skin
Place the steps in the production of vitamin D as they occur, starting at the top.
-Production of dehydrocholesterol in skin cell -production of cholecalciferol with the help of sunlight -production of calcittiol in liver and kidney cells
How is melanin protective?
Absorbs UV radiation from sunlight
The dermis consists of two layers: the superficial_____ layer and the deep _____ layer.
Blank 1: papillary Blank 2: reticular
In most areas of the body, the epidermis contains four layers called stratum. basale, stratum ______, stratum________ , and stratum corneum.
Blank 1: spinosum Blank 2: granulosum
Why do the cells of the epidermis die as they are pushed towards the surface of the skin?
They are too far from their nutrient supply.
What is the function of a keratinocyte
To produce a waterproofing protein.
How is melanin protective?
absorbs UV radiation from sunlight
Cancer called cutaneous carcinoma originates with what cell type?
basal
Cell division by cells of the stratum _________replaces the shedding skin cells of the stratum corneum.
basale
Cell division by cells of the stratum _____replaces the shedding skin cells of the stratum corneum.
basale
Within the epidermis, cell division and growth occur in the stratum
basale
Melanocytes are found within the stratum
basale epidermis
In the epidermis of thin skin, where is the stratum spinosum found?
between the stratum basale and stratum granulosum
Lack of a blood supply within the epidermis is the cause for what characteristic of epidermal cells? Multiple choice question.
cells near the skin surface are dead
What are the two protective functions of sebum?
contains an anti-microbial compound prevents water loss
The outermost layers of the epidermis are called the stratum
corneum
Sweat glands consist of coiled tubes that originate in what layer of the skin?
deep dermis
Which of the following are cells found within the stratum spinosum that are responsible for protecting the skin from pathogens?
dendritic cells
The epidermis is avascular (lacks blood vessels). Therefore, oxygen, nutrients, and wastes must diffuse to and from blood vessels found in what region of the skin?
dermis
The papillary and reticular layers are the two layers of the
dermis
Within the skin, the ______ is the thicker layer composed primarily of connective tissue, while the ______ layer is composed of stratified squamous epithelium
dermis; epidermal
Within the skin, the ______ is the thicker layer composed primarily of connective tissue, while the ______ layer is composed of stratified squamous epithelium.
dermis; epidermal
What variation in melanin accounts for the differences in skin tone between individuals?
differences in the amount of melanin produced
What layer of the skin lacks blood vessels?
epidermal layer
Patches of oxidized sweat gland secretion commonly called "age spots" or "liver spots", occur in the ______ as a person ages.
epidermis
The layer of the skin called __________the lacks blood vessels.
epidermis
The skin contains two distinct layers,
epidermis and dermis
List three of the functions of the skin.
excretion of waste materials protective covering regulation of body temperature
Indicate the factors that stimulate melanin production.
exposure to sunlight exposure to X-rays exposure to ultraviolet light
True or false: Skin color is primarily due to a protein in skin cells called keratin.
false
True or false: The number of melanocytes in a person's skin determines how dark their skin tone will be.
false
The secretion released by sebaceous glands are ______ secretions.
fatty
A hair ______ is a tubelike depression from which a hair develops.
follicle
a hair ____is a tubelike depression from which a hair develops.
follicle
What is the tubelike depression from which a hair grows and emerges at the skin surface?
hair follicle
Which of the following are included in the integumentary system?
hair, skin, nails, and sebaceous and sweat glads
Cellular metabolism results in the production of ______ as energy is lost.
heat
The skin and its accessory organs form the
integumentary system
Which statement describes the stratum basale of the epidermis?
it contains cells that are dividing
The scaly appearance of the skin of older individuals results from changes in the protein called ______, found within epidermal cells.
keratin
The process by which epidermal cells begin to harden due to the accumulation of the protein keratin is called
keratinization
Cells in the epidermis that produce keratin are called
keratinocyte
What type of epidermal cell produces the protein keratin?
keratinocyte
Merkel cells in the epidermis respond to _____
light touch
The epidermis of thick skin contains an extra layer called the stratum _________ . This layer is typically lacking in thin skin.
lucidum
The stratum corneum of the epidermis is made of ______.
many layers of tough, tightly packed, dead cells
The primary determinant of skin color is a pigment-protein called
melanin
The substance called is produced in specialized skin cells. It absorbs ultraviolet radiation from sunlight, preventing it from causing mutations in the DNA of skin cells.
melanin
Cutaneous melanomas, a type of skin cancer, originate from specialized epithelial cells called
melanocytes
Specialized epidermal cells called ______produce the pigment melanin.
melanocytes
The pigment melanin is produced by ______ and contributes to the color that is observed in the skin.
melanocytes
Where on the body is thin skin (with four epidermal layers) found?
most body areas except palms and soles
A nail consists of two parts: a visible nail _____ that overlies a nail_____ .
nail plate and nail bed
The ends of fingers and toes are protected by structures called
nails
Where in the body is thick skin, with five epidermal layers, found?
palms of hands and soles of feet
Identify the two layers of the dermis.
papillary layer reticular layer
What are the two protective functions of sebum?
prevents water loss contains an anti-microbial compound
What is the function of dendritic cells found within the stratum spinosum of the epidermis?
protection from pathogens
The oily mixture secreted by sebaceous glands is called
sebum
Which organ protects, regulates body temperature, and excretes wastes?
skin
What effect can exposure to sunlight, UV radiation, and X-rays have on the skin?
stimulate melanin production
The epidermis only contains one type of tissue, namely
stratified squamous epithelium
What class of tissue forms the epidermis of the skin? Multiple choice question.
stratified squamous epithelium
In what layer of the epidermis are the melanocytes found?
stratum basale
The deepest layer of cells in the epidermis, which is nourished by dermal blood vessels, is called the
stratum basale
The production of new skin cells in what layer typically keeps pace with the loss of cells from the stratum corneum?
stratum basale
Where are tactile cells located in the epidermis?
stratum basale
What epidermal layer is found in thick skin, but not in thin skin?
stratum lucidum
What type of gland in the skin consist of coiled tubes that originate in the deeper dermis or superficial subcutaneous layer?
sweat glands
What is keratinization?
the process by which epidermal cells begin to harden
The palms of the hands and the soles of the feet are covered with ______ skin.
thick
Body areas such as the arms and the legs are covered with ______ skin.
thin
True or false: Body heat is a by-product of cellular metabolism.
true
The synthesis of which vitamin begins in the skin?
vitamin D
