Chapter 4, Skin and Body Membranes Flashcards
Name the 3 Epithelial membranes
Cutaneous membranes Mucous membranes Serous membranes
Name the type of Connective tissue membrane
Synovial membranes
Cutaneous membrane
= skin Dry membrane Outermost protective boundary Superficial epidermis is composed of keratinized stratified squamous epithelium Underlying dermis is mostly dense connective tissue
mucous membrane
Surface epithelium type depends on site Stratified squamous epithelium (mouth, esophagus) Simple columnar epithelium (rest of digestive tract) Underlying loose connective tissue (lamina propria) Lines all body cavities that open to the exterior body surface Often adapted for absorption or secretion
serous membranes
Surface is a layer of simple squamous epithelium Underlying layer is a thin layer of areolar connective tissue Lines open body cavities that are closed to the exterior of the body Serous membranes occur in pairs separated by serous fluid Visceral layer covers the outside of the organ Parietal layer lines a portion of the wall of ventral body cavity
Specific serous membranes
Peritoneum = Abdominal cavity Pleura = Around the lungs Pericardium = Around the heart
Synovial membrane
Connective tissue only Lines fibrous capsules surrounding joints Secretes a lubricating fluid
Name 4 Skin derivatives
Sweat glands Oil glands Hair Nails
Skin functions by protecting deeper tissues from: (6 things)
Mechanical damage (bumps) Chemical damage (acids and bases) Bacterial damage Ultraviolet radiation (sunlight) Thermal damage (heat or cold) Dessication (drying out)
In addition to protecting deeper tissues, skin also: (5 things)
Aids in body heat loss or heat retention as controlled by the nervous system Cutaneous sensations Temperature, touch, and pain Aids in excretion of urea and uric acid Synthesizes vitamin D
Epidermis
- Stratified squamous epithelium keratinized (hardened by keratin) -prevent H2O loss Avascular
Dermis
- Dense connective tissue - Contains the appendages of the skin
Subcutaneous tissue (hypodermis)
– mostly adipose Not technically part of the skin Anchors skin to underlying organs
Layers of the Epidermis: Stratum basale (stratum germinativum)
Deepest layer of epidermis Lies next to dermis Wavy borderline with the dermis anchors the two together Cells undergoing mitosis Daughter cells are pushed upward to become the more superficial layers
Layers of the Epidermis: Stratum lucidum
Formed from dead cells of the deeper strata Occurs only in thick, hairless skin of the palms of hands and soles of feet
Layers of the Epidermis: Stratum corneum
Outermost layer of epidermis Shingle-like dead cells are filled with keratin (protective protein prevents water loss from skin)
List the Layers of the Epidermis from deepest to most superficial (Bad School Girls Like Champagne)
Stratum basale Stratum spinosum Stratum granulosum Stratum lucidum (thick, hairless skin only) Stratum corneum
Melanin
Pigment (melanin) produced by melanocytes Melanocytes are mostly in the stratum basale Color is yellow to brown to black Amount of melanin produced depends upon genetics and exposure to sunlight
Dermis: Papillary layer (upper dermal region)
Projections called dermal papillae Some contain capillary loops Others house pain receptors and touch receptors
Dermis: Reticular layer (deepest skin layer)
Blood vessels Sweat and oil glands Deep pressure receptors
What are the 3 normal color determinants?
Melanin Carotene Hemoglobin
Melanin
Yellow, brown, or black pigments
Carotene
Orange-yellow pigment from some vegetables
Hemoglobin
Red coloring from blood cells in dermal capillaries Oxygen content determines the extent of red coloring
Alterations in Skin Color: Redness (erythema)
—due to embarrassment, inflammation, hypertension, fever, or allergy
Alterations in Skin Color: Pallor (blanching)
—due to emotional stress such as fear, anemia, low blood pressure, impaired blood flow to an area
Alterations in Skin Color: Jaundice (yellowing)
—liver disorder
Alterations in Skin Color: Bruises
—hematomas
Oil (sebaceous) glands 6 things
Produce oil (sebum) Lubricant for skin Prevents brittle hair Kills bacteria Most have ducts that empty into hair follicles; others open directly onto skin surface Glands are activated at puberty
Sweat (sudoriferous) glands
Produce sweat Widely distributed in skin
Sudoriferous Eccrine glands
Open via duct to pore on skin surface Produce sweat (clear)
Sudoiferous Apocrine glands
Ducts empty into hair follicles Begin to function at puberty Release sweat that also contains fatty acids and proteins (milky/yellowish color)
What’s sweat made out of?
Mostly water Salts and vitamin C Some metabolic waste Fatty acids and proteins (apocrine only)
What is the function of sweat?
Helps dissipate excess heat Excretes waste products Acidic nature inhibits bacteria growth
Hair: What is it? What’s it made out of?
Produced by hair follicle Consists of hard keratinized epithelial cells Melanocytes provide pigment for hair color Hair grows in the matrix of the hair bulb in stratum basale
Hair follicle
Dermal and epidermal sheath surround hair root
Arrector pili muscle
Smooth muscle Pulls hairs upright when cold or frightened
Nails
Scale-like modifications of the epidermis Heavily keratinized Stratum basale extends beneath the nail bed Responsible for growth Lack of pigment makes them colorless
What’s a burn? What are the dangers of a burn?
Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals Associated dangers are Dehydration, Electrolyte imbalance, and Circulatory shock
First-degree burns
Only epidermis is damaged Skin is red and swollen
Second-degree burns
Epidermis and upper dermis are damaged Skin is red with blisters
Third-degree burns
Destroys entire skin layer; burned area is painless Burn is gray-white or black
Burns are considered critical if there is:
Over 25 percent of body has second-degree burns Over 10 percent of the body has third-degree burns Third-degree burns of the face, hands, or feet
Basal cell carcinoma
Least malignant Most common type Arises from stratum basale
Squamous cell carcinoma
Metastasizes to lymph nodes if not removed Early removal allows a good chance of cure Believed to be sun-induced Arises from stratum spinosum
Malignant melanoma
Most deadly of skin cancers Cancer of melanocytes Metastasizes rapidly to lymph and blood vessels Detection uses ABCD rule
ABCD Rule
A = Asymmetry Two sides of pigmented mole do not match B = Border irregularity Borders of mole are not smooth C = Color Different colors in pigmented area D = Diameter Spot is larger then 6 mm in diameter
