BSC 2085 Exam #2 Yung Su FSU Questions And
Answers V erified 100% Correct
Describe the Stratum Granulosum layer - ANSWER -the "grainy layer", Stops
dividing, starts producing:
1. Keratin
A tough, fibrous protein
Makes up hair and nails
2. Keratohyalin
Dense granules
Cross-link keratin fibers
Note: as keratin accumulates, the cell flatten and its plasma membrane thickens
and becomes less permeable
Describe the Stratum Lucidum - ANSWER the "clear layer"
-Found only in thick skin
-Covers stratum granulosum
-Cells here are flattened, densely packed with keratin and are devoid of organelles
Stratum Cornuem - ANSWER -the "horn layer" (latin cornu=horn)
-Exposed surface of skin (15 to 30 layers of keratinized cells) lasts about 2
weeks -Water resistant, not water proof!
-Shed and replaced every two weeks
-All exposed skin surfaces (except the anterior of the eyes) undergo cornification
(keratinization)
- formation of protective, superficial layers of cells filled with keratin
,Cells of Stratum Granulosum - ANSWER -Produce protein fibers
-Dehydrate and die (organelles disintegrate)
-Create tightly interlocked layer of keratin surrounded by keratohyalin
-Keratohylain cross links keratin and dehydrates cell
Integumentary System- weight and area - ANSWER Is the largest system of the
body
16% of body weight
1.5 to 2 m2 in area
How many parts makeup the integumentary system? - ANSWER The integument
is made up of two parts
1. Cutaneous membrane (skin)
2. Accessory structures
Describe the Cutaneous Membrane - ANSWER consist of two components:
Outer epidermis
Superficial epithelium (epithelial tissues)
Inner dermis
Connective tissues
Accessory Structure - ANSWER Originate in the
dermis Extend through the epidermis to skin surface.
Includes:
Hair, Nails, Multicellular exocrine glands
Keratinization - ANSWER -The formation of a layer of dead, protective cells
filled with keratin Occurs on all exposed skin surfaces except eyes
,What is the skin life cycle? - ANSWER Skin life cycle
-It takes 7 to 10 days for a cell to move from stratum basale to stratum corneum
-Once there, cells may remain at stratum corneum for an additional 2 weeks before
shedding off
Two types of perspiration - ANSWER Insensible and sensible
What is Insensible perspiration - ANSWER -Interstitial fluid lost by evaporation
through the stratum corneum
-Lose approx. 500mL or 1 pint of H2O per day
What is sensible perspiration? - ANSWER Water excreted by sweat glands
What are dehydration results? - ANSWER -From damage to stratum corneum
(e.g., burns and blisters [insensible perspiration])
-From immersion in hypertonic solution (e.g., seawater [osmosis]) -skin is NOT
water proof!
What is hydration? - ANSWER -Results from immersion in hypotonic solution
(e.g., freshwater [osmosis])
-Causes swelling of epithelial cells, evident on the palms and soles
What pigments influence skin color? - ANSWER 1. Carotene
2. Melanin
-Blood circulation (red blood cells) can also affect skin color
What is Carotene? - ANSWER -Orange-yellow pigment
, -Found in orange vegetables
Carrots, squashes - if overconsumption, can turn skin orangish
-Accumulates in epidermal cells and fatty tissues of the dermis
-Can be converted to vitamin A - used for maintenance of epithelia and
photoreceptor function
What is Carotenemia? - ANSWER Over consumption of orange vegetables ex
Carrots, squashes
What is Nyctalopia and what causes it? - ANSWER Lack of Vitamin A causes
night blindness
What is melanin? - ANSWER -Yellow-brown or black pigment
-Produced by melanocytes in stratum basale
Stored in transport vesicles (melanosomes)
Transferred to keratinocytes
Note: albino individuals do have melanocytes. However, the melanocytes do not
have the ability to produce melanin. Difference in skin pigmentation caused by
amount of melanin synthesized, not by the number of melanocytes
What does the synthesis of melanin require? - ANSWER amino acid tyrosine
What is the function of Melanocytes? - ANSWER -Melanin protects skin from sun
damage
(Ultraviolet (UV) radiation)
-Melanosomes of keratinocytes concentrate around the cell nucleus to
protect DNA -Skin color depends on melanin production, not number of
melanocytes
Answers V erified 100% Correct
Describe the Stratum Granulosum layer - ANSWER -the "grainy layer", Stops
dividing, starts producing:
1. Keratin
A tough, fibrous protein
Makes up hair and nails
2. Keratohyalin
Dense granules
Cross-link keratin fibers
Note: as keratin accumulates, the cell flatten and its plasma membrane thickens
and becomes less permeable
Describe the Stratum Lucidum - ANSWER the "clear layer"
-Found only in thick skin
-Covers stratum granulosum
-Cells here are flattened, densely packed with keratin and are devoid of organelles
Stratum Cornuem - ANSWER -the "horn layer" (latin cornu=horn)
-Exposed surface of skin (15 to 30 layers of keratinized cells) lasts about 2
weeks -Water resistant, not water proof!
