Chapter 6 Flashcards
The integumentary system
separates and protects us from the external environment.
The epidermis is stratified squamous epithelium divided into five strata,
from deep to superficial: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.
Keratinization
is the transformation of the living cells of the stratum basale into the dead squamous cells of the stratum corneum.
Soft vs hard keratin
Soft keratin is present in skin and the inside of hairs, whereas hard keratin occurs in nails and the outside of hairs.
Thin vs thick skin
Thick skin has all five epithelial strata.
Thin skin contains fewer cell layers per stratum, and the stratum lucidum is usually absent. Hair is found only in thin skin.
Melanocytes
produce melanin inside melanosomes and then transfer the melanin to keratinocytes.
Carotene
an ingested plant pigment, can cause the skin to appear yellowish.
cyanosis.
Decreased oxygen content in the blood results in a bluish color,
The dermis is connective tissue divided into two layers.
Papillary and reticular layer
the subcutaneous tissue
Located beneath the dermis, is loose connective tissue that contains collagen and elastic fibers.
A hair has three parts
shaft, root, and hair bulb
Lanugo
fetal hair) is replaced near the time of birth
terminal hairs
(scalp, eyelids, and eyebrows)
vellus hairs
At puberty, vellus hairs can be replaced with terminal hairs.
Contraction of the arrector pili muscles
which are smooth muscles, causes hair to “stand on end” and produces “goose bumps.”
Sebaceous glands
produce sebum, which oils the hair and the surface of the skin.
Eccrine sweat glands .
produce sweat, which cools the body
Apocrine sweat glands
produce an organic secretion that can be broken down by bacteria to cause body odor.
ceruminous glands
, which make cerumen (earwax)
Nail root vs. body
The nail root is covered by skin, and the nail body is the visible part of the nail.
The lunula.
is the part of the nail matrix visible through the nail body
The nail
is stratum corneum containing hard keratin.
cholecalciferol
Produced by ultra violet light, which is modified in the liver and then in the kidneys to form active vitamin D.
Calcitriol
Active vitamin D, l, increases blood calcium levels by promoting calcium uptake from the small intestine.
