1-G Skin Histology Flashcards
Define the two types of skina and where they are found.
Thick skin is found on palms and soles of feet, areas that need greatest protection from abrasion; thin skin is found everywhere else on the body
What type of connective tissue is the papillary dermis
loose connective tissue
What type of connective tissue is reticular layer of the dermis
type I collagen densse irregular connective tissue; also includes vasculature, innervation, hair follicles and glands.
Reticular layer of dermis is organized in by ____ ____ (important in scarring)
Langer’s Lines
What types of tissue are found in hypodermis?
adipose and loose connective tissue
What are the 5 layers of the epidermis
basale, spinosum, granulosum, lucidum, coneum
Name important characteristics of the 5 layers.
Basale (basement membrane, spot desmosomes and hemidesmosomes); Spinosum (many spot desmosomes); Granulosusm (granules of keratohyalin and dense homogenous deposit granules of for water barrier); Lucidum (dead cells); Corneum (being sloughed off)
What is the function of Langerhans cells
they are the immune cells of the skin (easily damaged by UV)
What is the function fo Merkel cells
located in the basal layers of epidermis and contain neurosecretory granules and work with sensory neruons
What embryonic tissue are melanocytes derived from
neural crest
Describe the structure of hair follicles
interaction between dermis and epidermis cause the epidermis to invaginate into the dermis, at the base of mature follicle there is atuft of vascular loose connectibe tissue called the dermal papilla that stimulates the production of hair (hair made of karatinocytes and melanocytes); can go through cycles of growth and dormancy
What serves as the duct for sebaceous glands
hair follicle
Integrate the functional relationship between hair follicles, sebaceous glands and arrector pili muscles
Arrector pilli muscles can cause secretion of sebaceous glands into the hair follicles that are used as a duct
Explain how sebaceous gland produce and secrete sebum
cells fill with oily product until their death and then are excreted by holocrine secretion
Name the two types of sweat glands
eccrine (most common for thermoregulation and intiated by sympathetic ) Apocrine (secret into hair follicles in the axilla, nipple and genital area producing a viscous sweat)
