CYTOLOGY

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CYTOLOGY

• Biology 220
• Cellular Anatomy

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HUMAN CELLS - GENERAL

• Smallest living structural functional unit of
  the human body
• Produced by Cell Division or Fertilization
• 1 cell gives rise to 75 trillion
• Differentiates into 200 different types
• Contain specialized structural functional units
  organelles
• Exchange with surrounding extracellular fluid

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GENERAL CELLULAR FUNCTIONS

• Covers lines surfaces (e.g. epithelial)
• Storage (e.g. hepatocytes, adipocytes)

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GENERAL CELLULAR FUNCTIONS

• Movement (e.g. muscle cells)
• Attachment/Support (e.g. fibroblasts)

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GENERAL CELLULAR FUNCTIONS

• Defense (e.g. leukocytes)
• Communication (e.g. neurons)

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GENERAL CELLULAR FUNCTIONS

• Reproduction (e.g. gametes)

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GENERAL CELLULAR ANATOMY

• Basic Animal Cell Type Eukaryotic
• Nucleus
• Plasma Membrane
• Cytoplasm
• Organelles
• Cytosol
• Inclusions

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NUCLEUS

• Shape similar to cells
• Double Nuclear Membrane with Pores
• Nucleoplasm
• Nucleolus
• Organelle in nucleus (non-membranous)
• Production site of ribosomal subunits
• DNA
• Chromatin - loose protein synthesis
• Chromosomes - dense, rodlike cell division

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STRUCTURE OF THE NUCLEUS
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THE PLASMA MEMBRANE

• Selectively Permeable - regulates exchange with
  extracellular fluid
• SA/V limits cell size
• Composed mostly of lipids proteins
• Phospholipid bilayer is basic structure
• Proteins determine function

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Plasma Membrane continued

• Lipids insoluble in water
• Phospholipids
• Amphipathic molecules (polar non-polar regions)
• Hydrophobic tails and hydrophilic heads

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Plasma Membrane continued

• Lipids insoluble in water
• Cholesterol
• Effects membrane fluidity
• Thermal stability
• Glycolipids
• Outer surface
• Contribute to Glycocalyx cellular recognition

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Plasma Membrane continued

• Proteins highly diverse
• Integral - embedded
• Channels Carriers
• Receptors
• Enzymes
• Anchors
• Peripheral attached to surface may float
• Enzymes
• Anchors
• Glycoproteins - Contribute to Glycocalyx
  cellular recognition

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CYTOPLASM

• Material between plasma membrane nucleus
• 3 Components
• Cytosol intracellular fluid
• Inclusions temporarily stored substances (e.g.
  nutrients or pigments)
• Organelles
• Diverse structures with specialized functions
• Vary among cells
• Membrane-bound non-membranous

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Generalized Animal Cell
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ORGANELLES

• Little Organs
• Membrane-bound organelles
• Membrane isolates secretions, enzymes or toxins
• Non-membrane-bound organelles

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ENDOPLASMIC RETICULA (Membranous)

• Smooth endoplasmic reticulum (SER)
• Synthesis of Lipids metabolizes carbohydrates
  detoxifies
• Storage (Synthesized Materials or Ca)
• Rough endoplasmic reticulum (RER)
• Attached Ribosomes
• Protein synthesis for secretion, or inclusion in
  lysosomes in cell membrane

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GOLGI APPARATUS (Membranous)

• Structure
• Flattened Membranous Sacs w/vesicles
• Function
• Modifies, packages, sorts new proteins for
  secretion
• Source of lysosomes
• Renewal/modification of plasma membrane

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LYSOSOMES (Membranous)

• Structure Vesicles filled with Digestive Enzymes
  
• Function
• Intracellular digestion (wastes ingested
  macromolecules)
• Recycle worn-out organelles via Autophagy
• Self-digestion of cell via Autolysis
• Defense

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Generalized Animal Cell
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PEROXISOMES (Membranous)

• Membranous sacs of enzymes (oxidases)
• Break down amino acids fatty acids
• Detoxify harmful/dangerous substances
• Hydrogen peroxide (by-product of oxidation)
• Alcohol
• Formaldehyde
• Free Radicals

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MITOCHONDRIA (Membranous)

• Structure Double membrane w/cristae central
  fluid matrix
• Function Most ATP synthesis (cellular energy)
• Contains DNA
• Self-Replicating

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VACUOLES AND VESICLES (Membranous)

• Structure Membranous Sac
• Function Storage, Endocytosis, Exocytosis

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RIBOSOMES (Non-membranous)

• Structure Two subunits (rRNA protein)
• Function Protein synthesis
• Two types
• Free - synthesis of proteins for intracellular
  use
• Fixed - synthesis of proteins for secretion, or
  incorporation into lysosomes, plasma membrane, or
  cell membranes

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PROTEASOME(Non-Membranous)

• Ring of stacked proteins around a central core
• Breaks up un-needed, damaged or faulty proteins
  via proteases
• Thousands in cytoplasm nucleus

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VAULTS (non-membranous)

• Ribonucleoprotein (3 proteins an RNA)
• Concentrated in cytoplasm
• May be involved in transport between nucleus
  cytoplasm
• Associated with multidrug resistance in cancer
  cells

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CYTOSKELETON (Non-membranous)

• Network of protein structures
• Acts as cells muscles bones
• Determines cell shape
• Supports organelles
• Involved in internal transport cellular
  movements

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CENTROSOMES AND CENTRIOLES (Non-membranous)

• Centrosome Cell center
• Pericentriolar material near nucleus
• Contains hundreds of tubulins
• Builds microtubules in non-dividing cells
• Forms mitotic spindle during cell division
• Centrioles
• Paired perpendicular bodies in centrosome
• Assist in spindle formation

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CILIA FLAGELLA (Non-membranous)

• Both are motile projections of cell surface
• Both contain microtubules
• Cilia short, numerous, move substances over
  free surfaces
• Flagella long, singular, propel human sperm
  cells
• Microvilli microscopic projections of plasma
  membrane that increase surface area of the cell

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