ch 4 Tissues

hyaline cartilage

-amorphous but firm matrix; collagen fibers form an imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae -supports and reinforces, serves as resilient cushion; resists compressive stress -most of embryonic skeleton, covers long ends of bones, forms costal cartilages of ribs, cartilages of the nose, trachea, and larynx

cardiac muscle

-branching, striated, generally uninucleate cells that interdigitate at specialized junctions -as it contracts it repels blood into the circulation; involuntary control -walls of the heart

fibers in connective tissue

-collagen fibers: strongest and most abundant fibers resist tension -reticular fibers- bundles of a special type of collagen fibril, these cluster into a network that covers and supports the structures bordering the connective tissue (ex. cover capillaries and form part of basement membrane) allow more give than collagen -elastic fibers- contain rubberlike protein elastin which allows them to function like rubber bands

elastic tissue

-dense regular connective tissue containing a high proportion of elastic fibers -allows recoil of tissue following stretching; maintains pulsatile flow of blood through arteries; aids passive recoil of lungs following inspiration -walls of large arteries, within certain ligaments associated with the vertebral column, within the walls of the bronchial tubes

endocrine glands

-ductless glands that secrete directly into the tissue fluid that surrounds them -produce hormones which they release into extracellular space, these hormones then enter nearby capillaries and travel through the bloodstream to specific target organs

exocrine glands

-ducts carry products of exocrine glands to epithelial surface (mucus secreting glands, sweat and oil glands, salivary glands, liver and pancreas) -most glands derive from epithelia

mesenchyme

-embryonic connective tissue; gel-like ground substance containing fibers; star shaped mesenchymal cells -gives rise to all other connective tissue types -primarily in the embryo

additional cell types in connective tissue

-fat cells- (adipose) store nutrients -macrophages- specialize in phagocytosis they engulf a wide variety of foreign materials -mast cells- mediate inflammation and promote healing

Loose connective tissue, areolar

-gel-like matrix with all three fiber types; cells: fibroblasts, macrophages, mast cells, and some white blood cells -wraps and cushions organ; its macrophages phagocytize bacteria; plays an important role in inflammation -widely distributed under epithelia of body (ex. forms lamina propria of mucous membrane; packages organs; surrounds capillaries)

stratified cuboidal epithelium

-generally two layers of cubelike cells -protection -largest ducts of sweat glands, mammary glands, and salivary glands

bone

-hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae, very well vascularized -supports and protects, provides levees for the muscles to act on, stores calcium and other minerals and fat, marrow inside bones is site for blood cell formation -bones

skeletal muscle

-long, cylindrical, multinucleate cells; obvious striations -voluntary movement; locomotion; manipulation of the environment; facial expression -in skeletal muscles attached to bone or occasionally skin

multicellular exocrine glands

-made of two parts: an epithelium-walled duct and a secretory unit consisting of the secretory epithelium -classified by the structure of their ducts: simple glands (unbranched duct) compound glands (branched duct) -then they are further classified by their secretory they are tubular if their secretory cells form tubes and alveolar if their cells form spherical sacs; some are tubuloalveolar if they contain both units

fibrocartilage

-matrix similar to but less firm than hyaline; thick collagen fibers predominate -tensile strength with the ability to absorb compressive shock -intervertebral discs; pubic symphsis; discs of knee joint

connective tissue

-most diverse and abundant type of tissue, four main classes: connective tissue, cartilage, bone tissue, and blood -function to connect the tissues and organs of the body together, form the basis of the skeletal system, store and carry nutrients, surround all the blood vessels and nerves of the body, and lead the fight against infection

loose connective tissue, reticular

-network of reticular fibers in a typical loose ground substance; reticular cells lie on the network -fibers form soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages -lymphoid organs organs (lymph nodes, bone marrow, and spleen)

nervous tissue

-neurons are branching cells; cell processes extend from the nucleus-containing cell body; nonconducting supporting cells, neuroglia -transmit electrical signals from sensory receptors and to effectors (muscles and glands) that control the activity of the effector organs -brain, spinal cord, and nerves

dense irregular connective tissue

-primarily irregular arranged collagen fibers; some elastic fibers, major cell type is the fibroblast; defense cells and fat cells are also present -able to withstand tension exerted in many directions, provides structural strength -fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract

