BIOL 251 1st EditionExam #4 Study Guide Lectures: 18-231. Name one airway that is composed of cartilage-Trachea or bronchi 1. Circle which is greater: intrapleural pressure or intralveolar pressure 1. Briefly describe the events of inspiration that allow you to get fresh air into your lungs. -Respiratory muscles contract -Volume of chest cavity increases -Volume of lungs increases -Pressure in lungs drops below atmospheric pressure -Air moves down pressure gradient from environment into lungs 1. CO2 is converted into HCO3- and H+ inside the red blood cells. HCO3- then diffuses out of the red blood cells and __Cl-__ diffuses into the red blood cells to restore the electrical gradient. The H+ remaining in the red blood cells bind to __Hb___ 1. Fill in the following blanks using one of the following words (each word may be used once, more than once, or not at all): large, small, pulmonary, tissue, left, right, more, less A small change in Po2in the tissue capillaries results in a _large__ change in % Hb saturation. Increased metabolism _right___ shifts the Hb-oxygen saturation curve, which is functionally significant because it mean Hb is __more__ effective unloading oxygen in the tissue capillaries. 1. Fill in the following blanks using one of the following words (each word may be used once, more than once, or not at all): glucose, phosphate, urea, Cl-, actively, passively, pressure, electrical, chemical, osmotic __Glucose___is reabsorbed using a Na+ dependent secondary active transport that is poorly regulated, whereas _phosphate__ is reabsorbed using Na+ dependent secondary active transport that is tightly regulated. Cl- ions__passively__ follow the __electrical__ gradient of Na+; water molecules follow Na+ using a(n) __osmotic___ gradient 1. If the hypothalamic osmoreceptors detect that you have too much salt per volume of water (i.e., you are hypertonic), ___vasopressin_______ is released which cause the kidneys to reabsorb more water. This can result in an unintended and hazardous increase in your__blood pressure___ 1. Fill in the following blanks, using one of the following words or phrases (each word orphrase may be used once, more than once, or not at all): electrical, concentration, pressure, moves passively, is actively transported, does not move, more, less The primary purpose of the loop of Henle is to maintain a _____concentration__ gradient in the renal medulla. In the ascending loop, water ___does not move____ across the membrane, andNa+ __is actively transported___ across the membrane. In the collecting tubule, in the presence of vasopressin, water ___moves passively__ across the membrane, and Na+ __does not move__ across the membrane, resulting in a __more__ concentrated urine 1. What is one cause of metabolic acidosis, what chemical change occurs in this situation, and how do the lungs respond to this situation?-Severe diarrhea, diabetes, strenuous exercise, renal failure-HCO3- reduced-Lungs blow off CO2 1. The most precise regulation of ventilation occurs viaa) peripheral chemoreceptors that monitor PO2b) peripheral chemoreceptors that monitor PCO2c) peripheral chemoreceptors that monitor H+d) central chemoreceptors that monitor PO2e) central chemoreceptors that monitor H+ 1. Alveolar ventilation is what is truly important, what is the equation?-alveolar vent=(tidal vol-dead space) x respiratory rate 1. Before the start of inspiration, how is the pressure gradient?- the intra-alveolar pressure=atmospheric pressure 1. The bronchioles, and alveoli respectively, are surrounded by..-pulmonary capillaries 1. How are deeper inhalations achieved?-more forceful contraction of inspiratory muscles and with help form accessory inspiratory muscles to enlarge the chest cavity further 1. How does air move in and out of the lungs?-via pressure gradients between the lungs and the environment. Air flows in and out of the lungs by reversing pressure gradients between lungs and the environment. 1. How does intra-alveolar pressure work with breathing?-Whenever intra-alveolar pressure does not equal atmospheric pressure, air will move down its pressure gradient until intra-alveolar pressure equals atmospheric pressure. 1. How does intrapleural pressure work?-the pressure exerted outside the lungs within the thoracic cavity. Usually just less than intra-alveolar pressure and atmospheric pressure, averaging about 756mm Hg. Since the thoracic cavity is closed to the outside, air can not move down the pressure gradient into thoracic cavity. 1. How does respiration work?4-by changing the volume of the chest cavity, which changes the volume of the lungs, which changes the pressure in the lungs, and then air moves along its pressure gradient 1. How much air remains in the lungs after maximal expiration?-1200 ml 1. How much of the 500 ml of inspired air is actually useable for gas exchange?-only 350 ml of the 500 ml 1. In external respiration O2 and CO2 are exchanged between…-alveoli and blood 1. Scientific term for throat-Pharynx 1. Thinness of walls of each alveolus and huge surface area of all alveoli greatly facilitates what?-diffusion of gases 1. What aids in the transport of O2 and CO2 between lungs and tissue?-Blood 1. What are the six other functions of the respiratory system?-route for water loss and heat elimination-enhances venous return-helps maintain acid base balance-enables vocalization-defends against inhaled pathogens-removes and modifies materials passing through pulmonary circulation 1. What are the walls of the bronchioles composed of?-type 1 alveolar cells 1. What areas of the brain are involved in breathing?-medullary respiratory center and apneustic and penumotaxic centers in pons of brain stem 1. What causes bronchoconstriction?-parasympathetic stimulation 1. What causes bronchodilation?-sympathetic stimulation 1. What do bronchi branch into?-bronchioles; made of flexible smooth muscle1. What does the apneustic and penumotaxic center in pons of brain stem regulate?-regulate action potentials in inspiratory neurons to ensure smooth breathing 1. What does the trachea split into?-right and left brochi 1. What forms the floor of the chest cavity?-the diaphragm 1. What happens at the onset of inspiration so that the thoracic cavity enlarges?-the diaphragm contracts 1. What happens to the intra-aveolar pressure as the thoracic cavity expands, forcing the lungs to expand as well?-the intra-alveolar pressure drops because there is now a greater volume in the lungs