They hold us all together Connective Tissues They hold us all together

Connective Tissue Hold things together Provide support and protection Serve as frameworks Fill spaces Produce blood cells and prevent infection Help repair tissue damage Further apart than epithelial cells Have much matrix (intercellular fluid) between them Have good blood supply Can be rigid or flexible Can usually reproduce

TYPES OF CONNECTIVE TISSUE 1. True Connective Tissue a. Loose Connective Tissue b. Dense Connective Tissue 2. Supportive Connective Tissue a. Cartilage b. Bone 3. Liquid Connective Tissue a. Blood

True Connective Tissue Cells Fibroblasts: Secrete both fibers and ground substance of the matrix (wandering) Macrophages: Phagocytes that develop from Monocytes (wandering or fixed) Plasma Cells: Antibody secreting cells that develop from B Lymphocytes (wandering) Mast Cells: Produce histamine that help dilate small blood vessels in reaction to injury (wandering) Adipocytes: Fat cells that store triglycerides, support, protect and insulate (fixed)

Fibroblasts

Mast Cells

Macrophage

Connective Tissue Fibers (Matrix Fibers) Collagen Fibers: Large fibers made of the protein collagen and are typically the most abundant fibers. Promote tissue flexibility. Elastic Fibers: Intermediate fibers made of the protein elastin. Branching fibers that allow for stretch and recoil Reticular Fibers: Small delicate, branched fibers that have same chemical composition of collagen. Forms structural framework for organs such as spleen and lymph nodes.

True or Proper Connective Tissue Loose Connective Tissue: a. Areolar tissue Widely distributed under epithelia b. Adipose tissue Hypodermis, within abdomen, breasts c. Reticular connective tissue Lymphoid organs such as lymph nodes

Loose Fibrous Connective Tissue Forms thin, delicate membranes throughout body Mostly fibroblasts, separated by matrix loaded with collagenous, elastic fibers Glues skin down, fills space between muscle It’s beneath most epithelium, highly vascularized

LOOSE Connective Tissue: 1. Areolar CT consists of all 3 types of fibers, several types of cells, and semi-fluid ground substance found in subcutaneous layer and mucous membranes, and around blood vessels, nerves and organs function = strength, support and elasticity

LOOSE Connective Tissue: 2. Adipose tissue FAT Cells store fat droplets in their cytoplasm, enlarge Beneath skin, in spaces between muscle, behind eyeballs, in certain abdominal membranes, on the heart, around joints Stores energy, insulates, cushions organs, joints

Adipose Tissue http://www.youtube.com/watch?v=KVZht_IqT-8&safety_mode=true&persist_safety_mode=1&safe=active

Collagenous Fibers Thick threads made from the protein collagen Fibers in long, parallel bundles Flexible, though not overly elastic Have great tensile strength Tissue containing a lot of this: dense connective tissue (or white fibers) Present in tendons

ELASTIC MEMBRANES COLLAGENOUS FIBERS Aorta                                                                                                                                               Rat, Helly's fluid, Mallory's stain (A), Mallory-azan stain (B), 162 x.

Elastic Fibers Made from protein Elastin. Fibers are branched, form complex networks Stretchy Called yellow fibers In vocal cords

Elastic Fibers

Reticular Fibers Very thin collagenous fibers Highly branched, form delicate supporting networks Found in a variety of tissues Ex - the liver, the kidney, the spleen, and lymph nodes

Reticular Fibers

Loose Fibrous Connective Tissue

True or Proper Connective Tissue Dense Connective Tissue: a. Dense regular connective tissue Tendons and ligaments Function = provide strong attachment between various structures b. Dense irregular connective tissue Dermis of skin, submucosa of digestive tract

Dense Fibrous Connective Tissue Closely packed, thick, collagenous fibers and a fine network of elastic fibers Few cells, mostly fibroblasts Strong, dense, good tensile strength Common in ligaments and tendons In the white of the eyeball, deeper skin layers Poor vascularization; slow healing

Supportive Connective Tissue: CARTILAGE: Jelly-like matrix (chondroitin sulfate) containing collagen and elastic fibers and chondrocytes surrounded by a membrane called the perichondrium. Unlike other CT, cartilage has NO blood vessels or nerves except in the perichondrium. The strength of cartilage is due to collagen fibers and the resilience is due to the presence of chondroitin sulfate.

Cartilage Types distinguished by type of intracellular matrix Hyaline Cartilage Elastic Cartilage Fibrocartilage

Cartilage Is partly rigid, partly flexible It provides support, frameworks, attachments, serves as template for developing bones Much intercellular material composed of collagenous fibers embedded in a gel-like ground substance Chondrocytes (cartilage cells) are in small lacunae (small chambers), surrounded by matrix Perichondrium (fibrous connective tissue) encloses cartilagenous structure. It contains blood vessels

Hyaline Cartilage: Most common Has fine collagenous fibers in matrix Looks like white plastic Found on ends of bones in joints, soft part of nose, rings in respiratory passages Important in bone formation Found in embryonic skeleton, at the ends of long bones, in the nose and in respiratory structures.

Hyaline Cartilage

Elastic Cartilage Has dense network of elastic fibers More flexible than hyaline Provides framework for ears(external) and parts of larynx function = gives support, maintains shape, allows flexibility

Elastic Cartilage

Fibrocartilage Tough Contains many collagenous fibers Shock absorber for structures subjected to pressure Found in intervertebral disks, knees, pelvic girdle Function = support and fusion, and absorbs shocks.

Fibrocartilage

Bone Most rigid of connective tissues Mineral salts between cells Matrix contains collagen Supports, protects body structures Houses marrow (where blood cells form) Stores calcium, phosphate Matrix is deposited in layers called lamellae around osteonic canals Osteocytes in lacunae An osteon is osteocytes and matrix wrapped around an osteonic canal Osteons contain blood vessels Canaliculi are small tubes through which osteocyte cytoplasm extends

Bone

Blood Transport Matrix=plasma Red blood cells White blood cells Platelets Blood cells float in plasma, formed in bone marrow

Blood

Connective Tissue Summary

BODY MEMBRANES 1 Epithelial Membranes = epithelial layer of cells plus the underlying connective tissue. Three Types: 1. Mucous membranes 2. Serous membranes 3. Cutaneous membranes

Mucous membranes Mucous membrane = mucosa; it lines cavities that open to the exterior, such as the GI tract. The epithelial layer of the mucous membrane acts as a barrier to disease organisms. The connective tissue layer of the mucous membrane is called the lamina propria. Found as the lining of the mouth, vagina, and nasal passage.

Serous membranes Serous membrane = serosa, membrane lines a body cavity that does NOT open to the exterior and it covers the organs that lie within the cavity. a. pleura = lungs b. pericardium = heart c. peritoneum = abdomen The serous membrane has two portions: 1. parietal portion = lining outside the cavity. 2. visceral portion = covers the organ. .

Serous membranes 2 Serous membranes epithelial layer secretes a lubricating SEROUS FLUID, that reduces friction between organs and the walls of the cavities in which they are located. The serous fluid is named by location: Pleural fluid is found between the parietal and visceral pleura of the lungs. Pericardial fluid is found between the parietal and visceral pericardium of the heart. Peritoneal fluid is found between the parietal and visceral peritoneum of the abdomen.

BODY MEMBRANES

BODY MEMBRANES

BODY MEMBRANES