Chapter 4 Flashcards
What is a group of specialized cells that perform specific functions?
Tissue
What is the study of tissue called?
Histology
What are the four main types of tissue?
Epithelial, connective, muscle, nervous
What does epithelial tissue do?
Covers exposed surfaces, lines passages, forms glands
What does connective tissue do?
Fills internal spaces, supports other tissue, transports materials, stores energy
What does muscle tissue do?
Specializes in contraction
What does nervous tissue do?
Carries info through body via electrical impulses
Where are epithelial glands?
Surface of the skin, digestive, respiratory, reproductive, urinary
What do the epithelial glands do?
Physical protection from abrasions, dehydration, chemical and biological agents.. controls permeability, sensation, specialized secretions onto the epiderman surface
What are the characteristics of epithelial glands?
polarity, structure/function difference between apical and basal surfaces, cellularity, attachment to basement membrane, diffusional absorption, regenerates damaged/detached epidermal cells
What are stem cells?
Unspecialized general cells
What does apical mean?
Exposed
What does basal mean?
Attached
What are small finger-like projections of the plasma membrane?
Microvilli
What are small finger-like microtubules?
Cilia
What do microvilli do?
Absorption and secretion
What do cilia do?
Move fluids and secretions over epidermal surfaces
What does the ciliated epithelium do?
Lines the respiratory tract, moves mucus
What does mucus do?
Traps dust, pollen, and other foreign substances
What are cells firmly attached to?
Basement membrane and each other
What is a CAM?
Cell Adhesion Molecule
What are CAMs and what do they do?
Transmembrane protiens, attach opposing plasma membrane and to extracellular material (can attach by proteoglycans), prevent water loss
What is “intracellular cement” really called?
Proteoglycans
What are the three types of cell junctions?
Gap, tight, lumen
What does the gap cell junction do?
Holds cells together via interlocking transmembrane protiens
What are connexions and what do they do?
Transmembrane protiens, allow small molecules and ions to move between cells, common among epitheleal cells and cardiac muscle tissue
What does the tight cell juction do?
Lipid portions of two plasma membranes bound via interlocking junctional protiens, prevents water and solutes from passing between cells
What does the adhesion belt do?
Forms band to encircle cells, binds to cells
What does the lumen cell junction do?
Space inside tubular structures (ER, small intestine) in small intestine to keep enzymes, acid, and wastes in the lumen
What do desmosomes?
CAMs and proteoglycans link opposing plasma membranes, dense area connected to cytoskeleton
What are the two types of desmosomes?
Spot and hemi
What are spot desmosomes?
Small discs connected to intermediate filaments
What are hemi desmosomes?
Resemble half of a spot desmosome, attach cells to basement membrane
How is epithelia classed?
By number of layers and cell shape
Epithelium is thin and flat.
Squamous
Epithelium is like little boxes.
Cuboidal
Epithelium is tall and slender.
Columnar
Epithelium has only one layer.
Simple
Epithelium has multiple layers.
Stratified
What do simple epithelia do?
Thin and fragile, so they handle secretion and absorption
What do squamous epithelial cells look like?
Irregular in shape
Where are simple squamous epithelial cells found?
Alveoli, heart, blood vessels (reduces friction, in slick areas)
What are simple squamous epithelial cells called in the heart and blood vessels?
Endothelium
What are simple squamous epithelial cells called in the pleural, pericardial, and peritoneal cavities?
Mesothelium
What is the purpose of stratified squamous epithelial cells and where are they found?
Handle severe mechanical stresses, surface of skin and lining of mouth
What is the keratinized stratified squamous epithelium?
Superficial layers of epithelial cells packed with keratin filaments in exposed body surfaces
Where is keratinized stratified squamous epithelium found?
Epidermis
What is keratin?
Protien that is tough, flexible, and water resistant
What does nonkeratinized stratified squamous epithelium do and where is it found?
Resists abrasion and must be kept moist, esophagus, mouth, anus, vagina
What does cuboidal epithelial tissue look like?
Hexagonal boxes
What does simple cuboidal epithelial tissue do, and where is it found?
Limited protection, in glands and kidneys
Where is stratified cuboidal epithelial found?
Rare, in sweat glands, mammary glands
Where is transitional stratified cuboidal epithelial tissue and what does it do?
Looks cuboidal between stretched, can look squamous, tolerates repeated cycles of stretching, in urinary bladder
What does simple columnar epithelial cells do and where are they found?
Absorbs and secretes, found in stomach, small intestine, large intestine
What is pseudostratified columnar epithelial tissue and where is it found?
Appears layered but all cells are attached to the basement membrane, several types of cells of varying shape and function, cilla, in the nasal, trachea, bronchi, male reproductive ducts
Where is stratified columnar epithelial found?
