View
227
Download
5
Category
Tags:
Preview:
Citation preview
Lab (3) :connective tissue
Dr. Dalia Kamal Mohammed
Four basic types of tissue
EpitheliumConnective tissue
Connective tissue proper (examples: fat tissue, fibrous tissue of ligaments)
Cartilage Bone Blood
Muscle tissueNervous tissue
Originate from embryonic tissue called mesenchyme
Most diverse and abundant type of tissueCells separated from one another by large
amount of nonliving extracellular matrix Two components
Cells
Extracellular matrix (ECM).
o Protein fibers
o Ground substance
Cells in Connective Tissue
1. Fibroblasts2. Adipose (fat) cells3. Tissue Macrophages**4. Mast cells**
5. Lymphocytes & Plasma Cells (differentiated B-cells) **
6. “Leukocytes”**
Fixed (permanent residents)
** derived from hematopoietic stem cells and involved in immune function and inflammation
Free (transient residents)
(specifically, neutrophils, eosinophils, & basophils)
Active fibroblasts
Adipocytes predominate in adipose tissue
Single, large lipid droplet
Very active cells with many functions:• Triglyceride storage and glucose metabolism (insulin and glucagon receptors)• Secretion of many bioactive molecules:
leptin (regulates satiety) angiotensinogen (blood pressure) steroids (glucocorticoids & sex hormones)growth factors (e.g. insulin-like growth factor, tumor necrosis factor ) cytokines (e.g. interleukin-6)
Ross, M. Pawlina, W. Wheater’s Functional Histology: A Text and Atlas. Fifth Edition. 2006.
Adipocytes
Capillaries
Nucleus
Lipid (fat) droplet
Source Undetermined
Monocytes escape from blood vessels into connective
tissue where they differentiate into Macrophages
Primary function: phagocytosis and antigen presentationUniversity of Michigan Histology Collection
Plasma Cells are mature B lymphocytesthat constitutively secrete antibodies
White arrows = Golgi regionsBlack arrows indicate several plasma cells
Junqueira and Carneiro. Basic Histology. Tenth Edition. 2003. Figure 6.5.
University of Michigan Histology Collection
Fibers in Connective TissueCollagen
-Most abundant protein in human body
Reticular Fibers – Specialized type of collagen associated
with smooth muscle in organs
Elastic Fibers – Thin fibers composed of various
glycoproteins, including the protein elastin, providing elastic properties to tissues
Collagen fibers viewed by light microscopy H&E Trichrome
University of Michigan Histology Collection University of Michigan Histology Collection
Reticular Fibers
University of Michigan Histology Collection
Elastic Fibers
elastin stain (“Weigert’s”, “aldehyde fuchsin”, “Verhoeff”): elastic fibers are purple/black
Connective tissue proper Fluid connective tissue Supporting connective tissue
Connective Tissue
Dense connectivetissue
Loose connectivetissue
Lymph Cartilage BoneBlood
What are the subcategories of the three main categories of connective tissue?
Type of Connective tissue
Connective Tissues with Special Properties
• Reticular connective tissue
• Adipose connective tissue
• Elastic connective tissue
Adipose tissue
consists of :
Adipocytes; "signet ring"
appearing fat cells.
Function :
protects and insulates,
and serves as an energy
reserve
Reticular Tissue
Consists of :reticular fibers and reticular cells
Found in :
• Liver,
• spleen
• lymph nodes
composed of:
• branching elastic fibers
• network of collagen fibers
• fibroblasts Location:
• dermis,
• lungs,
• blood vessels
Elastic tissue
Recommended