Download Primary Tissues

Basic Histology
Primary Tissues
By Mrs. Bailey
1. Epithelial Tissue
2. Connective Tissue
3. Muscle Tissue
4. ervous Tissue
Epithelium
• Very cellular
• Supported by underlying connective tissue
Covering/Lining Epithelium
• Faces a space such as the lumen
of a blood vessel or intestine.
• Epithelial & connective tissue are separated by a basement
membrane, which is produced by both tissues.
Apical surface = adjacent
• Packed together tightly & orderly.
Tight junctions may occur between cells.
Basal surface = adjacent
to lumen
to basement membrane
• Avascular. Receives its nutrients
Hint: These surfaces are “places”
”, not “things”
”.
by diffusion from the underlying
connective tissue.
• Two types:
a. Covering/Lining
b. Glandular
•
Mucous membranes
- line organs and cavities
- secretion of mucous from glands
Serous membranes - cover and protect organs
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Glandular Epithelium
a.
Exocrine
secretions enter ducts
b.
Endocrine
secretions enter bloodstream
Epithelial Tissue Types
Layers :
Simple - single layer – provides a selective
barrier allowing diffusion, filtration, secretion,
and absorption.
Stratified - several layers –
subject to wear and tear –
forms a protective barrier.
Pseudostratified –
appears to be several layers,
but is actually only a single layer.
Shapes
•
Squamous - flattened
Cuboidal - cube
Columnar - cylindrical
•
Transitional – change shape
•
•
Types of Epithelial Tissue
They are rounder when the tissue
is relaxed and flatter when the
tissue is stretched.
OTE:
When viewed from
the apical surface, all epithelial
cells have a similar shape.
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Simple CUBOIDAL Epithelium
Simple COLUMNAR Epithelium
ame those parts!
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What would this area be called?
Pseudostratified Ciliated Columnar Epithelium
Connective Tissue
• Most abundant tissue in the body.
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3
2
1
• Supports epithelial tissue and connects it to other tissues.
Provides coverings that support and protect muscle and
nervous tissue.
• Most are not very cellular, usually containing more
matrix than cells.
• Most are vascular and regenerate easily.
EXCEPTIOS:
Tendons – poorly vascularized; do OT heal easily
Cartilage – avascular - does OT heal easily
Cells:
Fibroblasts, Macrophage, Plasma cells,
Mast cells, Adipocytes, WBC's
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Connective Tissue Matrix
Ground substance + Fibers
(Composition is used in classifying connective tissue)
Ground Substance = polysaccharides + proteins
Fibers:
• Collagen - most abundant protein in body
• Elastic fibers - stretchable (in skin, BV, lungs)
• Reticular fibers - support and strength
Types of Connective Tissue
• Loose
• Dense
Loose Connective Tissue
• Fibers are loosely arranged.
• Collagen, elastic, and reticular fibers provide strength,
elasticity, and support.
• Fibroblasts and adipocytes permanently reside here.
• Subcutaneous layer of skin.
• Cartilage
Areolar
• Bone
Reticular
• Blood
Adipose
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Areolar Connective Tissue
ow you try …………….
Refer to page 136
Fibroblast
nucleus
Mast cell
Elastic
fiber
Collagen
fiber
Ground
substance
ow you try …………….
Dense Connective Tissue
• Matrix is packed with fibers and contains very little ground
substance and few fibroblasts.
• Tendons, Ligaments, Skin dermis, Artery wall
Dense Regular
Dense Irregular
Dense Regular Elastic
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ow you try …………….
ow you try …………….
HIT: This is an ARTERY, which contains dense regular elastic CT.
• Peach
• Blue
outlines?
arrows?
• Green
arrow?
• Grey block
arrow?
• Yellow block
arrow?
ow you try …………….
Cartilage
Contains cells called chondrocytes housed in spaces called
"lacunae". Some lacunae contain more than one chondrocyte ...
these are daughter cells formed after division.
Hyaline - ends of bone; support rings of respiratory tubes
Elastic – elastin fibers; epiglottis; nose
Fibrocartilage - much collagen; intervertebral discs
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Bone
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• Dense - middle portion (osteon); Spongy – ends (trabeculae)
1.
2.
3.
Bone
• Haversian Canal - extends the length of each osteon
through its center; contains blood vessels, lymphatic
vessels, and nerves.
• Volkmann’
’s Canals – connect Haversian canals to each
other; communication; contain nerves and vessels that
carry blood and lymph from the exterior bone surface to
the osteons.
• Canaliculi – tiny canals radiating
in all directions from the lacunae
and connecting them to each other
as well as to the Haversian canal.
• Bone tissue is unlike other
connective tissues in that
the extracellular matrix
becomes calcified.
• Lamellae – layers of matrix;
concentric = within osteons;
interstitial = in between osteons.
• Contains cells called
osteocytes housed in
lacunae.
Bone
Osteon
Volkmann’
’s
canals
Concentric
lamellae
Interstitial
lamellae
Haversian
canal
Lacunae
Refer to page 140
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Canaliculi
ow you try …………….
1.
2.
3.
4.
What do you refer
to each of the
“larger circles”
”?
Muscle Tissue
Blood
Platelets
White
blood cells
(Leukocytes)
Red
blood cells
(Erythrocytes)
Plasma
matrix
Refer to page 142
• Contains muscle cells and connective tissue. Thin layers of
connective tissue surround muscle cells to protect and support
them.
• Very cellular.
Muscle cells = muscle fibers.
Fibers contain many microfilaments (myofilaments) - cause
muscle cells to shorten (contract) when stimulated.
Skeletal (striated; voluntary; multinucleated cells)
Cardiac (striated; involuntary; multinucleated cells;
branching cells; intercalated disks)
Smooth
(non-striated; involuntary; uninucleated cells;
tapered cells)
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Nervous Tissue
• Forms the brain, spinal cord, and nerves.
• Two basic categories of nervous tissue cells:
a. eurons – receive and send information; amitotic
REVIEW: axon, dendrite, cell body
Glial cells
b. euroglial cells – support the neurons; divide and
replace themselves
• Highly vascularized
Refer to page 146
ow you try …………….
1.
2.
1&2
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3.
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