1. Medical School Histology Basics Connective Tissue
VIBS 289
Mast cell
Macrophage
Fibroblasts
Fibroblasts
Plasma cell
Fat cells
Larry Johnson Texas A&M University

2. Function of Connective Tissue
The histological glue which binds the other tissues together to form organs
Mechanical support - stroma below epithelium, skeleton
Metabolite exchange - vascular beds
Energy storage - adipose tissue
Inflammation - site of action for blood borne immune cells
skin
Slide 109
Plasma cells
140

3. Distinguishing features and histological identification
Loose connective tissue – sparse collagen and elastic fibers, plentiful cells including fibroblasts, leukocytes
Dense connective tissue – concentrated collagen, few cells
Cartilage – avascular homogeneous matrix of collagen and protein-polysaccharides with few cells
Bone – calcified collagen matrix with few cells trapped in the caves of bone
Cartilage
Epithelium
Bone
Loose connective tissue
Dense connective tissue

4. SKIN Dense irregular connective tissue (few cells and lots of fibers)
Loose connective tissue
(lots of cells and few fibers)

5. Slide 109: Skin, hand, monkey
Irregular connective tissue, dense surface region and loose subdermal region
Adipose cells,
Location of a high density of collagen fibers
Loose connective tissue
Dense irregular connective tissue

6. Slide 109: Skin, hand, monkey
Dense Irregular
connective tissue
Collagen fibers in bundles
Fibroblasts Adipose cells
Loose connective tissue
Dermis
Epidermis

7. Skin, hand, monkey Slide 109 Fibroblasts subdermal region
Loose connective tissue
Dense irregular connective tissue
Nerve
Bundles of
collagen fibers
Dense Irregular
connective tissue
Endothelium
Epithelium of
the epidermis
Dense surface region
of dermis

8. SPLEEN

9. Spleen (reticulum stain)- capsule and reticulum fibers
218
Spleen (reticulum stain)- capsule and reticulum fibers
capsule
reticulum fibers

10. Slide 118: Liver & spleen with colloidal carbon, rat
Dense irregular connective tissue capsule
Macrophages
mesothelium

11. Kidney Capsule, urinary vascular poles slide #19713
Dense irregular
connective tissue
of capsule
fibroblasts
nephrons
Bundles
of collagen

12. Penis – transitional epithelium and surrounding slide 277 spongy cavernous of penal urethra
Skin
Dense irregular
connective tissue creating
the tunica albuginea
Erectile vascular tissue

13. Small intestinal villi
Epithelium
Lamina propria
Smooth muscle

14. Slide 32409: Rat intestine (toluidine blue)
Loose connective tissue (e.g., lamina propria)
Fibroblasts
Blood vessels

15. Dense irregular connective tissue
Dense regular connective tissue

16. Slide 202: Tendon Dense regular connective tissue
High density of collagen fibers
Fibroblasts

17. CELLS OF CT FIBROBLASTS MESENCHYMAL CELLS and RBC ADIPOSE CELLS
MACROPHAGE
PLASMA CELLS
MAST CELLS and WBC
CHONDROBLASTS
CHONDROCYTES
OSTEOBLASTS
OSTEOCYTES
OSTEOCLASTS

18. Cells of connective tissue

19. Cells of connective tissue

20. Blood cells are connective tissue cells
32583
Bone marrow cells

21. Slide 109: Skin, hand, monkey
Fibroblasts
Bundles of collagen fibers Smooth muscle
cells
Muscular artery
Venule
Endothelial cells

22. Slide 196: Spermatic cord
Loose connective tissue Fat cells Fibroblasts
Smooth
muscle
Nerve
Endothelial
cells
Bundles of
collagen fibers
Valve in vein
Fibroblasts

23. Slide 196 Vein of Spermatic cord
Fat cells
Large vein
Smooth muscle
Valve in a
large vein
Fibroblasts

24. Vein of Spermatic cord Slide 196 Smooth muscle cells Arteriole
Fibroblasts

25. Slide 19716: Tail of epididymis
Fibroblasts, Collagen fiber bundles
Fat cells
Fat cells

26. EM 8e: Fibroblasts
Fibroblasts
Collagen fibers

27. Slide 126:Bile duct with portal vein, monkey
Loose connective tissue (many cells and few fibers),
Adipose cells,
Fibroblasts
Bile
duct
Portal
vein

28. Slide 195 Fetal jaw White fat cells Fibroblasts
White fat cell cytoplasm can be seen surrounding the single fat droplet
Brown fat cell cytoplasm can be seen surrounding multiple fat droplets
Slide HISTO039

29. Slide HISTO42: Lung Mast cell
Light blue granules
Mast cells
Mast cells
Air
sac

30. Cardiac stomach w/chronic infection
140
Cardiac stomach w/chronic infection
Plasma cells
32409
Mast cell
Mast cells
epithelium
Loose connect tissue

