IPHY 3410 1st Edition Lecture 2 Outline of Last Lecture 1) Describe the functions and characteristics of plasma membrane, ER, Golgi, lysosomes, and mitochondria.2) Interpret the cell type based on the abundance of certain organelles3) Describe the function of three specialized contacts/junctions4) Predict the location of specialized junctions based on their functions5) Describe the function of three cytoskeletal elements6) Compare and contrast the three cytoskeletal elementsOutline of Current Lecture 1) List the four types of tissues found in the body.2) Describe the characteristics of epithelia (plural of epithelium) that distinguish them from other types of tissues.3) Describe structural classifications of epithelial tissues by layering: simple or stratified.4) Illustrate epithelial tissues by shape: squamous, cuboidal, or columnar.5) List epithelial types and their function. 6) Predict which epithelial cell type you would expect to find in an organ given the tissue functions.7) Name the specialized structures associated with the lateral, basal, and apical surfaces of epithelial cellsCurrent LectureCell Junctions – join cells together- Tight Junction – prevents molecules from passing through intercellular space; form a “tight seal with ‘Velcro dots’”- Desmosomes – bind adjacent cells at plaqueso Strong; prevent cell from being ripped aparto Linker proteins – interdigitate with other linker proteins within intercellular spaceo Intermediate filaments – span intracellular space to provide strength within cellNote: Intercellular – space between two cells; Intracellular – space within one cell- Gap Junction – allow for intercellular communicationo Hollow protein cylinders – channel connection between adjacent cellso Molecules can move quickly from cell to cellTissuesTissue – a group of similar cells and their extracellular matrix that perform a specific functionOrgan – structure made up of two or more tissue typesTissue Types- Epithelium – covering and lining- Connective – support- Nervous – control- Muscle – movementThese 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.Epithelial TissuesCharacteristics- Highly cellular; little extracellular space (space between cells)- Lots of cell junctions; seal, strength, and communication- Polar – distinct apical and basal regionso Apical – top of cello Basal – foundation or base- Sits on basement membrane for supporto Basal lamina – protein for surface of new cellso Reticular fibers – connective tissue - Avascular – no direct blood supply- Innervated – have nervous connections- Regenerative – high capacity to replace cells (ex: skin)Apical Surface Features- Microvilli – folds of plasma membrane of most epithelial tissueo Function: maximize surface area for digestion and absorption- Cilia – whiplike, motile extensions of cell surfaceo Function: movement of mucus (ex: trachea)Types of Epithelial - Membranous – majority of body coverings and linings- Glandular – produces glandular secretionsFunction LocationProtection SkinAbsorption Small IntestineFiltration KidneyDiffusion LungsChemoreception Nasal CavityMembranous Epithelium- Simple – 1 layer thick- Stratified – more than 1 layer thick- Squamous – flattened cells- Cuboidal – rounded cube shaped cells- Columnar – tall cells- Note: cells are named based on the cell shaped found on the apical surface (the more developed surface)Types of Membranous Epithelium – structure reflects function- Simple Squamouso Diffusion: lungso Filtration: kidneyo Secretion: serous membrane- Simple Cuboidalo Absorption: kidneyo Secretion: some glands- Simple Columnaro May or may not be ciliated o Absorption: GI tracto Movement: mucus in lungs (ciliated)o Secretion: mucus- Pseudostratified Columnaro All sit on basement membraneo Secretion and movement of mucus in respiratory systemo Usually ciliatedo Goblet cells: produce mucus- Stratified Squamouso Protection: skin and oral cavityo Can be keratinized or non keratinized Keratin is a protein for strength- Stratified Cuboidalo 2 layerso Protection: glandular ducts (salivary glands)- Stratified Columnaro Protection: male urethrao Secretion: some glandso Not very common- Transitionalo Multiple layers that change shape when stretchedo Unique – found mainly in bladdero Contains tight and desmosome junctionsGlandular Epithelium- Gland – collection of epithelial cells that make and secrete a substance- Endocrine – lacks ducts, produce and secrete hormones into surrounding tissue/blood vesselso Ex: thyroid glands- Exocrine – secrete via ducts into body cavities or onto body surfaceo Ex: salivary gland and duct- Simple – unbranched - Compound – branched- Tubular – tube shaped- Alveolar –