dense regular connective tissue

-primarily parallel collagen fibers; a few elastic fibers; major cell type is the fibroblast -attaches muscle to bones, bones to bone, withstands great tensile stress when pulling force is applied in one direction -tendons, most ligaments, aponeuroses

blood

-red and white blood cells in a fluid matrix -transports respiratory gases, nutrients, waste, and other substances -contained within blood vessels

transitional epithelium

-resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamous like depending on degree of organ stretch -stretches readily and permits distension of urinary organ by contained urine -lines the uterus, bladder, and part of the urethra

stratified columnar epithelium

-several cell layers; basal cells usually cuboidal; superficial cells elongated and columnar -protection and secretion -rare in the body, small amounts in the male urethra and in large ducts of some glands

elastic cartilage

-similar to hyaline but more elastic fibers in matrix -maintains the shape and structure while allowing great flexibility -supports the external ear and epiglottis

classifications of epithelial tissue

-simple- contains a single layer with each cell attached to a basement membrane -stratified- contains more than one layer of cells , the cells on the basal surface are attached to the basement membrane; those on the apical surface border an open space

pseudostratified columnar epithelium

-single layer of cells of differing heights, may -contain mucus-secreting goblet cells and bear cilia -secretion of mucus, propulsion of mucus by ciliary action -nonciliated type in males sperm-carrying ducts and ducts of large glands; ciliated variety lines trachea, most of the upper respiratory tract

simple cuboidal epithelium

-single layer of cube like cells -secretion and absorption -kidney tubules; ducts and secretory portions of small glands; ovary surfaces

simple squamous epithelium

-single layer of squamous cells, simplest of the epithelium -allows passage of materials by diffusion and filtration in sites where protection is not important, produces lubricating fluid in serosae -located in kidney glomeruli, air sacs of lungs, lining of heart, blood, and lymphatic vessels; lining of ventral body cavity

simple columnar epithelium

-single layer of tall cells with round oval nuclei -absorption; secretion of mucus, enzymes, and other substances ; ciliated type propels nucleus -nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands; ciliated lines small bronchi, uterine tubes, and some regions of the uterus

smooth muscle

-spindle-shape cells with central nuclei; no striations; cells arranged closely to form sheets -propels substances or objects along internal passageways; involuntary control -mostly in walls of hollow organs

cell shapes

-squamous- flat cells flat disc shape nuclei 1 layer= diffusion and filtration more than one layer= protection -cuboidal- cube shaped cells with cpherical centrally located nuclei 1 layer= secretion and absotion more than one layer=protection -columnar cells- taller, nuclei located near basal surface in oval shape

stratified squamous epithelium

-thick membrane composed of several layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened -protects underlying tissues in areas subjected to abrasion -nonkeratinized type forms the moist linings of the esophagus, mouth, and vagina, keratinized variety forms the epidermis of the skin, a dry membrane

specialized functions of epithelial tissue

1. cellularity- cells separated by a minimal amount of extracellular material 2. specialized contacts- adjacent epithelial cells are directly joined at many points by special cell junctions 3. polarity- the apical surface abuts the open space of a cavity, tubule, gland or hollow organ, the basal surface lies on a thin supporting sheet the basal lamina 4. support by connective tissue- all epithelial sheets are supported by an underlying layer of connective tissue 5. avascular but innervated- tissue receives their nutrients from capillaries in underlying tissues 6. regeneration- lost cells are quickly replaced by mitosis

for each connective tissue indicate the predominant types of fibers founded in the extracellular matrix 1. bone 2. loose areolar CT 3. dense irregular CT 4. reticular CT 5. fibrocartilage

1. collagen fibers 2. collagen fibers, elastic fibers, reticular fibers 3. collagen fibers 4. reticular fibers 5. collagen fibers

special characteristics of connective tissue

1. relatively few cells, lots of extracellular matrix- separates cells from one another 2. extracellular matrix composed of ground substance and fibers, they differ in their physical properties because of differences in cells and compostion of extracellular matrix but they all share similar structural elements: cells, fibers, and ground substance 3. embryonic origin- they all originate from the embryonic tissue (mesenchyme)

match the epithelial tissue to its function 1. functions in diffusion and filtration 2. functions in protection 3. functions in secretion and absorbtion 4. changes shape as the tissue stretches 5. produces movement of material

