Unit 3 (LT 3)

Question 1

Five layers(superficial to deep)

Answer 1

1. Stratum Corneum
2. Stratum lucidum
3. Stratum granulosum
4. Stratum spinosum
5. Straum Basale

Question 2

Stratum Basale

Answer 2

• deepest
• single layer of columner of cuboidal cells
• anchored to basement membrane
• desomosomes hold together kerotinocytes
• keratinocytes stem cells undergo mitosis and are pushed to the surface and become more and more keratinized as they go

Question 3

Stratum Spinosum

Answer 3

• 8 to 10 mayers thick
• spiny appearance is because they are shrunken cells with exposed desmosomes
• as cells are pushed to the surface, they flatten , desmosomes break apart, and new ones form
• contains a lot of RNA
• additional keratin fibers and lamellar bodies form inside keratinocytes

Question 4

Desmosomes

Answer 4

proteins that attach cells together

Question 5

Stratum Granulosom

Answer 5

-2 to 5 layers of diamond shaped cells
- contains protein granules of keratohyline for keratin formation
- lamellar bodies release lipid contents into the ECM
- Nucleus and other organelles start to die

Question 5

Lamellar bodies

Answer 5

organelles that contain lipids

Question 6

Keratohyalin

Answer 6

requred for keratin formation

Question 7

Stratum Lucidum

Answer 7

• consits of several layers of dead cells
• keratin is present, but no keratohyline
• thick skin
• palms and soles

Question 8

Stratum Corneum

Answer 8

• outermost layer
• 25 or more layers of dead, overlapping skin cells (squamous) that are joined together by desmosomes
• cormified cells
• lipids release from the lamellar bodies surrounding skin cells to cause a watertight seal
• desquamation

Question 9

Cornified Cells

Answer 9

• dead cells that have a hard protein envelope filled with keratin
• needed for strength and durability
• skin contains soft kerotin, while nails and parts of hair have hard kerotin

Question 10

Desquamation

Answer 10

cells are shed from surface of the skin