Unit 1

• Physiology


  The study of normal body function and the underlying mechanisms
• Pathology


  The study of abnormal body function
• In health and wellness normal function prevails
• The aim of Medicine is to restore the body from disease to normal
• Body function and structure are closely related
• Abnormal function is often associated with abnormal structure
• SI (International System of Units)

  Also known as the metric system, used for measurements in Physiology
• Units of measurement in the SI system

  • Length: meter (m)
  • Mass: kilogram (kg)
  • Time: second (s)
  • Amount of substance: mole (mol)
• Prefixes used in the SI System

  • Deci- (d):10^-1
  • Centi- (c): 10^-2
  • Milli- (m): 10^-3
  • Micro- (µ): 10^-6
  • Nano- (n): 10^-9
  • Angstrom unit (Å): 10^-10
  • Pico- (p): 10^-12
  • Femto- (f): 10^-15
  • Atto- (a):10^-18
  • Deca-(da):10^1
  • Hecta-(h):10^2
  • Kilo-(K): 10^3
  • Mega-(M): 10^6
  • Giga-(G): 10^9
  • Tera-(T): 10^12
• Cell


  The basic structural and functional unit of the body
• Tissue


  A group of cells performing specific functions
• The cells in a tissue are held together by intercellular supporting structures
• Organ


  Structures composed of two or more types of tissues that work together to carry out specific functions
• Examples of human organs


  • Brain, heart, lungs
• Organ system


  Groups of organs working together to perform complex tasks for the body's overall function
• Example of an organ system


  • The cardiovascular system, consisting of the heart and blood vessels that transport blood around the body
• Prokaryotes


  Unicellular organisms that lack a nucleus and membrane-bound organelles
• Examples of prokaryotes


  • Microbes in the gastrointestinal tract of man, referred to as the microbiota
• Prokaryotes play important roles in normal body function and disease
• Eukaryotes


  Organisms that contain cells with a clearly defined nucleus and other membrane-bound organelles, more complex than prokaryotes
• Human cells are eukaryotes
• Nucleus


  One of the two major parts of the human cell, separated from the cytoplasm by a nuclear membrane
• Cytoplasm


  The other major part of the human cell, enclosed by the cell membrane
• Protoplasm


  The substances within the cell, consisting of more than 70% water with dissolved or suspended substances such as electrolytes, proteins, lipids, and carbohydrates
• The human cell is eukaryotic, meaning each organelle is surrounded by a definite membrane
• Cell membrane (plasma membrane or plasmalemma)


  A thin, elastic structure 7.5 nanometers (75 Å) thick, composed mainly of proteins and lipids arranged as a lipid bilayer
• Cell membrane


  • Composed of phospholipids with hydrophilic heads and hydrophobic tails, forming a bilayer
  • Contains various proteins that carry out functions such as cell adhesion, ion transport, facilitated diffusion, and receptor binding
• Mitochondria


  The powerhouse of the cell, able to form the energy-rich compound ATP by the process of oxidative phosphorylation
• Mitochondria


  • Have an outer membrane, an intermembrane space, an inner membrane folded into cristae, and a central matrix space
  • Contain their own genome, but most mitochondrial proteins are products of nuclear genes
  • Inheritance is maternal as they are derived from the ovum
• Lysosomes


  Large membrane-bound structures in the cytoplasm, with an acidic interior (pH=5) that digest external material and worn-out organelles
• Lysosomes


  • Contain many hydrolytic enzymes that function best at acidic pH, a safety measure as their contents would not be able to digest the cytoplasm at neutral pH if they were to break open
  • When a lysosomal enzyme is congenitally absent, the lysosomes become swollen with the material the enzyme is supposed to digest, leading to lysosomal diseases
• Example of a lysosomal disease


  • Fabry disease, due to a lack of α-galactosidase
• Physiology


  The study of normal body function and the underlying mechanisms
• Pathology


  The study of abnormal body function
• In health and wellness normal function prevails
• The aim of Medicine

  To restore the body from disease to normal
• Body function and structure are closely related
• Abnormal function is often associated with abnormal structure
• Units of measurement in the SI system

  • Length: meter (m)
  • Mass: kilogram (kg)
  • Time: second (s)
  • Amount of substance: mole (mol)
• Prefixes used in the SI System

  • Deci- (d):10-1
  • Deca-(da):101
  • Centi- (c): 10-2
  • Hecta-(h):102
  • Milli- (m): 10-3
  • Kilo-(K): 103
  • Micro- (µ): 10-6
  • Mega-(M): 106
  • Nano- (n): 10-9
  • Giga-(G): 109
  • Angstrom unit (Å): 10-10
  • Tera-(T): 1012
  • Pico- (p): 10-12
  • Femto- (f): 10-15
  • Atto- (a):10-18