Lecture 6 & 7 Respiratory Flashcards
Why do we need to breathe?
Getting O2 to cells
Getting CO2 away from cells
Upper respiratory tract includes what?
Larynx
Stuff outside the chest is considered what?
Upper respiratory tract
The stuff inside the chest is considered?
Lower respiratory tract
Gas exchange involves?
Nasal cavity, pharynx (throat), trachea, airways in lungs, right n left lungs
Accessory structures, for the most part, don’t have direct contact with?
Air
Involved with helping MOVE THE AIR
Exception is oral cavity
You can breathe through your mouth but it doesn’t have the equipment to cause?
The air to be treated most efficiently
What are included in accessory structures?
Oral cavity, muscles that help move rib cage, and diaphragm
Diaphragm doesn’t have direct connection with ____, but it starts ____
Air, everything
functions we absolutely need to have respiratory system to work efficiently
Gas exchange
- Huge amount of surface area touching gas in lungs
- Huge amount of blood vessel surface area surrounding the air surface area
Ventilation
-Moving air in and out of the body
Protecting airways and gas exchange surfaces from hazardous chemicals, particles, dehydration
Production of sound
Chemical analysis of air (smell
Why do we have a ton of surface area in the lungs?
For gas exchange to take place
Major type of tissue lining large and medium sized airways
Pseudostratified ciliated columnar epithelium with goblet cells
Where does Pseudostratified ciliated columnar epithelium with goblet cells sit on?
Lamina propria
What is lamina propria
Thin layer of connective tissue
What do goblet cells do?
Secrete mucin
Mucin mixed with water created?
Mucus
When the goblet cells secrete mucus, we wind up with a layer of mucus on top of cilia…
When you breathe air in, it goes into the airways and as air starts to slow down, particles fall out and get stuck in the mucus
After particles fall on mucus, what does the muco ciliary escalator do?
Moves sheet of mucus
Cilia moves in one direction T/F
True
Cilia moves mucus and particles up towards?
Which causes you to?
Throat where you can cough it out or recycle
How can we digest mucus?
It is protein and water letting us digest it
There are not much that gets stuck in the mucociliary escalatory that can handle?
A pH of 1 so they go into the stomach to get digested
External structure of the nose is a framework to?
Put skin over
What do we have on the skin beneath and side of nose
Lots of sebaceous glands
Why would we want sebaceous glands beneath and side of nose?
- Protects skin when air dries it out while breathing
- protecting entrance to nasal cavity (Sebum is sticky and before we get air into nasal cavity, some particles before going in will get stuck on sebum)
Floor of nasal cavity and rood of oral cavity are?
The same thing
Hard palate involves two bony areas involving?
2 maxillae and 2 palatine ones
If the two hard palates fuse properly ___
Oral cavity is separated by nasal cavity
If the two hard palates do NOT fuse properly ___
they will have problems cuz swallowing involves pressure gradient
If there’s a hole in the nasal cavity ___
It’s easy for stuff to get into nasal cavity instead of back into the throat
- Increase likelihood of aspirating something you ate
If the two hard palates do NOT fuse properly, what does it also affect?
Development of speech
- a lot of sounds we make involve putting tongues on roof of mouth
The roof of nasal cavity has?
Olfactory epithelium that has chemoreceptors for smell and neurons that are going to get us a sense of smell
We have holes in cribriform plates in ethmoid bone, what gonna go in the holes?
Olfactory nerves NOT air
- last thing we want in brain is air
Cribriform plate is part of ?
Ethmoid bone
Structure of cribriform plate
Very thin and has a bunch of holes in it
Not very stable
If you hit someone in the nose, what happens?
Drive bony part of septum up into cribriform plate and fracture it
If very hard, you can drive cribriform plate up into the brain which can kill you
The outside of nostrils
Anterior or external nares (naris - singular)
Just inside external nares is?
Vestibule
Vestibule has some hairs coming from it that are called?
