The Integument

Question 1

What does the Integument provide for the body

Answer 1

Protection, sensation, thermoregulation, synthesis of Vit D3

Question 2

What are the 4 layers of thin skin epidermis

Answer 2

1. Stratum basale (deepest)
2. Stratum spinosum
3. Stratum granulosum
4. Stratum coneum (most superficial)

Question 3

What is the extra layer of epidermis found in thick skin

Answer 3

Stratum lucidum

Question 4

What 4 cells comprise the epidermis?

KeMML

Answer 4

Keratinocytes
Melanocytes
Merkel cells
Langerhans cells

Question 5

Define difference in thick vs thin skin

Answer 5

Thick - found in palms and soles, has 5 layers, much thicker

Thin - found throughout the body, has 4 layers, contains glands and hair follicles

Question 6

Define the stratum basale

Cell composition, function, contents

Answer 6

Single layer of keratinocytes with stem cells

Mitotically active

Contains melanin

Question 7

Define statrum spinosum

Cell composition, function

Answer 7

Several cell layers thick

Contains polyhedral keratinocytes with spiny processes

Produces corns and calluses

Question 8

Define stratum granulosum

Cell compositor, function

Answer 8

Thickest layer of non-keratinized portion of the epidermis

Assembles flaggrin, which is a precursor to keratin

Question 9

Define stratum corneum

Answer 9

A nuclear cells

Filled with mature keratin

Forms water barrier of epidermis

Continuously shed

Question 10

Define stratum lucidum

Answer 10

A subdivision of stratum corneum, only seen in thick skin

No organelles or nuclei

Question 11

What is the predominent cell within the epidermis

Answer 11

Keratinocytes

Question 12

Define keratinocytes

Answer 12

Cells that produce keratin, participate in epidermal water barrier

Question 13

Explain the process of keratinization

Answer 13

Begins with basal cell keratinocyte in the basal layer (stratum basale)

Basal cell - synthesize intermediate keratin filaments, grouped into bundles called tonofibrils

Basal cell pushed into stratum spinosum layer and becomes spinous cell

Spinous cell - begins synthesis of keratohyalin granules and glycolipid-containing lamellar bodies

Spinous cell pushed into stratum granulosum and becomes granular cell

Granular cells - discharge the laminar bodies to create a water barrier, filaggrin further promotes aggregation of keratin filaments

Now is a cornified cells which are now keratinized in the stratum corneum with no nucleus or organelles

Question 14

What affects the creation of cornified cells

Answer 14

Ph

Question 15

Define mealnocytes

Answer 15

Neural crest-derived cells found in stratum basale

Produced melanin and transfers it to keratinocytes

Question 16

What type of tissue is the epidermis

Answer 16

Keratinized, stratified, squamous

Question 17

Define melanin

Answer 17

Pigment protein that protects nuclei from UV radiation

Question 18

Define the epidermal-melanin unit

Answer 18

One melanocyte maintains an association with a specific number of keratinocytes

Question 19

How is melanin produced and excreted

4 steps

Answer 19

1. Through the oxidation of tyrosine into DOPA by tyrosinase
2. DOPA then polymerized into melanin with is UV sensitive
3. Mealnosome now heads toward keratinocytes
4. Transferred into keratinocytes via phagocytocis

Question 20

Define langerhans cells

Answer 20

Antigen-presenting cells that provide defense against pathogens

Question 21

Define the function of langerhans cells

Answer 21

Antigen is phagocytized and displayed on the cell surface

Cell then migrates to nearby lymph node to activate T-lymphocytes to destroy antigen

Question 22

What are the two layers of the dermis

Answer 22

Papillary layer

Reticular layer

Question 23

Define papillary layer

Answer 23

Loose CT immediately beneath epidermis

Contains thinner collagen fibers and elastic fibers

Includes vasculature and nerve endings

Question 24

Define reticular layer

Answer 24

Deep to papillary layer

Thicker and less cellular

Contains Type I collagen and corse elastic fibers

Forms irregular lines of tension, called langer’s lines

Question 25

Define meissner’s corpuscle

Answer 25

Touch receptors sensitive to low-frequency stimuli Tapered cylinder oriented perpendicular to the skin surface Present in the dermal papillae just beneath the epidermis

Question 26

Define pacinian corpuscle

Answer 26

Large ovoid structure found in the deeper dermis and hypodermis Detects pressure or vibration Has myelinated nerve endings surrounded by a capsule structure

Question 27

Define sebaceous glands and function

Answer 27

Produce a lipid mixture called sebum via holocrine secretion to lubricate and soften skin and hair

Question 28

Where is sebum dischraged into

Answer 28

The pilosebaceous canal

Question 29

What is sebum and its function

Answer 29

A waxy mix of triglycerides and cholesterol Lubricates and softens skin and hair

Question 30

Define eccrine sweat glands and function

Answer 30

Coiled glands distributed over the entire body except lips and genitalia Uses myoepithelial cells to facilitate expulsion of secretions Regulates temp via cooling

Question 31

What do eccrine glands use to facilitate expulsion of secretions

Answer 31

Myoepithelial cells

Question 32

Define apocrine sweat glands and fucntions

Answer 32

Large lumen, tubular glands Use merocrine secretion of a ammonia rich secretion Odorless until mixed with bacteria Also uses myoepithelizl cells to facilitate expulsion of secretions

Question 33

Draw out process of keratinization

Answer 33

Draw