Rare, in the pharunx, epiglottus, anus, urethra
What is the epiglottus?
Controls whether you use your esophagus or trachea
What are glands?
Collections of epithelial cells that produce secretions
What are the two types of glands?
Endocrine and exocrine
What do endocrine glands do, and what are some?
Release hormones into bloodstream for distribution (ductless), thyroid, thymus, pituitary
What do exocrine glands do, and what are some?
Release secretions onto epidermis surface like perspiration, tears, milk (sweat glands, tear ducts, mammary glands)
What is connective tissue?
Matrix composed of extracellular protien fibers, specialized cells, and ground substance fluid, composes most tissue, surrounds cells
What are some functions of connective tissue?
Structural framework of the body, transport fluids, dissolve matierals, protect organs, support, surround, and interconnect other types, store energy, defend body from pathogens
What kind of tissue are triglycerides stored in?
Connective tissue
What is connective tissue proper?
Viscous ground substance with many types of cells and extracellular fibers, spil into two
What are the two types of connective tissue proper?
Loose and dense
What is fluid connective tissue?
Watery matrix with dissolved protiens and populations of suspended cells (blood and lymph)
What is supporting connective tissue?
Matrixes are densely packed with extracellular fibers (cartilage, bone)
What are fibroblasts and what do they do?
Always present, most abundant fixed cells, secrete hyaluronan, secrete protien subunits that make large extracellular fibers, produce collagen, elastic fibers, reticular
What is hyaluronan?
Polysaccharide derived from ground substance
What are adipocytes?
Fat cells, contain a single enormous lipid droplet, number varies among connective tissue types, body regions, individuals
What are mesenchymal?
Stem cells respond to injury or infection by dividing into two daughter cells that differentiate into fibroblasts and microphages, or other connective tissue cells
What are melanocytes?
Synthesize and store brown pigment melanin, has a major role in determining skin, eye, and hair color
What are macrophages?
Large eating cells of immune system that engulf bad stuff and release cytokines that activate immune system to recruit more microphages
What is cytokines?
A help alert from macrophages to signal others to come in and fight a problem
What are the two types of macrophages?
Fixed and free
What do fixed macrophages do?
Stay in one tissue
What do free macrophages do?
Roam tissue and come to help with fixed
What is a mast cell?
Immune cell that releases histamine and heparin
What does histamine do?
Stimulates inflammation
What does heparin do?
Anticoagulant that enhances blood flow during inflammation
What are lymphocytes?
Immune cells that migrate and can develop into plasma cells that produce antibodies
What is a collagen fiber?
Most common, long, straight, unbranched, very strong and flexible
What are tendons?
Collagen fibers that connect skeletal muscle to bone
What are ligaments?
Collagen fibers that connect bone to bone
What is reticular fibers?
Form branching interwoven framework that is tough and flexible despite being thinner, stabilize positions of parenchyma, blood vessels, organs, nerves, and structures of organs
What is parenchyma?
Functional cells
What is elastic fibers?
Branched, wavy fibers that return to original length after stretching, relatively rare elastic ligaments, in vertebreal column, made of elastin
What is the epidermis?
Top layer of skin
What is the dermis?
Middle layer of skin
What is the subcutaneous layer?
Not-real layer of skin that holds adipose tissue (fat)
What does the sebaceous gland do?
Produces sebum
What is the hair root?
Part of hair in the skin
What is the hair shaft?
The part of the hair that’s visible
What does the arrector pili muscle do?
Makes the hair stand up (goosebumps)
What does a sweat pore do?
Lets sweat leave the body onto the skin
What does the outer root sheath do?
Protects follicle from the outside
What does the inner root sheath do?
Protects follicle from the inside
What is adipose tissue?
Fat cells/tissue
What does the sweat gland do?
Produces perspiration
What is the stratum basale?
Deepest layer, stem cell layer
What is the stratum spinosum?
Where cells get flat and make keratin
What is the stratum granulosum?
Dead skin, keratin granules
What is the stratum corneum?
Very top, dead skin
What does a vein do?
Carries blood from the heart
What does an artery do?
Carries blood back to the heart
What does the sensory nerves do?
Provides sensation in skin
What does the hair bulb do?
Originates the hair
What is the free edge of the nail?
The part of the nail that isn’t surrounded
What is the nail body?
The nail that’s visible
What is the eronychium?
“Cuticle”
What is the lateral nail fold?
Side of the nail
What is the lunula?
Air-exposed part fo the nail, white crescent shape
What is the proximal nail fold?
Over the bottom of the nail
What is the nail root?
Where the nail originates from
What is the phalanx?
Finger bone
