Pre-Week 3 Assignment (Integumentary System)
Melanocyte
cells that contribute to skin color
Keratinocyte
cells that make up the majority of the epidermis
Stratum lucidum
clear dead layer of the keratinocytes that lack organelles
Langerhans cell
immune cells fighting off pathogens
Stratum corneum
layer of dead keratinocytes that are exfolicated (sloughed off)
Stratum basale
layer of keratinocytes touching the dermis
Stratum spinosum
layer where desmosome form between keratinocytes
Stratum granulosum
layer with protein-packed granules in the keratinocytes
Cells that contribute to skin color are found in which of the following layers?
stratum basale; Melanocytes located in the stratum basale produce the pigment (an organic molecule) called melanin. Melanin can absorb a large portion of the UV rays that hit the skin; therefore, protecting underlying layers of tissue from damage. As melanocytes produce melanin, it is released and surrounding keratinocytes absorb the pigment. The amount of pigment produced (not the total number of melanocytes) will contribute to the person's skin color. Sun exposure will trigger melanocytes to produce more melanin, thereby producing a "tan".
The reticular layer of the dermis is in direct contact with the epidermis. T/F
False; The epidermis makes contact with the papillary layer of the dermis. This layer is called the papillary layer because of the finger-like (or nipple-like) projections called papillae that extend toward the epidermis. Papillae means "nipple" in Latin.
The tough material that is also found in animal hooves and protects our skin is _____.
Keratin
Which of the following layers of skin contains the deepest part of a sweat gland?
Reticular dermis
Rapid cell division of keratinocytes occurs in which of the following layers?
Stratum basale
The epidermis does not contain blood vessels and hence, receives its nutrients from the dermis via diffusion. T/F
True; The papillary dermis is highly vascularized with vessels compared to the epidermis that has no vascularization.
