week 1 - tissue level of organization

what are tissues

collections of specialized tissue and cell products that perform specific functions

four types of tissues

(abbreviation C-MEN)

connective

muscle

epithelial

nervous

what are tissues

collections of specialized tissue and cell products that perform specific functions

four types of tissues

(abbreviation C-MEN)

connective

muscle

epithelial

nervous

function of epithelial tissue

protection

• covers exposed areas

• lines internal passagewats

• forms glands

• control permeability

• provide sensation

function of connective tissue

scaffolding

• fills internal spaces

• supports other tissues

• establishes a structural framework

• medium to transport materials

• stores energy

• protects and cushions

• matrix slows down invading microorganisms

function of muscle tissue

specialized for contraction for movement

• skeletal muscle

• heart muscle

• smooth muscle

  • walls of blood vessels

function of nervous tissue

carry electrical signals from one part of body to another

allows brain to communicate w/ other parts of body

what combine to form tissues

extracellular material and fluids

cells

what consists of epithelial tissue

epithelia and glands

what is epithelia

(singular of epithelium)

layers of cells covering internal/external surfaces

what are glands

structures that produce fluid secretions

to enter the body what is the first tissue you will have to cross

epithelium

characteristics of epithelia

• has polarity

  • a top and bottom surface

• cell junctions

  • provide adhesion

• the continuous sheets anchor to the basement membrane

• avascular

• regeneration

what is stratified

many layers

what is squamous look like

flat, spread out cells (looks like a fried egg)

simple squamous

one layer

thin, flat cells

stratified squamous

many layers

flat cells

cuboidal

cells shaped like cubes

simple cuboidal

one layer, cube cells

stratified cuboidal

many layers, cube cells

columnar

cells look like tall columns

have cilia

simple columnar

one layer, column-like cells

stratified columnar

many layers, column-like cells

function of simple squamous

absorption and easy diffusion across membrane

mesothelium

lines body cavities

endothelium

forms inner lining of heart and vessels, and fluid-filled chambers

function of stratified squamous epithelia

protect against mechanical stress

what does keratin add in skin

water resistance and strength

where can you find simple squamous epithelium

as serous membrane

where can you find stratified squamous epithelium

skin, mouth, throat, esophagus, anus, rectum, vagina

function of simple cuboidal

secretion and absorption

where can you find simple cuboidal epithelium

glands, portions of kidney tubules

function of stratified cuboidal

rare

protection, secretion, absorption

where can you find stratified cuboidal epithelium

ducts of sweat glands and mammary glands

function of transitional epithelia

to tolerate repeated cycles of stretching w/o damage

where can you find transitional epithelium

bladder

physical characteristics of transitional epithelium

round when normal

becomes flatter when stretched

function of simple columnar epithelia

absorption and secretion (has cilia)

where can you find simple columnar epithelium

stomach, small and large intestine

function of stratified columnar epithelia

protection

(no cilia)

where can you find stratified columnar epithelium

pharynx, anus, urethra

function of pseudostratified columnar epithelia

protection, secretion

move mucus with cilia

where can you find pseudostratified columnar epithelium

nasal cavity, trachea, bronchi (bc of cilia)

why is it called pseudostratified columnar epithelium

looks stratified but has cilia

what are glands

collections of epithelial cells that produce secretions

endocrine glands

releases hormones directly into bloodstream

so no ducts

exocrine glands

discharge secretions through ducts onto epithelial surfaces

what are the two types of glands

unicellular and multicellular

what are unicellular glands

made of goblet cells

exocrine glands

where are unicellular glands

epithelia of intestines

what do unicellular glands secrete

mucin, which mixes with water to make mucus

what are the three classifications of multicellular exocrine glands

structure of duct

shape of secretory portion of gland

relationship between ducts and glandular areas

what are the two options of duct structure

simple (undivided)

compound (divided)

what are the two options for the shape of the secretory portion of the gland

tubular (tubes)

alveolar/acinar (bag-like pockets)

what can the relationship between ducts and glandular areas look like

branched

• one duct having many secretory areas

what do compound glands look like

upside down trees

what do serous glands produce

watery secretions

what do mucous glands secrete

secrete mucins

what do mixed exocrine glands secrete

serous and mucous

three components of connective tissues

specialized cells

extracellular protein fibers

ground substance

what is ground substance

fills space between fibers and cells

gelatinous mixture

what is a matrix

composed of extracellular components of connective tissue

(fibers and ground substance)

what is the importance of matrix

makes up the majority of tissue volume

determines the specialized function

what are the 3 categories of connective tissues

connective tissues proper

fluid connective tissues

supporting connective tissues

function of connective tissue proper

connect and protect

function of fluid connective tissues

transport nutrients

function of supporting connective tissues

structural strength (like rebar and concrete)

what are the two types of connective tissue proper

loose

dense

what is the composition of loose connective tissue

more ground substance

less fibers

what is an ex of loose connective tissue

fat (adipose tissue)

what is the composition of dense connective tissue

more fibers

less ground substance

what is an ex of loose connective tissue

tendons

from the textbook, know the different cells in the connective tissue proper, and their function

more work srryyyy

what are the three types of connective tissue fibers

REC

reticular

elastic

collagen

what is the most common fiber in connective tissue proper

collagen

where is collagen most abundant

tendons and ligaments

how does collagen resist force

in one direction

what are the qualities of collagen

long, straight, unbranched

strong and flexible

how does reticular fibers resist forces

in many directions

what are the qualities of reticular fibers

strong

flexible

function of reticular fibers

stabilizes functional cells and structures

forms a network of interwoven fibers

stroma

network of interwoven fibers (like a blanket that can be pulled in different directions

what is the unique quality of elastic fibers

returns to OG length after stretching bc they are branched and wavy

what do elastic fibers contain

elastin

function of loose connective tissue

fills spaces between organs, cushions cells and supports epithelia

function of ground substance

fill spaces between cells and slows pathogen movement

what are the 3 types of loose connective tissue

areolar

adipose

reticular

function of areolar tissue

holds capillary beds

has phagocytic cells that provide defense to pathogens

cushions organs

qualities of areolar tissue

open framework

viscous ground substance

elastic fibers make it resilient

what are the two cells in adipose tissue

adipocytes (fat cells) and mesenchymal cells

qualities of adipocytes

do not divide

• expand to store more fat

• shrinks as fats are released

qualities of mesenchymal cells

they divide and differentiate when more storage is needed

what are the two types of fat

white and brown

what is the most common type of fat

white fat

functions of white fat

stores fat

absorbs shocks

slows heat loss (insulation)

where is brown fat found in

babies and young children

qualities of brown fat

more vascularized

adipocytes have more mitochondria

why is brown fat important to have

for babies bc regulating temp is more important and much harder

where is reticular tissue

liver

kidney

spleen

lymph nodes

bone marrow

function of reticular tissue

provides supporting framework

has a complex stroma that can stretch in different directions

what does dense connective tissue consist of

collagen fibers