Integumentary System
The secretions of the eccrine glands are:
99% water, sodium chloride, and trace amounts of wastes , lactic acid, and urea
Which two body areas were least sensitive to touch?
Back of neck & forearm
Has abundant elastic and collagenic fibers
Dermis
Major skin area where derivatives (nails and hair) reside
Dermis
Avascular region
Epidermis
Which two body areas are most sensitive to touch?
Fingertips & palm
Structure that houses a hair
Hair follicle
Pain receptors do not adapt. Why is this important?
If we were able to adapt to pain we would not be able to recognize the hazardous conditions that could cause permanent tissue damage
What is true about the papillary layer of the dermis?
It produces the pattern for fingerprints It contains nerve endings that respond to touch and temperature stimuli It is highly vascular It is located immediately beneath the epidermis
Acne is an infection of a
Sebaceous gland
Epidermal region exhibiting the most mitoses
Stratum Basale
Accounts for most of the epidermis
Stratum Corneum
Dead cells
Stratum Corneum
Most superficial epidermal layer
Stratum Corneum
Region where melanocytes are most likely to be found
Stratum basale
Layer containing sacs filled with fatty material or keratin subunits
Stratum granulosum
More numerous variety of perspiration gland that produces a secretion containing water, salts, and vitamin C; activated by rise in temperature
Sweat gland- eccrine
Why is it advantageous to have pain receptors that are sensitive to all vigorous stimuli, whether heat, cold, or pressure?
To warn quickly if any type of harm or danger to the body and protects underlying tissues
The white, cheesy-looking substance that is produced by the sebaceous glands and protects a baby's skin while it is floating in its water-filled sac inside the mother is called
Vernix caseosa
What substance is manufactured in the skin (but is not a secretion) to play a role elsewhere in the body?
Vitamin D, stored in the bone, used in intestine, absorbs calcium
Define adaption of sensory receptors
When the receptor discharge slows and conscious awareness of the stimulus declines or is lost untile some type of stimulus change occurs
Subcutaneous tissue (hypodermis)
adipose tissue
Specialized structures that respond to environmental stimuli
arrector pili
Dermal Papillae
attach it to the epidermis, produce finger prints
Layers of the epidermis
basale, spinosum, granulosum, lucidum, corneum
Stratum Spinosum
cells appear spiky because as skin is prepared for histological examination the cells shrink but their desmosomes hold tight, cell division also occurs in this layer , only layers that receive adequate nourishment
Superficial epidermis
composed of epithelium
Dermis
connective tissue
the only dry membrane is the
cutaneous membrane
In a hair, the outermost single layer of cells that overlap one another like shingles is called the __________
cuticle
Reticular layer
deepest skin layer, contains blood vessels, sweat and sebaceous glands, and pressure receptors (pacinian receptors)
the two major categories of membranes are
epithelial and connective
epithelial membranes contain two types of tissue,
epithelial and connective tissue
Keratinocytes
epithelial cells that produce keratin
Primarily dead/keratinized cells
hair & nail
Found everywhere on body except palms of hands and soles of feet
hair follicle
Sheath formed of both epithelial and connective tissues
hair follicle
synovial membranes are found in the
joint cavities
although you get wet while swimming, a tough protein within the skin prevents it from soaking up moisture like a sponge. This substance is:
keratin
the white crescent area located over the nail matrix is called the
lunula
"Sports" a lunula and a cuticle
nail
Stratum Granulosum
named for abunant granules in its cells, contain waterproofing glycolipid that is secreted, contains subunits of keratin, cells are beginning to die
The sebaceous glands produce?
oil
Stratum Corneum
outermost layer, 20 to 30 cell layers thick, accounts for most of the epidermal thickness, cells are dead full of keratin
Two regions of the dermis
papillary and reticular
The more superficial dermis layer
papillary layer
The dermis is composed of the reticular and the ______________
papillary layers
The deepest layer of the dermis is called the __________ layer
reticular
the part of the hair enclosed in the follicle is known as the
root
Its secretion contains cell fragments
sebaceous gland
Acne and seborrhea are caused by problems with:
sebaceous glands
Which type of membrane contains fluid between the visceral and parietal layers?
serous
The part of a hair that projects from the surface of the scalp or skin is called the__________
shaft
Stratum basale
single row of cells, constantly undergoing cell division, about a quarter of cells are melanocytes
Melanocytes
spidery, black pigment producing cells
The epidermis is composed of
stratified squamous epithelium
A needle would pierce the epidermal layers of the forearm in what order?
stratum corneum, stratum granulosum, stratum spinosum, stratum basale
Type of perspiration-producing gland that produces a secretion containing proteins and fats in addition to water and salts
sweat gland- apocrine
the type of connective tissue membrane found in joints is the
synovial membrane
In order to warm the body up when cold:
the arrector pili muscles contract to stand hairs upright
What organ system controls the activity of the eccrine sweat glands?
the nervous system
Which skin area- the forearm or palm of hand- has more sweat glands?
the palm of hand
Stratum Lucidum
thin translucent band of fattened dead keratinocytes
Full-thickness burn
third-degree burns
Keratin
tough fibrous proteins that gives the epidermis its durability and protective capabilities
Papillary Layer
very uneven and has fingerlike projections from superior surface called dermal papillae, capillaries furnish nutrients for epidermis and allow heat to radiate to skin surface. pain receptors are also found here
the layer of the serous membrane that covers an organs is known as the
visceral layer
