Anatomy/physiology ch 5

epithelial tissue

epithelial tissue

composed of 1 ort more layers

cover the body surfaces, lines both body and organ cavities

form glands

cellularity

epithelial composed of tightly packed cells

polarity

epithelium has both apical and basal surface

apical

exposed to external environment

may have either microvilli or cilia

basal

epithelium is attached to basement membrane, underlying connective tissue

avascularity

all epithelial tissue lacks blood vessels

nutrients obtained by diffusion through basal surface from blood vessels

or directly across apical surface

extensive innervation

epithelia are supplied with nerves to detect changes in the environment

high regeneration capacity

epithelial cells undergo cell division frequently.

epithelial cells

stem cells

epithelia primary functions

physical protection, selective permeability, secretions, sensations

simple epithelium

1 layer of epithelial cells

found in areas with minimal stress.

filtration, absorption, or secretion is the primary function

contact with basal layer

stratified epithelium

contains 2 or more layer of epithelial cells

resembles brick wall

provides structural support /better protection for underlying layer

found in basal layer

pseudostratified epithelium

appeared to be layered

simplest type of epithelium

attached to basement membrane (basal)

squamous cell s

cells are flat, wide and irregularly shaped

nucleus is flattened

cuboidal cell s

tall as they are wide. rounded squares

nucleus is spherical and in the middle of the cell

columnar cell s

slender and taller than they are wide

nucleus is oval

transitional cell s

can change shape when distended and relaxed

ex lining if the bladder that filles with urine then empties

simple squamous epithelium

single layer of flattened cells

thinnest possible barrier

allows rapid movement of molecules and ions across epithelium by membrane transport

simple epithelium

simple squamous, simple cuboidal, simple columnar, pseudostratified columnar

stratified epithelium

stratified squamous, stratified cuboidal, stratified columnar, transitional, keratinized, nonkeratinized

endothelium

name of simple squamous epithelium that lines both blood vessels and Lympth vessels

mesothelium

name given to squamous epithelium that forms serous membranes of body cavities

simple cuboidal epithelium

1 layer uniform shaped cells

located in spherical nucleus

allows absorption and secretion s

simple columnar epithelium

single layer of cells

ideal for absorptive and secretory function s.

2 forms- has no cilia and covered with cilia

nonciliated simple columnar

contains microvilli and scatters unicellular galnd’s called goblet cells- secrete mucin

mucin

glycoprotein

when mixed with water forms mucus

ciliated simple columnar epithelium

has cilia projecting from apical surface of the cell

mucus covers apical cell and is moved by cillia

pseudostratified ciliated columnar epithelium

conations cilia on its apical surface

performs protective structures

pseudostratified nonciliated epithelium

lacks cilia

preforms protective functions

pharynx

throat

larynx

voice box

stratified squamous epithelium

multiple cell layers and only in the deepest layer is indirect contact with basal membrane

keratinized squamous epithelium

superficial layer composed of cells that are dead filled with protein called keratin

keratin

tough protective protein that strengthens the tissue

nonkeratinized stratified squamous epithelium

lack keratin but remain alive

line oral cavity, pharynx, larynx esophagus,, vagina and anus

stratified cuboidal epithelium

contains 2 or more layers of cells

forms tubes and ducts

protects/.secretes

tissues found in the walls of most exocrine glands

stratified columnar epithelium

rare

2 or more layers of cells

found in large ducts of salivary glands, conjunctiva covering the eye, and segment of male urethra.

transitional epithelium

limited to urinary tract

binucleated- 2 nuclei

able to stretch ensures urine does not seep to other organs

glands

either individual or multicellular organs composed of epithelial tissue

secrete substances hormones, enzymes etc

endocrine glands

lack ducts and secrete hormones into the blood to be transported through the body

exocrine glands

excrete waste or other substances

sweat glands mammary glands and salivary glands

duct

epithelium lined tube where secretion are discharged

unicellular exocrine glands

do not contain ducts

located close to the surface of epithelium

most common type is goblet cell

multicellular exocrine glands

multiple cells work together to produce a secretion

consist of acini- clusters of cluster of cells that produce secretions

simple glands

single unbranched ducts

compound glands

branched ducts

tubular

gland

if the secretory portion and the duct have the same diameter

ainar

secretory portion forms and expanded sac

apocrine glands

produce secretory material when cells apical portion pinches off

releasing cytoplasmic content

holocrine glands

formed from cells that accumulate product

entire cell disintegrates

sebaceous glands oil glands

connective tissue

support, protect and bind organs

tendons - muscle to bone

ligaments-bone to bone

adipose, cartilage, bone and blood

resident cells

stationary cells housed with connective tissue

support/maintain/repair extracellular matrix

fibroblasts - produce fibers

adipocytes - fat cells

mesenchymal - embryonic stem cell

fixed macrophages

large irregular shape cell derived from leukocyte- white blood cell.