1. simple squamous epithelium 2. stratified epithelium and transitional epithelium 3. simple columnar epithelium 4. transitional epithelium 5. ciliated epithelium

inflammation

a response to tissue injury and infection, localized to the connective tissue and the vessels of the injury site -response begins with dilation of blood vessels which increases the blood flow (causing redness and heat) the resulting accumulation of fluid, edema (causing swelling and pain) edema helps to dilute toxins secreted by bacteria and brings in oxygen and nutrients from the blood and brings in antibodies to fight infection; stasis results and white blood cells migrate into injured tissue

adhesive

a type of anchoring junction: transmembrane linker proteins attach to the actin microfilaments of the cytoskeleton and bind adjacent cells, this junction reinforces the tight junction particularly when tissues are stretched

match the epithelial type with its location a. pseudo stratified ciliated columnar b. simple columnar c. simple squamous d. stratified squamous e. transitional

a. lines much of the respiratory tract including tracheas b. lines inside of stomach and most intestines c. lines inside of mouth d. mesothelium e. lines inside of urinary bladder

what embryonic layer primary forms in a. connective tissue b. muscle tissue c. nervous tissue

a. mesoderm b. mesoderm c. ectoderm

describe the cell structure a. cilia b. microvili c. desmosome d. tight junction e. basement membrane

a. whiplike extensions that move fluids across the epithelial surfaces b. little fingers on apical epithelial surfaces that increase cell surface area and anchor mucus c. the cell junction that holds cells together by linking the intermediate filaments of adjacent cells d. the cell junction that closes off the extracellular space e. of the basement membrane and the basal lamina, the one that can be seen by light microscopy

the type of gland that secretes products such as milk, saliva, bile, through a duct is known as a

an exocrine gland

neuroglial

are support cells that aid neurons

basal feature: the basal lamina

at the border between the epithelium and the connective tissue deep to its supporting sheet (basal lamina) this thin noncellular sheet consists of proteins secreted by the epithelial cells. Functionally it acts as a selective filter, it determines which molecules from capillaries in underlying connective tissue are allowed to enter the epithelium. Acts as scaffolding along which regenerating epithelial cells can migrate. Deep to the basal lamina is a layer of reticular fibers together they form the basement membrane

repair

begins during inflammation and may involve tissue regeneration, fibrosis (scarring), or both -regeneration: replacement of destroyed tissue by new tissue of the same kind -fibrosis: involves proliferation of a fibrous connective tissue (scar tissue) -organization: the clot is replaced by granulation tissue the surface epithelium begins to regenerate growing under the scab until it falls away

in which connective tissues are the cells located in lucunae

both cartilage and bone tissues

the muscle tissue that is striated is

cardiac and skeletal

how do cancerous cells differ from other highly mitotic cell types

cell division in cancerous cells is uncontrolled and cells expand beyond their normal tissue boundaries

which structural element of connective tissue resists tension? which resists compression? which allows for recoil? which element produces the matrix?

collagen fibers, ground substance, elastic fibers, the blast cells (fibroblasts, chondroblast, osteoblast) produce the tissue matrix then the fibrocytes, chondrocytes, and osteocytes secrete matrix components to keep the matrix in tact and healthy

membranes

combine epithelial tissues and connective tissues, cover broad areas within the body, consist of epithelial sheet plus underlying connective tissue

epithelial tissue

covers body surfaces and forms most of the body glands 1. protects underlaying tissue 2. secretion (release of molecules from cells) 3. absorption (bringing small molecules into cells) 4. diffusion (movement of molecules down their concentration gradient) 5. filtration (passage of small molecules through a siev like membrane) 6. sensory reception

why is columnar epithelium not found in locations where diffusion occurs

diffusion is a distant-dependant process; columnar epithelium is too thick for efficient diffusion , simple squamous epithelium is found in these locations

which embryonic layer or layers form epithelium

ectoderm, mesoderm, endoderm

in addition to epithelial tissue what other types of tissues contain gap junctions

