chegg physio

FVC (functional vital capacity) vs. FEV1 (forced expiratory volume in one second)

- FVC: Forced vital capacity is the amount of airthat can be exhaled from the lungs after taking the deepest breath possible - One of the important uses of FVC is to help distinguish obstructive lung diseases, such as asthma and COPD - FEV1 is the maximal amount of air you can forcefully exhale in one second. - FEV1 is one of the most common indices used to assess airway obstruction. - In restrictive lung disease, both forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) are reduced

vital capacity vs. residual volume of lungs

- Vital capacity (VC) is the maximum amount of air a person can expel from the lungs after a maximum inhalation. - A healthy adult will have a vital capacity between 2 and 5 liters. - Residual volume of lungs (RV) is the amount of air that remains in a person's lungs after maximum exhalation. - both are measrured using a spirometer - RV prevents the lungs from collapsing. Even after we have expelled as much air as possible also prevents the inner surfaces of the lungs sticking together.A

%PaO2 vs. %SaO2

-PAO2 or the partial pressure of oxygen, is the pressure exerted by oxygen on the arterial walls -Oxygen saturation or SAO2 is the overall percentage of hemoglobin binding sites occupied by oxygen. -Dissolved oxygen concentration affects PAO2. -Number of available oxygen binding sites affects SAO2. -PAO2 and SAO2 can be used to measure respiratory efficency

Your body is built on the principle of supply matching demand - quite a reasonable idea. One such example is the oxygen delivery by the cardiovascular system, which needs to match oxygen demand by systemic tissues. This is achieved by two separate mechanisms: active hyperaemia and changes in oxygen-haemoglobin binding affinity. Elaborate how local regulation fine-tunes each mechanism to match blood oxygen transport to local metabolic demand for oxygen. (I strongly recommend you use of a diagram of a capillary bed in the former case, and a graph for Hb-O2 dissociation in the latter.

1) Hyperamia( The increase of blood flow to different tissues in body) When tissue increase in activity, theres a fall in PO2 and PH and increase in PCO2. - increased in metabolic activity of tissue leads to local increase in extracelleular conc. of CO2, and lactic acid and decrease O2 and PH. This will cause a vasodilation.Decrease of Resstance in wall of caps will allow for increase flow towards target tissue. This will help match the metablic demand. 2. O2 HB dissco curve. Hb molecule only binds to 4 O2 molecules. Saturation of O2 in blood will acount for how much O2 will be transported to your other tissues How to increase affiinity? - lowering PH, shifting curve - increase temprature shifts curve to right and vise versa with cold

PART A Your favourite uncle suffers from emphysema, pulmonary hypertension, and pulmonary oedema. This is all a result of his 30 years of daily cigarette smoking. Emphysema entails loss of alveoli in lungs, whereas pulmonary oedema involves accumulation of fluid in alveoli. Explain how each of these two factors affects your uncle's rate of gas exchange across the airblood barrier.

Alveoli is the medium through which gas exchange occurs. These are single cell structures in the terminal portions of lung. Three processes are essential for oxygen exchange between air and blood flowing through the lungs: ventilation, diffusion, and perfusion. Ventilation is the process by which air moves across the lungs. Diffusion is the spontaneous movement of gases, without the use of any energy, between the alveoli and the blood in the capillaries in the lungs. Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs In emphysema, since there are less alveoli, there is less gaseous exchange. In Pulmonary edema, since there is fluid accumulation, ventilation is impaired and hence less gaseous exchange.

respiratory muscle activity in inspiration vs. expiration

INSPIRATION - Active proccess - Contraction of external intercostals - relax internal intercostals - Diahphram contracts and flattens - strernalcleidmastoid contracts to elevate sternum Expiration - Passive proccess - relax of external intercostals - contract internal intercostals - diaphram relax

PART C On one graph (pressure on y-axis, volume on x-axis), draw two examples of the work loop performed by the right side of the heart: one for a healthy human adult, and another for a smoker with pulmonary hypertension. Assume the stroke volume is the same for both. How does work performed by the right ventricle compare between these two cases? Explain.

Pulmonary hypertension will cause hypertrophy of right ventricle because more amount of work will be done by the right ventricle to pump blood in the pulmonary trunk because there will be greater resistance in the pulmonary trunk.

A friend of yours is trying to sell you the idea of "de-acidifying your body". She says that you should only drink "miracle water", which is certified acid-free and has a pH of 8.0. Your friend offers to sell you this "miracle water" at a BFF discount of $10/L. She guarantees it'll boost your energy level and make you look younger, or your money back! You are not convinced but, like any curious physiologist, decide to try and expose the hoax. You drink 1L of "miracle water" along with a big dinner and... You are no longer thirsty, but not sure you feel any different than after a regular dinner. You test your blood plasma pH and find it has risen from 7.4 (pre-dinner) to 7.5 (post-dinner). Can you ascribe this rise in your blood plasma pH specifically to imbibing "miracle water"? Explain your reasoning.

The blood pH is rises after drinking miracle water due to presence of some ions like sodium in that water due to alkaline nature of sodium pH rises.

PART B Your uncle always lugs around a pressurised canister, which bleeds pure oxygen at a low flow rate via tubing hooked up to his nostrils. Why? How does this affect his PaO2? Would extra oxygen improve blood oxygen transport in a healthy human? Why?

These increase the PaO2 and help assist laboured breathing. This is because at room air oxygen saturation (21% saturation), less amount of oxygen is carried by the haemoglobin, whereas when low flow oxygen (100% oxygen saturation) is introduced haemoglobin is better able to carry oxygen, and hence better breathing.

PART C: But your friend is not giving up. She argues that "miracle water" allows you to maintain a higher concentration of ATP in muscle fibres, and therefore must make you stronger. Explain to her (nicely, please) that this argument is just a "load of bulls***" from the perspective of force generation at molecular level of muscle function.

these are the functions of ATP at molecular level of muscle function as(1) Its hydrolysis by an ATPase activates the myosin head so it can bind to actin and rotate; (2) Its binding to myosin causes detachment from actin after the power stroke; and (3) It powers the pumps that transport calcium ions from the cytosol back into the sarcoplasmic reticulum.

You decide to have a little fun with your gullible friend. You tell her that her "miracle water" has actually made your blood acidic. What can you do to turn your arterial blood (slightly) acidic on short notice (in approx. 1 min), in case your friend asks you to test your blood pH right in front of her? Explain. (Hint - use the dissociation equation for carbonic acid.)

when the pH of arterial blood is high then kidney starts releasing bicarbonate ions so it maintain the environment slightly acidic as bicarbonate ions dissociate into carbon dioxide and hydrogen ions.