Chapter 5 Integumentary System

Question 1

Evaluating burns

Answer 1

1st degree - only the epidermis is damaged. Redness and swelling
2nd degree - epidermis and upper region of the dermis is damaged with blisters appearing
3rd degree - full thickness burns involve all of the skin tissue

Question 2

What are the divisions of the skin?

Answer 2

Epidermis - composed of epithelial cells
Dermis - tough, leathery layer composed of dense connective tissue.
Only the dermis is vacularized.

Question 3

What is subcutaneous tissue?

Answer 3

Also known as the hypodermis. it is superficial to the connective tissue (fascia) of skeletal muscles.

Question 4

What cells are found in the epidermis?

Answer 4

Keratinocytes - produce keratin a protective fibrous protein. These are tied together by desmosomes.
Malnocytes - these are epithelial cells that synthesize melanin. They transfer melanin to keratinocytes to protect their nucleus from UV damage.
Dendritic cells - arise from bone marrow and migrate to epidermis they ingest foreign substances
Tactile Epithelial Cells - these are sensory receptors

Question 5

What are the 5 layers of thick skin?

Answer 5

From deep to superficial
1 - Stratum basal - germinating layer
2 - stratum spinosum - many keratinocytes with desmosomes anchoring a shrinking cell appear to look like ‘spine’ vertebrae
3- stratum granulosum - keratinization begins
4- stratum lucidum - found only in thick skin - strong bonding layer
5 - stratum corneum - outermost layer, extracellular glycolipid is waterproofing, keratin and proteins that accumulate inside the plasma membrane protect the skin against abrasion.

Question 6

What do melanocytes do?

Answer 6

Convert tyrosine to melanin.

Question 7

Is a small red bump on the skin from a tanning bed an issue?

Answer 7

UV radiation damages DNA bases. It also appears to disable tumor suppressor genes.
The degree of threat relates to the type of cancer.
Basal Cell carcinoma rarely metastisizes and fixable 99% of the time with excision.
Squamous cell carcinoma can metastisize.
Melanoma - the cancer of melanocytes is the most dangerous, metastasis is common, can erupt spontaneously and from pre-existing moles.