Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Physiology Topic 13
Respiratory System
| Question | Answer |
|---|---|
| Describe what Boyle's law is | As volume increases, pressure decreases (for a given # of same molecules) |
| What is Patm at sea level? | 760mmHg |
| T or F Ppul in between breath is equal to Patm? | T |
| T or F in a healthy body Ppul is always less than Pip? | F opposite, Ppul always greater than Pip |
| What is holding the lung and thoracic wall together? | Fluid in the pleura, like pulling to panes of glass apart |
| Describe the four stage process of quiet inspiration | 1.) Diaphragm, external intercostal muscles contract, increase the volume of thoracic cavity 2.) As they contract lungs resist expansion so Pip decreases 3.) Dif in Ppul and Pip pushes lungs outward, expanding them 4.) Air flows in down P gradient |
| Along with the diaphragm and external intercostal muscles what other muscles are involved in forced inspiration? (3) | Sternocleidomastoids, pectoralis minors, scalenes |
| T or F quiet expiration is an active process? | F it is a passive process, no energy required all we are doing is relaxing muscles that were contracted during inspiration |
| What muscles contract during forced expiration? | Internal intercostals and abdominals |
| Stretch in the lungs is determined by 2 things what are they and what are the 2 things that aid these processes? | Compliance and recoil both aided by the presence of elastic CT and surfactant |
| What is a pneumothorax? | When air gets into the pleural cavity, so that all pressures equal out, thoracic wall's volume increases but lung isnt dragged along with it because no pressure gradient |
| What is surfactant in what is its purpose? | Lipoprotein/phospholipid mixture, coats the alveoli reducing surface tension allowing easier stretch of lung and preventing alveolar collapse |
| What happens when there are low levels of surfactant within the lungs? | Compliance of lungs (alveoli) greatly decrease taking a lot more effort to breathe leading to exhaustion and then death |
| How do we calculate air flow? | difference pressure (Patm - Ppul) divided by the resistance |
| What determines the resistance of air flow? | Diameter of bronchi/bronchioles |
| T or F SNS is responsible for dilating the bronchioles and PSNS contracts them? | T |
| What is tidal volume (TV) measuring? | Inspired or expired air during quiet respiration (average about 500ml) |
| What is inspiratory reserve volume (IRV) measuring? | Excess air over TV taken in on a max inspiration (average about 3000ml) |
| What is expiratory reserve volume (ERV) measuring? | Excess air over TV pushed out on max expiration (average about 1200ml) |
| What is residual volume (RV) measuring? | Volume of air lungs after max expiration (average about 1200ml) |
| How do we calculate minute respiratory volume? | Tidal volume x Respiratory rate (500ml x 12 breaths per min = 6L air/min on average) |
| T or F FEV1 is measuring the volume of air expired in 1 second after a max inspiration? | T |
| What is inspiratory capacity (IC) measuring and how do we calculate it? | How much total volume air can we fit in our lungs at once Calculated by TV + IRV |
| What is vital capacity (VC) measuring and how do we calculate it? | Largest volume of air in/out of lungs Calculated by TV + IRV + ERV |
| How to we measure our total lung capacity (TLC) | TV + IRV + ERV + RV (= VC + RV) |
| What is an obstructive disease and give 3 examples | Constricts airways on expiration Emphysema, asthma, cystic fibrosis |
| What is a restrictive disease and give 2 examples | Restrict lung expansion (inspiration) Scoliosis, pneumothorax |
| What two things are occurring during external respiration? | O2 from alveoli are going into blood CO2 in blood is going into alveoli to be expelled |
| What 3 factors aid external respiration? | Thin respiratory membrane Large surface area on capillaries and alveoli Blood velocity slow compared to gas diffusion (because RBC are moving so slow they have ample time to pick up gases) |
| What is occurring during internal respiration? | O2 from blood to cells CO2 from cells to blood |
| What is Po2 in the atmosphere? | 160mmHg |
| What are the 2 ways that oxygen is transported in the blood? | 1.5% transported free in the plasma 98.5% transported on hemoglobin |
| What is Po2 after being deposited from the alveolus into the capillary? | 95mmHg |
| What is the Po2 within the ISF? | 40mmHg |
| What is the Po2 within the average cell? | Less than 40mmHg |
| How many iron can bind to a single hemoglobin, why? | 4 O2 per Hb, this is because the iron bind to the Fe within the Hb and there are only 4 iron within the Hb |
| T or F the max amount of O2 saturation that can occur is only 97% not 100%? | T |
| Where is the plateau range on the Hb saturation graph, between what mmHg? | 60mmHg - 100mmHg = plateau, very little change in Hb saturation |
| At rest (ISF Po2 = 40mmHg) what percentage of O2 is unloaded to cells if hemoglobin is fully saturated? | 22%, this answer is given by the O2-Hb dissociation curve |
| What is occurring during the plateau section of the O2 Hb dissociation curve? | This is occurring around the Po2 range of 60 - 100mmHg O2 from the lungs is being loaded into the blood and thus onto the hemoglobin down its pressure gradient |
| What is occurring during the steep section of the O2 Hb dissociation curve? | This is occurring around the Po2 range of 0 - 60mmHg O2 from the lungs O2 on the hemoglobin within the blood is being offloaded into the cells down there pressure gradient |
