Anatomy Physiology II Final Exam New Material 1 What is Dalton s law of partial pressures what is a partial pressure Dalton s Law of Partial Pressure the partial pressure of a gas is the amount of pressure exerted by one gas on a entire mixture of gases 2 What gases make up the atmosphere and what are their partial pressures Nitrogen 79 Oxygen 20 9 Carbon Dioxide 0 04 Water H2O in gas form vapor 0 4 3 How does respiration occur based on the pressure of gases Respiration only occurs if there are differences in partial pressure between air in alveoli and blood Oxygen will move from areas of high partial pressure to low partial pressure Ventilation gets the air into the alveoli then it relies on partial pressures of substances to get them across the membrane and into the blood At sea level Air 152 mmHg PO2 PCO2 0 3 mmHg Alveoli 104 mmHg 40 mm Hg Blood by alveoli 100 mmHg 45 mmHg Blood by tissues 40 mmHg 45 mmHg Tissues below 40 mmHg above 45 mm Hg Both O2 and CO2 move from areas of high partial pressure to areas of low partial pressures therefore oxygen goes in and carbon dioxide goes out Partial pressure in the tissues varies based on the needs of the cells during exercise partial pressure of oxygen will decrease to about 10 mmHg and carbon dioxide will increase to about 100 mmHg because you are using a lot of oxygen and producing a lot of carbon dioxide Why isn t the partial pressure of oxygen the same in the alveoli as it is in the air Dead space traps both air going in and air going out Gases you are trying to eliminate use the same tubes as gases you are trying to get in 4 How is oxygen transported in body 98 is bound to hemoglobin oxyhemoglobin 2 is dissolved in the blood plasma 5 How is carbon dioxide transported in the body 23 is bound to hemoglobin carbominohemoglobin 7 is dissolved in the blood plasma 70 is in the form of carbonic acid H2CO3 CO2 H2O byproducts of respiration in mitochondria H2CO3 leaves cell as carbonic acid When carbonic acid enters blood is splits into HCO3 bicarbonate and H The free hydrogen moves into the red blood cell and binds to hemoglobin hemoglobin carries the hydrogen to make sure it doesn t do anything bad At the same time sodium and chloride gets shifter between red blood cell and plasma sodium goes into plasma and binds with HCO3 to produce sodium bicarbonate Red blood cells that contain HHb and blood plasma with NaHCO3 all travel to the lungs As soon as they get to the lungs sodium lets go of the bicarbonate and goes back into the red blood cell and the H lets go of the hemoglobin and exits the red blood cell H and HCO3 recombine to produce carbonic acid again The carbonic acid gets pushed into the alveoli where is splits back up into H2O and CO2 You exhale and release CO2 and H2O Carbon dioxide and water can t travel in the blood so they combine together to form something else in order to be transported in the blood 6 What is the oxyhemoglobin saturation curve and what factors might cause it to change and what are the results of these changes The oxyhemoglobin saturation curve shows the amount of O2 that is bound to hemoglobin every 1 Hb molecule can carry up to 4 O2 molecules Altitude body temperature and pH levels can change saturation and cause the curve to shift Altitude as you travel to higher altitudes Hb saturation decreases because PO2 is less there is less O2 in the air so less in blood Body temperature 1 if body temperature increases PO2 decreases Hb saturation decreases 2 if body temperature decreases PO2 increases Hb saturation increases pH levels 1 if pH increases less acidic PO2 increases Hb saturation increases 2 if pH decreases more acidic PO2 decreases Hb saturation decreases What is exercise s effect on oxyhemoglobin saturation When you exercise body temperature increases and pH decreases due to the production of carbonic acid and lactic acid in the blood therefore Hb saturation decreases The drive for respiration during exercise is related to getting CO2 and H out NOT related to wanting O2 in It is easier to get oxygen in than it is to get carbon dioxide and hydrogen out because hemoglobin can carry up to 4 molecules of oxygen at one time but only 1 molecule of carbon dioxide During exercise CO2 increases and H acidity increases which signals an increase rate in unloading of O2 in After exercise heart rate is elevated and falls slowly body stops making excess CO2 and H so unloading tissues which results in a decrease in Hb saturation decreases and saturation increases to above 98 7 What is the function of the respiratory centers in the brain Respiratory centers located in the medulla of the brain can make you breath faster or deeper by further inducing bronchiomotion Dorsal group back of medulla responsible for normal breathing Sends messages to the phrenic nerve Phrenic nerve innervates the diaphragm and induces respiration Part of normal breathing when body needs O2 Ventral group front of medulla responsible for forced breathing Sends messages to all accessory muscles obliques abs intercostals These muscles all contribute to forced breathing like during exercise 8 What are the apneustic and pneumotaxic centers and what is their role Apneustic and pneumotaxic centers are responsible for breathing rate and depth Apneustic center Responsible for depth Engaged during exercise Inhibited by the pneumotaxic center you can t breath deep and fast and speed always trumps depth Pneumotaxic center Responsible for breathing rate Engaged during exercise Inhibits the apneustic cetner 10 What are the functions of the urinary system Disposal of metabolic wastes and ions Regulation of blood volume how much blood you have regulates plasma and RBC concentrations Regulation of RBC production by secretion of EPO Production of the enzyme Renin which is responsible for regulating blood pressure Converting vitamin D into an active form so it can be used for RBC production 11 Know the role of the components of a nephron and their role in urine formation i e where filtration reabsorption and secretion occur and how Fluid enters through the afferent tube and enter the glomerulus and filtration begins Capillaries in the glomerulus are fenestrated meaning they contain pores that allow molecules to leave blood stream and enter Bowman s capsule that surround the glomerulus Molecules like glucose and protein are too large to pass through capillary pores therefore they won t enter Bowman s capsule and won t be found in urine although their building