Vibrissae
Structure of vibrissae
Coarse hairs that have sebaceous glands associated in them
- sebum in them, they get sticky, they help filter out particles coming into nasal area
What else is on the vestibule?
Sweat glands
Why would you want sweat glands in vestibule?
Secretions from sebaceous glands are thin and when you add particles to that, it can get solid quickly and secretions from sweat glands thin it out and make it possible to get it out of nose
Nasal cavity divided into two areas by?
Nasal septum
Nasal septum has?
Bony portion and cartilage portion
Bones involved in nasal septum
Perpendicular plate of ethmoid bone, base of vomer bone, septal nasal cartilage, and vomeronasal cartilage
Where do all paranasal sinuses empty into?
Nasal cavity
When a person has a deviated septum, what does it do to the drainage?
Disrupt it
People who have deviated septum’s have recurrent ____
Sinus infections
Sinus infections can cause?
Chronic bronchitis
Why does the nasal cavity not have wide open space?
Important to respiratory function overall and for protection to gas exchange surfaces
Septum (bony and cartilage part) is covered by?
A mucus membrane
- has a large blood supply
Why do we have a lot of blood going into nasal septum?
Air has to move past blood, and the blood /moistness there of epithelium over septum helps warm incoming air and humidify it so it doesn’t dry out gas exchange surfaces and make them crack
Warming, filtering, and humidifying starts where?
Nasal cavity and into lungs
Trace pathway of air
Starts outside body, through external nares, into vestibule, air goes through all three meatuses simultaneously or one meatus, internal or posterior nares (space right behind conchae), beginning of pharynx (nasopharynx)
What are the 3 bones and spaces below the bones called?
Bones: superior/middle/2 inferior nasal conchae,
Spaces below: Inferior, middle, and superior meatus
Septum is pink to red, mucosa on conchae is pink to red but when we get to the roof ____
It is yellow because there’s a lymphatic plexus on rood of nasal cavity and epithelial cells with chemoreceptors
Function of nose
- Get air to and from lungs
- warm, filter, and humidify incoming air
- chemically examine incoming air
- conchae slow and stir air (more particles can fall out and get stuck to mucosa and get moved out of respiratory system)
- smell
What is another thing that protects gas exchange surfaces
Smell
- if you smell something that is unbearable or makes you cough, you go somewhere where stuff is not irritating respiratory tract cuz you don’t want to hurt gas exchange surfaces
Stirring the air makes our sense of smell ___
More effective
- if we can mix up all the air coming in through nasal cavity, we’re more likely correctly identify what’s in that air
What does Hb + O2 = HbO2 tell you?
Hemoglobin and oxygen can bind to each other and can separate from each other
In places where we have a high Po2 like lung capillaries, after gas exchange, we’re gonna blind…
Oxygen to hemoglobin to transport it
When you get to places where O2 levels are low, like systemic capillaries, what do you need to do?
I need to be able to drop off oxygen
Transporting oxygen is wonderful but not enough, what else do you need to do?
Deliver it so you can use the oxygen
When you get to places where PO2 is low, this is gonna reverse and free up oxygen, and what happens to the oxygen?
Oxygen will diffuse down its concentration gradient and into the cells that need it
If pH gets more acidic, instead of being 60% saturated at 20mm Hg PO2…
Now I need a higher po2 to get that oxygen to load
The more acidic it gets..
The harder it is to get the oxygen to attach to the hemoglobin
As we get acidic,
Globin chains will tweak their shape a bit making it harder for oxygen to get to the heme group
If we get a little basic, what happens to the saturation?
Now at 20mm Hg, I have a higher saturation
Your ability to bind and deliver oxygen is affected by?
pH
Someone who has poorly controlled diabetes and keto acidosis, how does it affect their hemoglobin?
It’s gonna have affect on their ability to load and unload their hemoglobin
What is another component that has an effect on this?
Temperature
Someone that has a fever, what happens to the loading of oxygen?
