ANAT2241 Connective Tissue Types

From Embryology

ANAT2241 course banner.jpg

ANAT2241 This practical support page content is not part of the virtual science practical class and provides additional information for student self-directed learning purposes. All practical class pages are located on Moodle - ANAT2241

General Objective

To recognise various components of connective tissue and understand their functions.

Specific Objectives

  1. To recognise the histological appearance of mesenchymal and mucoid connective tissue, and revise loose and dense fibrous connective tissue.
  2. To recognise adipose tissue (white and brown fat) and understand its functions.
  3. To recognise the histological appearance of the different forms of cartilage: hyaline, elastic and fibrocartilage.
  4. To understand the role of the perichondrium in the formation of cartilage, and the mechanisms of appositional and interstitial growth.

Learning Activities

Examine the following virtual slides. Identify, draw and label the main features and note their function.


Connective Tissue Types | Histology Drawings

Terms

  • CT - connective tissue
  • Dense CT - connective tissue mainly occupied by fibres (dermis of skin).
  • Loose CT - connective tissue mainly cells, vessels and nerves. Generates a soft and compliant CT (mucous connective tissue, reticular connective tissue and adipose tissue).
  • irregular CT - fibres do not show a clear orientation within the tissue and form a densely woven three-dimensional network.
  • regular CT - fibres show a clear parallel orientation within the tissue.

Adipose Tissue

Adult skin histology 02.jpg Pacinian corpuscle histology 01.jpg

White Adipose

White adipose 01.jpg White adipose 02.jpg

unilocular - single lipid drop in cytoplasm. Nucleus flattened on edge of cell.

Brown Adipose

Brown adipose histology.jpg

Cartilage

Developing cartilage
Fetal cartilage 01.jpg Endochondral ossification.jpg
Mesenchyme forming cartilage Endochondral ossification


  • Mesenchyme - is an embryonic (undifferentiated) connective tissue

Cartilage Growth

  1. Interstitial - Chondroblasts within existing cartilage divide and form isogenic groups (small cluster of cells) produce matrix to become separated from each other by a thin partition of matrix. Mainly in immature cartilage.
  2. Appositional - Mesenchymal cells around cartilage in perichondrium (chondrogenic layer) differentiate into chondroblasts. In both immature and mature cartilage.
Cartilage nest.gif

isogenic group development

Hyaline


Articular cartilage
  • specialised form of hyaline cartilage
  • articulating ends of bones
  • lubricated, wear-proof, slightly compressible surfaces
    • exhibit very little friction
  • not surrounded by a perichondrium
  • partly vascularised and nourishment by synovial fluid
Articular cartilage.jpg Articular cartilage 01.jpg

Elastic Cartilage

  • occurs in tissues where "flexibility" required
  • histologically similar to hyaline cartilage with the addition of a elastic fibres
    • elastic fibres - dense network of delicately branched fibres, individual fibres are difficult observe
  • Examples - epiglottic cartilage, larynx (corniculate and cuneiform cartilage), external ear and auditory tube


Epiglottis cartilage 01.jpg Epiglottis cartilage 02.jpg

Elastic cartilage (elastin stain)

Fibrocartilage

  • Transitional between dense connective tissue and hyaline cartilage
  • merges into neighbouring tissues (tendons or articular hyaline cartilage)
  • difficult identify the perichondrium
  • Examples - joints (intra-articular lips, discs and menisci) and intervertebral discs.

Chondrocytes

  • form short rows between dense bundles of collagen fibres
    • lie singly or in pairs
  • collagen type I


Fibrous cartilage 01.jpg Fibrous cartilage 02.jpg


Tendon

Skeletal muscle histology 044.jpg Dense Regular Connective Tissue
  • Regular - if the fibres run parallel to each other
  • van Gieson stain - collagen stains dark red, other tissue components appear in shades of grey (nuclei) and yellow (cytoplasm)
  • Coarse collagen fibres - aligned with each other very narrow spaces between
  • Only a few cells between the fibres, cytoplasm is difficult to identify but the nuclei can be seen scattered among the collagen fibres.
    • Nuclei are often elongated and aligned parallel to the collagen fibres


Tissue Examples - tendons, ligaments, fasciae and aponeuroses of muscles.

