ULM BIOL 1014 Chapter 4-8

Epithelial Tissue

-Little extracellular matrix

-covers/lines body surfaces

-free border

-basement membrane attaches it to underlying tissue

-avascular- gases/nutrients must diffuse across basement membrane

simple

one layer

stratified

multiple layers

pseudostratified

Looks like it is stratified but each cell is in contact with the basement membrane.

squamous

flat, pancake-shaped

-secretion and absorption

cuboidal

cube shaped, box-like

columnar

tall and narrow like a rectangle

-secretion or absorption

Stratified squamous 

mouth, esophagus, vagina, rectum

keratinized

outer cells, dead, contain keratin

keratin

tough, moisture-resistant protein.

transitional epithelium

stratified, stretches without tearing

-cell layers slide past one another

simple tissue function

diffusion (lungs), secretion (glands), filtration, absorption (intestines)

Stratified tissue functions

protection/barrier function

-found in areas where abrasion occurs

goblet cells

produce mucus

microvilli

increase surface area

cilia

directed movement across cell membrane

desmosomes

disk-shaped structures with sticky glycoproteins

-reinforce cell-cell connections at stress points

hemidesmosomes

attach epithelial cells to basement membrane

tight junctions

form a permeability barrier

-material can’t pass between cells but must pass through them instead

zona adherens

girdle of glycoproteins, binds cells together

zona occludens

ring around cells

gap junctions

small protein channel, allows small polar materials to pass between cells 

-important coordinating function

glands

secretory function, composed primarily of epithelia

exocrine

have ducts

endocrine

ductless, produces hormones

unicellular

goblet cells —> mucus

(multicellular) simple

duct with a few branches

(multicellular) compound

duct with many branches

(multicellular) tubular

duct ends in straight/coiled tubes

(multicellular) acinar

ducts end in a cluster of small sacs

(multicellular) alveolar

ducts ends in hollow sacs

merocrine

secretion with no loss of cytoplasm

apocrine

secretion with some loss of cytoplasm

holocrine

cell becomes part of the secretion

Connective tissue

abundant nonliving, extracellular matrix

Matrix components

-protein fibers present

-ground substance present

-fluid present

-generally well-vascularized

-blasts

cells that build/create matrix

-cytes

cells that maintain matrix

-clasts

cells that breakdown/remodel the matrix

Collagen fibers

strong and flexible, doesn’t stretch primary protein in the body

Reticular fibers

fine collagen fiber networks

Elastin fibers

stretch and recoil (return to original shape)

ground substance

hyaluronic acid and proteoglycan

hyaluronic acid

polysaccharide, slippery, acts as a lubricant

proteoglycan

CHO + protein, traps H20 —> resiliency

Loose Fibrous CT

aka CT proper aka Areolar

-protein fibers form lacy network with fluid-filled spaces, all three types of fibers present

-loose packing material of most organs, “space-filler”

-most abundant CT in body

Fibroblast

cell that produces fibrous matrix of CT

Dense CT

fibers fill nearly all of the extracellular space

Regular dense CT

fibers run in a single direction

Collagenous tissue

seen in tendons and ligaments

elastic tissue

seen in ligaments of vertebrae

irregular dense CT

fibers run in many different directions

Collagenous irregular

reticular layer of dermis

elastic irregular

walls of large arteries

Adipose tissue

Fat cells (adipocytes) surround lipid droplet

-energy storage, insulation, protection

Adipocytes

fat cells

Reticular tissue

network of fi and liver.ne collagen fibers form framework of lymphoid tissue, bone marrow

Yellow bone marrow

fat storage

Red bone marrow 

blood cell production

Hemopoiesis

blood cell production

Cartilage

rigid matrix, lacunae surround chondrocytes (cartilage cells), avascular

Cartilage cells

chondrocytes

Hyaline Cartilage

rigid with some flexibility, principle cartilage of body

(costal cartilage, articular cartilage, fetal skeleton, trachea, epiphyseal plate, nasal septum)

Fibrocartilage

withstands great pressure (shock absorber)

(intervertebral discs, meniscus of knee, pubic symphysis)

Elastic Cartilage

high elastin, most flexible

(pinna, epiglottis)

bone

solid matrix with organic and mineralized inorganic material

inorganic matrix

hydroxyapatite crystals contain Ca/P —> rigidity

organic matrix

primarily collagen —> flexible strength

cancellous (spongy) bone

bone spicules arranged in trabecular network.

compact bone

dense bone with regular repeating structural units = osteon

blood

liquid matrix = plasma

Red blood cell (erythrocyte)

O2/CO2 transport

white blood cell (leukocyte)

defense

platelet (thrombocytes)

blood clotting

Muscle Tissue

excitable tissue and contracts

Skeletal tissue

striated, voluntary, multinucleate, cylindrical fibers, attached to bones, responsible for body movement.

Cardiac tissue

striated, involuntary, branched fibers, 1-2 nuclei/cell, intercalated discs

smooth tissue

nonstriated, involuntary, walls of hollow organs, spindle-shaped fibers.

Nervous tissue

irritable, conducts electrical pulses

neurons

conducting cells

neuroglia

supportive, protective cell, insulate neurons

axon

carries signal away from soma

dendrites

carry signal towards soma

Embryonic tissue development

3 germ layers

-endoderm

-mesoderm

-ectoderm

Endoderm

inner layer- some epithelia

mesoderm

middle layer - muscle and CT

ectoderm

outer - nervous tissue and epidermis

Membranes

cover a structure or line a cavity; have an epithelia and a CT component

Serous membranes

lines cavities that do no open to the outside; produces serous fluid.

mucous membranes

line cavities that open to outside; secrete mucus

synovial membrane

line joint cavities; secrete synovial fluid

Tissue repair

substitute new live cells for existing dead cells

regeneration

new cells are same type; function restored

replacement

new tissue is nonfunctional Ct that serves as a space filler —> causes scar, loss of function

labile

divide mitotically throughout life (skin)

stable

cells replicate until growth stops; will regenerate if injured

permanent

cannot replicate, replaced by nonfunctional CT

inflammatory response

isolates injurious agents; attacks/destroyed agents

edema

increase in tissue fluid due to movement of blood proteins into damaged tissue

stages of wound repair

clot > scab> granulation tissue appears > scab falls off > granulation tissue is replaced by permanent tissue