BIOS 255 Exam 3 Review Questions and Answers

BIOS 255 Exam 3 Review Questions and Answers Respiratory distress syndrome (surfactant) Condition often seen in premature infants, caused by lack of surfactant, a substance that helps keep the lungs inflated and reduces surface tension in the air sacs. Without enough surfactant, the lungs collapse and there will be difficulty breathing. Conducting Zone The conducting zone of the respiratory system consists of those passages that serve only for airflow, essentially from the nostrils through the major bronchioles. Respiratory Zone The respiratory zone consists of the alveoli and other gas-exchange regions of the distal airway. Mechanism in which lungs exchange gas Simple Diffusion: Lung gas exchange occurs through simple diffusion, where oxygen moves from the air in the lung's alveoli to the blood, and carbon dioxide moves from the blood to alveoli to be exhaled. Difference between pulmonary respiration vs ventilation Pulmonary Respiration: refers to the exchange of gases (oxygen and carbon dioxide) between lungs and blood Ventilation: physical process of moving air in and out of lungs Ventilation Movement of gases into and out of lungs; between lungs and external environment Inhalation: air moving from external environment into the lungs Exhalation: air moving from the lungs to the external environment Respiration Exchange of gases across a membrane into and out of a blood vessel. External (pulmonary) respiration: oxygen moves from the alveoli across alveolar membrane into pulmonary capillary bed; carbon dioxide moves from pulmonary capillary bed across alveolar membrane into the alveoli Internal (tissue) respiration: carbon dioxide moves from interstitial fluid across systemic capillary membrane into systemic capillary bed; oxygen moves from systemic capillary bed across systemic capillary membrane into interstitial fluid where it is used by the cell to create ATP Oxygen dissociation curve (Oxygen loading and unloading) The binding of oxygen to hemoglobin is affected by several factors. These are reflected in the image as a right (increased dissociation) or left (decreased dissociation) shift of the oxygen dissociation curve. Boyle's Law Boyle's law is a gas law that states that a gas's pressure and volume are inversely proportional. When the temperature is kept constant, as volume increases, pressure falls and vice versa. Describes air flow in and out of lungs during ventilation Charles's Law Charles's Law states that the volume of a given mass of gas varies directly with the absolute temperature of the gas when pressure is kept constant. Dalton's Law (Law of Partial Pressures) Dalton's Law, or the Law of Partial Pressures, states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases in the mixture. In a mixture of gases each gas exerts a partial pressure as if no other gas is present (PTotal = PGas1 + PGas2 + PGas3...) Nerve that supplies diaphragm Phrenic nerve Respiratory Cycle (What is the diaphragm doing?) Diaphragm contracts and moves downwards toward the abdominal cavity, which increases the volume of the thoracic cavity. This enlargement creates more space for the lungs to expand. When the diaphragm relaxes during expiration, it moves back to its dome-shaped position, reducing the thoracic cavity's volume and pushing air out of the lungs. Tracheal cartilage anatomy Arterial blood gas (Oxygen and CO2 normal values) PCO2 = 40 mm Hg PO2 = 100 mm Hg Exterior anatomy of lungs (pleural membrane layers) Breathing Patterns: Tachypnea abnormally fast, rapid breathing Breathing Patterns: Apnea temporary cessation of breathing, especially during sleep. Breathing Patterns: Bradypnea abnormally slow breathing rate Capacities of lungs (Vital, total, etc) (Picture) Tidal volume (TV) Amount of air inhaled and exhaled in one cycle during quiet breathing Inspiratory reserve volume (IRV) Amount of air in excess of tidal volume that can be inhaled with maximum effort Expiratory reserve volume (ERV) Amount of air in excess of tidal volume that can be exhaled with maximum effort Residual volume (RV) Amount of air remaining in the lungs after maximum expiration; the amount that can never be voluntarily exhaled Vital capacity (VC) The amount of air that can be inhaled and then exhaled with maximum effort; the deepest possible breath (VC = ERV + TV + IRV) Inspiratory capacity (IC) Maximum amount of air that can be inhaled after a normal tidal expiration (IC = TV + IRV) Functional residual capacity (FRC) Amount of air remaining in the lungs after a normal tidal expiration (FRC = RV + ERV) Total lung capacity (TLC) Maximum amount of air the lungs can contain (TLC = RV + VC) Internal vs. External Respiration Internal Respiration: exchange of gases between blood in systemic capillaries and tissue cells; blood loses O2 and gains CO2 External Respiration: exchange of gases between the alveoli of the lungs and the blood in the pulmonary capillaries across the respiratory membrane; pulmonary capillary blood gains O2 and loses CO2 Minute ventilation (show your work!) Minute ventilation = tidal