| What is happening as the O2 Hb dissociation curve is being shifted to the right? | For a given Po2 we get less Hb saturation, O2 is unloaded more easily and not loaded as easily |
| What 3 factors contribute to moving the O2 Hb dissociation curve to the right, what is normally the cause for the curve shifting to the right? | Increase in Pco2 and temperature and decrease in blood pH These things usually occur during higher levels of cellular metabolism (exercise) |
| What is the Bohr effect describing? | It is stating that as the pH of the blood decreases (increase of CO2 and H+ within blood) it is harder for O2 to bind to the hemoglobin (or vice versa) |
| What 3 factors contribute to moving the O2 Hb dissociation curve to the left? | Decreased levels of Pco2 and body temperature and higher pH |
| What 3 ways is CO2 transported in the blood and what % is transported in each way? | 8% dissolved in plasma 20% bound to hemoglobin 72% as bicarbonate |
| Durning internal respiration what is the path CO2? | ICF Pco2 = >45mmHg ISF Pco2 = 45mmHg Arterial Pco2 = 40mmHg CO2 flows from cell to ISF to artery down its pressure gradient |
| During external respiration what is the path of CO2? | Resting arterial Pco2 = 45mmHg Alveolar Pco2 = 40mmHg CO2 flows from the artery into the alveolus to be expelled down its pressure gradient |
| What is resting venous Pco2 during internal and external respiration? | Internal = 45mmHg External = 40mmHg Just think these are measured after the processes of both internal and external respiration occur, so think of what those processes are |
| T or F CO2 binds to deoxyHb better than oxyHb? | T |
| T or F arterial RBCs contain more Cl- ions? | F venous blood contains more Cl- as it is participating in the chloride shift so that bicarbonate can be exported from the RBC without changing the charge of the RBC |
| Describe the process of CO2 being transported as bicarbonate (HCO3-) | CO2 diffuse out of cell to ISF and then ISF to RBC, the CO2 binds to H20 in the RBC, carbonic anhydrase combines them into H2CO3 (carbonic acid), this spontaneously dissociates into HCO3- and H+ this is process is then reversed so that CO2 can be expelled |
| What part of the body is responsible for setting the rate, depth, and rhythm of your breathing? | Respiratory centres within the medulla |
| What are the functions of the VRG and DRG neurons in terms of breathing? | VRG = sets the rate of breathing, VRG neurons innervate the in muscles for inspiration and expiration DRG = receives info from chemoreceptors in blood and modifies VRG output |
| What nerve innervates the diaphragm? | Phrenic nerve |
| What nerve innervates the external intercostals? | Thoracic nerve |
| T or F inspiratory neurons fire on muscles to contract and cause inspiration while expiratory neurons fire on those same muscles to relax? | F tricky but F, expiratory neurons fire on the inspiratory neurons and inhibit them which cause relaxation of the muscles causing the inspiration which causes them to expire the inhaled air |
| T or F VRG neurons are also active for forced inspiration and expiration? | T help recruit the extra muscles needed |
| T or F respiration may cease if the VRG neurons become damaged by alcohol or morphine? | T |
| What is the function of the pontine respiratory centre? | Works with medullary respiration centres to make breathing smooth, damage to this = gasping and extremely irregular breaths (in, in, in out, in, out, out) |
| What is the Hering-Breur reflex? | Describing the reflex that prevents over inflation of the lungs |
| How does the Hering-Bruer reflex work? | Stretch receptors in lung detect that they are overstretch and send impulses via the vagus nerve to VRG (inspiratory) neurons which inhibits them causing them to relax and expel air and preventing over inflation |
| T or F if your medulla is damaged you must actually remember to breathe even when you're asleep? | T |
| T or F you can hold your breath so long that you die? | F medulla will eventually overide voluntary control and cause you to breathe |
| Where can you find peripheral and central chemorecptors? | Peripheral = aortic and carotid bodies Central = medulla oblongata |
| There are 2 instances where peripheral chemoreceptors will increase the ventilation rate, what are they? | Respond to bloods pH decreasing, if too low will increase vent rate (takes large change of pH to trigger this) Can be triggered when the Po2 gets below plateau region (below 60mmHg) |
| What 2 things factors can contribute to low levels of Po2? | Lung disease and or low Patm |
| What do central chemoreceptors respond to? | They respond to Pco2 within the brain and CSF, CSF has a poor pH buffer and so the set point for Pco2 is very narrow |
| How does hyperventilation cause dizziness? | Hyperventilation causes a decrease in arterial Pco2, this triggers cerebral vasoconstriction which in turn decreases the Po2 within the brain causing dizziness |
| What does hypoventilation cause and how does it cause it? | Hypoventilation results in an increase of arterial Pco2 and therefore an increase in H+ (acidosis) changing the pH causing the brain to not work properly |
| Why is CO poisoning so deadly? | CO binds to Hb 210x more strongly than O2 this results in less O2 binding to Hb therefore less transportation of O2, not only that because the Po2 and Pco2 hasn't changed within the body the brain does nothing to stop ventilation allowing more CO in |
Created by:
McWhinnster