Transcript Slide 1

Tissues
Tissue – a groups of cells with
similar structure & function.
Histology- the study of tissue
strictures.
4 Major Tissue Types
1. Epithelial Tissue
Cells that are closely packed with
little intercellular material
between them.
AVASCULAR- no blood vessels
can penetrate the tissue .
Functions
1. Protection
2. Barriers
3. Permitting the passage of certain
substances.
4. Secreting substances
5. Absorbing substances.
Two Major grouping of Epithelial Tissues
A. Covering Epithelium
Covers body surfaces
B. Lining Epithelium
Lines the walls of cavities &
organs.
Epithelial tissue is categorized
on the basis of the cells
shape & arrangement.
1. Simple Squamous –
One layer thick
Thin flat cells
Lines blood vessels, walls of capillaries,
& walls of air sacs in the lungs (alveoli).
Prevents abrasion between organs in
the cavities
2. Simple Cuboidal –
Cube-shaped cells in a single
layer. Forms the walls of
kidneys & ducts.
3. Simple Columnar –
Cylindrical cells. Lines the
digestive-tract organs & uterus.
4. Stratified Squamous
- A multiple -layer arrangement with
the surface layer composed of
flatten cells. Usually a protective
function & forms the outer layer of
the skin.
5. Pseudo stratified Columnar –
single layer of irregularly shaped
cells that visually appears to be in
multiple-layer arrangement. Line
the respiratory tract & contains
cilia.
.
6.
Transitional –
multiple-layered arrangement of
cube like or irregularly shaped
cells that can be greatly
stretched.
Lines the urinary bladder &
ureter.
Epithelial Review
B. Glandular Epithelium - closely
packed cells that are specialized
to manufacture & secrete
products. Forms glands.
1. Exocrine Glands - glands that
empty their products into ducts,
which channel the secretions to
the body surface or into a cavity.
Examples
salivary
sweat
oil glands
.
2. Endocrine Glands - glands that
secrete their products into the
extracellular space, where they
diffuse into the bloodstream.
Examples
pituitary
thyroid
adrenal glands.
They are also organs that are
composed of more than one type of
tissue; and together they make up
the endocrine system (Hormones).
C. Structural & functional relationship
among epithelial tissue.
Shape is determined by the function.
1. Free cell surfaces.
Smooth
microvilli
Cilia
goblet
2. Cell connections
a. Tight junctions – prevents passage
between them.
b. Desmosomes – mechanical links that
binds cells together.
c. Hemidesmosomes – anchor cells to
basement membranes.
3. Gap junctions – small channels that
allow passage of material between cells.
Ground Substance
Appears shapeless but has
specialized molecules that can
trap a large amount of water.
Connective
tissue
PROTEIN FIBERS
A. Collagenous Fibers
B. Elastic Fibers
C. Reticular Fibers
Classification of
Connective Tissue
Blast---Produce matrix
Cyte--Cells maintain it
Clast--Cells break it down for
remodeling
Cells for Immunity
Macrophages
Macro---large
Phago---to eat
Mast cells--Cells that release chemicals
that promote inflammation
Function of Connective tissue
1. Enclosing & separating
2. Connecting tissues to one another.
3. Supports & moving
4. Storing
5. Cushing & Insulating
6. Transporting
7. Protecting
A. Loose Connective Tissue –
(Areolar Tissue)
Has some ECM
Very few elastic fibers
More collagen
Fibers are widely spread apart from one
another
B. Adipose Tissue –
Has very little ECM
Does have both collagen and elastic
fibers
Cells are large and closely packed.
Filled with lipids.
Specialize fibroblasts known as
adipocytes or adipose cells which
store large amounts of fat.
C. Dense Connective Tissue – Intercellular
material contain fibers that are packed tightly
together & the tissue has fewer cells & less
ground tissue, but more fibers than connective
tissue.
1. Dense Collagenous (Regular) Connective Tissue
- Extend parallel to one another.
Resist physical stress & found in tendons
ligaments.
&
D. Dense Irregular Connective Tissue
–
Fibers branch from dense matting.
Found in the deep layer of the skin.
E. Dense Elastic
Connective Tissue
Abundant elastic fibers among
collagen fibers.
ex. Vocal cords, walls of arteries
Review
How is connective tissue different from
epithelial tissue?
Match the connective tissue with its
function/location…
– Dense regular
Adipose
Dense elastic
vocal cords
energy storage
anchoring (tendons)
F. Cartilage – MADE UP OF
Chondrocytes - produces and maintains
the cartilage.
