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Cells and Tissues - Anatomy & Physiology

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Terms in this set (47)

  • What are the three basic parts of a generalized cell?
    Nucleus, Plasma membrane, and Cytoplasm.
  • What is the function of the nucleus in a cell?
    The nucleus contains DNA and controls cell activities, including protein synthesis and cell reproduction.
  • What is the plasma membrane composed of?
    A double layer of phospholipids with embedded proteins, cholesterol, and attached sugar groups.
  • What is the role of cholesterol in the plasma membrane?
    Cholesterol strengthens the membrane and makes it less permeable to water-soluble substances.
  • What are the main functions of membrane proteins?
    They act as receptors, ion channels, transporters, cell recognition proteins, enzymes, and anchors for the cytoskeleton and extracellular matrix.
  • What are the three major elements of the cytoplasm?
    Cytosol (fluid), organelles (metabolic machinery), and inclusions (chemical substances).
  • What is the function of mitochondria?
    Mitochondria produce ATP through cellular respiration and are the major site of energy production in the cell.
  • What is the difference between rough and smooth endoplasmic reticulum?
    Rough ER has ribosomes and synthesizes proteins; Smooth ER synthesizes lipids, detoxifies drugs, and lacks ribosomes.
  • What is the function of the Golgi apparatus?
    It modifies, sorts, and packages proteins and lipids received from the rough ER for secretion or internal use.
  • What are lysosomes and their function?
    Membrane-bound sacs containing digestive enzymes that break down worn-out organelles and foreign substances.
  • What role do peroxisomes play in the cell?
    They detoxify harmful substances and convert free radicals to hydrogen peroxide and then to water.
  • What are the three types of cytoskeletal elements?
    Microfilaments, Intermediate filaments, and Microtubules.
  • What is the function of microfilaments?

    Smallest. Composed of actin and myosin, they help produce changes in cell shape and cell motility.

  • What is the function of intermediate filaments?

    Middle-sized. They help form desmosomes and provide structural support.

  • What is the function of microtubules?

    Largest. They maintain cell shape, distribute organelles, and form the mitotic spindle during cell division.

  • What are centrioles and their role?

    Rod-shaped microtubule structures near the nucleus that direct the formation of the mitotic spindle during cell division (chromatid separation).

  • What is the difference between cilia, flagella, and microvilli?
    Cilia move materials across the cell surface, flagella propel sperm, and microvilli increase surface area for absorption.
  • What is diffusion and what conditions are necessary for it to occur?
    Movement of molecules from high to low concentration; requires membrane permeability and a concentration gradient.
  • What is osmosis?
    The diffusion of water across a selectively permeable membrane through aquaporins or the lipid bilayer.
  • What happens to cells in isotonic, hypertonic, and hypotonic solutions?
    Isotonic: no change; Hypertonic: cells shrink; Hypotonic: cells swell.
  • What is endocytosis and its types?
    Process of engulfing large molecules; includes pinocytosis (cell drinking) and phagocytosis (cell eating).
  • What is mitosis and its main phases?
    Cell division producing two identical daughter cells; phases are prophase, metaphase, anaphase, and telophase.
  • What occurs during DNA replication?
    DNA uncoils and each strand serves as a template for a new complementary strand, producing two identical DNA molecules.
  • What is the function of ribosomes?
    Sites of protein synthesis, either free in cytoplasm or attached to rough ER.
  • What are the four main tissue types?
    Epithelial, connective, muscle, and nervous tissues.
  • What are the special characteristics of epithelial tissue?
    Tightly packed cells, apical surface, basement membrane, avascular, and high regeneration capacity.
  • What are the three shapes of epithelial cells?
    Squamous (flat), cuboidal (cube-shaped), and columnar (column-shaped).

  • Nuclear membrane and exchange

    The nuclear envelope is a double membrane enclosing the nucleus. Nuclear pores regulate exchange of materials with

    the cytoplasm.

  • Phospholipid arrangement

    A bilayer: water-loving heads face extracellular and intracellular fluid; water-fearing tails point inward toward one

    another.

  • Hydrophilic versus hydrophobic membrane structure

    Hydrophilic = attracted to water (polar phospholipid heads). Hydrophobic = repelled by water (nonpolar fatty-acid tails

    in the bilayer interior).

  • Solution, solute, solvent

    Solution: uniform mixture. Solvent: dissolving medium (usually water). Solute: dissolved substance (e.g., salt).

  • Intracellular versus interstitial fluid

    Intracellular: fluid inside cells. Interstitial: extracellular fluid bathing cells.

  • Active versus passive transport

    Passive: does not require cellular ATP. Active: requires ATP

  • Four passive-transport types

    Simple diffusion High → low concentration; Small lipid-soluble substances

    Facilitated diffusion High → low; protein channel/carrier; Water-soluble or charged solutes

    Osmosis Water moves toward higher effective solute concentration; Cell swelling/shrinking

    Filtration: High → low hydrostatic pressure

  • Mitosis versus meiosis

    Mitosis: somatic cells; growth/repair; 1 division → 2 genetically identical diploid cells (46 chromosomes). Meiosis: reproductive organs; gamete formation; 2 divisions → 4 genetically different haploid cells (23 chromosomes).

  • Two main cell-cycle stages

    Interphase (growth and DNA preparation) and cell division (mitosis + cytokinesis).

  • DNA pairing memory aid

    A = T → C ≡ G → each new helix = 1 old + 1 new strand

  • PMAT memory sequence

    Prophase: prepare → Metaphase: middle → Anaphase: apart → Telophase: two nuclei

  • Cytokinesis and timing

    Division of cytoplasm; starts around late anaphase and completes during telophase in the lecture’s animal-cell

    description. A cleavage furrow pinches cell into two.

  • Two steps of protein synthesis

    Transcription: DNA → RNA in nucleus. Translation: mRNA instructions → protein at ribosomes in cytoplasm.

  • Endocrine versus exocrine glands

    Endocrine: ductless; hormones enter blood. Exocrine: secrete through ducts onto surfaces.

  • Three connective-tissue fibers

    Collagen: tensile strength/flexibility. Elastic: stretch and recoil. Reticular: fine support networks

  • Osteon: from center outward

    central canal → concentric lamellae → lacunae with osteocytes → canaliculi connect spaces

  • Osteocyte versus chondrocyte

    Osteocyte: mature bone cell in lacuna. Chondrocyte: cartilage cell in lacuna.

  • Liquid-matrix tissue

    Blood; matrix = plasma; formed elements = red blood cells, white blood cells and platelets.

  • Three muscle tissues

    Skeletal Long cylindrical, striated, many nuclei; Attached to skeleton; voluntary; body movement

    Cardiac Short, branched, striated, intercalated discs; Heart; involuntary; pumps blood

    Smooth Spindle-shaped, single central nucleus, nonstriated; Walls of hollow organs; involuntary;

    moves contents

  • Nervous tissue

    Located in brain, spinal cord and peripheral nerves. Neurons transmit electrical impulses; neuroglia support/protect

    neurons.