Integumentary System Flashcards
Accessory Structures of the Skin
Hair, Nails, Glands- sebaceous, eccrine sweat, apocrine
Types of Tissues of Skin
Epithelium, CT, Muscles, Blood Vessels, Nerve Tissue
Functions of Skin
Protection, Prevention, Regulation, Sensation, Immune Function, Production of Vit D
Epidermis
maximally keratinized stratified squamous epithelium
composed of keratinocytes
Stratum Basale
Deepest layer of epidermis
single layer of cuboidal cells
How long does it take for Keratinocytes to be completely renewed?
3-4 weeks
Melanocytes
in stratum basale
make melanin
Merkel Cells
in stratum basale
respond to continuous touch stimuli
Stratum Spinosum
has polyhedral keratinocytes (more flattened)
Desmosomes
connects cells of stratum spinosum to plasma membrane
Langerhans Cells
modified macrophages in stratum spinosum
Stratum Granulosum
has kerato-hyalin granules
more prominent in thick skin
Stratum Lucidum
only in thick skin
cells begin to degenerate
Stratum Corneum
cells completely filled with keratin, have no nuclei or organelles- dead
Dermis
contains blood vessels, nerves, afferent sensory receptors, Meissner corpuscles, free nerve endings
Hypodermis
aka Subcutaneous
contains loose CT, Adipose, N, A, V
Thick Skin
over palms and soles
stratum corneum very thick
no hair follicles
Papillary Layer of Thick Skin
superficial
Loose CT
Reticular Layer of Thick Skin
deeper
dense irregular CT
Epidermal Rete Ridge
part of epidermis that projects into dermis
Dermal Papilla
part of dermis that projects into epidermis
Thin Skin
Covers whole body except palms and soles
has hair and sebaceous glands
Pacinian Corpuscle
respond to vibration stimuli
in hypodermis
most abundant in fingers and toes
Meissner Corpuscle
sensitive to fine touch
in dermis, mainly thick skin
Clear Cells
Melanocytes, Merkel Cells, Langerhans Cells
Sebaceous Gland
simple branched acinar glands
most numerous in scalp and face
secrete Sebum into hair follicle
Holocrine Secretion
entire cell disintegrates
Sebaceous glands
Sebum
lubricates skin
coats and protects hair shafts from becoming brittle
Eccrine Gland
sweat glands
coiled tubules
Apocrine Sweat Glands
simple coiled tubular glands, larger than eccrine
release by apocrine secretion
aka sexual scent glands
axilla, areola, perianal, genital areas
Apocrine Secretion
release by shedding part of apical cytoplasm
Hair Follicle
make hair and maintain growth
from hypodermis to epidermis
Nails
keratinized sheet on the tip of each digit
