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Respiration & Immunity Chs 14 & 13 Announcements • • • • • • • • Tentative outline: Nov 23- (Today)- Respiration and Immunity Nov 30- Digestion & Nutrition Dec 2- Reproduction & Genetics Dec 7- DNA and Biotechnology Dec 9- Evolution Dec 14- Ecology & Review Dec 16- Final Outline • Respiration – The Lungs & gas exchange – The throat • Immunity – Innate immunity vs. adaptive immunity – T lymphocytes and B lymphocytes – Primary vs. secondary adaptive immunity – Lab: Finish old labs & STD activity Respiration • • • • Gas exchange & Circulation Structures of the respiratory system Other structures of the respiratory system Disorders of the respiratory system The Respiratory System • In the respiratory system, oxygen and carbon dioxide are exchanged across a moist body surface • Pressure changes within the lungs cause breathing • Blood transports gases between the lungs and the cells • Breathing is controlled primarily by respiratory centers in the brain • Respiratory disorders have many causes The Respiratory System • The function of the respiratory system is to provide the body with essential oxygen and dispose of carbon dioxide The Respiratory System Breathing moves air in and out of the lungs. External respiration is the exchange of oxygen and carbon dioxide between the lungs and the blood. Gas transport moves oxygen and carbon dioxide between the lungs and the body tissues. Internal respiration is the exchange of oxygen and carbon dioxide between blood and the body tissues. Oxygen transport Lungs Gas diffusion Carbon dioxide transport Gas diffusion Tissue Figure 14.1 The Respiratory System UPPER RESPIRATORY SYSTEM • Filters, warms, and moistens air Sinuses • Cavities in skull • Lighten head • Warm and moisten air Nasal cavity • Produces mucus • Filters, warms, and moistens air • Olfaction Pharynx • Passageway for air and food RESPIRATORY MUSCLES • Cause breathing Intercostal muscles • Move ribs during breathing Diaphragm • Muscle sheet between chest and abdominal cavities with a role in breathing Figure 14.2 (1 of 2) The Respiratory System LOWER RESPIRATORY SYSTEM • Exchanges gases Larynx • Air passageway • Prevents food and drink from entering lower respiratory system • Produces voice Bronchi • Two branches of trachea that conduct air from trachea to each lung Bronchioles • Narrow passageways to conduct air from bronchi to alveoli Epiglottis • Covers larynx during swallowing Lungs • Structures that contain alveoli and air passageways • Allow exchange of oxygen and carbon dioxide between atmosphere and blood Trachea • Connects larynx with bronchi leading to each lung • Conducts air to and from bronchi Alveoli • Microscopic chambers for gas exchange Figure 14.2 (2 of 2) The Respiratory System • The nose – Cleans incoming air – Warms and moistens the air – Provides for the sense of smell The Respiratory System Figure 14.4a The Respiratory System • The sinuses – Lighten the head – Adjust air quality • The pharynx – The space behind the nose and mouth – Provides a passageway for food and air The Respiratory System • The larynx – An adjustable entrance to the respiratory system – Controls the position of the epiglottis to prevent materials from entering the lower respiratory system – The source of the voice The Respiratory System Epiglottis Larynx Upper trachea Front view (a) The epiglottis is open during breathing but covers the opening to the larynx during swallowing to prevent food or drink from entering the trachea. Figure 14.5a The Respiratory System Vocal cords Glottis Top view of larynx During quiet breathing, the vocal cords are near the sides of the larynx, and the glottis is open. Top view of larynx During speech, the vocal cords are stretched over the glottis and vibrate as air passes through them, producing the voice. (b) The vocal cords are the folds of connective tissue above the opening of the larynx (the glottis) that produce the voice. Figure 14.5b The Respiratory System • The trachea – Tube that conducts air between the environment and the lungs • Heimlich maneuver – Can be used to dislodge food from the