BIOL235 Unit 1 Ch 4

Tissue

groups of cells that usually have common origin in embryo and function together to carry out specialized activities

Histology

study of tissues

Pathologist

physician who examines tissues for diagnosis

Epithelial tissue

tissue that covers body surfaces and lines hollow organs, body cavities and ducts, and forms glands which allows the body to interact with internal and external environments

Connective tissue

tissue that protects/supports body organs, binding organs together, store energy reserves as fats, and help provide body with immunity against disease

Muscular tissue

tissue composed of cells specialized for cotraction and generation of force, also generates heat for warming the body

Nervous tissue

tissue that detects changes in a variety of conditions inside and outside the body, and responds by generating action potentials

Cell junctions

contact points between plasma membranes of tissue cells

Tight junctions

cell junctions with web like strands of transmembrane proteins that fuse together the outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells

Plaque

dense layer of proteins on inside of plasma membrane

Adheren junctions

cell junctions that contain protein plaques on the inside of a plasma membrane that attach to membrane proteins and microfilaments of the cytoskelaton

Cadherin

Transmembrane glycoprotein that joins cells in adheren junctions and desmosomes

Adhesion belt

when cadherin proteins insert into plaque from opposite side of plasma membrane, partially crosses intracellular space and connects to cadherins of adjascent cell that encircles cell

Desmosomes

cell junctions that contain plaques and transmembrane glycoproteins that extend into the space between adjacent cell membranes attatching to the intermidiate filaments within

Spot-weld

description for desmosomes junctions

Epidermal cells

in _______________ desmosomes are most comon and function to prevent seperation under tension

Hemidesmosomes

resemble desmosomes but do not link adjacent cells

Integrin

Transmembrane glycoprotein of hemidesmosomes

Laminin

protein on outside of plasma membranes that integrin attatches to which is present in basement membranes

Gap junctions

cell junctions that allow the passage of cytosol, ions and small molecules to between cells

Connexins

membrane proteins of Gap junctions

Connexons

tiny fluid filled tunnels of gap junctions

High, low

epithelial tissue has a ____ number of cells and a ____ amount of extracellular matrix

Low, high

connective tissue has a ____ number of cells and a ____ amount of extracellular matrix

Avascular, vascularized

epithelial tissue is ________ whereas connective tissue is highly _________

Surface layers

epithelial tissue almost always forms ________

Close

epithelial tissue is often ________ to connective tissue because

Epithelial tissue

consists of cells arranged in continuous sheets in single or multiple layers, functionally protects, secretes, absorbs, and excretes

Apical surface

surfaces facing towards the lumen/outside away from tissue origin

Lateral surface

surface between cells in the side by side plane

Basal surface

surface facing towards cellular origin

Basement membrane

thin extracellular layer formed at the deepest basal surface level, where epithelium attaches/anchors to underlying connective tissue, and form surface along which epithelial cells migrate during growth/wound healing

Basal lamina

lamina of basement membrane that is next to epithelial cells

Reticular lamina

lamina of basement membrane that is next to underlying connective tissue

Covering/Lining/Surface epithelium

1 of 2 forms of epithelium that forms outer coverings of the skin and internal organs

Simple epithelium

single layer of cells that functions in diffusion, osmosis, filtration, secretion or absorption

Secretion

Production and release of substances such as mucus, sweat or enzymes

Absorption

The intake of fluids or other substances such as digested food

Pseudostratified epithelium

appears to have multiple layers of cells because the cell nuclei lie at different levels and not all cells rest on the basement membrane but it is a single layer of cells

Stratified epithelium

consists of two or more layers of cells that protect underlying tissue in locations where there is considerable wear and tear

Squamous cells

epithelial cells that are thin which allow for rapid passage of substances through them

Cuboidal cells

epithelial cells that are as tall as they are wide to protect underlying tissues

Columnar cells

epithelial cells that are much taller than they are wide, protecting underlying tissues

Transitional cells

epithelial cells that change shape from squamous when stretched to cuboidal when unstretched and back as bladder stretches (super elastic)

Simple squamous epithelium

single layer of flat cells that are present in areas of filtration/diffusion and not present in mechanically high stress areas

Endothelium

lines cardiovascular and lymphatic system

Mesothelium

epithelial layer of serous membranes

Simple cuboidal epithelium

single layer of cube shaped cells, functions for secretion and absorption, lines ovaries, lens capsule, pigmented retina and kidney tubules

Globlet Cells

Modified columnar epithelial cells that secrete mucus

Noncilliated simple columnar epithelium

Has microvili, and globlet cells. It lines GI tract, ducts of many glands, and gallbladder. Has higher level secretion and absorption than cuboidal

