Anatomy - Integumentary System

Exam 2

Skin = ______ = ________ _______

Skin = integument = cutaneous membrane

What is largest organ of the body?

Skin

Where on the body contains thick skin

Soles of feet & Palms of hands

Everywhere else on the body contains

Thin Skin

What is range of thickness of skin

0.5mm to 4.0mm

Skin is comprised of

The superficial epidermis and the deeper dermis

What are the accessory skin structures also known as

Skin appendages

What are the accessory skin structures

Sweat (sudoriferous) glands, Sebaceous (oil) glands, Hair/hair follicles, Nails

What layer of skin is only present in thick skin?

Stratum Lucidum

What are the strata of the epidermis

Stratum Basale: Deepest stratum
Stratum Spinosum: contains tonofilaments
Stratum Granulosum: contains granules
Stratum Lucidum (only in thick skin)
Stratum Corneum: Superficial stratum

Stratum Spinosum: contains tonofilaments

Stratum Granulosum: contains granules

Stratum Lucidum (only in thick skin)

Stratum Corneum: Superficial stratum

CLGSB

Come (Stratum Corneum), Let's (Stratum Lucidum) Get (Stratum Granulosum) Some (Stratum Spinosum) Brownies (Stratum Basale)

What cells are contained in the Stratum Basale

Keratinocytes, Melanocytes, Merkel cells

What is deepest layer of strata

Stratum Basale

What are keratinocytes

Mitotically active, produces cells for superficial layers

What is stratum basale also known as

stratum germinativum (because of active mitosis)

What are melanocytes

Produce the pigment melanin that is contained in melanosomes

Where do melanosomes accumulate

Accumulate on the superficial surface of keratinocytes in the stratum basale

What is the function of melanin

Acts as a chemical shield to protect nuclei of the keratinocytes from harmful effects of UV in sunlight

What gives skin its color?

Melanin

What is albinism

Genetic condition where melanin is not synthesized

How does tanning work?

Cells make extra melanin to protect you from UV rays

Merkel cells are present at the

Epidermal-dermal junction

Merkel cells associate with

free nerve endings

When associated with free nerve endings, Merkel cells

form Merkel discs which acts a touch receptors

The stratum spinosum is comprised of

several layers of cells

Cells in the stratum spinosum are connected by

desmosomes

What is the function of desmosomes in the stratum spinosum

Holds cells together which makes them appear spiny during histological preparation

During histological preparation, what cells appear spiny? What causes this

Stratum Spinosum, desmosomes

stratum spinosum cells contain an intermediate filament called

Tonofilaments

What are dendritic cells

cells that are special immune cells in your skin that act like guards. They spot germs and alert your body's immune system so it can fight them

What are epidermal dendritic cells called

Langerhans cells

Langergan cells act as macrophages to

engulf and digest pathogens

Why are macrophages not present in the epidermis

the epidermis is avascular

how many layers of cells is the stratum granulosum composed of

3-5 layers

What two types of granules do stratum granulosum contain

Lamellated granules & Keratohyaline granules

Lamellated granules

contains glycolipids, lipids that make the epidermis waterproof

Keratohyaline granules

Contains keratin, which makes the epidermis tough and abrasive resistant

describe keratin

tough, insoluble protein