1. C. Connective Tissue
1.1. Functions ~ CT does much more than connect body parts 1. Binding 2. Support 3. Protection 4. Insulation 5. Storage 6. Transportation
1.2. Provide a protective structural framework for other tissues Are all derived from Mesenchyme (a particular type of embryonic tissue) Are comprised not just of cells but also of an extensive extracellular matrix that make ct good at withstanding lots of force or tension
1.3. Types
1.3.1. 1. Cartilage
1.3.2. 2. Bone
1.3.3. 3. Blood
1.4. Constitution
1.4.1. 1. Extracellular matrix
1.4.1.1. 1. Ground subs Fills space btw cells & connect all fibers. Made up of interstitial fluid, cell adhesion protiens & proteoglycans.
1.4.1.2. 2. Fibers (reticular, elastic, collagen) Within gs. a. Collagen fibers: strongest, made of protein collagen (most abundant protein in the body) these proteins assemble into cross-linked fibrils then R bundled together to form fibers (stronger than steel, prevent things from being pulled apart). b. Elastic fibers: long & thin, made of stretchy protein called elastin, they form networks within the extracellular matrix c. Reticular fibers: similar to collagen fibers form networks supporting other types of tissue
1.4.2. 2. Cells
1.4.2.1. Mature
1.4.2.1.1. Ends in "cyte' 1. Fibrocytes 2. Chondrocyte 3. Osteocyte 4.…
1.4.2.2. Immature
1.4.2.2.1. undifferentiated or unspecialized Are actively mitotic They secret gs & fibers of the cells they will become
1.4.2.2.2. End in "blast" 1. Fibroblast forms CT proper 2. Chondroblast→ cartilage 3. Osteoblasts→ bones 4. Hematopotetic stem cells→ blood cells
1.5. Types
1.5.1. 1. CT proper
1.5.1.1. 1. Loose CT
1.5.1.1.1. 1. Areolar Have many fibers that support & bind other tissues. Have empty space for storing tissue fluid Most abundant CT, wrap around or cushion structures
1.5.1.1.2. 2. Adipose CT Contain fat cells that store nutrients & serve to insulate body
1.5.1.1.3. 3. Reticular Similar to 1st but only contain reticular fibers & support some structures
1.5.1.2. 2. Dense CT
1.5.1.2.1. 1. Regular Many collagen fibers packed w/ fibroblasts in btw Can resist alot of tension thus forming tendons & ligaments
1.5.1.2.2. 2. Irregular Collagen fibers not arranged in any pattern This offers resistance in many directions
1.5.1.2.3. 3. Eladtic CT similar to 1st but but is more elastic
1.5.2. 2. Cartilage
1.5.2.1. Like CT proper withstands tension, but also withstand compression, this make it an intermediate btw dense CT & bone It is not innervated nor vascularized, it receive nutrients by diffusion from bv tin a nearby Ct mem Contain alot of tissue fluid this assist in withstanding compression
1.5.2.2. 1. Hyaline cartilage Most abundant, Amorphous but firm, Good at reinforcing & cushioning structues
1.5.2.3. 2. Elastic cartilage Has many elastic fibers in its matrix
1.5.2.4. 3. Fibrocartilage Btw dense CT & hyaline cartilage W/ rows of chondrocytes alternating w/ rows of collagen fibers making it compressible but can withstand tendion Found in discs separating vertebrae of spine
1.5.3. 3. Bones
1.5.3.1. Or osseous tissue Matrix contain collagen & inorganic calcium salts which makes bone hard Contain bvs
1.5.4. 4. Blood
1.5.4.1. Fluid in Bvs No support function Called CT bcz it develop from mesenchyme && BCs r surr by a nonliving fluid matrix called plasma
2. D. Nervous tissue
3. A. Tissue
3.1. Tissue is a collection of cells that is similar in structure & function
3.2. 4 types of tissues Epithelial Connective Nervous Muscle
4. B. Epithelial tissue
4.1. Functions 1. Protection 2. Absorption 3. Filtration 4. Excretion 5. Secretion 6. Sensory reception
4.2. 1. Covering Epithelium Cover things including our entire body Outer layer of skin Body cavities covering Line blood vessels & various organs Act as a boundary
4.2.1. Epithelial cells exhibit polarity Opposite sides exhibiy # features Then opp ends have # functions
4.2.2. 1. Apical surface exposed to exterior Often smooth Can be lined with microvilli that maximize the surface area 1. Microvilli: for secretion & absorption 2. Cilia: hair like, for propelling subs aling
4.2.3. 2. Basal surface of the cell Attached to basal lamina (not made of cells) but of glycoproteins & collagen fibers that act as a scaffolding Basal lamina + Reticular lamina = basement membrane Supported by this mem, epithelial cells are found in sheets next to each other
4.2.4. 3. Adjacent cells are bound by filaments or desmosomes (junctions) Acc to specific function of tissue, there can be 1. Tight junctions: block flow of fluids btw cells 2. Gap junctionsl: pores that connect adjacent cells allowing comm via exchange of ions that can carry electric current
4.2.5. Epithelial tissues are Avascular (no vasculation) but are Innervated (supplied w/ nerves)
4.2.6. Ecells regenerate v. Quickly, due to friction & injury they are exposed to especially at body exterior
4.3. 2. Glandular Epithelium Makes up all kinds of glands in body
4.3.1. Found in glands Are collections of 1 or more cells Generate & secret subs, often signaling molecules like hormones
4.3.2. 1. Exocrine glands Produce & secret subs through a duct onto an epithelial surface
4.3.3. 2. Endocrine glands Secret products directly to blood
4.3.4. New Topic
4.4. Classification of epithelia
4.4.1. 1. Numbers of layers in tissue
4.4.1.1. 1. Simple epithelia -Single layer of cells
4.4.1.2. 2. Stratified -Several layers of cells 2+
4.4.2. 2. Specific shape of each cell
4.4.2.1. Each cell has a hexagonal base this allow close packing but height will vary
4.4.2.2. 1. Squamous cells -Flat & scale like
4.4.2.3. 2. Cuboidal cells -Boxy of medium height
4.4.2.4. 3. Columnar cells - v. tall like columns
4.4.3. So we have
4.4.3.1. 1. Single squamous epithelia- single layer of flat cells with disc shaped nuclei. This is great for rapid exchange of materials by diffusion is imp. Ex. 1. Endothelium 2. Mesothelium
4.4.3.2. 2. Simple cuboidal epithelium Single sheet with boxy cells, perfect for secretion & absorption
4.4.3.3. 3. Simple columnar epithelium Single layer of v. tall cells Ideal for secretion & absorption
4.4.3.4. 4. Pseudostratified columnar epithelium Nuclei staggered in position Cells vary in heights with some not reaching apical surface ~ gives appearance of being stratified hence the name
4.4.3.5. 5. Stratified squamous epithelium Several layers of thin cells Common & perfect for protection ~Outer most part of skin, able to regenrate if rubbed away, as we go deeper cells become cuboidal or even columnar
4.4.3.6. 6. Stratified cuboidal epithelia Several layers of boxy cells
4.4.3.7. 7. Stratified columnar epithelium Several layers of tall cells
4.4.3.8. 8. Transitional epithelium Able to stretch & change shape to accomodate a cavity being filled w/ liquid