Skin, hairs, nails lab and lecture Flashcards
Explain keratinization
As new keratinocytes move from the stratum basale to the skin surface, they accumulate more and more keratin, die, and form dead surface layers. This process takes 7-10 weeks.
sebaceous glands
What is the other name for the skin?
cutaneous membrane
thin skin
What are the two main parts of the skin?
epidermis and dermis
What is the name of the muscle attached to the hair, where is it located, and what is its function?
arrector pili muscle of hair (smooth muscle)
extends from papillary dermis to the dermal rooth sheath around the base of the hair follicle
create goose bumps during cold or fright
What are the functions of the stratum basale?
This is the only layer of the skin that undergoes mitosis and creates keratinocytes to replace the regularly shed ones from the top layer. The mitosis happens in the epidermal stem cells.
What are the three layers of the root and shaft of the hair starting from the inside?
medulla, cortex, and cuticle
What is the order of the layers of the epidermis starting from the most deep?
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (in thick skin), stratum corneum
stratum basale or germinativum
What is the average thickness of skin?
1-2mm
Pacinian corpuscle
What are two disorders that related to melanin production?
Albinism- complete lack of melanin production and genetic based
Vitaligo- parital or complete loss of melanocytes from patches of skin. Autoimmune based.
What is contained in eccrine and apocrine sweat?
Ions, urea ,uric acid, ammonia, amino acids, glucose, and lactic acid
dermal root sheath
Define sebaceous glands?
Oil glands that are simple, branched acinar glands.
nail bed or hyponychium
define the cortex
forms the major part of the shaft and consists of elongated cells
What are free nerve endings?
Dendrites that lack apparant structural specialization. Sense warmth, coolness, pain, tickling, and itching.
hair bulb
Structures?
dermal papillae
What are the two types of granules found in the stratum granulosum?
keratohyalin and lamellar granules
What do lamellar granules do?
release a water-repellent sealant that decreases water entry and loss and inhibits the entry of foreign materials
eccrine sudoriferous gland
epidermis
How many layers of cells are in the stratum spinosum?
8-10 layers of keratinocytes
matrix
Pacinian corpuscle
What is type of tissue is the stratum basale made of?
single row of cuboidal or columnar keratinocytes
What are the two additional cells present in the stratum spinosum?
Langerhans cells and the projections of melanocytes
hair shaft
What are the four principal cells in the epidermis?
keratinocytes, melanocytes, Langerhans/dendritic cells, and tactile epithelial cells.
Which layer of skin is vascular?
dermis
apocrine sudoriferous gland
what are the two types of epidermis?
thin(hairy skin) and thick(hairless skin)
What do sebaceous glands secrete and what is it’s function?
sebum which is a mixture of trigycerides, cholesterol, proteins, and inorganic salts. Coats the surface of hairs to keep them supple. Prevents excessive evaporation of water from skin, keeps skin soft, and inhibits the growth of some bacteria.
cortex
What is the inner/internal root sheath?
Produced by the matrix and forms a cellular tubular sheath of epithelium between the external root sheath and the hair. Provides a channel for the hair to grow in.
What is the integumentary system composed of?
skin, hair, oil and sweat glands, nails, and sensory receptors
What is in the subcutaneous tissue?
fat, large blood vessels that supply the skin, and pacinian corpuscles.
What is the other name for merkel cells?
tactile epithelial cells
cuticle
keratinocytes
How many layers does the stratum granulosum have?
3-5 layers of keratinocytes
texture of hair
straight
What is this in yellow?
medulla
Where is hair not located?
nipples, palms, palmar surfaces of digits, soles, plantar surfaces of feet, labia minora, and prepuce of the penis.
matrix cells
What are the three types of hair and what are their characteristics?
lanugo-fetal hair
terminal hair- coarse, heaily pigmented hair, often associated with secondary sexual characteristics at puberty
vellus hairs-peach fuzz
males have more terminal hair than females
What affects hair growth?
illness, radiation treatment, chemo, age, genetics, gender, and severe emotional stress. Extreme dieting, weightloss, and post partum.
nail body
hair follicle
Define apocrine sweat glands?
coiled tubular glands found mainly in the armpit, groin, areola, and beard areas. Release secretions via exocytosis NOT APOCRINE. Located in the reticular dermis and their ducts open into hair follicles.
Hair root
When do each type of sweat gland begin working?
Eccrine after birth
Apocrine during puberty
What is the other name of langerhans cells?
dendritic cells
What are the two types of melanin?
Eumelanin and pheomelanin
What is alopecia?
partial or complete lack of hair caused my genetic factors, aging, endocrine disorders, chemo, or skin diseases
Label starting with top left.
eponychium (cuticle), lunula, nail body, hyponychium, nail matrix
dermis
eccrine sudoiferous gland
dense irregular connective tissue
What two structures are associted with hair?
sebaceous glands and smooth muscle fibers
What causes fingerprints?
papillary ridges?? epidermal ridges?? sources differ
arrector pili
Label starting at top right