Electron Microscopy - Collagen

Collagen EM1

CollagenEM01-icon.jpg

 ‎‎Mobile | Desktop | Original

EM Slides
Collagen Synthesis

Collagen synthesis 01.jpg

Collagen is the major extracellular matrix protein found in connective tissues.
  • Collagen Type I - skin, tendon, vascular, ligature, organs, bone (main component of bone)
  • Collagen Type II - cartilage (main component of cartilage)
  • Collagen Type III - reticular fibers with type I.
  • Collagen Type IV - forms bases of cell basement membrane
  • Collagen Type V - hair and nail


Cartilage Histology: Developing | Hyaline HE | Hyaline VG | Hyaline HE | Hyaline VG | Elastic 1 | Elastic 2 | Fibrous - articular disc | Fibrous - intervertebral disc | Articular 1 | Articular 2


Course Links

Moodle - ANAT2241 - 2019

Histology Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | ANAT2241 Support | Histology | Histology Stains | Embryology Glossary


Common Histology Stains  
Histology Stains - Common Stains and Their Reactions
Stain
Nucleus
Cytoplasm
Collagen
RBCs
Other
Haematoxylin
blue
-
-
-
mucins - light blue
Eosin
-
pink
pale pink
bright red
colloid - pinkmuscle - red
Iron Haematoxylin
blue/black
-
-
-
Van Gieson
-
brown/yellow
red
yellow
muscle: yellow/browncartilage - pink
Verhoeff's Elastin
black
-
-
-
elastic fibres - black
Tartrazine
-
yellow
yellow
yellow
Silver Impregnation
-
-
grey/brown
-
reticular fibres - black
Methyl Green
dark green
light green
light green
green
Nuclear Fast Red
red
pink
pink
pink
Gomori's Trichrome
purple/red
purple
green
red
keratin - redmuscle - purple/red
Heidenhain's Azan
red
purple/red
deep blue
red
muscle - red
Osmium Tetroxide
-
-
brown
brown
myelin, lipids - black
Alcian Blue
-
-
-
-
mucins, - blue
Periodic acid-Schiff (PAS)
-
-
pink
-
mucins, glycogen, glycocalyx - magenta
Phosphotungstic Acid-Hematoxylin (PTAH)
blue
-
red
blue
muscle bands - blue
Masson's Trichrome
blue/black
red
green/blue
red
cartilage, mucins - blue or green; muscle - red
Luxol Fast Blue
-
-
-
variable
myelin - blue
Aldehyde Fuchsin
-
-
-
-
elastic fibres, mast cells - deep purple
Light Green
-
-
light green
-
Gallocyanin
dark blue
-
-
-
nucleic acids, Nissl granules - dark blue
Romanowsky (e.g. Leishman's)
blue
pink
acidophils - red, basophils - blue, azurophilic - purple
Aldehyde Pararosanilin elastic fibres - purple
Haematoxylin and Eosin
One of the most common staining techniques in pathology and histology. Acronym "H and E" stain. (H&E, HE).


Haematoxylin
  • Stains nuclei blue to dark-blue.
  • Stains the matrix of hyaline cartilage, myxomatous, and mucoid material pale blue.
  • Stains myelin weakly but is not noticeable if combined with eosin stain.
  • combined with Orange G (H & Or. G.) instead of eosin, specifically stains the granules of acidophilic cells of the adenohypophysis (anterior pituitary).
Eosin
  • Stains cytoplasm pink to red; red blood cells are also bright red.
  • Common counterstain to hematoxylin.
  • Stain intensity varies with the formula as well as the fixative.

Practical Support

Pages can be accessed from any internet connected computer.

ANAT2241 Support Links: The Virtual Microscope | Covering and Lining Epithelia | Glandular Epithelia | CT Components | CT Types | Bone, Bone Formation and Joints | Muscle | Nervous | Blood | Eye | Cardiovascular | Respiratory | Integumentary | Gastrointestinal | Gastrointestinal Organs | Lymphatic and Immune | Endocrine | Urinary | Female Reproductive | Male Reproductive | Histology Stains | Histology Drawings | Practicals Health and Safety 2013 | Moodle - 2019


ANAT2241 This practical support page content is not part of the science practical class and provides only background information for student self-directed learning purposes.


Cite this page: Hill, M.A. (2024, March 19) Embryology ANAT2241 Connective Tissue Types. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/ANAT2241_Connective_Tissue_Types

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G