volume x respiratory rate (normal is 4-6 L/min) Variables that effect/influence oxygen affinity for hemoglobin Hemoglobin affinity and oxygen saturation When more oxygen is present, a higher saturation of Hb can occur. There are several factors that can affect Hb saturation with oxygen: -Partial pressure of carbon dioxide -Temperature -pH -2,3-BPG (a by-product of glycolysis) -The makeup of Hb itself (fetal vs adult hemoglobin) o Hb is said to have been LEFT-shifted if it has a greater affinity than normal (stronger attraction to oxygen - so it is more likely to pick-up oxygen) o Hb is said to have been RIGHT-shifted if it has a lesser affinity than normal (weaker attraction to oxygen - so it is more likely to release oxygen) Antigen An antigen is any substance that the immune system can recognize and react to. It's often a foreign protein found on pathogens like bacteria and viruses, but can also be on other non-pathogenic substances. The immune system identifies these antigens as "non-self" and mounts a response against them. Epitope An epitope, also known as an antigenic determinant, is a specific part of the antigen that is recognized by the immune system. It's a small, specific sequence or structure on the antigen to which an antibody binds. Each antigen can have multiple epitopes, each capable of being recognized by different antibodies. Antibodies Antibodies are Y-shaped proteins produced by B cells of the immune system. They are crucial for identifying and neutralizing foreign objects like bacteria and viruses. Each antibody is specific to a particular epitope and can bind to it precisely, helping to tag the antigen for destruction or directly neutralize its harmful effects. Binding Sites An antibody has two identical binding sites located at the tips of its "Y" shape, where it can bind to the epitope on an antigen. These sites are highly specific and can bind to the epitope with high affinity, allowing the immune system to precisely target and neutralize specific pathogens or foreign substances. Function of WBC's WBC's identify, attack, and remove pathogens like bacteria and viruses, as well as clearing debris and damaged cells, thereby maintaining lung health and function. Natural Killer Cells (NK) large lymphocytes that attack and destroy bacteria, transplanted tissue, host cells infected with viruses or that have turned cancerous B-lymphocytes -produce humoral immunity -Activated B cells develop into plasma cells -Plasma cells secrete antibodies into the blood -Circulating antibodies produce humoral immunity -directly attack pathogens T-lymphocytes directly attack and destroy diseased or foreign cells, and the immune system remembers the antigens of those invaders and prevents them from causing disease in the future Perforins -kill cells in the same manner as NK cells -Polymerize a ring and create a hole in its plasma membrane Defensins -peptides in the skin that kill microbes -destroy bacteria, viruses, and fungi Interferons infected cell alerts neighboring cells to protect them from becoming infected Eosinophils -Phagocytize antigen -antibody complexes, allergens, and inflammatory chemicals -Release enzymes that weaken or destroy parasites Complement Proteins Aid in destruction of toxins and microorganisms Granzymes Granzymes are enzymes released by certain immune cells, like natural killer cells and cytotoxic T cells, that induce death in virus-infected or cancerous cells. Describe Complement System and what is does -a group of 30 or more globular proteins that make powerful contributions to both innate immunity and adaptive immunity -complement the action of antibodies -pathways to complement activation: classical: activates only after an antigen-antibody complex is formed and is part of adaptive immunity alternative and lectin: part of innate immune system and bind directly to tumor cells and pathogens without the need of antibody-antigen complexes -enhances chemotaxis, phagocytosis, inflammation, and the destruction of cells via membrane attack complexes Innate and adaptive immunity (primary and secondary response) (Igm vs Igg) Innate immunity is the body's first, non-specific defense against pathogens. Adaptive immunity, specific and with memory, has two responses: the primary response produces IgM antibodies for initial defense, while the secondary response, upon re-exposure to the same pathogen, rapidly produces IgG antibodies, offering longer-lasting protection. Antigen presenting cells (dendritic, macrophages, and their functions) Antigen presenting cells, like dendritic cells and macrophages, engulf pathogens, process their antigens, and present these antigens on their surface to activate T cells, initiating the adaptive immune response. Dendritic Dendritic cells capture antigens, process them, and present them to T cells, playing a key role in initiating the adaptive immune response. Macrophages -Phagocytize tissue debris, dead neutrophils, bacteria, and other foreign matter -Process foreign matter and display antigenic fragments to certain T cells alerting immune system to the presence of the enemy