From Mesoderm

Dermis

Has many projections w/ foldings

Dermal Papillae

Loose Connective tissue

Dermal Papillae

Has Fibroblasts, Mas cells, and, Macrophages

Dermal Papillae

Has Meissner’s Corpuscle

Meissner’s Corpuscle

Oblong, Cigar shape, Nerve endings, Sensitivity to light and touch

Meissner’s Corpuscle

Meissner’s Corpuscle

Dermal Reticulae

Dense Irregular Connective Tissue

Dermal Reticulae

Has BVs, Lymph vessels, and Nerves

Dermal Reticulae

Has skin appendages, Sweat gland, Sebaceous gland, Hair follicle, Pilil arrector muscle

Sweat Gland

Sweat/ Sebaceous: In thick and thin skin

Sweat Gland

Sweat/ Sebaceous: Simple Coiled Tubular

Sweat Gland

Sweat/ Sebaceous: Eccrine/ Merocrine or Apocrine

Sebaceous Gland

Sweat/ Sebaceous: Thin skin only except in w/o hair

Sebaceous Gland

Sweat/ Sebaceous: Acinar short duct

Sebaceous Gland

Sweat/ Sebaceous: Holocrine

Sweat Gland

Sweat/ Sebaceous:

Sebaceous Gland

Hypodermis

Has Adipocytes (Panniculus adiposus if thick) + Pacinian corpuscle

Pacinian corpuscle

Pacinian corpuscle

Onion-shaped, nerve endings, sensitivity to vibration and pressure