The easier it is to load oxygen because the colder you get, the harder it is
Temperature and pH affects hemoglobin how?
The shape and the ability to load and unload oxygen
Every 100 ml of plasma, there’s about 3/10ths of ml dissolved, basically that dissolved stuff is..
Stuff that’s moving into the capillary but hasn’t made it into the red blood cell yet or moving out of the RBC to diffuse to where gas exchange happens
What is the state of that dissolved stuff?
Transitional state
Each gram of Hb can carry around
1.34 ml of O2
If Hb is fully saturated, in 100 ml of blood, there is 20.1 ml of oxygen bound to hemoglobin which is how many times of oxygen?
60 more times of oxygen as it’s dissolved in the plasma
Which transport mechanism is the most important?
Hemoglobin
Since fetal hb has a higher affinity to o2 than adult, it makes it possible for…
For hemoglobin to bind up the loose stuff which will cause more to come off the adult hb so that fetal hb can bind to it
If fetal and adult hb has the same oxygen affinity ..
Then fetal wouldn’t get enough oxygen to grow and develop
What is the percentage of CO2 getting transported dissolved in the blood,plasma
About 10% of CO2
What is the second way that transported in the blood?
Carbamino compounds
What are carbamino compounds?
Is something where CO2 binds through a protein
Carbamino compound is the term you wanna use because?
It covers the sub two categories
What is subcategory #1?
Carbon dioxide bound to globin chains of hemoglobin inside RBC
What is subcategory #2?
Carbons dioxide bound to plasma proteins
Those two groups together are gonna carry somewhere between how much percent of CO2
20%- 25% of co2 that has to be transported in blood
CO2 binding to globin chains or plasma proteins is reversible T/F
True
Why is it reversible?
Just like oxygen, we need to be able to bind the carbon dioxide in places where we have high co2 levels, systemic capillaries,
And we need to be able to transport it to a place where we have lower CO2 levels like pulmonary capillaries
When CO2 comes off protein…
Then it can diffuse into alveolus and we can breathe it out
CO2 + H2O = H2CO3 = HCO3- + H+
- Water and CO2 combined using an enzyme called carbonic acid
- bicarbonate and free hydrogen ions
For respiratory, Carbonic acid is only found in
RBC
Carbonic acid is called a weak acid meaning?
Som of its molecules will lose hydrogen ions and others won’t
Between the dissolved CO2 and Carbamino compounds, that carries how much CO2
1/3 of CO2 that we need to transport in the blood
What happens to the other 2/3?
Carried by carbon
In places where you have high PCO2 like systemic capillaries, the CO2 being high,
I’m gonna put water together with CO2 to make carbonic acid
Where is carbonic anhydrase located?
Inside RBC
How can we hide hydrogen ion and bicarb?
Hb as some slightly negative areas on it, that will attract that hydrogen ion and Hb will buffer it. It’s not free anymore so it doesn’t contribute to the pH.
The problem still is that hydrogen binding it very weak, we don’t trust that and so what we will do is..
We want to get rid of bicarbonate and out of the RBC and put it in plasma that has more room. We also separated our hydrogen ion and bicarb
Bicarb has a negative charge T/F
True
The more bicarb I move out of RBC..
The more positive it starts to get inside the RBC
(You keep taking negative things out and it becomes les and less negative in there)
What happens eventually?
It will get so positive inside the RBC that I’m not gonna be able to move anymore bicarb in n out and then I have a problem
What is the chloride shift?
When I want bicarb to leave the cell, it goes out in exchange for a chloride ion coming in
(I move something negative out and I’m exchange for something negative coming in and now I no longer have a charge problem and I can move all the bicarb into the blood that I want)
Bicarb is outside the plasma, chloride is inside the cell and if you move chloride out then..
Bicarb comes back in so now I can set the conditions to make this run backwards so I get back to CO2 and that can leave and go into the lung
There’s a PO2 in the interstitial fluid that’s ____ than the PO2 in the capillary
Lower
The PO2 in the cell is even lower or higher
Lower
Oxygen is gonna go from the capillary into?
