integumentary system: test 1 Flashcards
What is the integumentary system?
includes skin, muscle, and nerve endings. Epidermal derivatives.
what is largest organ in the body? Organ is multiple tissues working together for a common purpose.
skin
what is the most superficial layer of skin and is Keratinized stratified squamous epithelium?
epidermis
what are keratinocytes?
90% of the epidermal cells. Squamous epithelial cells contain keratin protein.
what is keratin?
a tough, semi-waterproof protein. Strengthens cells to prevent abrasion and makes skin semi-waterproof.
what are melanocytes?
8% of cells. make melanin pigment and put it in keratinocytes. Melanin is a dark pigment to protect skin from UV radiation.
what are langerhans cells (dendritic cells)?
immune cells. Crawl around in lowest levels of epidermis and fight pathogens. (makes up 2% of epidermis along with merkel cells)
what are merkel cells (tactile cells)?
sensory receptors for touch. In lowest levels of epidermis. (makes up 2% of epidermis along with merkel cells)
what is the deepest layer of epidermis? Once cell layer thick, Cells divide here, and Cells are square and alive.
stratum basale
what layer is 8-10 cells thick. Cells are still alive. Melanocytes put melanin into keratinocytes here.
stratum spinosum
what layer is 3-5 cells thick. Keratinocytes begin to die and flatten here. Keratinocytes make keratin here.
stratum granulosum
what layer is only in thick skin. On the palms of the hands and soles of the feet. 3-5 cells thick. Cells are dead and transluscent.
stratum lucidum
what layer is most superficial layer. 25-30 cells thick. All keratinocytes are dead, flat and full of keratin. The purpose is protection.
stratum corneum
what is the dermis?
the dermis is the deepest skin layer. Made of dense irregular connective tissue with lots of collagen and elastic fibers.
what is the papillary region?
papillary region is the upper 20% of dermis. Has projections called papilla. In papilla are corpuscles of touch sensory receptors for touch.
what is the reticular region?
the reticular region is the lower 80% of dermis. Has nerve capillaries. Some adipose tissue and epidermal derivatives. At lower dermis are lamellated corpuscles sensory receptors for touch.
What is the term for the layer between skin and skeletal muscle? Made of areolar connective tissue can contain lammelated corpuscles contains lots of adipose cells.
Subcutaneous layer (hypodermis)
What are structures formed by epidermis that grow into dermis and give skin extra functions ?
Epidermal derivatives
What is the part of hair past the skin ?
Shaft
What is the part of the hair under the skin?
The root
What is the medulla ?
Inner cylinder 3-5 cells thick
What is the cortex ?
3 cells thick
Cylinder around medulla
Has pigment cells for color
What is 1 cells thick, flat epidermal cells filled with keratin arranged like shingles ?
Cuticle (hair)
What is a hair follicle ?
Epidermal structure
In dermis surrounding each hair.
What is the external root sheath ?
Epithelial cells next to dermis
What is the internal root sheath?
Epithelial cells against the hair
What is the swelling at bottom of follicle, capillaries enter here?
Bulb of hair
What is the hair root plexus ?
Nerve ending attached to bulb
What is the arrector pili muscle?
Smooth muscle attached to follicle pulls hair straight
What type of gland secretes oil into skin to moisten skin and hair uses hair follicles as ducts ?
Sebaceous glands
What is eccrine gland ?
All over body. Sweat is water and ions to cool body.
What type of gland is in arm pits and pubic area, active at puberty? Sweat has organic chemicals pheromones to attract males.
Apocrine glands
What type of gland makes wax in ear canal?
Ceremonious glands
What are plates of very tightly packed highly keratinized squamous epithelial cells?
Nails
What is the nail body ?
Part above the skin
What is the free edge of the nail?
End/tip of the nail that extends past the digit
What is the nail root ?
Part under the skin ends at nail matrix (nail grows from matrix )
What is the lunula ?
At proximal body light patch of skin this is stratum basale.
