Chapter 4-Skin and Body Membranes Flashcards
Cover surfaces, line body cavities, and form protective (and often lubricating) sheets around organs.
Body membranes
Two major groups of body membranes
Epithelial membranes and connective tissue membrane
These includes the cutaneous, mucous, and serous membrane. This is also called as the covering and lining membrane.
Epithelial membrane
This is represented by synovial membranes
Connective tissue membrane
It is exposed to air and is a dry membrane
Cutaneous membrane
Composed of stratified squamous epithelium
Superficial epidermis
It is mostly dense (fibrous) connective tissue.
Dermis
It is composed of epithelium resting on a loose connective tissue membrane
Mucous membrane (mucosa)
A loose connective tissue membrane where one of the membrane rests
Lamina propria
This membrane type lines all body cavities that open to the exterior such as the respiratory, digestive, urinary, and reproductive tracts.
Mucous membrane
They are moist membranes that are almost continuously bathed in secretions.
Mucous membrane
It is also called as serosa, and is conposed of a layer of simple squamous epithelium resting on a thin layer of areolar connective tissue
Serous membrane
These line the body cavities that are closed to the exterior
Serius membrane
It lines a specific portion of the wall of the ventral body cavity.
Parietal layer
It covers the outside of the organs in that cavity.
Visceral layer
These separated by a scanty amount of thin, clear fluid
Serous fluid
That lines the abdominal cavity and covering the organs
Peritoneum
Surrounding the lungs
Pleura
Around the heart
Pericardia
Composed of loose areolar connective tissue and contain no epithelial cells at all.
Synovial membrane
These membranes line the fibrous capsules surrounding joints where the provide a smooth surface and secrete a lubricating fluid
Synovial membrane
Small sacs of connective tissue
Bursae
Tubelike of connective tissue
Tendon sheaths
Functions of integumentary system
Mechanical damage (bumps and scars) Chemical damage (acids and bases) Bacterial damage (microbes) Ultraviolet radiation (damaging effects of sunlight) Thermal (heat or cold) damage Desiccation (drying out) Aids in body heat loss or heat retention (controlled by the nervous system) Aids in excretion of urea and uric acid Synthesizes vitamin D
Resists abrasion on the skin’s surface and also reduces water loss through the skin
Epidermis
Bulk of f skin. 10-20 times thicker than the epidermis
Responsible for the structural strength of the skin
Dermis
Made up of stratified squamous epithelium and is avascular
Epidermis
Cell types
Keratinocytes
Melanocytes
Langerhans cells
Merkel cells
Produces a protein mixture called keratin, which makes the cells hard
Keratinocytes
Contribute to skin color
Melanocytes
Part of the immune system
Langerhans cells
Specialized epidermal cells associated with the nerve endings for detecting light touch and superficial pressure
Merkel cells
Process of new formed cells, the push older cells to the surface when they slough off
Desquamatio
Deeper epidermal layers move to the surface, the cells change shape and chemical composition
Keratinization
5 epithelial strata/ layers of epidermis
Stratum basale Stratum spinosum Stratum granulosm Stratum lucidum Stratum corneum
Deepest cell layer of the epidermis and it also lies closest to the dermis
Stratum basale
Stem cells in this layer are constantly dividing, and millions of new cells are produced daily; hence its alternative name is __________
Stratum germinativum
As these cells are constantly dividing and the daughter cells are destined to become epidermal cells are pushed forward, away from the nutrition, to becom part of the more superficial layers, the ________________ and _______________
Stratum spinosum and stratum granulosm
As they leave the stratum granulosm, theh die, forming the clear _______, which is only present where the skin is hairless and extra thick like the palms of the hands and soles of the feet
Stratum Lucidum
The outermost layer, 20-30 cell layers thick and three quarters of the epidermal thickness
Stratum corneum
The dermis consists of two major regions
Papillary layer and reticular layer
Superficial dermal layer
Papillary layer
It is uneven and has peglike projections from its superior surface called
Dermal papillae
Deepest skin layer
Reticular layer
It contains dense irregular connective tissue, as well as blood vessels, sweat and oil glands, and deep pressure receptors called
Lamellar corpuscles
What are found throughout the dermis?
Collagen and elastin fibers
These are fibers that are responsible for the toughness of the dermis; they also attract and bind water and thus help to keep the skin hydrated.
Collagen fibers
Gives the skin its elasticity when we are young
Elastic fibers
What are the three pigments contribute to skin color?
Melanin, carotene, and hemoglobin
The amount and kind (yellow, reddish brown, or black) in the epidermis
Melanin
Deposited in the stratum corneum and subcutaneous tissue. The skin tends to take on a yellow-orange cast.
