Notes on gas exchange

Question 1

The main part of breathing is to make sure you have oxygen and to make sure we get the waste out as efficiently as we can

Question 2

Primary function of respiration is to remove waste and add oxygen

Question 3

How can hypoxemia occur?
Hypoventilation
____________diffusion of gases
Inadequate circulation of blood through the pulmonary capillaries
Mismatching ventilation and perfusion

Answer 3

Impaired

Question 4

Mismatch of ventilation and perfusion: we are not bringing in or our ventilation isn’t good enough…we are not bringing enough air into our lungs to give it to the blood that’s there or the blood isn’t there but the oxygen is

Question 5

What is one example of a disease that can cause ventilation difficulties? _________, COPD, __________

Answer 5

Asthma, cystic fibrosis

Question 6

What is an example of a disease that has perfusion difficulties? Pulmonary hypertension,____________

Answer 6

Heart failure

Question 7

Any space you can’t use in your lungs is going to limit your lung capacity

Question 8

If we have too much CO2 we start to see a decreased pH and this is called ______________

Answer 8

respiratory acidosis

Question 9

______________ caused by too much CO2

Answer 9

Respiratory acidosis

Question 10

If respiratory acidosis is caused by too much CO2 what is the respiratory alkalosis caused by?

Answer 10

not enough CO2

Question 11

(((Shunt: blood is able to go from one side of the heart to another without passing through respiratory system)))

Question 12

How could blood move from the venous to the arterial side of circulation without passing through the lungs? There’s a hole in the heart…that’s our anatomic shunt…we have unoxygenated?? blood moving back to the circulation

Question 13

One of the most important things for gas exchange for diffusion is _________…the more area we have that connects the alveoli the capillaries the more likely gas exchange is to occur and it needs that surface area

Answer 13

surface area

Question 14

Remember it’s a passive process we go from high levels of oxygen to low and high levels of CO2 to low from the blood into the lungs and lungs out of the blood so the more space you have the easier it is for that to occur…this is in a high pressure or high volume process it really depends on space so if aveoli get inflamed for example its harder to breathe

Question 15

What is it called when the alveoli get inflamed?

Answer 15

pneumonia

Question 16

The thicker they are the harder it is for diffusion to occur
Partial pressure of the gases (moving from high pressure to low pressure…the greater the
differences the better gas exchange is going to be)

(Solubility and molecular weight of the gas)

Question 17

(Diffusion occurs passively and whats happening is your going from high amounts to low amounts so the greater the difference in those partial pressures the more oxygen in the lungs versus in the blood the more likely oxygen is to move versus in the blood the more likely oxygen is to move from one to the other and is trying to get to homeostasis again. The less carbon dioxide that’s there and more carbon dioxide that’s in the blood the more likely carbon dioxide is to leave…so the greater those differences the higher the pressure versus the lower the pressure and the more exchange occurs because the closer that is to equilibrium the less exchange occurs because its just going from high amounts to low amounts

Question 18

Disorders of the pleura

We have a number of things that surround our organs…one of these is called the pleural space and this is a membrane space that exists to help protect the lungs and give them a chance to expand and contract and protect them in some ways so any collection of fluid within this cavity that surrounds the lungs whats that going to do you have a space its kind of protective and you start to fill it what does that do what do our lungs have to do first of all expand and contract is it harder to expand if your being covered by water or blood?

Any collection of fluid in this pleural cavity that surrounds the lungs makes it harder for the lung to expand…makes it harder to breathe…lungs have to work a lot harder to expand if there is an increase pressure that is pressuring them to collapse

________=fluid

Hemothorax=hemo is going to mean blood

Pneumno is air

Pleuritis is inflammation

Answer 18

effusion

Question 19

Atelectasis
Lungs need to expand and contract and its able to do that with pulmonary surfactant and if you lose this its harder for lungs to expand and contract and you can have a partial lung collapse due to it.
Asthma can be triggered by pollen and dust and cause bronchiole to overrespond so hyperresponsiveness and they will constrict even tighter and inflammation occurs in the area which will contribute to making it harder to get air through so all of these combinations are making bronchioles tighter and your inflaming them and constricting them and makes it difficult to breathe and get air in…prevalence is increased…asthma is becoming more common in children

Question 20

What does extrinsic mean?

