chapter 4 A & P89y

tissues

collections of cells and cell products that preform specific, limited functions

4 types of tissues

epithelial, connective, muscle, neural

characteristics of epithelial tissue

covers exposed surfaces, lines internal passageways, forms glands

characteristics of connective tissue

fills internal spaces, supports other tissues, transports materials, stores energy

characteristics of muscle tissue

specialized for contraction

3 types of muscle tissue

skeletal, cardiac, smooth

skeletal muscle

voluntary

cardiac muscle

only in heart

smooth muscle

in walls of hollow organs

characteristics of neural tissue

carries electrical signals from 1 part of the body to another

polarity in epithelial tissue

cells have a definitive top and bottom

apical surface

apex = highest point

basolateral

the bottom, attaches either to another cell or basement membrane

attachment

epithelia are anchored to a layer of extracellular material

basement membrane is also known as

basal lamina

glands

structures that produce secretions

auscularity

unlike most tissues, epithelial lack blood vessels

what are areas of adjacent cell membranes interconnected by

transmembrance protein

what is the process of adjacent cell membranes interconnected by transmembrance protein called

cell adhesion molecules (cams) “purple paddles”

CAMS can exist…

on their own or as part of cell junctions

cell junctions

forms bonds between cells or between a cell and extracellular material

3 junctions of cell junctions

tight, gap, desmosomes

location of tight junctions

between the apical portions of 2 neighboring plasman membrance

what do tight junctions cells do…

band tightly in a way that prevents water and substances from leaking between the cells

tight junctions ensure…

enzymes, acids, wastes, stay inside the lumen

gap junctions allow

rapid communication between 2 connected cells

in gap junctions, the 2 neighboring cells are held together by…

channel proteins

physical traits of desmosomes

very strong and can endure stretching & twisting

2 kinds of cell junctions

usual kind, hemidesmosomes

usual kind of desmosomes

joins 2 cells together

hemidesmosomes

connect 1 cell to the basement membrane

basement membrane is made of…

layers of proteins that provide strength to epithelia

shapes

squamous, cuboidal, columnar

physical of squamous

thin and flat

cuboidal

square/cube

columnar

tall, slender rectangles

glands

collections of epithelial cells that practice secretions

2 types of glands

exocrine and endocrine

exocrine glands

release their secretions into ducts that empty onto an epithelial surface

endocrine glands

their secretions are chemical messengers called hormones

most common type of secretion

merocrine secretion

vesicles

bubble-like organelles that store and transport substances in a cell

all connective tissue arises from…

an embryonic tissue called mesnchyme

in contrast to epithelial tissue, CT is…

never exposed to the outside environment and highly vascular and has sensory receptors

all CT have 3 basic parts

1. specialized cells

2. extracellular protein fibers

3. fluid extracellular ground substance

ground substance

this is thicker and stickier than interstitial fluid

matrix makes up

the majority of the tissue volume

supporting CT

only 2; one and cartilage

fluid CT

only 2 tissues; blood and lymph and transports materials and cells in the body

CT proper

connect and protect

adipocytes

store energy in lipid

lymphocytes are responsible for

the specific defenses

traits of lymphocytes

basis of immunity, how vaccines work

plasma cells

lymphocytes that make antibodies

mesenchymal cells

stem cells that can divide to produce new fibroblasts, adipocytes and other CT cells

mast cells

trigger local inflammation by releasing chemicals

fibroblasts

most common cell type in CTP

fibroblasts produce

ground substance and the extracellular protein fibers

melanocytes

produce melanin

macrophages (WBC)

move through tissues using ameboid and engullf/destroy pathogens

free macrophages

patrol around

fixed macrophages

don’t move

collagen fibers

major component of tendons and ligaments

collagen fibers give strength to…

many tissues in the body including skin and bones

elastic fibers contain the protein

“elastin”

elastic fibers are relatively ___ compared to collagen

rare

reticular fibers form…

a branched network

reticular fibers support…

the structure of organs

Characteristics of loose CT

more ground substances, fewer fibers

dense CT

mostly protein fibers, less ground substance, what tendons and ligaments are made of

aerolar tissue

least specialized CT, has some elastic fibers

types of cartilage

hyaline, elastic, fibrocartilage

most common type of cartilage

hyaline

hyaline cartilage

connections between the ribs and sternum

elastic cartilage

found in external ear

fibrocartilage

very tough, prevents bone to bone contact

interstitial growth

cell division and additional matrix added from within the interior of the cartilage

appositional growth

cell division and additional matrix around the outside

purpose of appositional growth

repairs cartilage in adulthood

2/3 of bone matrix =

minerals

1/3 of bone cells =

osteocytes

how are osteocytes arranged in their lacunae

circular layers around central canals

osteocytes acccess the blood supply through…

small channels that run through bone matrix

matrix of fluid connective tissues

watery with dissolved proteins

matrix of blood

plasma

Red blood cells are called

erythrocytes

how much of blood volume do erythrocytes make up

1/2

function of RBCs

carry oxygen and Co2 in blood

white blood cells =

leukocytes

how many different types of WBC

20 types

platelets

cell fragments

function of platelets

blood clotting

lymph contains lots of

white blood cells, lymphocytes

3 major subdivisions of the extracellular fluid

plasma, interstitial fluid, lymph

plasma

the extracellular fluid in blood

origin for interstitial fluid

water and small solutes

what does interstitial fluid do to cells

bathes cells in tissue

lymph forms as…

interstitial fluid drains into lymphatic vessels

Eventually, all lymph in the body ends up in

2 large lymphatic ducts

what do lymphatic ducts do

empty all the lymph into large veins near the heart