FINALS

• Immune system


  Essential for our survival, keeps us healthy by defending against pathogens
• Immune system


  • Vast network of cells and tissues constantly on the lookout for invaders
  • Can distinguish our tissue from foreign tissue - self from non-self
  • Recognizes and clears away dead and faulty cells
• Immune response


  1. Cell types work together to recognize antigen as an invader

  2. B lymphocytes secrete antibodies that lock onto antigens

  3. T lymphocytes destroy compromised cells and alert other leukocytes
• Lymphoid organs


  • Thymus
  • Spleen
  • Bone marrow
  • Lymph nodes
• Types of leukocytes


  • Phagocytes
  • Lymphocytes
• Phagocytes


  Cells that surround and absorb pathogens, breaking them down
• Lymphocytes


  Help the body remember previous invaders and recognize them if they return
• B lymphocytes


  Produce antibodies and help alert T lymphocytes
• T lymphocytes


  Destroy compromised cells and help alert other leukocytes
• Antigen


  Any substance that can spark an immune response
• Antibodies


  Special proteins that lock onto specific antigens
• Types of immunoglobulins

  . Immunoglobulin G (IgG) — marks microbes so other cells can recognize and deal with them.

  b. IgM — is expert at killing bacteria.

  c. IgA — congregates in fluids, such as tears and saliva, where it protects gateways into the body.

  d. IgE — protects against parasites and is also to blame for allergies.

  e. IgD — stays bound to B lymphocytes, helping them to start the immune response.
• Immunity


  • Immune system becomes stronger during adulthood as we are exposed to more pathogens
  • Antibodies remain in the body to quickly destroy the same antigen if it appears again
• Types of immunity


  • Innate
  • Adaptive (acquired)
  • Passive
• Innate immunity


  Immune system attacks foreign invaders from day one, includes external barriers like skin and mucous membranes
• Adaptive (acquired) immunity


  Develops as we are exposed to diseases or get vaccinated, builds up a library of antibodies
• Passive immunity


  Borrowed from another source, such as antibodies received from mother before and after birth, but does not last indefinitely
• Immunizations


  Introduce antigens or weakened pathogens to produce antibodies without causing illness
• Lymphatic system


  Network of tissues, vessels and organs that work together to move lymph back into the bloodstream
• Functions of the lymphatic system


  • Maintains fluid levels in the body
  • Absorbs fats from the digestive tract
  • Protects the body against foreign invaders
  • Transports and removes waste products and abnormal cells
• Parts of the lymphatic system

  • Lymph
  • Lymph nodes
  • Lymphatic vessels
  • Collecting ducts
  • Spleen
  • Thymus
  • Tonsils and adenoid
  • Bone marrow
  • Peyer's patches
  • Appendix
• Digestive system


  Includes the digestive tract and accessory organs that process food into molecules that can be absorbed and utilized by the body
• Food processing in the body

  1. Digestion

  2. Absorption

  3. Elimination
• Functions of the digestive system

  1. Ingestion

  2. Mechanical digestion

  3. Chemical digestion

  4. Movements
• Digestive enzymes speed up the hydrolysis process of breaking down complex molecules
• Movements that propel food through the digestive tract are called peristalsis
• Mechanical digestion


  1. Chewing or mastication in the mouth

  2. Churning and mixing actions in the stomach
• Chemical digestion


  1. Transformation of complex molecules of carbohydrates, proteins, and fats into smaller molecules

  2. Hydrolysis using water and digestive enzymes
• Deglutition


  Swallowing, the movement of food particles from the mouth into the pharynx, then into the esophagus
• Mixing movements


  1. Smooth muscle contraction in the stomach

  2. Mix food particles with enzymes and other fluids
• Peristalsis


  Rhythmic waves of contractions that move the food particles through the digestive tract
• Absorption


  Simple molecules from chemical digestion pass through cell membranes of the lining in the small intestine into the blood or lymph capillaries
• Elimination


  Removal of indigestible wastes through the anus, in the form of feces
• Each part of the digestive system helps to move food and liquid through GI tract, break food and liquid into smaller parts, or both
• Once foods are broken into small enough parts, the body can absorb and move the nutrients to where they are needed
• The large intestine absorbs water, and the waste products of digestion become stool
• Nerves and hormones help control the digestive process
• Food move through GI tract

  1. Peristalsis

  2. Muscle contraction behind the food contracts and squeezes the food forward

  3. Muscle in front of the food relaxes to allow the food to move
• Digestive process starts when you put food in your mouth

  1. Tongue pushes the food into the throat

  2. Epiglottis folds over windpipe to prevent choking

  3. Food passes into esophagus
• Esophagus


  Brain signals the muscles of the esophagus and peristalsis begins