embryonic tissues, connective tissues, cardiac muscle, and smooth muscle

an _________ gland secretes into the tissue fluid and its secretion is carried to a target organ by the blood stream

endocrine

which tissues regenerate easily which do not

epithelia and connective tissues (bone, areolar connective, dense irregular connective, blood) regenerate easily; cardiac muscle tissue and nervous tissue in brain and spinal cord do not

how do epithelial tissues differ from connective

epithelial tissues contain lots of cells of similar extracellular matrix , connective tissue contain fewer cells of various types separated from each other by extensive extracellular material

four tissue types

epithelial, connective, muscle, nervous

in connective tissue proper the cell type that secretes the fibers and ground substance is the

fibroblast

cells in connective tissue

fibroblasts- in proper connective tissue, make the protein subunits of fibers, they also secrete the molecules that form the ground substance of the matrix -chondroblasts- secret matrix in cartilage -osteoblasts- secret matrix in bone once these tissue forming cells are not actively secreting new matrix they are termed fibrocytes, chondrocytes, an osteocytes and they function to repair and maintain the tissue matrix -cells in blood do not secret matrix they function to carry respiratory gases (RBC), to fight infections (WBC) and to aid in blood clotting (platelets)

apical surface features: microvili

fingerlike extensions of apical epithelial cells, each contain a core of actin filaments that extend into the actin microfilaments of the cytoskeleton and function to stiffen the microvillus. Occur on almost every moist epithelium in the body but are longest and most abundant on epithelia that absorb nutrients (small intestine) and transport ions in the kidney, maximize surface area across which small molecules enter or leave cells

which of the following are not found in connective tissue

goblet cells

unicellular exocrine glands

goblet cells scattered within the epithelial lining of the intestines and respiratory tubes between columnar cells with other functions; they produce mucin that dissolves in water when secreted resulting in mucus; mucus covers, protects, and lubricates many internal body surfaces

the ground substance in connective tissue proper functions to

hold tissue fluid

tight junctions

in apical region of most epithelial tissues, the adjacent cells are so close that some proteins in their plasma membranes are fused, this fusion forms a seal that closes off the extracellular space; thus they prevent molecules from passing between the cells of epithelial tissue (ex. in the digestive they keep digestive enzymes, ions, and microorganisms in the intestine from seeping into the blood stream

which component of cartilage tissue functions to resist compressive forces

in cartilage compressive forces are resisted by the gel-like ground substance

what causes the heat and swelling in an infected tissue

increased blood flow to an infected tissue and increased fluid leakage from capillaries serving to the infected area

tissues response to injury

inflammation- non specific, local response that develops quickly and limits the damage to the injury site immune response- takes longer to develop and is highly specific, it destroys particular infectious microorganisms and foreign molecules at the site of infection

how do the intermediate filaments within the epithelial cells function to bind together the entire sheet of epithelia

intermediate filaments extend across the cell and anchor at desmosomes on the opposite side, linker proteins from the desmosomes link to adjacent side

is the scar tissue that creates a scar located in the epithelium or in the underlying connective tissue

it is located in the underlying connective tissue

why are cuboidal or columnar cells found in epithelia that functions in secretion and absorption

larger sized cells allow for more room for cellular machinery necessary for producing cellular secretions

which type of connective tissue forms the following structures; ligaments and tendons; the hypodermis of the skin; the tissue that underlies the epithelia; lymph nodes?

ligaments and tendons are formed from dense regular connective tissue; the hypodermis is composed of adipose and loose areolar connective tissue

mucous membrane (mucosa)

lines the inside of every hollow internal organ that opens to the outside of the body (respiratory, digestive, reproductive, and urinary); all moist, consist of an epithelial sheet underlain with layer of lamina propria

which connective tissues contain collagen fibers

loose areolar, adipose, dense regular, and irregular connective tissues, hyaline, elastic, and fibrocartilage

loose connective tissue, adipose

matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet -provides reserve food fuel; insulates against heat loss; supports and protects organs -under skin in the hypodermis; around kidneys and eyeballs; within abdomen; in breasts

