Ch.3- Cells and Tissues

• Tissues are groups of cells that are in similar.........


  Structure and function➡️ organs ➡️ organ system ➡️ organism
• Cells are not all the same


  Size, shape, and function very different
• cells are organized into 3 main regions

  nucleus, cytoplasm, plasma membrane
• Nucleus


  Control center of the cell; contains genetic material(DNA)
• Three regions in the nucleus

  nuclear membrane, nucleolus, chromatin
• nuclear membrane


  barrier of the nucleus; Consists of selectively permeable, double phospholipids membrane;
• Nucleoli


  Nucleus contains one or more nucleoli;

  Sites of ribosome assembly;

  Ribosomes migrate into the cytoplasm through nuclear pores
• Chromatin


  Compound of unwound DNA and protein used for making proteins; Scattered throughout the nucleus; Chromatin condenses to form chromosomes when the cell divides
• plasma membrane


  Barrier for cell contents; Semi-permeable, Double phospholipids layer
• cardiac muscle


  found only in the heart; function is to pump blood(involuntary); Cells attached to other cardiac muscle cells at intercalated disks; Cells are striated; One nucleus per cell
• Hydrophilic head


  water loving
• hydrophobic head


  water hating
• Other materials in plasma membrane

  protein, cholesterol, glycoproteins
• Protein


  receptors, cell recognition and communication, channels for transport
• Regeneration


  replacement of destroyed tissue by the same kind of cells
• Cholesterol


  keeps membrane fluid and stable
• Glycoproteins


  receptors, cell-to-cell interactions
• Determination of method


  1) The type of tissue damaged 2) The severity of the injury
• plasma membrane specializations


  microvilli, tight junctions, desmosomes, gap junctions
• Microvilli


  Finger-like projections that increase surface area for absorption
• tight junctions


  impermeable, leakproof sheets
• Desmosomes


  that prevent cells from being separated
• gap junctions


  Allow communication between cells through connexons that span the two cell membranes
• Cytoplasm


  Material outside the nucleus and inside the plasma membrane
• What is cytoplasm?


  cytosol, organelles, and inclusions
• Cytosol


  Fluid containing nutrients dissolved in water that suspends other elements
• Cells of reproduction


  ovum (egg) and sperm
• Solution


  A homogeneous mixture of two or more components
• Solvent


  dissolving medium
• Solutes


  Components in smaller quantities within a solution
• intracellular fluid


  nucleoplasm and cytosol
• interstitial fluid


  fluid on the exterior of the cell
• membrane transport


  movement of substances into and out of the cell
• Transport is by two basic methods

  passive transport and active transport
• passive transport


  no energy required
• active transport


  the cell must provide metabolic energy
• selective permeability


  Plasma membrane allows some materials to pass while excluding others; influences movement into and out of the cell
• Diffusion


  Particles tend to distribute themselves evenly within a solution; Movement is from high concentration, or down a concentration gradient; Movement is due to kinetic energy in the molecules and affected by size and temperature
• types of diffusion


  simple, osmosis, facilitated
• simple diffusion


  passive diffusion; Unassisted process; solutes are lipids- soluble materials or small enough to pass through membrane pores