BIO 240 1st Edition Lecture 5 Outline of Last Lecture A. LocationsB. GlandsC. Ways to classifyI. Tissue Growth and Development A. Growth Outline of Current Lecture B. Stem CellsC. Tissue RepairII. Connective TissueA. TypesB. Characteristics Current LectureB. Stem Cellsi. Embryonic Stem Cells Composed of human embryos. Embryos start out as just one ball; a diploid cell. Then division occurs, and once it gets over 32 cells it becomes a morula, then blastula. Are just cells (no specialized tissue yet). 1. Totipotent: Stem cells that can develop into any type of cell or tissue in the body. Have the blueprint to turn into anything in yourbody. ii. Adult stem Cells Occur in small numbers in mature organs throughout life. 1. Multipotent: Able to develop into 2 or more different cell lines, but not just any body cell type. Are already much more specializedthan embryonic stem cells (can’t take a Multipotent skin stem cell from the skin and grow a kidney).2. Unipotent: Can produce only one mature cell type. Examples: sperm, eggs, keratinocytes. C.Tissue Repair These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Regeneration The replacement of dead or damaged cells by the same type of cells as before. It restores natural function. Examples: small cuts or wounds and mild sunburns. ii. Fibrosis The replacement of damaged tissue with scar tissue. (Holds the tissue together, but does not restore natural or normal function, nerves andblood vessels can be severed so function cannot be restored. It’s possible tohave a tingling sensation or no sensation on the scar because of the nerve being severed). Examples: heart attacks (cardiac muscle cells do not have the ability to regenerate themselves, so it always repairs itself by fibrosis), severe (second and third degree) burns, and deep cuts. II. Connective TissueA. Typesi. Loose Connective Tissue1. Areolar Connective Tissue 2. Adipose Connective Tissue3. Reticular Connective Tissueii. Dense Connective Tissue1. Regular Connective Tissue2. Irregular Connective Tissue3. Elastic Connective Tissueiii. Specialized Connective Tissue1. Cartilagea. Hyalineb. Fibrocartilagec. Elastic2. Bone3. BloodB. Characteristics i. Embryonic tissue – The prototype of all connective tissue is mesenchyme.This is an embryological tissue that lays out much of our skeleton. ii. Has more than one cell type. Cells are widely scattered. (This is a major difference from epithelial tissue, which is composed of one cell type). Specialized cells:1. Fibroblasts Secrete the fibers and gives rise to fibrocytes. Fibrocytes are very important for wound repair. 2. Mast cells Perform an inflammatory response by releasing histamine and heparin. Are involved in wound repair. a. Histamine Serves as a warning to your body that something around you is dangerous to your body (i.e. cat allergy)b. Heparin Blood thinner.3. Adipocytes Fat cells. Serve as an insulator and for nutrient storage. 4. Chondroblasts Only in cartilage. These cells make the matrix and turn into chondrocytes. 5. Osteoblasts Only in bone. Make the matrix and turn into osteocytes. 6. Macrophages Immune response from monocytes. Monocytes are a type of white blood cell. 7. Plasma cells Immune response from B cells that produce antibodies. B cells are a type of white blood cell. iii. Matrix – The ground substance and the fibers1. Ground substance a. Liquidb. Semi (semi liquid to semi solid). “gel-like”c. Solid2. Fibersa. Collagen Big and wide, stains smoothb. Elastic Stains dark purple to black. Can be long and wavy, or short and blunt.c. Reticular Stains dark purple to black like elastic, but tends to have branches in
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