API
Chapter 4 TISSUE: The Living
Fabric
I. Definition
A.
groups of closely associated cells that are similar in structure and perform a
common function
B.
Tissues are organized into organs
C.
Study of tissues is histology
II. Types
A.
epithelial tissue
1.covering
and linings
2.glands
3.
Functions: protection, absorption, filtration, excretion, secretion, sensory
reception
B.
connective tissue
1.support
C.
muscle tissue
1.movement
D.
nervous tissue
1.control
III. Epithelium
A.
Characteristics
1.close
cells
2.very
little extracellular matrix
3.intercellular
junctions to hold cells together
a.
desmosomes
b.
tight or gap junctions
4.
polarity:
a.
apical or luminal surface
i.
free side or top of cells
ii.
faces outside of body or inside cavity (lumen)
iii.
microvilli (brush border)
iv.
cilia
b.
basal surface
i. attached surface of cell
5.
basement membrane
a.attaches
and supports base of epithelial layer
b.basal
lamina
(1)glycoprotein
secreted by the cells
c.reticular
lamina
(1)collagenous
fibers
(a)secreted
by connective tissue cells
d.defines
the boundary for epithelial cells
(1)cancerous
cells can invade
6.avascular
a.no
blood vessels
b.depends
on underlying tissue for nutrients
7.
innervated
8.can
renew and repair
B.Classification
1.structural
a.layers
(1)monolayer
= simple
(2)multiple
layers = straitified
b.shape
(1)cuboidal
=cube
(2)columnar
=height>width
(3)squamous
=flattened (fried eggs)
2.Simple
epithelium
a.simple
squamous
(1)interdigitating
cells
(2)on
basement membrane
(3)Type
(a)mesothelium
i)serosal
lining
a)pleural
serosa
b)pericardial
serosa
c)peritoneal
serosa
(b)endothelium
i)lines
lumen
a)blood
vessels
b)heart
c)lymphatic
vessels
b.simple
cuboidal
(1)secretory
portions of glands
(2)lines
gland ducts
(3)lines
kidney tubules and ducts
c.simple
columnar
(1)nuclei
may be close to basal surface
(2)lines
uterus, oviducts
(3)central
canal of the spinal cord
(4)digestive
tract
3.Stratified
epithelium
a.basal
cell layer anchored to basement membrane, to cells above, and adjacent cells
b.In
thick layers of cells the top layer of cells is far away from nutrients and may
be malnourished and die.
c.Lower
layer undergoes mitosis and cells move up.
d.stratified
squamous epithelium
(1)mixture
of cell shapes
(2)superficial
layers are squamous
(3)basal
layers more columnar
(4)middle
layers more cuboidal shape
(5)basal
and middle layers undergo mitosis
(6)noncornified
stratified squamous epithelium
(a)superficial
cells remain active until lost by friction
(b)loss
of cells stimulates deeper layers to
divide
(c)lining
of
i)oral
cavity
ii)esophagus
iii)anus,vagina
(7)cornified
stratified squamous epithelium
(a)superficial
cells lack nuclei
(b)dehydrated
due to exposure to air
(c)far
from capillary bed
(d)become
hardened (cornified)
(e)protection
(f)skin
e.stratified
cuboidal epithelium
(1)rare
(2)ducts
of sweat glands
f.stratified
columnar epithelium
(1)rare
(2)areas
in the larynx
g.pseudostratified
columnar epithelium
(1)nuclei
appear at various levels
(2)almost
every cell is anchored
(3)located
(a)large
excretory ducts of glands
(b)urethra
(c)cilia
on cells in respiratory and uterine tubes
h.Transitional
epithelium
(1)transition
between stratified squamous and stratified columnar
(2)urinary
bladder
(3)very
thin basement membrane
4.Glandular
Epithelium
a.gland
(1)one
or more cells that make and secrete a product
(2)endocrine
(a)secrete
to blood stream
(b)product
is a hormone
(3)exocrine
(a)secrete
to a surface
(b)unicellular
i)goblet
cell
a)mucin
in water=mucus
(adjective
=mucous)
(c)multicellular
i)duct
to surface
ii)secretory
cells
iii)simple
or compound shape (branched ducts)
iv)secretory
parts
a)tubular
b)alveolar
=acinar (flask shaped)
c)tubuloalveolar
(4)exocrine
classed by secretion
(a)merocrine
i)
exocytosis
ii)
sweat, salivary glands
(b)holocrine
i)rupture
and secretions include cell fragments
ii)sebaceous
or oil producing glands
(c)apocrine
i)apex
of cell pinches off
IV.Connective Tissue (CT)
A.General
1.Living
cells surrounded by a matrix
a.cells+extracellular
matrix (ECM)=stroma
b.structural
framework
2.most
abundant tissue in body
3.functions
in
a.binding
and support
b.protection
c.insulation
B.Characteristics
1.derived
from mesenchyme (embryonic tissue)
2.generally
vascular
a.except
cartilage
3.ECM
C.Composition
1.ECM
more than glue
a.
