SKIN AND BODY MEMBRANES Flashcards
also referred to as tissue membranes; a thin layer or sheet of cells that cover the outside of our body (skin), organs (pericardium), internal passageways that open to the exterior of the body (mucosa of stomach), and the lining of the moveable joint cavities
body membranes
make up the lining of many tissues in the body, when packed tightly create a barrier that protects us from the pathogens found externally, they also allow sweating to keep our body cool; are also flexible
epithelial cells
are compromised of both epithelial tissue and connective tissue, they are also called covering ang lining membranes
epithelial membranes
this is our skin; is composed of a keratinizing stratified squamous epithelium which has an underlying dermis; differs from other membranes because it is exposed to air and is a dry membrane
cutaneous membrane
wet membrane; composed of epithelium resting on a loose connective tissue membrane called lamina propria; found usually surrounding body organs and body orifices; differs from the cutaneous membrane as it is always moist and is often adapted for secretion and absorption
mucuous membrane
also called serosa; composed of a layer of simple squamous epithelium resting on a thin layer of areolar connective tissue, in contrast with the mucous membrane, serous membranes line cavities closed to the exterior (except dorsal and join cavities)
serous membranes
function is lubrication; if there is no fluid in the space rupturing may occur
serous fluid
wall outside the organ
parietal
touching the organ
visceral
serous membrane lining the heart (fluid is pericardial fluid)
pericardium
serous membrane lining the digestive tract (fluid is peritoneal fluid)
peritoneum
serous membrane surrounding the lungs (fluid is pleural fluid)
pleura
is attached to the rib cage
parietal pleura
is attached to the lung itself
visceral pleura
represented by synovial membranes that are composed of areolar connective tissue and contain no epithelial tissue at all; they line the fibrous capsules surrounding the joints; layers of membrane form a synovial sac containing the synovial fluid designed to lubricate the joints allowing free movement
connective tissue membranes
preventing the entrance of harmful foreign material into the body
protection
maintaining body temperature; the keratin prevents water loss because when water evaporates it brings with it heat (in sweat)
insulation/heat regulation
protects the body from bumps leading to mechanical injury
cushion
excretes salts like sodium chloride, urea via the sweat
excretion
manufactured in the skin through the cholesterol found in the skin by the action of sunlight
vitamin d synthesis
our ability to feel changes outside
sensation
made up of stratified squamous epithelium that is capable of keratinizing or becoming hard and tough; it is avascular; sensory receptors are here
outer epidermis
contains column shaped basal cells that constantly divide and are pushed to the surface; it is also home to melanocytes that produce melanin; most adequately nourished as it is the first layer after the dermis
stratum basale
germinating layer in stratum basale
stratum germinativum
areas of our skin with high concentration of melanin
freckles and moles
composed of basal cells that have matured into squamous cells called keratonicytes, which are responsible for producing protein, a protective protein that make up skin, nails, and hair
stratum spinosum
made up of keratonicytes that have moved up from the squamous cells; as these cells move out, they flatten and stick together, eventually drying and dying out
stratum granulosum
is not present in all skin regions, occurs only where the skin is hairless and thick (palms of the hands and soles of the feet)
stratum lucidum
outermost layer of the epidermis consisting of 20 to 30 dead layers of keratinocytes that are constantly being shed are referred to as corni fed or horny cells
stratum corneum
represent the major cells type of the epidermis, the outermost of the layers of the skin, making up about 90 percent of the cells there
keratinocytes
from membrane bound granules called melanosomes; produced by melanocytes
melanin
also referred to as the “hide”; the strong stretchy envelope that binds the body together; leather bags and goods are treated animal hides
dermis
is the upper dermal region or the outer layer of the dermis; it is uneven and has peglike projections from its superior surface called dermal papillae, which indent the epidermis above.
papillary layer
responsible for the fingerprints because of its peg-like projections and have a furrow between projections forming the fingerprint.
dermal papillae
a sensory receptor for pain
nociceptors
for touch (mechanoreceptor)
Meissner’s corpuscle
detects changes in temperature
Thermoreceptors
associated with sensory nerve endings and serve as touch receptors called Merkel discs
Merkel cells
deepest layer of the skin where the pressure receptors are located (Pacinian corpuscles); contains irregularly arranged connective tissue fibers, as well as blood vessels, sweat and oil glands and deep pressure receptors
reticular layer
deep pressure receptors
lamellar corpuscles
a defect in collagen production; skin becomes very elastic and also affects the joints; there will be hypermobility of the skin meaning it stretches a lot
Ehlers-Danlos syndrome
when the skin in hyperelastic making it fragile
Dermatosparaxis
the adipose layer or hypodermis that acts as shock absorber and acts as a padding for the body. Stores excess fat and acts as a cushion to protect the body from injury.
