Simple squamos epithelium
flat with flattened nucleus, found in areas of diffusion-BV, alveoli of lungs, also protects,
Simple Squamous Epithelium(Serous membranes) lining pleural, peritoneal, and pericardial cavities
Simple squamous epithelium lining BV, heart, and lymphatic vessels
Single layer cube shaped cells with round nucleus, forming walls of smallest ducts of glands and kidney tubules, secretion and absorbtion
SIngle layer of tall cells with oval to round nucleus found in GI tract from stomach to anus as well as uterus, with cillia or microvilli, absorption, propulsion by cillia
Psuedo stratified columnar
Single layer of cells of differing heights, only tallest cells reach apical layer, secretion and propulsion of mucus by cillia,, in sperm ducts and ducts of large glands in upper respiratory tract
Thick membrane of several cell layers, surface cells are flattened, protects underlying tissues from abraison, in keratinized (Epidermal) cells are flattened dead sacs of keratin, in nonkeratinized-line mouth, esophogus, and vagina they are moist and slick
Generally 2 layers of cube like cells, protection, largest ducts of sweat, mammary, and salivary glands
Superficial cells elongated and columnar, cuboidal basal cells, protection and secretion, small amounts in male urethra, some ducts and glands
Combination cuboidal and columnar, stretch readily and permit distenstion by urine, found in ureters, bladder, and part of urethra
Unicellular gland produces mucin, precusor to mucus, which protects, covers, and lubricates many internal body surfaces
Release substances (sweat, oil, milk) to outside of body
Eccrine and Apocrine glands
Release sweat, suderiferous glands to outside body, only found on thin skin areas, Eccrine more numerous and produce true sweat, Apocrine are confined to axilary, genital, and anal areas, larger than sweat glands, open in to hair follices, release sweat including fatty substance and proteins that is source of body odor, mature and activate at puberty
Tight Junction- Belt like junction at apical region of epithelial tissues that holds adjacent cells closely to eachother, closing off extracellular space, Adherens Junction-just below the tight junction, reinforces tight junction particularly when tissue is strectched, Desmosomes- join together with neighboring cell's linker proteins as well as intermediate fillaments to form a continuous network of "guy-wires" , desmosomes are most plentiful in tissue that experiences great mechanical stress
Glands that release proteins (hormones) directly into blood stream
Border between epithelium and CTP, thin, noncellular, consists of proteins secreted by epithelial cells, acts as selective filter as well as scaffolding for migrating regenerating epithelium
Together the Basal Lamina and reticular fiber layer deep to it create the basement membrane
Fingerlike extensions of plasma membrane of apical epithelial cells, increase surface area, aid in absorbtion, exist on every moist epithelia, but most dense in small intestine and kidney
Whiplike motile extensions of apical surface of certain epithelial cells, contains core of microtubules pairs in 9 outer + 2 inner arrangement called axoneme, longest and most abundant on epithelia that transport or absorb, or secrete mucus =GI Tract, Lungs
Connective tissue proper-realatively few cells, lots of extracellular matrix composed of ground substance(most -soft, gel like substance that holds tissue fluid, In bone it's hard and holds calcium salts) and fibers. Fibrous portion is collagen, reticular, and elastic fibers. 2 types-loose(areolar, adipose, reticular, and dense (irregular, regular, and elastic)
Areolar connective tissue
Most plentiful connective tissue in body, supports and binds other tissues, holds body fluids, defends body against infection, stores nutrients as fat, Contains collagen, reticular and elastic fibers, ground substance holds fluid, defense cells fight infection as areolar tissue contains Macrophages(big eaters), Plasma cells(secrete antibodies), Mast cells (inflammatory process), and Neutrophils, Lymphocytes, and eosinophils. A minor function is that it's fat cells store nutrients.
Similar to areolar in structure and function, but with greater nutrient storing function, 90% of mass is fat cells, most lin layer beneath skin called hypodermis, also in messenteries (between stomach and intestines, and cushioning pads behind eyeballs, around kidneys,.
Reticular connective tissue
Network of reticular fibers in loose ground substance, reticular cells lie in network, forms a soft skeleton to support other cell types like WBCs, macrophages, and mast cells, found in lymphoid organs and spleen
Dense Connective Tissue
Aka fibrous connective tissue, can be regular(evenly arranged collagen fibers) or irregular(randomly arranged collagen fibers) in make up, contains more collagen than areolar connective tissue, extremely strong and resists pulling forces, composes fibrous capsules(regular) that surround organs like kidneys, lymph nodes, and bones, makes up 80% of the dermis(irregular),
Keratinized stratified squamous epithelium containing 4 distinct types of cells, melanocytes(pigment)merkel cells(touch receptors)ketatinocytes(produce keratin) and langerhans cells(police outer body surface/immune response cells) and either 4 or 5 layers depending on whether thin(everywhere on body except) or thick(soles and palms) skin. Avasulcar but innervated, reproduces quickly -entirely new epidermis every 35-45 days.
Basal layer aka stratum germanitivum, a single row of cells, rapidly dividing, merkel cells distributed amongst keratinocytes,
several cell layers thick, spiny appearance to cells from artifacts from desmosomes, cells contain tonofilaments-tension filaments. Langerhans cells found here police outer body surface.
Consists of 1 to 5 layers of flattened kertatinocytes, abundant tonofilaments, keratohylin and lamellated granules, slow loss of water throughout epidermis, and thicken plasma membranes to toughen cells approaching outer layer.
Many thick, dead flattened cell layers, dead cells filled with keratin,protect against abrasions and penetration.
Second major layer of the skin, richly supplied with nerve fibers and blood vessesls, holds entire body together like a body stocking
Deep blood vessel network located between hypodermis and dermis, nourishes hypodermis and deep dermal structures,
just below dermal papillae, nourishes superficial dermal structures, dermal papillae, and deep epidermis, also aids in temperature regulation. Dermal BV hold 5% of blood in body.
The superficial 20% of dermis, areolar connective tissue containing very thin collagen and elastic fibers. Dermal papillae are projections into epidermis that increase surface area, on soles and feet they lay on ridges that create foot/hand prints.
80% of thickness of dermis, dense irregular connective tissue,
aka superficial fascia consists of adipose and areolar connective tissue, but adipose predominates,anchors the skin to underlying structures, stores fat, acts as an insulator.
small bands of smooth muscles that connect each side of the hair follicle to the dermal tissue, cause hair to stand on end when frightened or cold