macromolecules
b.
tissue fluid like plasma
c.
organized lattice
d.
cells migrate withing and interact
e.
varies in composition among CT
(1)ground
substances (fills EC space)
(a)
noncollagenous proteins
(b)
proteoglycans – attach glycosaminoglycins (GAGS)
to
bind water and act as medium to deliver nutrients
i)hyaluronic acid and chondroitin
ii)more
GAGS, more fluid held in ECM
(2)
fibers
(a)
collagen - strength; fresh appear as white fibers
(b)
elastic fibers- protein elastin -
stretch
(c)
reticular - fine collagen fibers, forms network
2.cells
a.
fibroblast
(1)
CT proper
b.
chondroblast
(1)
cartilage
c.
osteoblast
(1)
bone
d.
hemocytoblast or hematopoietic stem cell
(1)
forms blood cells only
e.
NOTE "blast"
(1)
mitotic cells
(2)
indicates cell secretes ECM
(3)
matures to "cyte" to maintain CT
f.
most CT also contain
(1)adipocytes (store fat)
(2) cells important in defense against
disease
like mast cells, macrophages, plasma
cells to secrete antibodies
D. Types
1.CT
Proper (fibroblasts)
a.
loose
(1)
areola
(a)
packing between tissues
(b)
separates muscles
(c)
bsorbs fluid
i)
edema
(2)
adipose
(a)
adipocyte - cell filled with oil
(b)
pushes nucleus to side
(3)
reticular
(a)
reticular cell = fibroblast
(b)
supports tissue - stroma
(c)
fine network
b.
dense (fibrous CT)
(1)
regular
(a)
tendons
i)
connects muscles/bones
(b)
ligaments
i)
bone/bone
(c)
aponeuroses
i)
sheet connects muscle/muscle or muscle/bone
(2)
irregular
(a)
dermis
(b)
organ covering
c.
elastic
(1)
vocal cords
(2)
ligamentum flava connects vertebrae
(3)
walls of aorta
2.cartilage
a.
hyaline
(1)embryonic
skeleton
(2)ends
of bones
(3)trachea
b.elastic
cartilage
(1)more
elastin
(2)external
ear
c.fibrocartilage
(1)more
collagen
(2)intervertebral
discs
(3)knee
d.characteristics
of cartilage
(a)avascular
(b)covered
with vascular perichondrium
i)dense
irregular CT membrane
(c)chondrocytes
i)mature
chondroblasts
ii)located
in lacunae(cavities)
3.Bone
a.osseous
tissue
b.deposits
of inorganic calcium salts
(1)strength
c.osteoblasts
-> osteocytes
d.More
in later chapter
4.Blood
a.cells
in liquid matrix (plasma)
b.Red
blood cells and white blood cells
(1)produced
from hemocytoblast
V.Epithelial Membranes
A.mucous
membranes
1.lines
cavities that open to outside
2.absorption
and secretion
3.epithelial
sheet with lamina propria
a.loose
CT deep to basement membrane
B.Serous
membranes
1.lines
internal ventral body vavity
a.parietal
b.visceral
2.pleural
3.peritoneum
4.pericardium
VI.Muscle tissue
A.elongated
cells
1.fibers
2.myofilaments
a.contraction
b.proteins
(1)actin
(2)myosin
B.Types
1.skeletal
muscle
a.packaged
by CT
b.attach
to bones
c.contraction
moves bones
d.voluntary
muscle
2.cardiac
muscle
a.walls
of the heart
b.pumps
blood
c.intercalated
discs
(1)join
branched fibers
d.striations
e.involuntary
muscle
3.smooth
muscle
a.no
striations
b.one
central nuclei
c.involuntary
muscle
VII.Nervous
A.neurons
1.specialized
cells to conduct nerve impulses
2.located
in brain, spinal cord and nerves to and from organs
3.cell
body and long extensions
VIII.Tissue Repair
A.Parenchyma
1.functioning
cells
B.Stroma
1.supporting
cells
C.Regeneration
1.replace
tissue
D.Fibrosis
1.scar
tissue
a.nonfunctioning
if this is in parenchyma
E.Damage
initiates the inflammatory response
1.histamine
a.
agent released from mast cells
b.increases
blood flow to damage site
2.white
cells migrate to injury
a.clean
up crew
3.blood
clots
4.clot
replaced by granulation tissue
a.becomes
scar tissue
b.collagen
fiber with few cells
F.Tissues
vary in ability to repair
1.easy
a.epithelium,bone,
skin, mucous membranes
2.difficult
a.skeletal
muscle, cartilage
3.very
little repair
a.cardiac
muscle, nervous
IX.Primary Germ Layers
A.three
layer embryo
1.ectoderm
(outer)
a.nervous
tissue
b.epithelium
(skin)
2.mesoderm(middle)
a.muscle
b.connective
tissue
c.endothelium(epithelium)
3.endoderm
(inner)
a.mucosae(epithelium)
B.Tissue
Growth
1.Epithelium
and Connective tissue continue dividing (mitosis) as adults