31. EM 8d: Mast cell
Granules,
Mitochondria,
Golgi region

32. 432 lung macrophages Lung Type II pneumocytes Air space Air space Air

33. Macrophage in lamina propria of rat intestine
Slide 32409
Macrophage
Slide 109

34. Note varied densities in Macrophage in vacuoles. aged rat testis
EM 8h: Macrophage in testis; 30,000x
Enlarged basal lamina
Heterophagic vacuole
Leydig cell cytoplasm
Nucleolus
Myoid cell

35. Kupffer cells
EM 18
Slide 118 liver
Hepatocytes
Blood bathing of the
hepatocytes travels through portal sinuses
Slide 118 carbon deposits
in the macrophages in the spleen

36. Slide 126: Bile duct with portal vein, monkey
Loose connective tissue,
plasma cells

37. Cardiac stomach w/chronic infection
140
Cardiac stomach w/chronic infection
Plasma cells
neutrophils
eosinophils
endothelium
Fibroblasts in loose connect tissue
Parietal cells of stomach

38. 111 Skin Large bundles of collagen fibers
running in different directions (irregular) and of high density (dense) = dense irregular connective tissue in the dermis of skin
111 Skin
Epithelium
ocotillo plant
Nuclei of fibroblasts

39. Slide 109 skin
High density of collagen fibers
regularly or irregularly arranged
Slide 202 tendon
dermis
fibroblasts
With flexibility, high tensile strength, and impressive resistance to stretch, concentrations of these fibers are found where these attributes are crucially important.

40. Slide HISTO039: Larynx Bundles of collagen fibers
Loose connective tissue
of the lamina propria
Dense irregular connective tissue
in capsule
Fibroblasts
cartilage
perichondrium
Epithelium
Bundles of collagen fibers

41. Fibroblast
EM 10d: Schwann cell
Collagen fibers

42. EM 8e: Fibroblasts
Fibroblasts
Bundles of collagen
fibers
111 Skin

43. Slide 218 spleen with dark, branched reticular fibers

45. Slide 427: Aorta Elastin lamina Lumen Smooth muscle cells
Muscle and elastic fibers

46. Slide 426: Renal artery and vein with nerves
Elastin fibers
Elastin lamina
Smooth muscle

47. EM 9: Smooth muscle cells
Elastic
lamina

48. EM 10f: Arteriolar Wall
Elastic fibers

49. Slide 32409 Intestine: Connective Cells

50. In summary
Blood cells
Marrow cells

51. Questions on Connective Tissue
a. provides mechanical support and metabolic exchange for epithelia
b. provides site of battle for blood borne immune cells
c. stores energy in striated muscle cells
d. a and b
e. a, b, and c
Classification of connective tissue proper is based on:
a. ratio of cells to extracellular matrix
b. arrangement of fibers
c. the density of fibers in the extracellular matrix
Cells of connective tissue that are progenitor (stem) cells are:
a. adipose cells
b. macrophages
c. plasma cells
d. fibroblasts
e. mast cells

52. Many illustrations in these VIBS Histology YouTube videos were modified from the following books and sources: Many thanks to original sources!
Bruce Alberts, et al Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY.
Bruce Alberts, et al Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY.
William J. Banks, Applied Veterinary Histology. Williams and Wilkins, Los Angeles, CA.
Hans Elias, et al Histology and Human Microanatomy. John Wiley and Sons, New York, NY.
Don W. Fawcett Bloom and Fawcett. A textbook of histology. W. B. Saunders Company, Philadelphia, PA.
Don W. Fawcett Bloom and Fawcett. A textbook of histology. Chapman and Hall, New York, NY.
Arthur W. Ham and David H. Cormack Histology. J. S. Lippincott Company, Philadelphia, PA.
Luis C. Junqueira, et al Basic Histology. Lange Medical Publications, Los Altos, CA.
L. Carlos Junqueira, et al Basic Histology. Appleton and Lange, Norwalk, CT.
L.L. Langley, et al Dynamic Anatomy and Physiology. McGraw-Hill Book Company, New York, NY.
W.W. Tuttle and Byron A. Schottelius Textbook of Physiology. The C. V. Mosby Company, St. Louis, MO.
Leon Weiss Histology Cell and Tissue Biology. Elsevier Biomedical, New York, NY.
Leon Weiss and Roy O. Greep Histology. McGraw-Hill Book Company, New York, NY.
Nature ( Vol. 414:88,2001.
Arthur C. Guyton,1971.Textbook of Medical Physiology W.B. Saunders company, Philadelphia, PA
WW Tuttle and BA Schottelius Textbook of Physiology C.V. Mosby Co.
A.L. Mescher Junqueira’s Basis Histology text and atlas, 13th ed. McGraw

53. ocotillo plant
Mexico
Big Bend TX, USA

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