Cilliated simple columnar epithelium

Has cillia that beat in unison to move mucus up respiratory tract, oocytes to uterus through uterine tubes, and CSF through central canal of spinal cord

Noncilliated pseudostratified columnar epithelium

lines epididymus, large ducts and male urethra, function to absorb and secrete

Cilliated pseudostratified columnar epithelium

lines upper respiratory tract and contains globelt cells. This functions to trap foreign particles in the mucus it secretes and then sweep them out of the body with the cillia

Stratified squamous epithelium

multilayer epithelium with a squamous apical surface that protects against abrasion, water loss, UV radiation, and foreign invasion

Keratin

tough fiberous intracellular protein protecting from heat, microbes, and chemicals

Keratinized stratified squamous epithelium

tougher superficial layer of external skin

Nonkeratinized stratified squamous epithelium

lines wet surfaces (mouth, epiglottis, pharynx, esophagus, vagina, tongue)

Stratified cuboidal epithelium

line ducts of sweat glands, esophageal glands, and male urethra with the function of protection along with some limited secretion and absorption

Stratified columnar epithelium

often consists of shortened irregular shaped cels under a columnar apical layer. Lines urethra, large excretory ducts of some glands, mucosal membrane, and conjunctiva of eye

Glandular epithelium

1 of 2 forms of epithelium that makes up secreting portion of gland

Gland

epithelium that secretes substances into ducts, onto a surface or into the blood

endocrine

secretes hormones into interstitial fluid and then diffuse into blood stream and have far reaching effects throughout th body

exocrine

secretes products into ducts that empty onto surface like skin or organ lumen with limited reaching effects

unicellular

single celled glands are termed

multicellular

composed of many cells that form distinctive microscopic structure or macroscopic organs

simple gland

a gland that doesn't branch

compound gland

a gland that branches

tubular gland

a gland with tube shaped secretory paths

acinar glands

a gland with rounded secretory paths

tubuloacinar glands

a gland with tube shaped and rounded secretory paths

Simple tubular glands

Tubular secretory part is straight and attaches to a single unbranched duct

Simple branched tubular glands

Tubular secretory part is branched and attaches to a single unbranched duct

Simple coiled tubular glands

Tubular secretory part is coiled and attaches to a single unbranched duct

Simple acinar glands

Secretory portion is rounded, attaches to single unbranched duct

Simple branched acinar glands

Rounded secretory part is branched and attaches to a single unbranched duct

Compound tubular glands

Secretory portion is tubular and attaches to a branched duct

Compound acinar glands

Secretory portion is rounded and attaches to a branched duct

Compound tubulaoacinar glands

Secretory portion is both tubular and rounded and attaches to a branched duct

merocrine glands

classification of exocrine gland where secretory vesicles from the golgi containing proteins from the RER are released via exocytosis (most common exocrine gland)

apocrine glands

classification of exocrine gland where products accumulate at the apical surface of a cell and then bud off with it via exocytosis

holocrine glands

classification of exocrine gland where products accumulate in the cytosol and as the cell matures it ruptures releasing its product

Connective tissue

binds together, supports and stregthens other body tissues; protects and insulates organs; compartmentalizes structures; serves as major transport system; primary location of stored energy reserves; and main source of immune response

Cells and extracellular matrix

2 main components of connective tissue

mesenchymal cells

embryonic cells that make connective tissue

blast

suffix for immature connective tissue cell

cyte

suffix for mature connective tissue cell

fibroblasts

large, flat cells with branching processes which are presnt in all general connective tissues often most numerous

macrophages

large, phagocytes that develope from monocytes

fixed

macrophages that reside in particular tissues like alveoli/spleen are ______

wandering

macrophages that can move through tissue and gather at sights of inflammation are ______

plasma cells

found throughout the body particularly in connective tissue of the GI and respiratory tracts (develope from B cells that have been activated)

mast cells

cells involved in inflammatory response that act in the bodies reaction to injury or infection, and can bind to and inject/kill bacteria

adipocytes

connective tissue cells that store triglycerides, found deep to the skin and around organs like the heart and kidneys

Leukocytes

cells that are few in number in connective tissue but migrate from blood to connective tissue during infection or allergy

Ground substance

extracellular matrix component of connective tissue between cells and fibers that can be fluid, semi-fluid, gelatonous, or calcified

Hyaluronic acid

viscous slippery substance that binds cells together, lubricates joints, and maintains eyeball shape

Fibronectin

adhesion protein of the connective tissue that helps link components in ground substance

Fibers

embedded in the extracellular matrix between cells and function to strengthen and support connective tissue

Collagen fibers

fibers that are strong resistant to pulling and stretching but not stiff and allow for continuous flexibility

Elastic fibers

fibers that are smaller in diameter, and branch, and join together to form fiberous networks in connective tissue; can stretch up to 150% and return to original shape