Connective Tissue S1M1

• Structural support
• Medium for exchange
• Defense and protection

Fibroblasts, macrophages, plasma cells, leukocytes and adipose cells

• Has a loose arrangement of fibers
• Has ground substance (diffusion of gases, nutrients and waste products)
• Abundance of cells

Inflammation and allergic (immune) responses

Beneath epithelia, it surrounds the blood vessels and nerves, and helps to hold organs in place

Fibers but few cells and capillaries

Dense irregular C. T.

In bundles and are oriented in various directions, it gives it strength

Dense regular connective tissue

Densely packed collagen bundles and oriented into parallel arrays of fibers and cells

Parallel bundles of coll 1 fibers and rows of fibroblasts called tendinocytes (Dense C.T.)

• Elastic fibers and fewer collagen fibers.
• e.g. ligamenta flava

Bone to bone

• In multiple layers.
• Parallal rows arranged at 90 degree angles to the adjacent layer

Aponeuroses (dense C.T.)

Fibroblast cells

• 1. Collagen fibers (most abundant)
• 2. Reticular fibers
• 3. Elastic fibers

Stain with eosin and other acidic dyes, aniline blue or light green dye

Fibrils

Tropocollagen molecules

• Type I – loose and dense C.T., bone, dentine
• Type II – cartilage
• Type III – reticular fibers
• Type IV – basal lamina
• Type V - cells surfaces

• III and produced by fibroblast cells
• Do not form bundles but will form fibrils and fibers

• Arranged in a mesh-like network
• Provide support for tissues and organs

Around nerves, small blood vessels, muscle cells, red bone marrow and lymphatic tissues but not thymus.

Also found in endocrine organs and liver

Is lack of reticular fibers (Coll 3). Hyperelasticity of the skin and hypermobility of joints, ruptures in large arteries and intestines are common

Elastin core and a sheath of fibrillin microfibrils

Fibroblasts, chondroblast, chondrocyte and smooth muscle cells

The organizer center. It forms first, and elastin materials are deposited on surface of microfibrils to form elastic fibers.

Formation of elastin sheets or lamellae e.g. aorta

Covalent bonds

• The rubber like qualities of this protein which is about 5 times more extensible than rubber.
• 

• 
• A mutation of fibrillin gene
• Lack of resistance in tissues rich in elastic fibers. Aortic or arterial rupture (High BP)

Solar radiation resulting in decreased skin elasticity and appearance of deep wrinkles of photoaged skin

• GLY's
• Glycosaminoglycans (GAG), proteoglycans
• adhesive glycoproteins

Acts as both a lubricant and a barrier to microorganisms

Basic dyes

• A core of protein and many GAG molecules. They can act as binding sites for growth factors and other signaling molecules.
• 

Extracellular matrix molecules

• Ground substance of cartilage.
• Cartilage resist compression thus acting as shock absorbers.

Stabilize the extracellular matrix by binding to cell surface, collagen, proteoglycans, and GAGs

Chops hyaluronic acid into smaller pieces thus converting the gel state into a sol state in the extracellular matrix (ground substance). This results in a breakdown of the ground substance and causes the rapid spread of the microrganism thru the connective tissue spaces

Fixed (FAMM) – fibroblast, adipose cells, macrophage, mast

Transient – lymphocytes, plasma, neutrophils, eosinophils, basophils, monocytes, and macrophages

Fibroblast Cell

Synthesis of collagen, reticular & elastic fibers and all ground substance

Spindle shaped cell with tapering extensions

• Active fibroblast
• Fibrocyte

Smaller spindle shaped with less processes & less RER

Irregularly branched and has an abundant cytoplasm

• Fibroblasts having features of both fibroblasts and smooth muscle cells.
• Important for wound healing

Months

Monocytes of blood and they migrate from blood vessels by diapedesis (escape the blood vessel) into C.T.

Phagocytose large foreign bodies

• Nucleus is oval or kidney shaped and eccentric
• Well dev. Golgi, lots of RER and lysosomes
• Many microfilaments and microtubules for locomotion and phagocytosis

• Phagocytosis and pinocytosis
• Presents antigens to lymphocytes (APCs)

• Production of antibodies
• Lifespan – 10-30 days

B – lymphoctes

• Large ovoid cell extensive RER, and well dev . Golgi
• Nucleus is large and spherical, alternating patches of heterochromatin and euchromatin

Bone marrow

• Nucleus – small and spherical, centrally located
• Cytoplasm has large membrane bound granules

Dilates and increases permeability in postcapillary venules and increase mucus and contraction of smooth muscle in bronchioles causing bronchiospasm

• (HHELP)
• 1. Heparin
• 2. Histamine
• 3. Eosinophil and Neutrophil chemotactic factors
• 4. Leukotrienes
• 5. Prostaglandins

• "ProstaGLANDins"
• Mucus secretion

Permeability and smooth muscle contraction.

• Have multi potential capability
• Are stellate in shape
• Are found in close association to small vessels

Differentiate into smooth muscle cells as well as Endothelial cells.

Embryonic mesenchyme cells

Brown (multilocular) tissue – in fetal life and newborn . Diminishes during 1st 10 yrs. Nucleus is centrally located

White (unilocular) tissue - is predominant type in adults

• Energy reserves
• Insulation
• Padding of vital organs
• Cells have receptors for insulin, GH
• Uptake and release of fatty acids and triglycerides

Connective tissue

Mesoderm

IgG, IgE, IgA, IgM, IgD (GAME Day)

Mast cells

By an antibody reaction occuring at the mast cells surface

Neurtophils

Absolutely not