BI 259 UNIT 2 Study Guide.docx

UNIT 2 Study Guide BI 259 A&P II \| Dr. Sabra Coop **Blood** & Cardiovascular System Functions of Blood - Transport: - Oxygen and nutrients - Metabolic waste - hormones - Regulation: - Body temperature - pH - Fluid volume - Protection: - P...

UNIT 2 Study Guide BI 259 A&P II \| Dr. Sabra Coop **Blood** & Cardiovascular System Functions of Blood - Transport: - Oxygen and nutrients - Metabolic waste - hormones - Regulation: - Body temperature - pH - Fluid volume - Protection: - Prevent blood loss: platelets and plasma proteins - Prevent infection: antibodies, complement proteins, and leukocytes (WBC's) Composition of Blood - Considered specialized connective tissue -- contains fibrous proteins - Living blood cells - called formed elements -- suspended in a nonliving fluid matrix called plasma - Formed elements = - Buffy coat: leukocytes and platelets - \ - Red pulp: - Location for RBC and pathogen are destroyed -- macrophages engulf them - Spleen Functions: - Site for lymphocyte proliferation and immune surveillance - Extract aged and defective blood cells and platelets - Macrophages remove debris and foreign matter - Recycles RBC products - Store platelets and monocytes - May be a site for erythrocyte production in fetus MALT: Mucosa-Associated Lymphoid Tissue - Lymph tissue located in mucous membranes throughout the body - Helps protect us from pathogens - Largest collections of MALT: tonsils, peyer's patches, and appendix - MALT also occurs in mucosa of respiratory and genitourinary organs, as well as digestive tract (GALT = gut-associated lymph tissue) Tonsils - Ring of lymphoid tissue around the entrance of the pharynx (throat) - Named according to location: - Palatine tonsils: posterior end of oral cavity - Largest and MC to be infected - Lingual tonsils: lymphoid follicles at the base of the tongue - Pharyngeal tonsils (Adenoids): posterior wall of nasopharynx - Tubal tonsils: surround auditory tubes into the pharynx - Follicles - Germinal centers surrounded by lymphocytes - Primary site for B cell maturation and antibody production - Tonsillar crypts: epithelium that form channels that go deep into the lymphoid tissue - Trap bacteria and particulate matter to be destroyed - Immune cells have memory for the trapped pathogens -- over time this gives a heightened immunity Peyer's Patches (aggregated Lymphoid nodules) - Similar to tonsils -- except they are located in the distal small intestine Appendix - Tubular offshoot of the 1^st^ part of the large intestine - Contains high concentrations of lymphoid follicles - Prevents bacteria from breaching intestinal wall - Generates many memory lymphocytes for long-term immunity Thymus - T lymphocyte precursors mature to become immunocompetent lymphocytes - Increases in size during 1^st^ year of life, then slowly atrophies after puberty - Thymus is Primary lymphoid organ (3 differences to secondary organs): - No follicles (lacks B cells) - Does not directly fight antigens (strictly maturation site) - Stroma consists of epithelial cells (instead of reticular fibers) **Respiratory System** - Major function: supply the body with oxygen and dispose of carbon dioxide -- this is done by respiration - 4 processes of Respiration: 1. Pulmonary Ventilation - - - 2. External respiration - O2 diffuses from the lungs to blood - CO2 diffuses from blood to lungs 3. Transport of respiratory gases - CVS transports gases using blood as transporting fluid - O2 is transported from lungs to tissue cells of the body - CO2 is transported from tissue cells to lungs 4. Internal respiration - O2 diffuses from blood to tissue cells - CO2 diffuses from tissue cells to blood - Cellular respiration = use of oxygen and production of carbon dioxide by tissue cells Respiratory system includes: nose (nasal cavity), paranasal sinuses, pharynx, larynx, trachea, bronchi, lungs, alveoli (diaphragm also considered part of RS) Respiratory System Zones - Respiratory zone: site for gas exchange - Bronchioles, alveolar ducts, alveoli, and microscopic structures - Conducting zone: respiratory passageways from nose to bronchioles - Conducts air, Cleanse, humidify, and warm incoming air Alveoli: Gas exchange -- simple diffusion across respiratory membrane: O2 passes from alveolus into blood, and CO2 leaves blood and enters alveolus. - Type II alveolar cells secrete surfactant and antimicrobial proteins Respiratory Physiology - [Breathing (aka pulmonary ventilation]) has 2 phases: - Inspiration = air flows into lungs - Expiration = gases exit lungs - **Volume changes cause pressure changes, which cause air to move** - Respiratory pressures described in relation to atmospheric pressure - [Intrapulmonary] (intra-alveolar) Pressure (Ppul) = pressure in the alveoli - Always wants to equalize with atmospheric pressure, this is the one used when discussing pulmonary ventilation - Intrapleural pressure (Pip) = pressure in pleural cavity - Transpulmonary Pressure (TP) = Ppul -- Pip: keeps lungs from collapsing Pulmonary ventilation ([Inspiration and Expiration]) - Volume changes cause pressure changes, which cause air to move - Boyle's Law: relationship between pressure and volume of a gas - at constant temperature, the pressure (P) of gas varies inversely with its volume (V) (example: car tire) - if volume increases, pressure decreases; if volume decreases, pressure increases - **Inspiration:** - **Expiration:**  Pulmonary Function Tests - Spirometry evaluates loss in respiratory function - Differentiates between obstructive pulmonary diseases (chronic bronchitis) and restrictive diseases (pulmonary fibrosis) - [Obstructive diseases] = TLC, FRC, and RV increase (lungs hyperinflate) - [Restrictive diseases] = VC, TLC, FRC, and RV decrease (limited lung expansion) - Force vital capacity (FVC) - Air expelled when a person takes a deep breath and forcefully exhales as much and as fast as possible - Forced Expiratory Volume (FEV) - Amount of air expelled during specific time intervals of the FVC test - FEV1 = air exhaled in 1 second - Healthy: 80% of FVC - Obstructive Diseases: \ - **External respiration** = pulmonary gas exchange, [effected by]: - Partial pressure gradients and gas solubilities: - O2 has steep gradient, diffuses rapidly into pulmonary capillary blood - CO2 only has 5 mmHg gradient difference - CO2 is 20x's more soluble in plasma and alveolar fluid - Thickness and surface area of respiratory membrane - 0.5-1um thick (very thin!) - The greater the surface area, the more gas can diffuse across in a given time period - About 40x's more surface area of lungs compared to our skin - Ventilation-perfusion coupling: see next slide - Ventilation = amount of gas reaching alveoli - Perfusion = blood flow in pulmonary capillaries - PO2 controls perfusion by changing arteriolar diameter - PCO2 controls ventilation by changing bronchiolar diameter - **Internal Respiration** = capillary gas exchange in body tissues - Partial pressure and diffusion gradients are reversed from external respiration and pulmonary gas exchange - Tissue cells constantly use O2 to make energy (ATP) and produce CO2 - O2 moves rapidly from blood into tissues until equilibrium is reached - Tissue PO2 is 40mmHg and systemic arterial blood is 100mmHg - CO2 moves rapidly from tissues into blood at the same time Oxygen Transport: - O2 is carried in blood in 2 ways: - Bound to hemoglobin in RBC's: 98.5% occurs this way - Hemoglobin has 4 polypeptide chains, each bound to an iron-containing heme group -- 4 molecules of O2 per hemoglobin - Oxyhemoglobin = oxygen attached to hemoglobin - Deoxyhemoglobin = hemoglobin that has released its oxygen - Dissolved in plasma: only 1.5% occurs this way, it is poorly soluble Carbon Dioxide Transport - Blood transports CO2 from tissue cells to lungs in 3 ways: - Dissolved in plasma (7-10%) - Chemically bound to hemoglobin (roughly 20%) = carbaminohemoglobin - 1 hemoglobin can carry up to 4 CO2 molecules - [Bicarbonate] (HCO3-) ions in plasma (roughly 70%): - CO2 enter RBC's quickly, so the conversion of CO2 to HCO3- happens inside RBC's (1000x's faster compared to in plasma due to carbonic anhydrase in RBCs). - [HCO3-] and H+ play a role in [regulating blood pH] - As CO2 enters the systemic bloodstream, it causes more oxygen to dissociated from hemoglobin ([Bohr effect]). The dissociation of O2 allows more CO2 to combine with hemoglobin ([Haldane effect)]