trachea The Heimlich maneuver is only a last resort A person who is choking cannot speak or breathe and needs immediate help. The Heimlich maneuver is a procedure intended to force a large burst of air out of the lungs and dislodge the object blocking air flow. Step 1: Stand behind the choking person with arms around the waist. Step 2: Make a fist and place the thumb of the fist beneath the victim’s rib cage about midway between the navel (belly button) and the breastbone. Figure 14.6 (1 of 2) The Respiratory System Step 3: Grasp the fist with your other hand and deliver a rapid “bear hug” up and under the rib cage with the clenched fist. Be careful not to press on the ribs or the breastbone because doing so could cause serious injury. Blocking object Step 4: Repeat until the object is dislodged. Figure 14.6 (2 of 2) The Respiratory System • The trachea divides into the bronchial tree which conducts air to each lung The Respiratory System Figure 14.7 The Respiratory System • The alveoli – Functional units of the respiratory system – Minute sacs where oxygen diffuses from the air into the blood • For alveoli to function properly they are coated with phospholipid molecules called surfactant that keep them open The Respiratory System Figure 14.8 The Respiratory System • Carbon dioxide produced by the cells diffuses from the blood into the alveolar air to be exhaled Pressure Changes within the Lungs Cause Breathing • Pressure changes within the lungs cause breathing Pressure Changes within the Lungs Cause Breathing • When the diaphragm and intercostal muscles contract, the volume of the thoracic cavity increases, causing the pressure in the lungs to decrease Pressure Changes within the Lungs Cause Breathing • Inspiration – Occurs when the pressure in the lungs decreases Pressure Changes within the Lungs Cause Breathing Inhalation Rib cage moves up and out Air flow Intercostal muscles contract Diaphragm contracts and flattens The chest cavity increases in size, and pressure within the lungs decreases. Diaphragm contracts The lungs expand, and air moves in. (a) Figure 14.9a Pressure Changes within the Lungs Cause Breathing • Expiration – When the same muscles relax, pressure in the lungs increase Pressure Changes within the Lungs Cause Breathing Exhalation Air flow Rib cage moves down and inward Intercostal muscles relax Diaphragm relaxes and moves upward The chest cavity decreases in size, and pressure within the lungs increases. Diaphragm relaxes The lungs recoil, and air moves out. (b) Figure 14.9b Pressure Changes within the Lungs Cause Breathing • The volume of air inhaled or exhaled during a normal breath is called the tidal volume • The volume of air moved into and out of the lungs is an indication of health Pressure Changes within the Lungs Cause Breathing 6000 Lung Volume (ml) 5000 Inspiratory reserve (forced inhalation) volume 4000 Total lung capacity Vital capacity Tidal volume 3000 2000 Expiratory reserve (forced exhalation) volume 1000 Residual volume 0 Figure 14.10 (1 of 2) Pressure Changes within the Lungs Cause Breathing Tidal volume (~500 ml) Amount of air inhaled or exhaled during an ordinary breath Inspiratory reserve volume (~1900–3300 ml) Amount of air that can be inhaled in addition to a normal breath Expiratory reserve volume (~1000 ml) Amount of air that can be exhaled in addition to a normal breath Vital capacity (~3400–4800 ml) Maximum amount of air that can be inhaled or exhaled in a single forced breath Residual volume (~1100–1200 ml) Amount of air remaining in the lungs after maximum exhalation Total lung capacity (4500–6000 ml) Total amount of air in the lungs after maximal inhalation (vital capacity + residual volume) Figure 14.10 (2 of 2) Blood Transports Gasses between the Lungs and the Cells • Most oxygen is carried by the blood where it is bound to hemoglobin in a molecule called oxyhemoglobin Blood Transports Gasses between the Lungs and the Cells • The carbon dioxide produced as the cells use oxygen is removed by the blood in one of three ways 1. Dissolved in the blood 2. Carried by hemoglobin 3. As a bicarbonate ion Blood Transports Gasses