Carotene
Oxygen-rich (pigment in RBC’s) in the blood vessel
Haemoglobin
Large amounts of melanin are found in certain regions of the skin
Freckles Moles Nipples Areolae Axillae Genitalia
Less melanin areas
Lips
Palms of the hands
Soles of the feet
What condition does a person have if the hemoglobin is poorly oxygenated and both the blood and the skin of light-skinned people appear blue?
Cyanosis
Reddened skin
Erythema
And abnormal yellow skin tone usually signifies a liver disorder in whivh excess bile pigments accumulate in the blood, circulate throughout the body and is deposited in body tissues
Jaundice
The black and blue marks, where blood has escaped from the circulation and has clotted in the tissue spaces
Brusies
Clotted masses
Hematomas
Bleeder’s disease
Hemophilia
Recessive genetic trait that causes a deficiency or an absence of melanin
Albinism
What are the appendages of the skin?
Cutaneous glands
Hair and Hair follicles
Nails
Cutaneous glands is made up of two groups
Sebaceous glands and sweat glands
This is found all over the skin except on the palms of the hands and the soles of the feet
Sebaceous (oil) glands
What is the by-product of the sebaceous glands, which is a mixture of oily substances and fragmented cells?
Sebum
What happens when sebaceous gland ducts are blocked by sebum and is an active infection of the sebaceous glands?
Acne
If the accumulated material oxidizes and dries, it darkens and forms a _______
Blackheads
It doesn’t dry or darken
Whitehead
Known as the “cradle cap” in infants, is caused by overactivity of the sebaceous glands
Seborrhoea
This is also called as sudoriferous glands.
Sweat glands
Two types of sweat glands
Eccrine and apocrine
They produce sweat (water+salts, vit. C, traces of metabolic wastes, lactic acid) and is important and highly efficient part of the body’s heat-regulating equipment
Eccrine sweat glands
Largely confined to the axillary and genital areas of the body
Apocrine glands
The secretion is odourless, but when bacteria live on the skin use its proteins and fats as source of nutrients for their growth, it can take on a musky, sometimes unpleasant odor.
Apocrine glands
It is flexible epithelial structure
Hair
Part of the hair enclosed in the hair follicle
Root
Part projecting from the surface of the scalp or skin
Shaft
Made by melanocytes in the hair bulb
Hair pigment
hair is smooth, silky, and wavy
Hair shaft is oval
Hair is curly or kinky
Shaft is flat and ribbonlike
Hair is straight and tends to be coarse
Shaft is perfectly round
Composed of epithelial tissue and forms the hair
Epithelial root sheath
Dermal connective tissue
Outer fibrous sheath
Provides the blood supply to the matrix in the hair bulb(deepest part of the follicle)
Hair papilla
Small bands of smooth muscle cells that connect each side of the hair follicle to the dermal tissue. “Goose bumps”
Arrector pili
It is a scalelike modification of the dermis that corresponds to the hoof or claw of other animals
Nail
Each nail has ________________
Free edge, body(visible attached portion), and a root
Stratum basale pf the epidermis extends beneath the nail
Nail bed
Borders of the nail are overlapped by folds of skin
Nail folds
Edge of the thick proximal nail fold
Cuticle
Itchy red, peeling condition of the skin between the toes, resulting from an infection with thw fungus (tinae pedis)
Athelete’s foot
Caused by inflammation of hair follicles and surrounding tisses, found on the dorsal neck
Boils
Cluster of boils often caused by the bacterium (staphylococcus bacteria
Carbuncles
Small fluid-filled blisters that itch and ating, caused hy human herpesvirus 1 infection. Occurs usually around the lips, and the oral mucosa of the mouth and nose
Cold sores(fever blisters)
Itching, redness, and swelling of the skin, progressing to blistering
Contact dermatitis
Caused by the exposure of the skin to chemicals
Contact dermatitis
Pink, fluid-filled, raised lesions (commonly around the mouth and nose) that develop a yellow crust and eventually rupture. Highly contagious and common in elementary school aged children
Impetigo
Reddened epidermal lesions covered with dry, silvery scales that itch, burn, crack, and sometimes bleed.
Psoriasis
A chronic condition believed to be an autoimmune disorder in which the immune system attacks a person’s own tissues, leading to overproduction of skin cells. And is triggered because of trauma, infection, hormonal changes, or stress.
•Psoriasis
Blood in the potential space of the lungs
Hemothorax
Water inside the potential fluid of the lungs
Hydrothorax
Air inside the potential fluid of the lungs
Pneumothorax
