Lec 10 Intro to Integumentary System: Biol 302 Histology Midterm #2

Identify the Number 5

Eccrine Sweat Gland

Identify the Number 6

Adipose Cells

Identify the Number 7

Hair Follicle

Identify the Number 8

Sebaceous Gland

Identify the Number 9

Apocrine Sweat Gland

Identify the Number 10

Pacinian Corpuscle

Identify the Number 11

Arrector Pilli Muscle

Identify the Number 12

Blood Vessel

Identify the Number 13

Sensory Root Ending

Identify the Number 14

Dermal papillae

Identify the Number 15

Rete ridges

Functions of Skin/Integument?

• Protection (UV abs by melanin, nails, glabrous skin)

• Temp Regu (Vasoconstrict/dilate)

• Moisture Control

• Sensory

What are the Cells?

1) Melanocyte (clear, makes melanin) in basale

2) Langerhans (APC, macrophage derivative) in spinosum

3) Merkel (touch) in basale

4) Keratinocytes in spinosum!

What are the Epidermis Strata?

Top → Bottom: Stratum corneum, (lucidum in Thick skin), granulosum, spinosum, basale

CLGSB

What are Epidermis Features?

Epithelium, Keratin, Protection

Rete Ridges down (Dermal papillae is Dermis up)

What are Stratum basale Features?

• single cell layer

• mitotic cells differentiating upto keratinocytes in spinosum

• simple cuboidal epit

Identify the layer above the light pink?

Stratum basale in Epidermis

Identify the structure

Dermo-epidermal junction; where Epidermis meets Dermis, connects to S.basale via hemidesmosomes

What are Stratum spinosum Features?

• 2-10 cells thick

• Connected through Desmosomes

• Majority is Keratinocytes

Identify the Structure

Keratinocytes (in spinosum)

Identify the Structure

Keratinocytes (in spinosum)

Features of Keratinocytes?

• help make up majority of epidermis

• prickle cells = desmosomes

• 2-3 cells thick in thick skin

Identify the Structure

Melanocytes (in basale, die in spinosum)

Identify the Structure

Melanocytes (in basale, die in spinosum)

Identify the Structure

Melanocytes (in basale, die in spinosum)

Identify the Structure

Melanocytes (in basale, die in spinosum) and their dendrites

Features of Melanocytes?

• clear, round, make melanin

• made in basale and die in spinosum

• UV protected nuc makes melanin when UV abs, gives to keratinocytes in spinosum

Identify the Structure on top

Langerhans cells (in spinosum)

Identify the Structure

Langerhans cells (in spinosum)

Identify the Structure

Langerhans cells (in spinosum)

Identify the Structure

Langerhans cells (in spinosum)

Features of Langerhans cells

• irreg shaped

• dendritc

• APC for allergies

What are Stratum granulosum Features?

• 3-5 layers

• die and become corneum (lose nuc and organelles)

• Granules sec for water sealant

Identify the layer?

Stratum granulosum in Epidermis

Identify the layer below the keratin?

Stratum granulosum in Epidermis

What are Stratum lucidum Features?

• ONLY in thick skin

• in soles and palms

• glabrous = no hair

• anuc keratinocytes = water barrier

Identify the layer below the keratin?

Stratum lucidum in Epidermis (thick skin)

Identify the layer below the keratin?

Stratum lucidum in Epidermis (thick skin)

What are Stratum corneum Features?

• dead cells

• densly packed keratin

Identify the layer on top?

Stratum corneum in Epidermis

Features of Dermis?

• has L and DI CT - for structural support and protection

• Bv + nerves + sensory receptors

• epidermal specializations like hair, sweat glands, sebaceous glands

• Adheres Epidermis junction

Identify the layer?

Papillary Dermis of Dermis

Identify the layer?

Reticular Dermis of Dermis

Papillary vs Reticular Dermis?

Pap = LCT, highly vascular, has Dermal papillae

Ret = DICT, has Bv and epidermal specializations

Identify the layer?

Hypodermis (Loose Multilocular Adipose CT)

Identify the layer?

Epidermis

Thick vs Thin Skin?

Thick = has lucidum, more corneum, glabrous (no hair)

Thin = no lucidum, thin corneum

Identify the top vs bottom layer?

Top = Papillary Dermis

Bottom = Reticular Dermis

Identify the layers?

1 = Stratum corneum

2 = Stratum granulosum

3 = Stratum spinosum

4 = Stratum basale

5 = Papillary Dermis

Identify the layers?

1 = Epidermis

2 = Keratin

3 = Papillary Dermis

4 = Reticular Dermis

5 = Hypodermis

6 = Ducts

7 = Glands (either hair foll, sebaceous, eccrine sweat)

Identify the layers?

1 = Stratum corneum

2 = Stratum granulosum

3 = Stratum spinosum

4 = Stratum basale

5 = Papillary Dermis