between the Lungs and the Cells Figure 14.11 (1 of 2) Blood Transports Gasses between the Lungs and the Cells Figure 14.11 (2 of 2) Disorders of the respiratory system Respiratory Disorders Have Many Causes Figure 14.14 Lung Cancer • Lung Cancer – Changes in the cells of the airway linings • Eventual uncontrolled cell division forms a tumor – Often caused by inhaled carcinogens, including those found in tobacco smoke Cigarette smoke Figure 14.4b The Immune System • Overview • Innate vs. Adaptive The Immune system is the body’s defense system • Against: – – – – – – – Bacteria Viruses Protists Other living invaders Toxins Foreign debris Cancerous cells • The immune system is complex • Defends against threats known and unknown Elements of the Immune system • Many lines of defense, for many kinds of threats • Skin • Blood • Thymus • Spleen • Lymphatic system • Mucous membranes • Bone marrow Innate vs. Adaptive immunity Innate Immunity • Non-specific • Defends against known invaders • Skin, lysozyme • Pre-existing • Cannot adapt to changing threats Adaptive Immunity • Mechanisms which fight specific invaders • For unknown threats • Responsive • Requires time to build defense (days) • Cannot anticipate threats • Remembers previous threats Humoral vs. Cell-mediated Immunity Cell- Mediated Immunity • Live cells kill invaders • Innate: Phagocytic cells (e.g. macrophages, neutrophils) • Adaptive: B lymphocytes and T lymphocytes create specific responses to unique invaders Humoral immunity • Proteins in blood (“humors”) • Innate- complement system, clotting factors, cytokines, etc. • Adaptive: Antibodies Blood is a mixture of cells and plasma Human Blood after centrifugation • ~55% Plasma • ~45% Red blood cells • <1% White blood cells and platelets (“buffy coat”) Blood plasma • Water • Nutrients • Solutes- Na+, Cl-, wastes, CO2, etc. • Contains humoral immune elements • Some innate immunity Hematopoetic stem cells differentiate into all blood cells • Pluripotent- able to become any one of many cell types • Includes T cells, B cells, macrophages, etc. Red blood cells carry oxygen and CO2 • Lose nucleus in development • Short-lived, no repair • Packed solid with hemoglobin • Membranes designed to maximize surface area • Facilitate gas transfer Platelets assist with blood clotting • Recruit plasma protein fibrinogen to a cut • They release clotting factors • Clotting factors convert fibrinogen to fibrin • Fibrin net prevents blood loss White blood cells come in a great variety of types Elements of Innate Immunity Nonspecific (Innate) Immunity • First line – Surface barriers • Second line – Cell-mediated immunity- defensive cells – Humoral Immunity- Defensive proteins – Inflammation & fever Nonspecific Surface Barriers work against multiple threats Figure 13.2 (1 of 2) Nonspecific Surface Barriers Figure 13.2 (2 of 2) Lysozyme- an innate enzymatic defense • Enzyme that cuts bacterial cell walls • Also cuts chitin, a constituent of fungal cell walls and arthropod exoskeleton • Found in mucous, tears, egg whites Nonspecific Internal Defenses • The second line of defense – Defensive cells – Defensive proteins – Inflammation – Fever Nonspecific Internal Defenses • Defensive cells include neutrophils and macrophages – They engulf pathogens, damaged tissue, or dead cells by the process of phagocytosis Phagocytic white blood cells devour bacteria Nonspecific Internal Defenses Figure 13.3 Nonspecific Internal Defenses • The body’s non-specific cellular defenses use two types of defensive proteins – Complement system – Interferons Interferons are nonspecific anti-viral signalling molecules Nonspecific Internal Defenses • Before a virally–infected cell dies, it secretes small proteins called interferons that – Attract macrophages and natural killer cells – Stimulate neighboring cells to make proteins that prevent the viruses from replicating Nonspecific Internal Defenses • The complement system – A group of proteins that enhance both nonspecific and specific defense mechanisms by • Destroying pathogens • Enhancing phagocytosis • Stimulating the inflammatory response Nonspecific Internal Defenses