Final-Chapter 13 Respiratory Physiology Flashcards
What is the difference between internal respiration and external respiration?
Internal Respiration is equal to cellular respiration and use of O2 and production of CO2 within mitochondria. While external Respiration is equal to the exchange of O2 and CO2 between atmosphere and body tissues or a way to get oxygen from atmosphere into your body.
Describe external respiration?
- Pulmonary Ventilation is breathing. All individual gasses diffuse down concentration or pressure gradient. Oxygen flow out of air into your lungs because pressure is higher in the atmosphere than in
your lungs. - Gas exchange between lungs and blood is done via diffusion. Gas moves down pressure gradients, oxygen moves into the blood and CO2 leaves.
- Transport of O2 and CO2 in blood to tissues.
- Gas exchange between blood and tissues via diffusion.
What are the parts of the respiratory system?
- Alveoli are located at the very end of the lungs surrounding by capillaries;. Alveoli are leaky allowing O2 to leave and CO2 to enter, this is where gasses get exchanged from lungs and blood. They are little balloons that inflate.
- The diaphragm runs directly under your lungs. Whenever you inhale the diaphragm contracts, gets shorter, and moves toward feet. The chest cavity gets bigger, allowing lungs to expand. When you exhale diaphragm relaxes putting more pressure on the lungs.
- Upper airways are the air passages in head and neck.
- Pharynx is the tube for both air and food.
- Respiratory tract is the air passages form pharynx to lungs. It is the conducting zone that moves air from larynx to lungs, humidifies and warms air (thick walls). The Respiratory zone is the actual sight of gas exchange (thin walls).
Describe the anatomy of the Alveoli.
Alveoli have very thin walls and are surrounded by capillaries. They are leaky to O2, CO2, and this makes them ideally suited for gas exchange. Thinness of alveolar wall facilitates gas exchange. High density of alveoli and capillaries creates lots of surface area for gas exchange. Two things that make them ideally suited for diffusion of gas into and out of the blood stream are the very thin walls and very lots of them. Alveoli and capillaries have very thin walls. There is also a high density of each in the lungs, both which help with O2/CO2 diffusion. Thin wall means they have to diffuse a short distance. Alveoli do die.
What is breathing?
Breathing consists of inspiration and expiration. Inspiration is inhalation, the process of getting oxygen into your lungs. And expiration is exhalation, getting CO2 out of your lungs.
What are the mechanics of pulmonary ventilation?
Contraction of breathing muscles changes the volume of the lungs and alveoli. These volume changes create air pressure gradients between outside air and alveoli. These air pressure gradients also drive the movement of air into and out of the body. Pressure gradients is when more oxygen in atmosphere than in your lungs. One of the ways to lower the amount of pressure in your lungs, i.e to get more oxygen moving in to lungs, is by increasing volume of your lungs because a increase in volume means a decrease in pressure. When you inhale, these external intercostal muscles and diaphragm, they contract. Chest gets bigger so volume increases. When you exhale, these muscles relax unless coughing or choking. Chest gets smaller and volume decreases and pressure increases and CO2 leaves as well, this forces air in and out of your lungs. Air moves from high pressure to low pressure.
The pressure outside needs to be higher than in our lungs for inhalation and vice versa for exhalation. We do this by changing the volume of our lungs.
What is Boyle’s law?
Boyle’s law is based on the Ideal Gas Law: P=nRT/V. There are the same number of molecules in each container, but the bigger container will have a lower pressure than the smaller container. Increase volume, gas pressure decreases. And i you decrease volume, gas pressure increases. Same thing happens in our lungs-Increase in pressure means inspiration and decreases in pressure means expiration.
Describe the airflow in the lungs.
Driving force for air movement during breathing (pulmonary ventilation) is the difference between atmospheric pressure and alveolar pressure. It moves from area of high concentration to low. Air flow is equal to atmospheric pressure minus alveolar pressure divided by resistance[mechanical]. Atmospheric pressure is generally the same and resistance asks are you choking, i.e. is something blocking your airway. We can only manipulate alveolar pressure.
For a normal person in a room, atmospheric pressure and resistance is about the same and is constant. No resistance means nothing is blocking airways.
What is the difference between inspiration and expiration.
Inspiration occurs when inspiratory muscles contract and increase volume of alveoli and alveolar pressure decreases or becomes less than atmospheric pressure.
Expiration occurs when inspiratory muscles relax (and in forceful exhalation, expiratory muscles contract) and decrease volume of alveoli which increases alveolar pressure and becomes more than atmospheric pressure.
Describe gas exchange in the lungs.
Total pressure of gas mixture is the sum of pressures (partial pressures) of individual gases that make up gas mixture. Gases move down their partial pressure gradients from higher pressure to lower pressure (naturally without energy). Breathing forces air into your lungs, but doesnt force O2 into your blood. This is where pressure comes into play again.
More O2 in your lungs, less O2 in the blood: blood flows into the blood.
Describe the direction of CO2 and O2movement across respiratory membrane.
Across respiratory membrane, at the alveoli and where it meets capillary, inside of alveoli surrounding it is a capillary, there is more CO2 in your blood than there is in the alveoli. Because cells are producing CO2 from cellular respiration. This is deoxygenated blood. This is pulmonary circulation. CO2 will leave blood and go to alveoli. Blood in capillaries is low in O and this is why O2 flows into the blood. It is based in how much is there. Low on O and high in CO2.
What is partial pressure?
Partial pressure of a gas is the fractional concentration of that gas in gas mixture X total gas mixture pressure.
WHat is the partial pressures of oxygen and CO2.
In the air, outside of lungs. PO2 is about 160 an CO2 is .3. Alveolar air, air in your lungs PO2 is 100. Higher in atmosphere, oxygen enters alveoli. CO2 in alveoli compared to atmosphere is very high. CO2 leaves. Pulmonary artery is carrying deoxygenated blood from the heart to the lungs. Low on O and high on CO2. PO2 is 40. PCO2 is 46. Pulmonary vein very high in O = 100 and very low on CO2 which is 40. This is oxygenated blood and pumped back to left side of heart and delivers blood to all cells in the body and picks up CO2 from them.
Describe gas exchange in tissues.
Moves out of aorta to every cell in the body.
Once blood is to systemic capillaries it diffuses from high to low.
What is hypernea?
Hypernea is the physiological increase in alveolar ventilation to match increased demand by tissues. Alveolar ventilation can be increased by increasing volume or frequency of breaths or both. This happens anytime you’re breathing hard. So when exercising, having a panic attack, etc. Increased amount of O2 delivered to cells. You can take more breaths or deeper breaths. This is a compensating mechanism; not a bad thing.
