CONNECTIVE TISSUES LAB ©David B. Fankhauser, Ph.D., Professor of Biology and Chemistry University of Cincinnati Clermont College, Batavia OH 45103
dense irregular connective tissue  (dermis overlaid with epidermis)	This page has been accessed  times since 12 October 2001.  14 October 1991, rvsd 18 Oct. '94, 12 Sept '95, 23 Sept. '96, 10 Oct 96, 24 Sept '97. 11 Sept 99, 13 Oct 99, 28 Sept 01	loose connective tissue  (adipose tissue)

Connective tissue consist of cells embedded in an extracellular matrix. The matrix consists of fibers and ground substance. The characteristic traits of different classes of connective tissue are due to differences in the composition, relative density and arrangement of its components. Note how each of these connective tissues is unique in composition, and the manner in which that is related to its function.

We will first examine organs in the dissected cat which exemplify the types of connective tissue whose histology you will be studying:

Examine the following slides, identify the listed features, and illustrate a typical 400x field displaying these features (100x for Areolar).
(Follow instructions given in Notebook Illustrations and general directions given in Epithelial Tissues Lab Protocols.)

Histology	LOOSE CONNECTIVE TISSUE (AREOLAR)	Features
	a. (slide 7) Areolar Connective Tissue (VE: fig 2-1, p 31)  (subcutaneous tissue smeared) 100x Here is superficial fascia showing collagen fibers. Here is a labeled view of loose areolar connective tissue.	fibroblast pale, most common cell collagenous fibers pink, in masses elastic fibers stained purple difficult to distinguish: macrophage, larger and darker than a fibroblast mast cell, possesses granular cytoplasm
	b. (slide 8) Adipose Tissue (VE: fig. 2-11, p 39) also see Fig. 16-6 for ureter.) (many slides have a cross section of  a ureter )	adipose cells (or "adipocytes") cytoplasm looks empty because fat is dissolved away adipose nuclei compressed along edge of cell ("signet ring" appearance) fibroblast cells between adjacent adipose cells mesothelium at the edge, if present
	[Not required for this lab, but for completeness:] Reticular Tissue in a lymph node, slide 14 from lymphatic system, A&P 203 (VE: fig . 8-3. p. 127)	reticular fibers (stained with Ag/Au stain) Note the trabeculae (partitions) also composed of reticular fibers.

	DENSE REGULAR  CONNECTIVE TISSUE
	c. (slide 9) White Fibrous Tissue (tendon) (VE: fig.2-5, p 35) Draw a longitudinal section. Here is a labeled version of the Dense Regular Connective Tissue.	fibroblasts flattened in rows collagenous fibers in parallel bundles [bundle of tendon fibers seen in c.s.]
	d. (slide 10) Yellow Elastic (slide is from bovine nuchal ligament) (VE: fig. 8-4, p 115 in the aorta)  Draw the longitudinal section  (contrast appearance with white fibrous tissue) Here is a labeled version of the Yellow Elastic Connective Tissue	fibroblast nuclei distributed through tissue collagenous fibers woven in appearance (due to the contraction by elastin) elastic fibers occupy "open spaces"   (visible only if specially stained as with Verhoeff's stain)

	DENSE IRREGULAR  CONNECTIVE TISSUE
	e. (slide 15) Dense Irregular Connective Tissue (VE: fig. 2-7, p 37) (skin, mammal):	Here is a 100x view of a cross section of skin.  Note that the epidermis is on top, and the dermis underlies it. fibroblasts scattered throughout dermis collagen bundles in masses, irregularly arranged in various directions venule (Here is dermis with a venule)  Here is the dermis labeled.