IB Biology: Ventilation

12 flashcards · Other · by Gabrielle Wong

  1. Ventilation: the process of respiration, gas exchange, and cellular respiration

  2. Important asepcts of alveoli structure:

    Alveoli are sacs in lungs surronded by capillaries, the locaation of gas exchange Millions of alveoli in lung to increase SA for gas exchange Thin, single-layer walls for easy exchange of materials Blood capilarries with similar cells - minimal distance needed for gas to travel Type II Pneumocyes that produce a surfactant so oxygen can dissolve and diffuse and to decrease surface tension

  3. Mechanism of breathing

    Increased CO2 due to cellular respiration Threshold is reached Chemoreceptors detect Medullar oblongta sends nerve signals Nerve signals lead to contraction of diagphragm and external intercostal muscles Diagphragm moves down, pushing abdomen out, leading to a volume increase and pressure decrease Decreasing pressure creates a vaccum, leading to inspiration Stretch receptors sense the increase in volume, stopping the process Opposite muscle movement occurs Volume decreases, increasing pressure…

  4. Antagonistic muscles: muslces that come in pairs (when one contracts, the other relaxes)

    Example: Diaphragm and abdominal muscles are a pair

  5. Intercostal muslces: muscles that move the thoriac cavity, made of external and internal muscles

    External intercostal muscles: inhalation, expand volume of chest cavity Internal intercostal muscles: invovled in exhalation, decrease volume

  6. Emphysema

    Condition in which alveoli are destoryed throug hteh creaiton of irregularly shaped holes Caused by smoking tobacco/cannabis, manufacturing fumes etc. Leads to reduced SA for gas exahcne, damaging airways leading to alveoli No cure - mitigate risk by not soking, medication can provide relief, but eventually an oxygen tank is necessary

  7. Lung cancer

    Uncontrolled cell growth (tumor) in the lungs, prone to metastasis Caused by carcinogens, destorys lungs, may lead to internal bleeding, can be treated but has a high mortality rate

  8. Chemosensors: found in aorta and cartoid arteries to detect increases of CO2 and subsequent decreases in pH, which then send signals to the medulla oblongta, which will increase the rate of breathing

    The mechanism of breath doesn't change, just the frequency of the process

  9. pH buffering: the mechanisms that lead to the maintenacne of pH within the range of 7.35-7.45

    Temporary binding to hemoglobin Bound to proteins as solutes in plasma

  10. Mountain sickenss: a result of air pressure decreasing, leading to less efficient diffusion of oxygen into alveoli, causes fatigue, vision problems, higher pulse

    Some adaptions that occur as a result of living at a higher altitude: Larger lungs Increased capillaries Increased levels of hemoglobin and myoglobin

  11. Oxygen dissociation curves: patterns that explain how attracted molecules are to oxygen depending on the partial pressure of oxygen

    There is a curve for: Hemoglobin Myoglobin (muscle protein with a higher affinity for oxygen, only releases it in low-oxygen conditions to prevent the onset of lactic acid fermentation) Fetal hemoglobin (similar pattern as myoglobin allowing fetus to access oxygen from mother)

  12. Bohr shift: hemoglobin has a lower affinity for oxygen at higher concentrations of CO2

    Occurs because hemoglobin changes its shape when bound to CO2, decreasing its ability to retain O2