Connective Tissue Overview

Bell Ringer: 9.4.2013 Name 2 types of epithelial tissue and their function.

Connective Tissue Found everywhere in the body Includes the most abundant and widely distributed tissues Functions Binds body tissues together Supports the body Provides protection Insulates to maintain body temperature Transportation of other molecules

Special Characteristics 1. common origin- all arise from embryonic tissue (mesenchyme) 2. Degrees of vascularity- cartilage is avascular while other types have rich blood supply 3. Extracellular matrix- connective tissue more able to bear weight, withstand tension, and endure abuses because unlike other tissues it is not made up mostly of cells. Most abundant tissue in body

Structural Characteristics 3 Main Elements Ground Substance: unstructured material that fills the space between the cells and contains the fibers. This is consists mostly of fluid and proteins. Fibers: provide support. 3 types: collagen, elastic and reticular fibers. Collagen fibers: protein. Extremely tough and provide high tensile strength. (white) Elastic fibers: long and thin that form branches. Elastin protein. Moves like a rubber band. (yellow) Found in skin, lungs, blood vessels. Reticular Fibers: very fine fibers that branch extensively. Surround small blood vessels and support tissue of organs.

Structural Characteristics Cont. Cells- composed of many types 1. Blast Cells: undifferentiated cells -fibroblast - chondroblast -osteoblast -hematopoietic stem cells 2. Fat Cells- nutrient storage 3. Blood cells- defense 4. Plasma Cells-produce antibodies 5. Macrophages- dispose of dead tissue cells and act in immune response

Types of Connective Tissue

Types of Connective Tissue

Types of Connective Tissue Connective Tissue Proper Loose (Areolar) Connective Tissue Adipose Tissue Dense Connective Tissue

Loose Connective Tissue Fibers not abundant Extensive blood supply Examples of locations Between skin and muscles Around digestive tract Around blood vessels “Packing material” of body

Adipose Tissue Still loose connective tissue Most of the volume is adipocytes Provides padding, slows heat loss, food reserve Locations Common under skin of sides, gluteal, and mammary regions Wherever there is loose connective tissue

Adipose Tissue FG03_13B.JPG Title: Loose Connective Tissues Notes: This is the packing material of the body, filling spaces between other structures. (a)Loose connective tissue. (b)Adipose tissue. (c)Reticular tissue. Keywords: loose connective tissue, adipose tissue, reticular tissue, collagen fibers, mast cell, fibroblast, macrophage, elastic fiber, adipocytes, reticular fibers

Dense Connective Tissue Lots of collagen fibers Examples Tendons (muscle  bone) Ligaments (bone  bone) Some has elastic fibers

Supportive Connective Tissue: Cartilage & Bone Dense network of collagenous fibers & elastic fibers in a gel-like substance Avascular…repair capabilities limited Cells – chondrocytes in lacunae chondroblasts Perichondrium – surrounds surface of cartilage

Hyaline Cartilage Most common Provides flexibility and support Locations Ends of bones larynx Trachea, embryonic skeleton Connecting ribs to sternum

Fibrocartilage Visible collagenous fibers with scattered chondrocytes Provides strength and rigidity Locations Intervertebral discs Symphysis pubis

Elastic Cartilage Resilient and flexible External ear(pinna) Epiglottis Auditory tube Tolerates distortion without damage

Supportive Connective Tissue: Cartilage & Bone Bone (aka osseous tissue) Solid matrix (solid Ca cpds) Cells – Osteocytes in lacunae Osteoblasts Periosteum surrounds surface of bone

Bone FG03_17.JPG Title: Bone Notes: Bone is a supporting connective tissue with a hardened matrix. The cells in bone (osteocytes) are usually organized in groups around a central space that contains blood vessels. Keywords: bone, osteocytes, compact bone, canaliculi, central canal, lacunae, matrix, periosteum, fibrous, celluar, concentric lamellae

Table 4.3

Fluid Connective Tissue: Blood Functions Transport medium Regulation Protection Composition Plasma – fluid Formed elements – cells & cell fragments Red blood cell White blood cell Platelets (important in clotting)

Red Blood Cells FG20_02D.JPG Title: Anatomy of Red Blood Cells Notes: (a)Standard red blood smear. (b)Rouleaux formation as red blood cells travel through a capillary. (c)SEM of red blood cells; 3-dimensional structure. (d)Sectional view of red blood cell. Keywords: red blood cell, rouleaux, capillary, sectional view

A White Blood Cell FG20_05A.JPG Title: White Blood Cells Notes: Comparison of leukocytes as seen in blood smears. (a)Neutrophil. (b)Eosinophil. (c)Basophil. (d)Monocyte. (e)Lymphocyte. Platelets are visible in part (e) as small cellular fragments between the RBC's. Keywords: white blood cells, neutrophil, eosinophil, basophil, monocyte, lymphocyte, red blood cell, platelet