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This text covers the general anatomy of cells, including definitions, structures, and functions of cell components such as the nucleus, cytoplasm, and plasma membrane. Learn about organelles like mitochondria, endoplasmic reticulum, Golgi apparatus, and more. Discover the diverse roles of various cell types in the human body.
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Human Anatomy andPhysiology Chapter 3 –Cells and Tissues
Part I-Cells • Identified by _______________first as he looked at dead cork cells • Made of primarily 4 elements---_____________/other elements include Ca, I, Na, K..Some of these in water solution carry a charge ,at which point they are called_______________...Ca is used for blood clotting ,Fe to make hemoblobin, and I for Thyroid hormone C,H,O and N Robert Hooke electrolytes
~60% water/cells are in a dilute water solution called____________________________,derived from blood-HERE IS WHERE EXCHANGES BETWEEN CELLS & BLLOD TAKE PLACE! • Size ranges—2 micrometers-~1 meter • Overall structure may be related to function Interstitial fluid
ANATOMY of GENERALIZED CELL- • -nucleus,cytoplasm,plasma membrane • 1) Nucleus-____________-contains DNA which has info for making proteins-shape usually conforms to shape of cell • ___________or___________ fluid –filled space with nuclear pores penetrate through envelope-Contain jellylike nucleoplasm-other Nuclear elements suspended • _________-makes ribosomes • Chromatin-DNA and chromatin that constitute dense chromosomes during cell division Nuclear envelope OR membrane nucleoli Control center
2)Plasma Membrane(cell membrane) • Contains a phospholipids bilayer-“tail-to-tail” and proteins floating amidst this.-some having attached sugars---as channels to allow particles in and carb tags to specify what molecules are admitted/some proteins act as carriers to move something out membrane • Also contains cholesterol-helps keep the membrane fluid • Proteins may be enzymes or hormone receptors
Plasma membrane cont’d • Polar heads of bilayer are Hydrophilic-______________________ • Nonpolar tails are Hyrdrophobic-avoid water • General properties allows membrane to reseal easily Attracted to water
The “sugar proteins” are _____________________ producing the sugar rich or(sticky) known as Glycocalyx—-one of the many functions is to determine blood type,or as receptors for bacteria,viruses and toxins---see cancer connection p.68 Glycoproteins
Cell Membrane specializations: • Microvilli-Projections to increase surface area so absorption occurs more quickly
Membrane junctions 1-________________-impermeable and bind to prevent leakage between cells(acts like a “zipper”) 2-____________anchoring junctions that prevent mechanical stress(eg.skin cells)-prevent being pulled apart—thickenings_PLAQUES-of adjacent cell membrane-by protein filaments-”guy wires” TIGHT junctions Desmosomes
Membrane Junctions cont’d • 3---______________________-(in heart and between embryonic cells)—function for communication----place where chemicals pass----connect to neighboring cell by CONNEXONS(hallow cylinders composed of proteins to span width between cell) Gap Junctions
CYTOPLASM-material outside nucleus and inside cell membrane 1)cytosol fluid;2)organelles 3) inclusions-chemicals possibly present,depending on cell type—usually stored nutrients of cell products-eg.pigment or glycogen
ORGANELLES: • Most membrane bound • _______________-changes shape and has a double membrane-Inner cristae composed of enzymes and as well as dissolved in fluid-CARRY OUT CELLULAR RESPIRATION from which we get ATP-energy----many found in liver and muscle mitochondria
____________-have rRNA and mRNA is read here-tRNA-brings appropriate amino acid in to make PROTEINS…..some free in cytoplasm and some attached to ER • ER-endoplasmic reticulum-has fluid filled cisterns or coils ribosomes
Er cont’d • Rough-has ribosomes and sends proteins out as their intricate folding occurs to area of cell in transport vesicles or for export • Smooth-used in lipid metabolism and detox of drugs etc.,(many in liver) • ___________-stack of membranous sacs and exports proteins in SECRETORY VESICLES,then to plasma membrane-eg-digestive enzymes made by pancreas GOLGI
______________________-membranous bags w/ digestive enzymes-for worn out cell structures lysosomes
Perioxisomes-membranous sacs w/ oxidase enzymes that use O2 to detox poisons-like alcohol----also to convert FREE RADICALS to H2O2 and this is catalyzed to water….(What are Free radicals?-reactive chemicals w/unpr’ed electrons that can scramble proteins and nucleic acids….many in liver and kidney) • Cytoskeleton—network of protein structures,inc: • Intermediate filaments-help desmosomes • microfilaments-involved in motility and shape- • microtubules-give shape and for cell divisions
