Integumentary Flashcards
Integumentary system
body system comprised of the skin and accessory structures, including the hair, sebaceous and sweat glands, and nails
protects the body, maintains homeostasis, and provides sensory information about the external environment
epidermis
outermost layer composed of keratin and stratified squamous epithelium tissue
Nerve endings and blood vessels are not found in the epidermis
Keratin
keratinocytes, which toughen and waterproof skin
Fingernails and toenails are made of keratin, which is also found in the hair and skin
melanocytes (also in epidermis)
give skin its color
merkel cells
.
Langerhans cells
.
epidermis layers
stratum basale (innermost layer), stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum
Epidermal cells
Epidermal cells are found deep in the stratum basale and constantly undergo mitosis to make new cells. As new cells are made, they travel to the outer skin surface, producing the protein keratin.
Epidermal cells fill with keratin and die upon reaching the skin’s surface. When this happens, the leftover keratin from the dead cells help form the stratum corneum, which is the waterproof layer. These dead epidermal cells are gradually shed from the skin and replaced with new cells
dermis
found directly under the epidermis
deep, thick layer is made of tough connective tissue
connected to the epidermis by collagen fibers
nerve endings and blood vessels flow through the dermis
responsible for a person feeling the sensations associated with touch, pain, heat, and cold
Major regions. of Dermis
papillary region and reticular region
Both these regions provide elasticity to the skin, enabling it to stretch
exp: abdominal stretch while pregnant
Hair follicles
sites where hair strands originate before protruding from the epidermal layer and onto the skin’s surface
Sweat glands
produce a fluid that contains water, salts, and other waste products
made of ducts that extend through the epidermis and look like pores on the skin’s surface
Apocrine
glands are found primarily in the armpits and groin area, where hair follicles are abundant
attached to hair follicles and create a watery fluid that contains proteins and fats
inactive until a person reaches puberty
produce sweat when the body is anxious or experiencing stress
Eccrine
glands are found all over the body, primarily on the forehead, neck, palms, and soles of feet
not connected to hair follicles
regulate body temperature with sweating if the body becomes too hot
Sebaceous glands
oil-producing glands are typically attached to hair follicles
They release sebum, which is a fatty, oily substance.
It waterproofs the hair and skin, preventing both structures from drying out
Sebum
has antimicrobial properties, which help the skin fight off infections
hypodermis
contains fat, or adipose tissue, that supplies energy for cells and provides insulation to regulate body temperature
lunula
white space between the nail bed and cuticle
matrix
layer of tissue that contains blood vessels and nerves
Nail Anatomy
The nail plate is the hard outer part of the nail. Adjoining the nail plate is the free edge, which overhangs the fingertip. This is the part of the nail that is commonly groomed and cut down. The nail bed is a layer of skin found under the nail plate. This layer of skin is comprised of epidermal cells. The white space between the nail bed and cuticle is called the lunula. The cuticle is a layer of dead skin cells that accumulate and form a thick overhang layer at the base of the nail and around the nail edge. During nail care, cuticles are removed. Beneath the cuticle is the matrix, which is a layer of tissue that contains blood vessels and nerves.
causes of skin cancer
genetics
strongest risk factor is exposure to ultraviolet (UV) radiation
UV radiation
sunlight and tanning beds
Overexposure to UV radiation damages DNA in the body’s cells
Exposure to UV radiation causes distinct mutations in skin cells
If the body does not repair the damage to these cells, the mutations accumulate. As a result, the cells can transform into cancerous cells and grow uncontrollably. The uncontrolled cell growth can lead to cancerous tumor formations. Most tumors are harmless, but some produce cells that can move away from the original site of DNA damage and establish new tumors in other organs. This process is called metastasis.
Basal cell carcinoma
most common type of skin cancer that occurs in the basal cells of the epidermis. These cells are found in the stratum basale layer and divide to create keratinocytes. Basal cell carcinoma rarely spreads or undergoes metastasis
Squamous cell carcinoma
skin cancer occurs in the squamous cells of the epidermis. It affects the keratinocytes in the stratum spinosum. This is the second-most-common type of skin cancer. Because this type of skin cancer is more aggressive than basal cell carcinoma, if this carcinoma is not removed it can metastasize
Malignant melanoma
skin cancer occurs when there is an uncontrolled growth of melanocytes in the epidermis. Because melanocytes contribute to the pigmentation of the skin, melanoma is often associated with a dark patch on the body. It is the most dangerous and fatal type of skin cancer