Lacunae - the chamber which the
chondrocytes lie in.
Perichondrium – provides nourishment
to the chondrocytes
1. Hyaline Cartilage - Matrix is
dominated by chondroin sulfate in the
ground substance & contain
collagen.
Most abudnant type of cartilage
Locations:
upper respiratory tract
fetal skeleton.
2
2. Elastic Cartilage –
Matrix is dominated by elastic
fibers, providing cartilage with
elastic properties.
Locations:
ears
end of the nose.
.
3. Fibrocartilage - Matrix is dominate
by collagenous fibers.
Found in joints that deal with a lot of
stress. (compression & pulling)
Locations:
knees
intervertebral discs.
3. Bone - Intercellular material (matrix).
Consists of mineral salts & collagen which is
maintain by osteocytes.
Osteocytes lie in a chamber known as the
lacunae.
Functions:
A. Compact Bone –
Closely packed deposit of mineral salts, which
are laid down in concentrate layer (lamellae).
In the center lies a tube (Osteonic Canal), which
serves as a passage way for blood vessels.
The tube combined with the layers form the
Haversian Canal.
B. Spongy Bone –
Matrix Consists of small plates of mineral salts
& collagen (Spicules) that form a network with
spaces in between.
These spaces are filled with blood-forming tissue
-red bone marrow.
4. Blood-Forming Tissue & Blood - tissue
that manufacturers blood cells from
stem cells.
A. Red Bone Marrow (Hematopoietic) found in spongy bone.
Red bone marrow initiates production
of all blood cells.
B. Lymphoid Tissue - found in lymph
nodes, tonsils, spleen, & thymus in young
children.
Lymph Tissue produce two types of
white blood cells, monocytes,
lymphocytes.
Function:
Whole blood consists of formed
elements suspended in a FLUID
matrix known as plasma.
Transport material throughout the
body.
Review
What are the 4 types of connective
tissue?
What is the only liquid tissue of the
body?
How is compact bone different from
spongy?
3. Muscle Tissue –
Specialized to shorten (contract).
Composed of two main parts:
Actin & Myosin.
A. Skeletal Muscle –
Muscle that is attached to bone
by way of tendons.
Contract under conscious control
(Voluntary), contain striations & is
multinucleate.
B. Smooth Muscle Forms part of the walls of blood
vessels & visceral organs.
(Involuntary Control) and does not
contain striations.
Propels material as it passes
through body tubes & alters the
size of organs.
C. Cardiac Muscle –
Muscle that forms the walls of the
heart and helps propel blood through
the body’s system of vessels.
Not under conscious control, but can
be influenced.
Intercalated discs – specialized gap
junctions to coordinate the
contraction of the heart.
4. Nervous Tissue - Has conductivity &
excitability properties.
A. Neurons - conduct electric &
chemical signals very rapidly (action
potnetial).
B. Neuroglia Cells - support &
maintain the neurons.
Structure of a Neuron
5. Membranes –
Simplest combination of tissues in
the body that forms a functional
unit.
Consist of connective tissue usually
associated with epithelial tissue &
are highly vascular - epithelial
membranes.
A. Cutaneous Membrane – skin
B. Serous Membrane –
Simple squamous & produces a
watery secretion.
Lines the internal surfaces of
the thoracic & abdominopelvic
cavities.
Provides a watery fluid for
lubrication.
Pericardium surround the heart.
Pleural -surround
each of the lungs.
Peritoneum - lines
the abdominal
cavity & covers
most of the organs.
C. Mucous Membrane –
Various kinds of epithelium resting on a
layer of loose connective tissue.
Line the internal walls of the digestive tract,
respiratory tract, reproductive tract, urinary
tract, & urethra.
Secrete mucus that traps foreign particles &
maintain a moist environment. Forms a
protective layer over cells.
Rhinitis – swelling of the nasal membranes
due to a cold or allergies.
D. Synovial Membranes –
Line the wall of cavities of certain
joints.
Secrete a synovial fluid which
lubricates & nourishes joint cartilage.
Inflammation/ Injury
Results
Mediators/inflammation are
chemicals are released in the injured
tissue.
ex. Histamines, kinins,
prostaglandins.
Blood vessel dilation.
.
4. Edema
.
Mechanisms to help Injury
Chronic Inflammation
Whatever is causing the
inflammation is not removed.
Tissues & Aging
Athletic performance
declines 30-35
Cells divide slower (lower RBC
production, slower recovery from
injuries.
Matrix changes – less flexible streching,
walls of arteries