Centrioles-near nucleus-role in cell division • Cilia-on some cells to move things-as in respiratory tract • Flagella-whiplike---in sperm
CELL DIVERSITY-Trillions of human cells spell about 200 different cell types.Below are some of the specializations • 1) Cells that connect body parts: • ____________-elongated shape;secretes cable –like fibers;much ER and large Golgi to secrete proteins • ____________(RBC)carries O2 in blood;concave shape gives surface area for O2 uptake,yet streamlined for flow-absent of other organelles so can carry much O2 Erythrocyte Fibroblast
2)Cell that covers and lines body organs: • _______________________hexagonal shape-allows packing together in a sheet;filaments present to resist tearing • 3) Cells that move organs and body parts: • Skeletal and smooth muscle-long and filled w/ contractile filaments-to move bones or change size of internal organs. epithelial
4) Cell that stores nutrients • ____-large spherical shape-from large lipid droplet in cytoplasm • 5) Cell that fights diseases: • ________________________-phagocytic-sends pseudopods to reach infection and infection digested by lysosomes fat Macrophage
6)Cell that gathers info and controls body functions: • ______________-(neuron)-long extensions for receiving messages and transmitting;extensive plasma membrane • 7) Cells of Reproduction: • __________female-largest cell in body • __________male-long and flagellated Nerve Oocyte and sperm
III. CELL PHYSIOLOGY--for metabolism,digestion,waste disposal,reproduction,growth,movement,and irritability • ---MEMBRANE TRANSPORT • Solution basics- • __________=homogeneous mixture of 2 or more substances • _______________-does dissolving • _______________-gets dissolved solvent solution solute
__________________-nucleoplasm and cytyosol---containing sm amounts gases(O2 and CO2),nutrients,and salts in water solution • _____________-continously washes exterior of cells---many components,inc. amino acids,sugars,fatty acids ,vitamins/regulatory hormones and neurotransmitters,as well as salts and waste.CELL MUST OBTAIN THAT WHICH IT NEEDS FROM HERE AND REJECT REST. Interstitial fluid Intracellular fluid
Plasma Membrane is ___________________________________-choosy in what is allowed in and kept out….also certain substance smust remain in cell Selectively permeable
Movement in 2 ways: • 1) PASSIVE TRANSPORT—pass w/o energy • ________________molecules move AWAY from areas where more concentrated;move down concentration gradient;hydrophobic portion of membranes resists diffusion,but particles small enough will go through pores-in MEMBRANE PROTEINS-This is simple diffusion-either they are small enough or lipid soluble diffusion
_____________-water diffuses through selectively permeable membrane-water resisted through nonpolar lipid core-- by pores called____________-made by membrane proteins osmosis aquaporins
Facilitated diffusion-needed substance-eg.glucose-lipid insoluble and too big for pores protein membrane channel is used-transport vehicle • ____________-water and solutes forced through a membrane-or capillary wall by FLUID_HYDROSTATIC PRESSURE---usually by blood-is w/ a gradient,but the gradient actually MOVES the solution.The gradient is called a PRESURE GRADIENT….also used in kidney function Filtration
2) ACTIVE TRANSPORT PROCESSES-uses ATP-particles may be against gradient,too large,or lack a helper protein • Active Transport-solute pump-ATP energizes protein carriers(solute pump)-carries amino acids,sugars ,and most ions----Sodium potassium pump vital to nerve transmission{excess Na ions outside and excess K on inside
exocytosis • ______________________-w/ use of ATP moves large masses in or out(w/o crossing plasma membrane) • __________________- moves large masses out-package by golgi into vesicles and ruptiures outward • __________________-moves the same IN—sends to lysosome…..Phagocytosis-eats bacteria and dead cell bodies • Pinocytosis—pinches in liquids • Receptor mediated endocytosis-plasma membrane receptors target certain molecules Vesicular transport endocytosis
During interphase,cell must duplicate DNADNA REPLICATION/enzyme regulated—remember A_T and C_G
MITOSIS-number of chromosomes you start with—diploid is same at end,then followed by cytoplasm division-____________________ • PROPHASE-chromatin coils and shortens-CHROMOSOMES;centrioles move to opposite poles and mitotic spindle form to form a railway for chromosome movement cytokinesis