External factor

Question 21

Extrinsic Asthma: Allergen comes in and mast cells come through…mast cells release things like histamine,leukotrienes and then inflammation cells try to get involved as well…releasing cytokines and interleukins and other mediators these inflammatory cells lead to inflammation
Mast cells also start to cause bronchospasm which is another fancy way of saying constriction

Question 22

Bronchospasm is the same thing as bronchoconstriction

Bronchospasm the airways constrict and make it difficult to get air in and that makes airflow limitations

Question 23

Airway inflammation is inflaming whats there is adding fluid,addng responsiveness causing other things to get in the way of oxygen flowing and we have more airway inflammation. The other problem that occurs with this inflammation is there is more things there to respond so as the airways become inflamed…inflammatory mediators now they will start to respond to those allergens even more its almost like a positive feedback loop we are going to end up getting more response to the allergens and this increases airway responsiveness leads to more bronchospasm leads to more airway limitation

Question 24

So early phase comes on and it may not be as bad so this late phase kicks in and makes it worse
These asthma attacks gets worse like it starts off kind of small and your able to cut it off with a rescue inhaler or inhaler before it progresses to the late stage where it kind of kicks it up a notch

Question 25

Intrinsic asthma can be due to heavy _________,respiratory tract infections,hormonal changes

Answer 25

exercise

Question 26

Classifications of Asthma Severity

Mild intermittent-doesn’t happen often and when it does its mild
Mild persistent-still mild but its happening a lot its probably interfering with life a lot more so that intermittent would be
Moderate persistent-interfering with life and its happening a lot
Severe persistent: we are looking at recurring hospitalization
Asthma has a big scale of severities

Question 27

Emmanel, age 5 has had asthma for the past 2 years. He lives in an old worn down apartment thats dirty from the urban, dust,cockroaches, and mold.

One evening his mother poured him some milk and put him to bed. Shortly afterward, Emmnanuel woke up wheezing and coughing. As he gasped for air, he became more and more anxious.

Emmanuel’s skin became moist with sweat, and he began to tire, his wheezing became quieter. His mother called 911 and waited anxiously for the ambulance to arrive

Answer:
Exhalation becomes difficult with pronounced ____________, bronchial edema, and increased mucus production.

Air trapping becomes a problem, and it takes an increased amount of energy to overcome tension in the lungs

The recruitment of the accessory muscles generated dyspnea and fatigue.

Answer 27

bronchospasm

Question 28

Why does someone with severe asthma become physically fatigued during a prolonged attack? If your not able to breathe you don’t have enough oxygen you start to tire and then the lung rate starts to slow down and that’s what gets more worrisome but its physically draining to have an asthma attack it takes a lot of oxygen your body is trying to respond for the lungs to be working as hard as they are eventually they tire they cant keep up especially as the amount of oxygen they get lowers

Exhalation becomes difficult with pronounced bronchospasm (as the lungs get tighter they need to work harder and harder to pump the air out. Air trapping becomes a problem and then the muscles that are being involved with all the pumping start to fatigue

Question 29

What are the effects of hypercapnia on the central nervous system? What happens if you have too much CO2? You start to tire and you start to get sleepy
Hypercapnia has a ____________ effect

Answer 29

sedation

Question 30

COPD is linked to smoking…early signs of the disease are generally absent. If symptoms are absent in early stages you may not know there is a problem so by the time this is discovered its usually pretty advanced

Question 31

What happens in the bronchial wall is inflamed? decrease ___________

Answer 31

decrease gas exchange

Question 32

What does fibrosis do? decrease _______

Answer 32

elasticity

Question 33

Fibrosis causing scarring…replacing lung tissue with scar tissue and now that tissue doesn’t work and its just taking up space

Question 34

COPD leads to decrease ___________ and decrease breathing

Answer 34

respiration

Question 35

Chronic obstructive bronchitis is usually called COPD instead

Question 36

There are differences between emphysema and chronic obstructive bronchitis

COPD has features of both emphysema and chronic obstructive bronchitis

Question 37

Major sign of pulmonary emphysema characteristic is often dramatic _________and you can detect through decreased _________________…normal blood gases until late in disease process, slowly debilitating disease

Answer 37

barrel chest, breathing sounds

Question 38

Normal adult has a chest where the transverse diameter is about ½

Barrel chest expands downward and outward so you can see increase in lungs its looks like a barrel within the chest and it goes down further and expands out and its one of the signs they look for to see that somebody may soon suffer from emphysema its an anatomical change