wandering cells

move through connective tissue

components of immune system

types of leukocytes

protein fibers

in connective tissue strengthen and support tissue

collagen fibers

unbranched long protein fibers that are strong and flexible

reticular fibers

similar to collagen fibers but thinner

abundant in stroma

stroma

connective tissue framework

lymph nodes, spleen and liver

elastic fibers

contain the protein elastin

recoil easily and abundant in the skin, arteries and lungs allowing them to be stretched back to their original shape

ground substance

molecular material produced by connective tissue cells

connective tissue and protein fibers reside inside

glycosaminoglycans (GAGs)

polysaccharides that have an attached amine group

negative charge and hydrophilic

attract cation (Na+)

can attract and absorb water

proteoglycan

when a GAG is linked to a protein and becomes bigger

mesenchyme

first type of connective tissue in developing embryo

all connective tissue comes from it

mucous connective tissue

immature protein fibers

located in the umbilical cord only

loose connective tissue

contains fewer cells and protein fibers than dense connective tissue

sparse and irregular shaped

areolar connective tissue

unconfined organization

present everywhere in the body

found in skin

protects and surrounds organs, nerve cells, muscke cells and blood vessels

adipose connective tissue

highly vascularized

loose connective

2 types - brown and white

brown adipose connective tissue

found in newborns and generate heat

white adipose connective tissue

long term energy storage

insulator

cushion against shocks

connective tissue proper

loose connective tissue - areolar, adipose, reticular

dense connective tissue - dense irregular, dense regular, elastic

supporting connective tissue

cartilage- hyaline, fibrocartilage, elastic cartilage

bone- compact and spongy

fluid connective tissue

blood and lymph

reticular connective tissue

houses leukocytes and fibroblasts

forms stroma- structural framework

dense connective tissue

composed of protein fibers

dominant in collagen fibers

dense regular connective tissue

contains few fibroblasts

found in tendons where stress is typically applied in 1 direction

few blood cells- long heal time

dense irregular connective tissue

bundles and clumps of fibers

supply blood between collagen fibers

found in most of the dermis

elastic connective tissue

composed of numerous fibroblasts

provide stability for tissue to stretch and recoil

walls of large arteries, trachea and vocal cords

cartilage

firm semisolid contains collagen and elastic protein fibers.

strong and resilient

more flexible than bone

chondrocytes

mature cartilage cells

hyaline cartilage

provides flexible structures

most common type

found in respiratory tract

fibrocartilage

weight bearing

good shock absorber

elastic cartilage

flexible and stringy

helps ear spring back to original shape

bone connective tissue

osseous

makes up mass of most bone structures

bone tissue is vascularized

osteocytes

mature bone cells

compact bone

appears solid but has neurovascular canals

form osteons

spongy bone

strong yet light weight

houses hematopoietic - blood cells

hematopoietic

blood cells- form reticular connective tissue that makes up blood - hematopoiesis

2 types of fluid connective tissue

blood and lymph

blood

composed of foamed elememts

plasma

liquid ground substance

within are proteins and solutes

lymph

derived from blood plasma

contains no cellular components

3 types of muscle tissue

skeletal muscle, cardiac mule, smooth muscle

skeletal muscle

striated / voluntary

responsible for movement of skeleton

cardiac muscle tissue

thick middle layer of heat wall call myocardium

pumping action of the heart to move blood through cardiovascular system

smooth muscle tissue

visceral/involuntary

lacks striations

appears smooth

involuntary we dint have control over this muscle

found in internal organs

nervous tissue

located in the brain, spinal cord, and nerves through the body

cells called neurons - receive process and transmit impulses

contain glial cells- support cells - protection and nourishment

cell body

houses nucleus and other organelles

dendrites

receive incoming signals and transmit info to the cell body

axon

carries outgoing signals to other cells

body membranes

formed from epithelial layer bound to connective tissue

4 types- mucous, serous, cutaneous, synovial