Exam 3 - Lecture 6 Flashcards
If starting at FRC, we take a VT breath, what is our new alveolar volume?
3.350 L
(3L + 350mL of alveolar air)
PAO2 fluctuates depending on where in the ____
respiratory cycle we are
Going to be higher during inspiration, lower the longer we get away from inspiration.
If we have a PAO2 of 100mmHg at the end of inspiration, how many mL of air is oxygen in the lungs?
100/760 –> 13.16% O2
(.1316) x (3.350L) = 0.395 L
Of the 0.395L of oxygen in the lungs at end of tidal volume, how much is used per minute? how does that equate to length of breath holding?
The body only uses 250mL/min, so that is why we can hold our breath from 1.5 - 2 minutes, because we have more than 250mL of oxygen in there.
A 30-year-old healthy man is scheduled for elective surgery. He is preoxygenated with 100% oxygen before induction of anesthesia. At baseline, he is upright, breathing room air, and at rest. His functional residual capacity (FRC) is approximately 3.0 L, and his pulmonary venous PO₂ is 100 mmHg.
Which of the following best approximates the volume of oxygen available in the lungs at the end of a normal expiration?
A) 210 mL
B) 315 mL
C) 395 mL
D) 440 mL
E) 525 mL
C
100/760 = .1316
.1316 x 3L = .395L
.395L = 395mL
this is the correct amount for end of a normal EXPIRATION
The previous example from class included alveolar volume of 350mL because it was at the end of INSPIRATION.
A 65-year-old man is undergoing general anesthesia for abdominal surgery. He is preoxygenated with 100% FiO₂ while in the supine position. His functional residual capacity (FRC) is reduced to 2.4 L due to body habitus and position. After preoxygenation, the PAO₂ reaches 663 mmHg. His tidal volume is 500 mL, of which 150 mL is anatomical dead space.
Assuming complete mixing and equilibration, what is the best estimate of the total volume of oxygen in the lungs at the end of inspiration?
2.4L + .35L = 2.75L
663/760 = ~.87
.87 x 2.75L = 2.399L or 2399mL
A patient has a hemoglobin of 10 g/dL, SaO₂ of 88%, and PaO₂ of 60 mmHg. What is their total arterial oxygen content?
11.972mL O2/dL
ABG shows a PaO₂ of 55 mmHg. Hemoglobin is 11.5 g/dL, and total arterial oxygen content is estimated to be 11.5 mL O₂/dL.
What is the arterial oxygen saturation?
55 x .003 = 0.165mL/O2/dL
11.5 - 0.165 = 11.335mL/o2/dL is BOUND
if that’s how much is how bound, and their Hb is 11.5
(11.5) x (1.34) x (?) = 11.335mL/O2/dL
To finish, 11.5 x 1.34 = 15.41
11.335 divided by 15.41 = .7355
Final answer = ~73.6%
What’s the arterial sat?
Hb = 14.2g/dL
PaO2 = 51mmHg
Total arterial oxygen content = 13.7mL/O2/dL
51 x .003 = 0.153
13.7 - 0.153 = 13.547
14.2 x 1.34 = 19.028
13.547 / 19.028 = 71.2%
Fresh inspired air should dilute the CO2 in the lungs by a factor of _____
4 mmHg
When PAO2 is 100mmHg, the O2 concentration is
13.16%
100/760 = .1316
The right lung is _____, ______, and has __________ than the left lung.
heavier, larger, and has more volume
Left lung is taller or shorter than the right lung, and why?
Taller. Heart sitting on central tendon of diaphragm causes it to depress lower than right lung.
Pleura on lung itself
visceral pleura
Pleura on inside of chest wall is
parietal pleura
What are the 2 fissures on right lung?
Horizontal and oblique fissure
Horizontal separates superior and middle lobe
Oblique separates middle and inferior lobe (at a goofy angle and off-kilter)
How many segments does the right lung have?
Left?
10; 8
What is a potential space?
Pleural space
What is the space between the top of the diaphragm and side of ribcage called?
Costodiaphragmatic recess
If we had any air or vacuum in the diaphragm, where would it be?
Costodiaphragmatic recess
where does the diaphragm bind to?
L1/Base of thorax at vertebral spinous processes
How many scalene muscles are there?
6 total; 3 on each side.
What muscles are used to take a deep inspiration?
obviously diaphragm, then scalene muscles and exterior intercostal muscles
What do the anterior scalene muscles bind to?
C3-C6
What do the middle scalene muscles bind to?
C3-C7
What do the posterior scalene muscles bind to?
C5-C7
What helps stabilize the thorax and hold it in place during stress?
Pec major and minor
Which pec is deeper and smaller? which is big and superficial?
minor;major
Pectoralis minior is at ____ and binds to _______
top of rib cage and binds to coracoid process in shoulder blade and ribs 3-5
what muscle do you use when you put your arms on the table and lean forward to inspire greater than normal?
Pectoralis minor
What are the abdominal muscles used for forceful exhalation?
Rectus abdominis and Oblique
Where is the sternocleidomastoid and where does it bind?
The exterior muscle along your neck, binds to mastoid process behind the ear and the midline sternum
The intercostal muscles each have ___ connection points which gives them a combined __
2;4?
Role of external intercostal muscles
rib cage/thorax gets pulled out by 2 connections helping with inspiration
Role of internal intercostal muscles
Compress thorax closer together to midline, helping with forceful exhalation
What are the IRV muscles?
