(CHAPTERS 6-9) A&P I (DR TIANGCO, ECPI)
EXAM SCRIPT 2026 COMPLETE QUESTIONS
AND ANSWERS
◉ List and describe each of the layers of human skin. Answer:
Cutaneous membrane-
* Epidermis-40-45 layers of stratified squamous epithelium.
* Dermis(dense irregular connective tissue)-2 layers
-papillary- little hill(nipple shaped) increases the surface area of the
dermis, so the epidermis can stick better. They line up the finger print,
allows friction.
-proteoglycan gel(heat, radiation, friction, disease-can separate
epidermis from dermis).
-Blister(delaminated, proteoglycan melts).
-reticular
Hypodermis-not part of skin
◉ List the characteristics of the epidermis and describe the cell types
and layers of the epidermis. Answer: From bottom to top layer:
*Stratum Germinativum(Basale)-single layer of keratinocyte(protein).
Active in mitosis(not making Keratin, just dividing).Cells are alive.
*stratum spinosum-8-10 layers of keratinocytes, some mitosis, start
making keratin inside the cell. Cells are alive.
,*Stratum Granulosum-3-5 layers, cells not dividing anymore(lots of
keratin production and lots of keratohyaline production(dehydrated cell,
non vascular, links up keratin protein together & forms them into
granules(visible). This is where Keratinocytes die(comes in alive but
leaves dead).
*Stratum lucidum-(only present on thick skin). Couple layers of flat,
dead, clear cells. Lucid-clear,doesn't stain.
*Stratum Corneum-15-30 layers of flat squamous dead keratinocytes.
Constantly being replaced.
◉ Describe the function of different epidermal cell types. Answer:
*Melanocytes-makes melanin(protects the nuclei of the keratinocytes),
found in stratum basale.
-it's in hair, skin, eyes
-constantly going mitosis. Cells spits melanin to protect cells in stratum
germinativum.
-uniform amount of melanocytes for everyone.
-skin color comes from how active the melanocytes and genetics.
they make amino acid(tyrosine) and change it to dopoquinone.
tyrosine-->tyrosinase-->dopoquinone-->melanin
*Langerhan cells-wandering macrophages(part of immune process).
*Cholecalciferol-Vitamin D3-made by some cells in the stratum basal
and spinosum-
, -used by the kidney to male calcitriol(hormone)-allows us to absorb
Calcium and potassium to manufacture bones.
◉ Thick and thin skin Answer: *Thick skin-has all 5 strata, has stratum
lucidum. Anterior part of hand and posterior part of feet
*Thin skin-does not have stratum lucidum.
Thickest skin is found in the dorsal back but it is not a thick skin(5
starta).
◉ Carotene and melanin Answer: *Carotene-is an orange yellow
pigment that normally accumulates in the epidermal cells.
-found in stratum corneum of light skin people, but also found in fatty
tissues (hypodermis)
-comes from orange vegetables and can be converted for vitamin A.
-Not so obvious for dark skin individual.
*Melanin-brown, yellow brown pigment that produced by the
melanocytes.
-protects us from UV rays.
◉ Epidermal growth factor Answer: Epidermal growth factor or EGF is
a growth factor that stimulates cell growth. produced by the salivary and
duodenum glands.
Roles:
-promote the division of basal cells and stratum spinosum.
EXAM SCRIPT 2026 COMPLETE QUESTIONS
AND ANSWERS
◉ List and describe each of the layers of human skin. Answer:
Cutaneous membrane-
* Epidermis-40-45 layers of stratified squamous epithelium.
* Dermis(dense irregular connective tissue)-2 layers
-papillary- little hill(nipple shaped) increases the surface area of the
dermis, so the epidermis can stick better. They line up the finger print,
allows friction.
-proteoglycan gel(heat, radiation, friction, disease-can separate
epidermis from dermis).
-Blister(delaminated, proteoglycan melts).
-reticular
Hypodermis-not part of skin
◉ List the characteristics of the epidermis and describe the cell types
and layers of the epidermis. Answer: From bottom to top layer:
*Stratum Germinativum(Basale)-single layer of keratinocyte(protein).
Active in mitosis(not making Keratin, just dividing).Cells are alive.
*stratum spinosum-8-10 layers of keratinocytes, some mitosis, start
making keratin inside the cell. Cells are alive.
,*Stratum Granulosum-3-5 layers, cells not dividing anymore(lots of
keratin production and lots of keratohyaline production(dehydrated cell,
non vascular, links up keratin protein together & forms them into
granules(visible). This is where Keratinocytes die(comes in alive but
leaves dead).
*Stratum lucidum-(only present on thick skin). Couple layers of flat,
dead, clear cells. Lucid-clear,doesn't stain.
*Stratum Corneum-15-30 layers of flat squamous dead keratinocytes.
Constantly being replaced.
◉ Describe the function of different epidermal cell types. Answer:
*Melanocytes-makes melanin(protects the nuclei of the keratinocytes),
found in stratum basale.
-it's in hair, skin, eyes
-constantly going mitosis. Cells spits melanin to protect cells in stratum
germinativum.
-uniform amount of melanocytes for everyone.
-skin color comes from how active the melanocytes and genetics.
they make amino acid(tyrosine) and change it to dopoquinone.
tyrosine-->tyrosinase-->dopoquinone-->melanin
*Langerhan cells-wandering macrophages(part of immune process).
*Cholecalciferol-Vitamin D3-made by some cells in the stratum basal
and spinosum-
, -used by the kidney to male calcitriol(hormone)-allows us to absorb
Calcium and potassium to manufacture bones.
◉ Thick and thin skin Answer: *Thick skin-has all 5 strata, has stratum
lucidum. Anterior part of hand and posterior part of feet
*Thin skin-does not have stratum lucidum.
Thickest skin is found in the dorsal back but it is not a thick skin(5
starta).
◉ Carotene and melanin Answer: *Carotene-is an orange yellow
pigment that normally accumulates in the epidermal cells.
-found in stratum corneum of light skin people, but also found in fatty
tissues (hypodermis)
-comes from orange vegetables and can be converted for vitamin A.
-Not so obvious for dark skin individual.
*Melanin-brown, yellow brown pigment that produced by the
melanocytes.
-protects us from UV rays.
◉ Epidermal growth factor Answer: Epidermal growth factor or EGF is
a growth factor that stimulates cell growth. produced by the salivary and
duodenum glands.
Roles:
-promote the division of basal cells and stratum spinosum.