subcutaneous layer
cold sores; caused by a virus and appears when there is a decrease in the immune system function
herpes simplex
type I; is transferrable to the labia
herpes simplex labialis (lips)
type II; is transferrable to the inguinal
herpes simplex inguinalis (pubic)
black-brown pigment
eumelanin
reddish yellow pigment
pheomelanin
is an orange-yellow pigment; plentiful in carrots and other orange, deep yellow, or leafy green vegetables
carotene
occurs evidently in Caucasian people when the hemoglobin is poorly oxygenated (cut of blood supply) causing the skin to appear blue; common during heart failure and severe breathing difficulties; checked in fair skinned people by pressing the nail beds to test circulation of blood (capillary check); in black people, it is apparent in their nail beds or the conjunctiva of the eyes or underneath their tongue
cyanosis
also known as bed sores; irritation and eventual disruption of skin integrity on pressure areas
decubitus ulcer
fluid filled space created by the separation of the dermal from the epidermal layers of the skin
blister
the active form of Vit. D
calcitrol
mother compound of which Vit. D came from
cholesterol
are all exocrine glands that release their secretions to the skin surface via ducts
cutaneous glands
glands that are found all over the skin except on the palms of the hands and the soles of the feet
sebaceous glands or oil glands
is a mixture of oily substance and fragmented cells; is a lubricant that keeps our skin soft and moist and prevents the hair from becoming brittle; contains chemicals that kill bacteria, so it is important in preventing the bacteria present on the skin surface from invading the deepest skin regions
sebum
forms when sebaceous glands are blocked by sebum
whiteheads
formed when whiteheads oxidizes and dries then it darkens
blackheads
is an active infection of the sebaceous glands accompanied by pimples on the skin
acne
also known as cradle cap in infants; is caused by overactivity of the sebaceous glands
seborrhea
also called sudoriferous glands; are widely distributed in the skin
sweat glands
glands that are far more numerous and are found all over the body. They produce sweat; are an important and highlt efficient part of the body’s heat-regulating equipment.
eccrine glands
a clear secretion that is primarily water plus some salts, vitamin C, traces of metabolic wastes, and lactic acid
sweat
a chemical that accumulates during vigorous muscle activity
lactic acid
glands that are largely confined to the axillary and genital areas of the body; their secretion contains fatty acids and proteins, as well as all the substances present in eccrine secretion, it may have a milky or yellowish color; are activated by pain, stress or sexual foreplay
apocrine glands
is a flexible epithelial structure; produced by hair follicles
hair
part of the hair that is enclosed in the follicle
root
part of the hair that is projecting from the surface of the scalp or skin
shaft
produces hair
hair follicle
small bands of smooth muscle that connect each side of the hair follicle to the dermal tissue
arrector pili
a scalelike modification of the epidermis that corresponds to the hoof or claw of other animals
nail
skin folds in the borders of the nails
nail folds
the edge of the thick proximal nail fold
cuticle
stratum basale of the epidermis that extends beneath the nail
nail bed
thickened proximal area of the nail that is responsible for nail growth
nail matrix
thickened nail matrix that appears as a white crescent
lunule
tissue damage caused by intense heat, electricity, ultraviolet radiation, or certain chemicals which denature proteins and cause cell death in the affected areas
burn
this is used to determine the volume of fluid lost and how much of the body surface is burned
rule of nines
burns where only the epidermis is damaged; the area becomes red and swollen; usually heals after 2-3 days; example is sunburn
first-degree burn
burn that involve injury to the epidermis and upper region of the dermis; the skin is red and painful, and blisters appear
second-degree burn
refers to the first and second-degree burns
partial-thickness burns
burn that destroy the entire thickness of the skin, so these burns are also full-thickness burns; the area appears blanched/blackened; no regeneration of tissues occur so grafting is needed
third-degree burns
are particularly dangerous because of the possibility of burns in respiratory passageways, which can swell and cause suffocation
facial burns
are troublesome because the scar tissue that eventually forms can severely limit joint mobility
joint injuries
itchy red, peeling condition of the skin between toes, resulting from fungus infection; also called tinea pedis
athlete’s foot
inflammation of hair follicles and sebaceous glands, common on the dorsal neck
boils
are composite boils typically caused by bacterial infection; often by straphylococcus aureus
carbuncles
small fluid-filled blisters that itch and sting, caused by herpes simplex infection
cold sores
itching, redness and swellin of the skin, progressing to blistering
contact dermatitis
pink, water-filled raised lesions that develop a yellow crust and eventually rupture
impetigo
a chronic condition characterized by overproduction of skin cells that results in reddened epidermal lesions covered with dry, silvery scales that itch, burn, crack, and sometimes bleed
psoriasis
is the least malignant and most common skin cancer; occur most often on sun-exposed areas of the face and appear as shiny, dome-shaped nodules that later develop a central ulcer with a “pearly” beaded edge
basal cell carcinoma
arises from the cells of the stratum spinosum; they appear as scaly, reddened papule that gradually forms a shallow ulcer with a firm, raised border
squamous cell carcinoma
is a cancer of melanocytes; accounts for only about 5 percent of skin cancers, but its incidence is increasing rapidly and it is often deadly
malignant melanoma
downy type of hair in soon-to-be-born infants
lanugo
white, cheesy-looking substance, produced by the sebaceous glands; protects the baby’s skin while it floating in its water-filled sac inside the mother
vernix caseosa
accumulations in the sebaceous glands which appears as small white spots
milia
hair thinning or some degree of baldness
alopecia