The interstitial fluid and into the cell and the cell is gonna use it
For the CO2, when we’re in the systemic capillary, the CO2 concentration is ____ in the cell
Higher
PCO2is ___ in the interstitial fluid
Lower
Where is the PCO2 lowest?
Systemic capillary
CO2 goes from the cell to?
Interstitial fluid and into the capillary
When you’re trying the get the CO2 back into pulm capillary, the co2 is?
The lowest
In the whole system, what has the lowest CO2
Alveolar air
Where is CO2 highest in?
RBC
No interstitial fluid due to?
In respiratory membrane, things are stuck together
Gas exchange: diffusing down the concentration gradient and no channels, no carriers, no help, just?
Just simple diffusion from higher to lower concentration
How do we control all of this?
By changing the amount we breathe
How do we change the amount we breathe..
By changing tidal volume, number of respirations I have per minute, and change both of them
What do we NOT change?
Resistance
We’re gonna adjust breathing, depth, or frequency by?
Adjusting how much or how often we contract the muscles that cause inspiration
In the medulla oblongata, we have 2 areas that are gonna be involved in controlling breathing
- Dorsal respiratory group (DRG)
- Ventral respiratory group (VRG)
Ventral respiratory groups is the part of the brain stem that controls?
Controls those muscles that trigger inspiration
The VRG is the?
Rhythm generator
(Thing that says breathe in now, out now)
By controlling diaphragm, and intercostal muscles and inviting friends to help out for big breaths in
What is the job of dorsal respiratory muscles?
To control the ventral respiratory
How does DRG do it’s job?
It gets information and integrate it and tell the VRG to speed up or slow down or not change
How is breathing controlled?
By CO2 levels and pH
If PO2 drops, and you want it to go up, should you breathe more or breathe less ?
More
When PO2 gets below a certain point, what does the brain do?
It tells you to stop breathing
What happens if you don’t breathe when PO2 gets low?
You die
Chemoreceptors are looking for changes in?
Chemicals
What are the chemoreceptors looking at?
What the PCO2 is and what the pH is
Where are the peripheral chemoreceptors
Right near the carotid baroreceptors
What are the peripheral baroreceptor most sensitive to?
Changes in PCO2
What is the peripheral baroreceptors second most sensitive to?
Changes in free hydrogen ions
Central chemoreceptors are located in?
The hypothalamus
Central chemoreceptors are most sensitive to?
Changes in hydrogen ion concentration
Central chemoreceptors are second most sensitive to
PCO2
What is the reason for the difference?
There’s a lot more protein in blood than cerebrospinal fluid
If you don’t have enough protein, what happens to pH?
The pH changes don’t get buffered
Spinal fluid is not buffered as well as blood T/F
True
This means that you are gonna see changes in?
hydrogen ions first
You see changes in hypothalamus before you would see them in
Peripheral ones
Both sets of chemoreceptors detect changes in?
PCO2 and pH
If PCO2 goes up, how are you gonna get rid of CO2?
Breathe more
If PCO2 is low,
You’re gonna breathe less
If you have a pH that is high, what does that tell you about the concentration of free hydrogen ions?
It’s low
High ph equals
Low hydrogen ions
What detects high PCO2?
Chemoreceptors detect
That information from chemoreceptors goes to?
Dorsal respiratory group
DRG will chew on this for a while and integrate other things that are going on and make decisions which will send the info to?
Ventral respiratory group
All we can do is
Breath more or less
What is the DRG gonna tell the VRG?
Increase respiration
More I breathe out, it will lower or rise PCO2?
Lower
Decreasing PCO2 will do what to the hydrogen ion concentration?
Decrease
Decrease of hydrogen ion will do what to pH?
Increase
pH and PCO2 move in opposite directions T/F
True
How do we transport most CO2?
Bicarb and H+
The more PCO2 I have, the higher?