Question 39

Age of onset in chronic bronchitis is earlier and you do have an early symptom of ____________ and there’s often this dramatic cyanosis, hypercapnia and hypoxemia may be present, and Numerous life-threatening episodes due to acute exacerbation and this is more dangerous and end up more likely to be in a hospital having life threatening issues and it occurs earlier on and one of the things you see here is this dramatic look of skin starting to turn blue(cyanosis), polycythemia (increase in red blood cells), frequent cor pulmonole (right sided heart failure)

Answer 39

shortness of breath

Question 40

What is cyanosis? Skin turning ________

Answer 40

blue

Question 41

Cystic fibrosis is a fairly common genetic disorder that shows up in the respiratory and major issues and causes of death tend to be difficulty in breathing sometimes people with cystic fibrosis are able to get a lung transplant….Caused by mutations in the cystic fibrosis transmembrane regulator CFTR which is a chloride channel in these cells and with that not working properly there’s this fluid buildup which makes it difficult to breathe…life expectancy use to be teens but now its in the 30s and 40s…this is an area where they are looking at gene therapy to try and cure this

Question 42

Cystic fibrosis

Causes: pancreatitis, excessive loss of ________in the sweat

Answer 42

sodium

Question 43

Pulmonary circulation
Pulmonary artery is the only artery in the body that carries unoxygenated blood so it is pressurized but its pretty low pressure

Question 44

Bronchial circulation arises from __________

Answer 44

thoracic aorta

Question 45

When talking about pulmonary circulation we are talking about moving blood to the lungs to get oxygenated

Question 46

Bronchial circulation is what supplies the lungs with the oxygen it needs to do its function

Question 47

______________ is any sort of blood borne substance that gets into the pulmonary arteries and stays there

Answer 47

Pulmonary embolism

Question 48

If you have a blood clot that’s in your veins what happens with the veins if something branches off think about blood flow so if you have a clot and that clot starts to move through the bloodstream and if it’s the veins its going from smaller to bigger to bigger to biggest when it comes to the blood system

Question 49

Veins are collecting so smaller goes to bigger to biggest and it goes to the vena cava eventually and it goes back to the heart where does it finally get small again? Pulmonary capillaries for gas exchange so it goes to the pulmonary artery then it goes to the smaller aspects of the artery

Question 50

(Skip this slide because its shorter in the powerpoint notes)

Anything that occurs in the veins its going to be an emboli that’s traveling through….the places its going to get stuck is the lungs so when we talking about deep vein thrombosis…anything venous causes tends to be lung…its in the arterial system..it can be other organs because that’s being oxygenated blood and its going smaller and smaller till it gets to capillary and it gets lodged…here its almost primarily the lungs where things go so primarily pulmonary embolism is due to anything that accumulates in a vein and it starts being brought back in to circulation…three major places this comes from the first is a clot…if you break a born one of the things that can happen is if some fat breaks off and starts traveling through the blood is that it can end up causing an embolism of fat..third one is amniotic fluid which can be worried about during the birthing process…if amniotic fluid somehow gets into a vein…it can lead to a pulmonary embolism as well

Question 51

3 major types of pulmonary embolism are thrombus,fat, and amniotic fluid

Question 52

Pulmonary circulation…we don’t want to move blood through this too quickly we just want it to move through but we want the gas exchange to occur

Question 53

Hypertension most often occurs secondary and there’s another reason why the hypertension is there…sometimes its COPD…we are not getting enough oxygen in so the body is responding by trying to move blood through more quickly to try to get a better response

Question 54

Thromboembolic disease (if you start blocking some of the area you have a higher pressure due to traffic build up

Question 54

Right sided heart failure so we will talk about heart failure in detail again when we get to cardiac system…one of the ways it can occur if its there is a problem with the lungs then its like a traffic jam almost where is the blood going to have to go where does it back up to the right side of the heart so cor pulmonale can be right sided heart failure resulting from lung disease and sometimes if you have hypertension there and in the lung and your not able to move as much through as you would expect and there’s too much blood staying in the heart…the heart can start to expand and the heart cannot pump as accurately as it should and you end up getting heart failure

Question 54

If the lungs aren’t working it can cause heart failure on the right side of the heart,wherever the blood backs up and it can lead to that heart to fail and its kind of cast cads

Question 54

Signs of secondary hypertension
Shortness of breath,__________,edema,ascites, and signs of right sided heart failure

Answer 54

tiredness