-Shed and replaced every two weeks
-All exposed skin surfaces (except the anterior of the eyes) undergo cornification
(keratinization)
- formation of protective, superficial layers of cells filled with keratin
,Cells of Stratum Granulosum - ANSWER -Produce protein fibers
-Dehydrate and die (organelles disintegrate)
-Create tightly interlocked layer of keratin surrounded by keratohyalin
-Keratohylain cross links keratin and dehydrates cell
Integumentary System- weight and area - ANSWER Is the largest system of the
body
16% of body weight
1.5 to 2 m2 in area
How many parts makeup the integumentary system? - ANSWER The integument
is made up of two parts
1. Cutaneous membrane (skin)
2. Accessory structures
Describe the Cutaneous Membrane - ANSWER consist of two components:
Outer epidermis
Superficial epithelium (epithelial tissues)
Inner dermis
Connective tissues
Accessory Structure - ANSWER Originate in the
dermis Extend through the epidermis to skin surface.
Includes:
Hair, Nails, Multicellular exocrine glands
Keratinization - ANSWER -The formation of a layer of dead, protective cells
filled with keratin Occurs on all exposed skin surfaces except eyes
,What is the skin life cycle? - ANSWER Skin life cycle
-It takes 7 to 10 days for a cell to move from stratum basale to stratum corneum
-Once there, cells may remain at stratum corneum for an additional 2 weeks before
shedding off
Two types of perspiration - ANSWER Insensible and sensible
What is Insensible perspiration - ANSWER -Interstitial fluid lost by evaporation
through the stratum corneum
-Lose approx. 500mL or 1 pint of H2O per day
What is sensible perspiration? - ANSWER Water excreted by sweat glands
What are dehydration results? - ANSWER -From damage to stratum corneum
(e.g., burns and blisters [insensible perspiration])
-From immersion in hypertonic solution (e.g., seawater [osmosis]) -skin is NOT
water proof!
What is hydration? - ANSWER -Results from immersion in hypotonic solution
(e.g., freshwater [osmosis])
-Causes swelling of epithelial cells, evident on the palms and soles
What pigments influence skin color? - ANSWER 1. Carotene
2. Melanin
-Blood circulation (red blood cells) can also affect skin color
What is Carotene? - ANSWER -Orange-yellow pigment
, -Found in orange vegetables
Carrots, squashes - if overconsumption, can turn skin orangish
-Accumulates in epidermal cells and fatty tissues of the dermis
-Can be converted to vitamin A - used for maintenance of epithelia and
photoreceptor function
What is Carotenemia? - ANSWER Over consumption of orange vegetables ex
Carrots, squashes
What is Nyctalopia and what causes it? - ANSWER Lack of Vitamin A causes
night blindness
What is melanin? - ANSWER -Yellow-brown or black pigment
-Produced by melanocytes in stratum basale
Stored in transport vesicles (melanosomes)
Transferred to keratinocytes
Note: albino individuals do have melanocytes. However, the melanocytes do not
have the ability to produce melanin. Difference in skin pigmentation caused by
amount of melanin synthesized, not by the number of melanocytes
What does the synthesis of melanin require? - ANSWER amino acid tyrosine
What is the function of Melanocytes? - ANSWER -Melanin protects skin from sun
damage
(Ultraviolet (UV) radiation)
-Melanosomes of keratinocytes concentrate around the cell nucleus to
protect DNA -Skin color depends on melanin production, not number of
melanocytes