Hydrogen ions are
PCO2 and hydrogen ions move in ?
The SAME direction
PCO2 and pH moves in?
OPPOSITE directions
The more CO2 I have, the more
Carbonic acid I make
The more carbonic acid I make,
The more free hydrogen ions I wind up with
If I lower the CO2, I lower?
Carbonic acid and hydrogen
If you put a bicarb and free hydrogen ion together, what happens to the hydrogen ion?
It isn’t free anymore so it can’t contribute to lowering the pH
What is the Hering Breuer Reflexes?
Get info from stretch receptors and when the stretch receptors get too stretched, the signals they’re sending inhibit the inspiration muscles and you automatically breathe ojt
Blocking any further inspiration and making you breathe out, what happens to stretch
Decreases the stretch and you don’t damage lungs
If there’s not enough stretch on stretch receptors, what will it trigger?
Contraction of inspiratory muscles
Now we use Hering Breuer inspiratory Reflexes because?
The smaller the lungs get, smaller alveoli get and the harder they get to open
This is only important in? And why
Very early in life before we have fully functional chemoreceptor loops
What else let’s us control breathing?
Cerebral cortex, highest level control
What type of muscles lets us breathe in and out?
All skeletal muscle
Under voluntary control
Choosing not to breath in happens at? (Singing, talkin)
Cerebral cortex controlling muscles that control breathing
If you hold your breath for too long, what happens
The voluntary control will be overridden by the chemoreceptor reflex, if PCO2 gets too high, the DRG doesn’t care what you want to do, you will breathe.
What are the miscellaneous things that control breathing?
Sudden painful stimulus
What does Sudden painful stimulus produce?
Reflex apnea
(Putting ice cube down your back)
Longer painful stimulus cause?
Faster and deeper respiration
What triggers chocking reflex?
Irritation of the larynx or pharynx by something touching it or fumes for chemicals
What goes into a choking reflex?
Temporary apnea
Why do you get temporary apnea?
If something is irritating throat, either physically or chemically, you will want to get away from that thing before you breathe again
What does the choking reflex also help you avoid?
Aspirating food or liquid
For respiratory system especially at gas exchange in the lungs to work effectively, what do you need?
Ventilation perfusion matching
What is ventilation perfusion matching?
I have an alveolus, and a capillary that we pass, what I need for this to work at it’s best is to have air going into alveoli that have blood going to the capillaries
If you have air coming in but no blood,what happens?
Im wasting air
If I have blood coming in with the alveoli, the alveolus isn’t getting air delivered to it, what happens..
Wasting blood
Blood coming back from venous side of circulation where blood is moving more slowly and blood is likely to clot, it goes through right side of heart and into lungs.
The lungs can act as?
Filters for some of those smaller blood clots
How does elastic recoil help with breathing?
It stretches and return to its resting size to help keep blood moving through diastole
Alveoli, chest wall, and diaphragm also have elastic recoil T/F
True
Helps us breath out
What is the opposite of elastic recoil?
Compliance
When talking about compliance, what are we talking about?
How much the pressure in something changes depending on how much volume we put in it
For our lungs to properly, we have to have a balance between?
Elastic recoil and compliance
Having too much elastic recoil happens in a?
premature baby
Elastic recoil in a premature baby
The alveoli, because they have elastic and surface tension, they get small really quickly
- no problem breathing out but crazy amount to breath in
Compliance happens in someone who has?
Emphysema
How can you tell someone has emphysema just by looking at them?
Barrel chest and well developed neck muscles
- they have to breathe out actively
In emphysema, the alveoli..
Is bigger than they should be and they don’t have any elastic recoil
At one end where you have too much elastic recoil, you have?
No problem at all breathing out but way too much work breathing in
At the other end where you have too much compliance, you have?
Work to breath out and you’re also gonna have higher residual volume which means when you breath in, you’re not gonna be able to get much air in bc there’s already so much air in your lungs to begin with
