1/26/15TISSUES II I. CHARACTERISTICS OF CONNECTIVE TISSUES: binds/supports/protects other tissues and organs, derived from mesenchyme(embryonic CT)A. Consists of:1. Cells: the cells don’t have a free surface (below the epithelial tissues) 2. Matrix = the non-living material surrounding the cells***must remember for connective tissues It contains:a. Fibers (protein)i. Collagen: provides strengthii. Elastin: protein provides elastic characteristicsiii. Reticular: usually there just for support (not too strong)b. Ground Substance: fibers suspended in ground substance 3. Vascularity varies II. CLASSIFICATION OF C.T. (all have a lot of matrix)A. Connective Tissue Proper : Matrix is gel-like; Two classes: Loose CT(fewer fibers-more ground substance) and Dense CT (more fibers-less ground substance)1. Loose CTa. Areolar CTi. Contains fibroblasts, many irregularly arranged fibers and it is very vascular (blast means a cell that is forming something)ii. Location: surrounds nerves, muscles, and some organsiii. Function: packing & binding materialb. Adipose (Fat Tissue)i. Contains adipocytes (adip=fat)ii. Location: primarily in skin iii. Functions: energy source; insulation against temperature changes (helps prevent heat loss), and protection(fat cells act as a layer of shock absorbers protecting against trauma/injury)****THIS TISSUE IS VERY VASCULAR (a lotof blood vessels to get oils into the cells and the blood stream)2. Dense CTa. Dense Irregular CT **(has a lot of collagen=strength)i. Contains fibroblasts; protein fibers (collagen) found are irregularly arranged bundles ii. Location: skin (dermis=middle layer of our skin) iii. Function: strength & support (in all directions) **VERY VASCULAR b. Dense Regular CT (a lot of collagen)i. Contains fibroblasts; protein fibers are arranged in parallel bundles. Poor vascularityii. Location: tendons(connects muscle to bone) and ligaments(holds bone to bone) iii. Function: Strength and support (in one direction---PARALLEL) ***VASCULARITY=VERY POORB. Cartilage: semisolid matrix; avascular(mature cartilage); flexible; heals slowly; cells = chondroblasts(cells that can make cartilage) and chondrocytes(cells that keep cartilage health); cells in lacunae(fluid filled space that cells sit in). ***Heals the slowest out of any tissue because it is avascularcells are not mitotic1. Hyaline(clear) Cartilage:a. matrix contains very fine collagen fibers (diameter=is super small and hard to see) b. Location: found on articular surfaces(ends of long bones-joints), nasal septum(cartilage in nose), trachea(wind pipe), fetal skeleton c. Function: support and protection 2. Fibrocartilagea. Matrix contains thick collagen fibers.b. Location: found in intervertebral disks, symphysis pubis & meniscic. Function: support & withstands compression 3. Elastic Cartilagea. matrix contains numerous elastic fibers b. Location: outer ear and larynx (voice box)c. Function: flexibility and strength C. Bone (Osseous Connective Tissue): matrix is rigid 1. 3 kinds of cells found in bone:a. osteoblasts – immature bone cellscreate bone b. osteocytes – mature bone cellsmaintain bone (keep it healthy) c. osteoclasts – break down/reabsorb bone (term clasts means to break down)2. Two kinds of bone tissue found within each of your bones:a. Compact (dense): outer shell of bone b. Spongy (cancellous): inner lattice-work of bone; hemopoietic (red bone marrow-blood forming tissue) tissue found within spaces ****BONE IS VERY VASCULARD. Vascular Tissue (Blood)1. Contains blood cells (or formed elements) and a liquid matrix called plasma (plasma=non living matrix containing protein fibers) 2. Function: transport III. MUSCLE TISSUE: moves body and materials within body (3 types ofmuscle tissue)A. Classification1. Smooth (Visceral) Muscle Tissue ***[this muscle tissue is found in the walls of hollow organs)-----every hollow organ has this muscle in it. ****INVOLUNTARY-do not have conscious control overthisa. spindle-shaped cells b. one centrally-located nucleus 2. Cardiac Muscle Tissue (found in the wall of the heart)—only organ that doesn’t have smooth muscle)***INVOLUNTARY a. Short, cylindrical cellsb. some cells are bifurcated (branching) c. Has one or TWO centrally- located nucleid. intercalated discs e. Striations 3. Skeletal Muscle Tissue***VOLUNTARYa. Long, cylindrical cellsb. multinucleated (has a bunch of nuclei)c. nuclei located at periphery of cell d. Striations IV. NERVOUS TISSUE: makes up the nervous systemA. Classification1. Neuronsa. Generate and conduct nerve impulses2. Supporting Cells (Neuroglia)b. Support, protect and nourish neurons Which of the following is found in the outer ear and larynx and functions to provide flexibility and strength?a. Dense regular connective tissueb. Areolar connective tissuec. Fibrocartilaged. Elastic cartilage *****e. Dense irregular connective