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Anatomical Model

Anatomy & Physiology: Week Seven

Chapter 20: Lymphatic System

Functions of the Lymphatic System

  • Returns interstitial fluid to the blood

  • Absorbs fats and fat-soluble vitamins

  • Helps the body defend itself against infection

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What is Lymph?

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  • A clear fluid that resembles plasma

  • Composed primarily of water, electrolytes, waste from metabolizing cells, and some protein that leaks out of the capillaries of the systemic circulation

  • It is formed from the plasma during capillary exchange

Lymphatic Vessels

  • Drain interstitial fluid

  • Parallel to the veins

  • Every organ in the body has a rich supply of lymphatic vessels

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What Causes Lymph to Move?

  • Milking action of skeletal muscles

          - Exercise is good

  • Movement of chest during respiration

          - Creates variations in pressure

  • Rhythmic contractions of lymphatic smooth muscle

          - Vessel walls contract to push lymph along

 Click to label the Lymphatic System

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Lymphatic Drainage: Main Ducts

  • Two drainage areas: Right lymphatic duct and thoracic duct

  • Both ducts drain into subclavian veins

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Lymph Node: Two Compartments

Lymph nodules

  • Lymphocytes and macrophages

  • Immunity, phagocytosis

Lymph sinuses

  • Are lymph-filled spaces

  • Bathe lymph nodules

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Lymph Node

  • Lymphatic vessels drain most of the body

  • Nodes are grouped:

          - Cervical

          - Axillary

          - Inguinal

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Lymphoid Organ: Thymus Gland

  • Assists development of immune system before puberty

  • Secretes thymosins

  • Produces T cells (lymphocytes)

Lymphoid Organ: Spleen

  • Red pulp: Venous sinuses filled with blood and phagocytes

  • White pulp: Contains lymphocytes

  • Stores RBCs and platelets

  • Removes old RBCs and platelets

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Lymphoid Organ: Tonsils

  • Palatine tonsils often target of tonsillectomy

  • Pharyngeal tonsils or adenoids

  • Lingual tonsils

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 Click to label the Tonsils

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 Click to review the lymphatic system

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Chapter 21: Immune System

Classification

  • Specific immunity protects against one substance

  • Nonspecific immunity protects against many substances

Immunity: Lines of Defense

  • Nonspecific immunity

          - First line: Mechanical or chemical barriers, reflexes

          - Second line: Phagocytosis, inflammation, fever, protective proteins, natural                     killer cells

  • Specific immunity

          - Third line: B and T lymphocytes or B and T cells

Nonspecific Immunity: Lines of Defense

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Second Line of Defense: Phagocytosis

  • Leukocytes go to site of infection

          - Diapedesis

          - Chemotaxis

  • Leukocytes “eat”

          - Pathogens

          - Cellular debris

Second Line of Defense: Inflammation

Classic signs

  • Redness

  • Heat

  • Swelling

  • Pain

Second Line of Defense: Fever (Pyrexia)

  • Phagocytosis releases pyrogens

  • Pyrogens reset body thermostat upward

  • Body temperature rises

  • Antipyretics can lower temperature

Second Line of Defense: Protective Proteins

  • Interferons are secreted by cells infected by a virus

  • Interferons protect other cells from viral replication

  • Complement proteins assist WBCs

Second Line of Defense: Natural Killer Cells

  • A lymphocyte that acts nonspecifically

  • Effective against many microbes and certain cancer cells

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Third Line of Defense: Specific Immunity

Lymphocytes

  • T cells - Cell-mediated immunity

  • B cells - Antibody-mediated immunity

  • Macrophages - Help activate T and B cells

Antigens

  • An antigen is a substance that stimulates the formation of antibodies

  • Generally large molecules; most are proteins, but a few are polysaccharides and lipids

Antibodies

Destroy antigens directly and indirectly

  • Antigen: Stimulates formation of antibodies

  • Antibody: Secreted by B cells, also called immunoglobulins

  • Antigen-antibody interaction à agglutination

  • Important immunoglobulins

                - Immunoglobulin G (IgG)

                - Immunoglobulin A (IgA)

                - Immunoglobulin M (IgM)

                - Immunoglobulin E (IgE)

Why is Secondary Response Stronger than Primary Response?

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Types of Immunity

  • Genetic: Inborn and species-specific

  • Acquired: How do you get it?

          - Naturally

          - Artificially

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Naturally Acquired Immunity

  • Active: You are exposed to the antigen and you produce antibodies

               - Exposure to a virus

  • Passive: Someone else makes antibodies

               - From mother

Artificially Acquired Immunity

  • Active

               - Vaccines

               - Toxoids

  • Passive

               - Immune globulin (antibodies made by others)

               - Antitoxins, antivenoms

Chapter 22: Respiratory System

Structure: Organs of the Respiratory System

  • Upper respiratory tract: Organs located outside the chest

  • Lower respiratory tract: Organs located inside the chest

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 Click to label the Tonsils

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Upper Respiratory System

  • Nose and nasal cavities: warm, moisturize, and conduct air

  • Pharynx: Nasopharynx, Oropharynx, Laryngopharynx: conducts air to lower structures

  • Larynx: Vibrates vocal cords, produces sounds, and conducts air to lower structures

  • Trachea: windpipe: Conducts air to right and left bronchus

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 Click to label the Tonsils

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Lower Respiratory System

  • Bronchi: Have cartilaginous rings, carina, conduct air to bronchioles

  • Bronchioles: Smooth muscle determines diameter, regulates air flow to the alveoli.

  • Alveoli: Single layered membrane, grapelike structures, air sacs that exchange oxygen and carbon dioxide with blood in pulmonary circulation

  • Lungs: large soft, cone-shaped organs, contain structures of lower respiratory tract. Right lug has three lobes. Left lung has two lobes.

  • Pleura: Parietal pleura lines outer serous membrane. Visceral pleura lines outside of the lungs. 

  • Pleural cavity

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Lung Volumes

  • Tidal volume

  • Inspiratory reserve

  • Expiratory reserve

  • Residual

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     Click to review
        week seven                  vocabulary words

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