1' dia

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HISTOLOGY 1.6. CONNECTIVE AND SUPPORTIVE TISSUES

• CLASSIFICATION OF CONNECTIVE AND SUPPORTIVE
  TISSUES
• Embryonic connective and supportive tissue
• Mesenchyme
• Gelatinous connective tissue
• Chordoid tissue
• II. Adult connective and supportive tissues
• Adult connective tissues
• 1. Loose connective tissue
• 2. Dense irregular connective tissue
• 3. Dense regular connective tissues
• Collagen
• Elastic
• 4. Reticular connective tissue
• 5. Adipose tissue
• White adipose tissue
• Brown adipose tissue
• Adult supportive tissues (see later)

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Embryonic connective tissues Mesenhyme Three-dimes
ional network of irregular-shaped cells
abundant ground substance (no fibers).
Function gives rise to various types of adult
connective tissue

• Occurrence
• Body of embryo
• In the adult
• around blood vessels

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Embryonic connective tissues Gelatinous
connective tissue
Tissue components Stellate fibroblasts, amorpho
us ground substance collagen fibrils
Cross-section of the umbilical cord Occurrence
in adult Omasal laminae Bovine glans penis Core
of rooster comb
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Embryonic supportive tissue Chordoid tissue
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3
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• Cross-section fo an embryo. The arrow points at
  the notochord
• Cross-section of the notochord
• The chordoid tissue in a young notochord composed
  of large polygonal cells

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ADULT CONNECTIVE TISSUES Loose connective
tissue The most widely distributed type of
CT Present around blood vessels and nerves,
between muscle bundles, beneath epithelia, in
pia mater and arachnoidea Functions support,
dampening tissue repair, defence
activities Tissue components free and fixed
cells (dominating, see before) collagen,
elastic and reticular fibers ground substance
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ADULT CONNECTIVE TISSUES Dense irregular
connective tissue Collagen fibers are the most
abundant tissue components arranged in bundles
crossing each other at various angles. From
among cell types fibroblasts and fibrocytes
predominate. Occurrence aponeuroses, muscular
fascia, capsules of organs, dermis, pericardium.
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ADULT CONNECTIVE TISSUES Dense regular
connective tissue The fibers are arranged in the
same plane and direction Occurs in collagen
tendons and elastic ligaments
Collagen tendon longitudinal section. Arrows
point at elongated nuclei of tendocytes. H.E.
staining
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Elastic ligament longitudinal section.
Resorcin-fuchsin staining
Elastic ligaments Ligamentum flavum (see
above) Ligamentum nuchae Elastic fasciae of
abdominal musculature of herbivores
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ADULT CONNECTIVE TISSUE Reticular connective
tissue forms the stroma fo all lymphatic organs
(spleen,lymph node, hemal node, tonsils,
etc.) Tissue components Stellate reticular cells
complex three-dimensional network of
reticular fibers
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ADULT CONNECTIVE TISSUES Adipose
tissues Specialized to multiple functions White
adipose tissue unilocular adipocytes collagen
and reticular fibers Functions thermal and
mechanical insulation, dampening (digital
pads) stored energy source hormone-production
(leptin)
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ADULT CONNECTIVE TISSUES Brown adipose tissue
multilocular adipocytes (lot of mitochondria)
collagen and reticular fibers Function
non-shivering thermogenesis
Occurrence in newborns, rodents and
hibernating animals (axillary and neck region,
interscapular fat, thoracic aorta, mediastinum,
mesenteries, vena cava dorsal to kidney)