integumentary Flashcards
skin comprises what percentage of total body weight
7%
Where are Langerhans cells most commonly found
stratum spinosum
the layers of the epidermis from most basal to most superficial are
germinativum, spinosum, granulosum, lucidum, corneum
what is the function of tonofilaments in the epidermis
they form keratin and attach intracellularly to desmosomes, hemidesmosomes
how many layers comprise the spinosum
8-10
What accounts for the spinosum’s distinct appearance
courser keratin
What non-keratinocytes are found in the spinosum
Langerhans and processes of melanocytes
desmosomes are most prominent at which epidermal layer
spinosum
major function of the stratum spinosum
strength and flexibility
how many layers make up the granulosum
3-5
At which layer are cells undergoing apoptosis
granulosum
what molecule causes the dark staining of granulosum kerationcytes
keratohyaline
what structure is responsible for waterproofing the skin
lamellar granules and their lipid-rich secretions (found in the stratum granulosum)
How many layers in stratum lucidum
4-6
How many layers in the stratum corneum
25-30
The layer that divides metabolically active cells and cells that have died
Granulosum
How long does the process of keratinizations from production to sloughing take? What influences this rate
4-6 weeks, epidermal growth factor
Which layer of the dermis is thickest and what fibers compose this layer
reticular layer - elastic and collagen
At what month of gestation do epidermal ridges form
3rd month
The two types of melanin
yellow/red pheomelanin and brown/black eumelanin
the two types of sudoriferous glands and their classification for secretion
eccrine and apocrine are both merocrine
What additional substances are secreted from apocrine glands (more so than eccrine)
lipids and protein
3 regions where sebaceous glands are found
hair, lips, glans penis, labia minora, tarsal glands of eyelids
The three portions of a hair
shaft root bulb
The three layers of a hair
medulla cortex cuticle
the layer of the hair making up the MAJORITY of the hair and consists of ELONGATED cells
cortex
The layer of the hair that consists of 2-3 layers of IRREGULARLY shaped cells that contain PIGMENT
medulla
The 2 regions of the follicle (surrounding the hair)
internal root sheath and external root sheath
OUTERMOST layer surrounding the hair follicle
dermal root sheath
papilla
region in the bulb of the hair/follicle where dermis containing blood vessels projects into the bulb
region of the bulb where active cell division occurs
hair matrix
3 structures assoc with hair follicle
sebaceous, nerve root plexus, erector pili
3 stages of hair growth and which is the longest
growth regression and resting. longest is 2-6 years of growth
growth rate for nails
1mm/week
the word for cuticle
eponychium
4 vitamins absorbed at the skin
A,D,E,K
What is excreted through the skin
ammonia, water+salts, urea, carbon dioxide
What does healing by primary intent mean
the edges of a wound are brought together (either naturally or via sutures, staples, glue)
The four stages of deep wound healing
Inflammatory phase, migratory, proliferative, and maturation
how are collagen fibers arranged during proliferative and maturation phases
randomly
