HUMAN ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGYJAEVEN B. BAÑAGA | BSMLS 1D1THE CELLULAR LEVEL OF ORGANIZATION:CELL PHYSIOLOGY PART 2OUTLINEStructure and functions of cytoplasm, cytosol, and organellesCELL STRUCTURECYTOPLASM-Cell contents-Includes organelles and cytosol-Excludes nucleusCYTOSOL-Is the fluid portion of the cytoplasm that surroundsorganelles-Constitutes about 55% of total cell volume-The site of many chemical reactions required for acell’s existenceCELL ORGANELLES-Cytoskeleton-Flagella, Cilia, and Centrioles-Endoplasmic reticulum-Golgi apparatus-Mitochondrion-Nucleus, Nucleolus, Nuclear envelope-Vesicles (e.g. Lysosome)CYTOSKELETONMaintains shape of cellPositions organellesChanges cell shapeIncludes:-Microfilaments-Intermediate filaments-microtubulesCENTROSOMEStructure:-Two centrioles arranged perpendicular to each otherComposed of microtubules: 9 clusters of 3(triplets)-Pericentriolar materialComposed of tubulin that grows the mitotic spindleFunction: moves chromosomes to ends of cell during celldivisionCILIA AND FLAGELLASpecialized for motionFlagellum: single tail like structure on sperm and functionsas motility-Propels sperm forward in reproductive tractCilia: hair-like projections-Found in respiratory system: moves mucusRIBOSOMESMade within the nucleus (in nucleolus)Sites of protein synthesis (on Endoplasmic Reticulum orfreely within cytoplasm)Consist of ribosomal RNA (rRNA) + proteinsContain large and small subunitsCan be attached to endoplasmic reticulum or free in cytosolFunction of ribosomes:-Ribosomes associated with endoplasmic reticulumsynthesize proteins destined for insertion in the plasmamembrane or secretion from the cell-Free ribosomes synthesize proteins used in the cytosolENDOPLASMIC RETICULUMStructure: network of folded membranesFunctions: synthesis, intracellular transportTypes of endoplasmic reticulum:-RoughEndoplasmicReticulum:studdedwithribosomes (sites of protein synthesis)