Figure 13.5 (1 of 3) Nonspecific Internal Defenses Figure 13.5 (2 of 3) Nonspecific Internal Defenses Figure 13.5 (3 of 3) Nonspecific Internal Defenses • Inflammatory response destroys invaders and helps repair and restore damaged tissue – Redness – Heat – Swelling – Pain Nonspecific Internal Defenses Figure 13.6 (1 of 2) Nonspecific Internal Defenses Figure 13.6 (2 of 2) Nonspecific Internal Defenses • Fluid leaks from the capillaries – Causes swelling • Blood flow increases – Causes redness and warmth Nonspecific Internal Defenses Figure 13.7 The Inflammatory response Keeping the body safe comes at a cost • Inflammation implicated in heart disease, etc. • Gum inflammation linked to heart attacks The adaptive immune system The lymphatic system collects lymph and houses white blood cells in nodes Adaptive Immunity contains humoral and cell-mediated components Adaptive Immunity is learned, and has memory Which of the following mobilizes nonspecific defense system? • A) active immunity • B) inflammation • C) passive immunity • D) cell-mediated immunity • E) none of these Antibodies- the Key component of humoral adaptive immunity • Two light chains, two heavy chains • Each contains a variable region and a constant region Antigen- anything which can be bound by an antibody B Cells- the source of antibodies Clonal selection musters B-cell defense forces against specific antigens Immune cells are the only cells with different DNA • VDJ recombination of light and heavy chains generate antibody diversity • Change is permanent • A form of Russian Roulette for the cell • Successful recombination creates a binding antibodycell survives • Unsuccessful- cell is destroyed • Finding a good cell takes time Bound antibodies are the mark of death for invaders Breast milk contains maternal antibodies • Infants have no acquired immunity • Mother’s acquired immunity is transferred to the baby through nursing • Passive immunity • Is not retained by the baby Vaccination gives the body active immunity • An antigen sample is given to a person • Person’s immune system mounts a response to the antigen • Antigen can be deactivated/destroyed virus particles, etc. • No waiting time for body to develop 2o immune response Antibodies can be used as therapy • Some growth factors are overactive in certain cancers • Antibody binds to growth factors, or their receptors Polyclonal Antibodies can determine blood type • From multiple B cells • Bind to different epitopes of an antigen Monoclonal antibodies • Obtained from a single B cell • Bind to a single epitope • A single B cell is fused to a myeloma cell • Myeloma cells are immortal Mouse antibodies can be humanized • Constant regions of mouse antibody are gradually replaced with human sequences Fluorescent antibodies can be used in scientific experiments • Fluorescent molecules can be linked to antibodies • Antibodies show us where proteins exist in vivo Home pregnancy tests utilize antibodies • The transfer of antibodies from breast milk to an infant is an example of __________ immunity. • A) nonspecific • B) passive • C) humoral • D) active • E) cell-mediated T cells are the primary cell-mediated adaptive immune response Major Histocompatibility Complex (MHC or HLA) • MHCI Found on all cells, recognized by TC cells • MHCII Found on B cells and Macrophages recognized by TH cells When presented with antigen, Helper T cells recruit other immune cells • The basic function of T cells is to identify and destroy invaders in our • A) blood or lymph. • B) interstitial fluid. • C) cells. • D) immune system. • E) brain. CD4 on the surface of TH cells is the site of HIV binding Any known stage of the HIV life cycle is a potential point for therapy Protease inhibitors prevent formation of HIV capsids AZT is a nucleoside analog reverse transcriptase inhibitor AZT Thymine Cytotoxic T cells destroy infected body cells In Autoimmune disease, the immune system attacks the self Allergies are immune responses to harmless antigens • A substance that can elicit an immune response is called a(n) • A) complement. • B) interferon. • C) histamine. • D) antibody. • E) antigen.