External intercostals and scalene muscles
Pharynx has 3 parts and is considered _____ airway
Nasopharynx, oropharynx, larynx; upper airway
What is part of the pharynx and is attached to the trachea?
Larynx
“The larynx is the part of the pharynx that attaches to the trachea”
Why does the patient “choke” when paralyzed?
The tongue and mouth muscles are skeletal muscles, so when paralyzed the tongue will “fall back” and occlude the larynx b/c skeletal muscles become flaccid
What is special about the nasal cavity bones?
Very porous for rich blood vessels to flow and hangout in to help provide moist and rapid heat/humidification
Increased risk of fracture
how much air goes through the nose and mouth?
50/50
Whats another name for conchae?
turbinates
why are conchae curved?
To generate turbulence in the nose, which helps air bind to mucous and filter out dust and pollen since they are large molecules.
What can the nose not filter?
smoke, too small of molecules
3 concha are
superior, middle, inferior.
What bone do the superior and middle concha come off of?
Ethmoid bone
What bone does the inferior concha come off of?
Maxillary bone (hard palate)
Whats the most stable concha to follow for nasal intubation?
inferior concha
Whats the most curved concha?
Inferior concha
How many sinuses do we have?
4 pairs (8 total)
What are the 4 pairs of sinuses?
Ethmoid, maxillary, frontal, sphenoid
What connects the falx cerebri to the ethmoid bone?
Crista Galli
What is CN V?
trigeminal nerve - sensory of face
What are the 3 branches of the trigeminal nerve?
Opthalmic (forehead), maxillary, mandibular (anterior 2/3rds of tongue somatic sensation
Whats the nerve that senses “brain freeze”
trigeminal
fix this by putting tongue here and warming up nerve
Whats good for drugs lmao
vascular nose
Where do olfactory neurons reside?
Cribriform plate of ethmoid bone
3 main nerves for oral/nasal cavity
V, IX, X
What does CN V innervate?
trigeminal: oropharynx, upper back behind nose
What does CN IX innervate?
Glossopharyngeal: Back of oropharynx, anterior portion behind epiglottis.
What does CN X innervate?
Vagus, back of oropharynx, laryngopharynx (larynx), trachea, epiglottis.
The pharyngeal anatomy consists of
hard palate, soft palate, uvula, palatine tonsils
Whats the reason most people snore
soft palate hanging down, its posterior to hard palate.
Where are the palatine tonsils?
back of tongue behind the uvula
Where are the pharyngeal/adenoid tonsils and if enlarged what do they cause?
In the nasopharynx, and it can push the soft palate forward and make the airway difficult to access
What tonsils hang off base of tongue between tongue and epiglottis?
Lingual tonsils
other than the nose what other structure did he mention has a high vascular?
Salivary glands
We have 3 sets of salivary glands called
Sublingual, submandibular, parotid gland (?)
What glands are most known for swelling in the face if you get hit?
Parotid
The glosspahryngeal nerve covers what part of the tongue for taste
back 1/3rd
What nerve covers taste for anterior 2/3rds of tongue
Facial nerve: CN VII
Whats the voice box?
Larynx
The larynx is held up by
connective tissue
Whats the most superior portion of larynx
Epiglottis (projects off back of tongue)
When youre swallowing, what moves back and down, and what moves up?
epligottis; larynx
What is the floating bone that is easy to break with a KARATE CHOP (from the front..)
hyoid bone (attaches cartilage and muscle)
If youre >10 years of age, the most narrow part of your airway is
transglottic space (between vocal cords)
If youre <10 years old, the most narrow part of your airway is
cricoid cartilage
Cricoid pressure is used to prevent
aspiration, its a continous ring so it will press back on esophagus
Whats a con of utilizing cricoid pressure?
Can blow out esophageal sphincters d/t increased pressure
What is used to reposition tongue via hooking and sweeping vallecula?
mac blade
What is the largest cartilage in larynx?
thyroid cartilage
Thyroid cartilage pushes ____ down and ____ up.
trachea; hyoid
What allows for movement of thyroid cartilage to pivot down? And what does it connect?
Cricothyroid joint; thyroid and cricoid cartilage.
What are the unpaired cartilages?
cricoid and thyroid, epiglottis.
what are the paired cartilages?
arytenoid, corniculate, cuneiform
The cricoid cartilage have 2 facet for
the inferior horns of thyroid cartilage.
The cricoid cartilage have 2 other articular facets for ___ to help with phonation and attach to vocal cords.
arytenoid cartilage
what cartilage have laminae?
Cricoid and thyroid
How long are the cords on an acoustic guitar?
3.5 feet, higher pitch.
Women have ___ vocal cords and ___ pitch voice.
short; high
Whats the adams apple called and what is important about it
laryngeal prominence, vocal cords attach here.
What sits next to thyroid lamina (2 of them)
thyroid gland…
Where does the hyoid bone connect to on thyroid cartilage?
Superior horns (2 of them)
Where does the cricothyroid joint connect to?
Inferior horns (2 of them)
What is the little appendage on the end of the arytenoid cartilage?
corniculate cartilage
Laryngeal muscles have __ sets.
6 sets (12 total)
What is responsible for contraction of thyroid cartilage, tightening vocal cords and pulling front of thyroid cartilage down?
Cricothyroid muscle.
the cricothyroid muscle is the most ___ laryngeal muscle and connects _____ to the thyroid cartilage.
external; cricothyroid cartilage