how do cilia differ from microvilli

microvilli- short extentions of plasma membrane with a core of actin microfilaments that extend into the cytoskeleton; they increase surface area of the plasma membrane -cilia- long extension of plasma membrane composed of a core of microtubules arranged in pairs linked by motor proteins and anchored to a centriole at its base, the bending of cilium produces movement of the fluid at the epithelial surface

which nerve cells function to transmit electrical impulses

neurons

cancer

oncogenes- result from mutations in normal genes that regulates cell division, differentiation, and growth when mutated these genes are abnormally activated causing abnormal growth and division which can lead to cancer tumor suppressor genes- function in normal cells to halt cell division repair damaged dna and initiate programmed cell death when cellular dna is severely damaged, mutations in tumor suppressor genes lead to inactivation and turn into uncontrolled cell division

ground substance

produced by primary cell type of the connective tissue (fibroblasts, chondroblasts, or osteoblasts), usually gel like material consisting of sugar and sugar protein molecules that soak up liquid like a sponge, functions to cushion and protect body structures (connective tissue proper), to withstand compressive stresses (cartilage), or to hold the tissue fluid that bathes all the cells in our body (areolar connective tissue) -blood is different plasma is not produced by blood cells its composed of water, proteins, nutrients, ions, gases, and other molecules

what feature distinguishes a simple exocrine gland from a compound exocrine gland

simple exocrine glands have unbranched ducts, compound exocrine glands are branched

serous membrane

slippery membranes that line closed pleural, pericardial, and peritoneal cavities; consist of a simple squamous epithelium called mesothelium lying on thin layer of areolar connective tissue

look at the photomicrograph of smooth muscle tissue how can you tell this tissue is not stratified squamous epithelium

smooth muscle tissue does not have an apical and basal region

an epithelium that has several cell layers with flat cells in the apical layer is called the

stratified squamous

distinguish between the terms striated and stratified name tissues of each

striated- (striped) specifically muscle tissue (cardiac and skeletal) stratified- (layered) epithelial tissue (stratified squamous, stratified cuboidal, stratified columnar epithelial)

describe the location of the apical region of an epithelial tissue

the apical region is the free, unattached surface of the epithelium

how does loose connective tissue differ from dense connective tissue

the fibers of loose connective tissues are separated from each other by ground substance; in dense connective tissue the fibers are tightly packed together

desmosomes

the main junctions for binding cells, scattered along the abutting sides of adjacent cells, have a complex structure: on the cytoplasmic face of each plasma membrane is a circular plaque, the plaques of neighboring cells are joined by linker proteins, bundles of these filaments extend across the cytoplasm and anchor at other desmosomes on the opposite side of the same cell. Found in cardiac muscle tissue and epithelial tissues

distinguish the matrix of a connective tissue from the ground substance

the matrix of connective tissue is composed of both ground substance and fiber , the ground substance is commonly a gel-like material that functions to hold fluid

cutaneous membrane

the skin covering the outer surface of the body; its outer epithelium is the thick epidermis, and its inner connective tissue is the dense dermis; it is a dry membrane

lateral surface features: cell junctions

three factors act to bind epithelial cells to one another: 1. adhesion proteins- in plasma membranes of adjacent cells link together in the narrow extracellular space 2. the wavy contours of the membranes of adjacent cells join in a tongue-and-groove fashion 3. there are special cell junctions, the most important of the factors are characteristics of epithelial tissue but are found in other types as well

gap junctions

tunnel like junction that can occur anywhere along the lateral membrane of adjacent cells, they function in intercellular communication by allowing small molecules to move directly between neighboring cells, the adjacent plasma membranes are very close and the cells are connected by hollow cylinder of protein: ions, simple sugars, and other small molecules pass through these cylinders from one cell to the next. Common in embryonic tissues and in many adult tissues including connective , also prevalent in smooth and cardiac muscle where the passage of ions through gap junctions synchronizes contraction

what type of gland are goblet cells

unicellular exocrine glands that secrete mucus

apical surface features: cilia

whiplike, highly motile extensions of the apical surface membranes, each cilium contains a core of microtubules held together by cross-linking and radial proteins, they are arranged in pairs with nine outer doublets encircling one central pair. Move in coordinated waves to push mucus and other substances over the epithelial surface