TT2 Flashcards
(91 cards)
1
Q
Why dont Amoebas need lungs
A
They are very small so simple diffusion of gasses through the cell membrane is enough
2
Q
What are the 4 functions of the respiratory system?
A
- Transfer of gases between air and blood 2. Regulation of body pH 3. Defence from inhaled pathogens 4. Vocalisation
3
Q
What muscles are involved in inspiration
A
Sternoclleido mastoids Scalenes External costals Diaphragm
4
Q
What muscles are involved in expiration
A
Internal costals Abdominals
5
Q
What sacs surround the lungs
A
- Pleural sacs
6
Q
What are the functions of the pleural sacs
A
Prevents lung from sticking to the ribs
7
Q
How does respiratory system modify the air?
A
- Warms the air to 37C 2. Humidifies air to 100% 3. Filters the air through cilia (nose and walls)
8
Q
Path of air from larynx?
A
Larynx → Trachea → Primary bronchus (right or left) → Secondary bronchus → Bronchioles → Alveoli
9
Q
Ciliated and goblet cell function
A
Goblet → Secret mucus into the trachea Cilia → Push the muscus back into the throat
10
Q
Why are bronchioles covered by muscles?
A
Allows the change diameter to increase/decrease air flow
11
Q
By what method does the alveoli exchange gas?
A
Passive diffusion
12
Q
Why do the lungs have low blood pressure?
A
- Fragile organ → Lungs are fragile so can’t expose to too much pressure 2. Right next to the heart → No need for high pressure
13
Q
What is the blood flow from right ventricle?
A
Right ventricle → Pulmonary trunk → Pulmonary Arteries → Pulmonary arterioles → Capillaries → Pulmonary venules → Pulmonary veins → Heart (Left atrium)
14
Q
How does pulmonary edema happen (caused by heart failure)
A
- Heart failure means not enough blood is pumped by heart 2. Right side of heart grows in size to compensate → a lof of blood on right side → Fluid pressure really high in blood 3. This pushes the fluid into alveoli → fluid filled lungs
15
Q
How does a spirometer work
A
- Inhaling, brings the balast down → brings the pen up (pulley system) 2. Exhaling, brings the balast up (increased air volume) → Brings the pen down
16
Q
How is FEV/FVC affected in obstructive lung disease?
A
FEV is lowered (problems with air escaping the lungs at high velocities) FVC is also lowered (Problems with air escaping lungs in general)
17
Q
Inspiratory restrictive lung disease affects
A
Lower IRV and TV
18
Q
Espiratory restrictive lung disease
A
Lower ERV
19
Q
How does atherosclerosis begin?
A
Build up of fatty material called plaque This is mainly made up of cholesterol, and it builds up under the lining of arteries
20
Q
What is a thrombus/thromboembolism
A
Blood clot/ embolism is when the blood clot moves
21
Q
Ischemic heart disease caused by what?
A
Imbalance beteween supply of oxygen and myocardial demand caused by blockage in coronary artery
22
Q
What is a common symptom on EKG of ischemia?
A
Elevated S-T interval
23
Q
Essential vs Secondary hypertension
A
Essential - Unknown causes (90% cases) Secondary - Known causes such as damage to sympa
24
Q
What muscles are active during expiratory phase?
A
Actually none at rest, but internal and abdominal muscles activate a lot when excersizing
25
Function of the intrapleural pressure
Prevents lung collapse Helps to keep lungs inflated
26
Intrapleural pressure inspiration vs expiration
When breathing in, it decreases, when breathing out it increases Same direction as lung pressure
27
Lung compliance and elasticity relationship
The less elastic the lung is, the more compliant (inverse relationship)
28
What fibers contribute to the elasticity of the lungs?
Elastin fibers
29
How to calculate compliance
Change in volume over change in pressure
30
How will a high vs low compliant lung look on the compliance curve
High compliant - Emphysema lungs → Will take very little pressure for increase in volume Low compliant - Fibrosis lungs → Will take a lot of pressure to reach for volume but ultimately fails to get to required volume
31
What is the role of surfactant in alveoli?
Prevents collapse of the alveoli during exhalation
32
Where is most air resistance found in the lungs?
Trachea and bronchi, bronchioles have low resistance because large crossectional area (split 22 times)
33
What is the dalton's law of partial pressures
PB = PO2 + PCO2 + PN2 (total of all gasses in atmosphere)
34
Formula for partial pressure
Fractional concentration (how much of that element is in the air) * total pressure (usually 760mmHg)
35
How does the atmospheric pressure change once inside the body (inspiration)
Due to humidification of the air by respiratory system, you have to minus the partial pressure of water so it is actually equal to 713mmHg (47 is PH2O)
36
How do you determine the amount of gas in solution?
1. Partial pressure of the gas (Higher the partial pressure, the more dissolving occurs) 2. Solubility of the gas (More soluble, higher amount) 3. Temperature of the solution (Higher temperature increase gas in the solution)
37
What does the fick's law of diffusion say about gas exchange?
Fick's law: Gas transfer = constant * partial pressure gradient * surface area/wall thickness (IDK IF U HAVE TO MEMORISE) Thus, maximising the partial pressure difference and minimizing the wall thickness is the best way to get more oxygen in blood
38
How does disease affect gas exchange?
Emphysema, Fibrotic lung disease, Pulmonary disease: causes PO2 in arteries to be very low Asthma and Emphysema: causes PO2 to be low inside alveoli and arteries
39
Why is PO2 lower, PCO2 higher in in the tissues?
1. Causes oxygen to enter tissues 2. Picks up CO2 so partial pressure is higher
40
What happens to PO2 during excersize
1. gets lowered, allows hemoglobin to off load oxygen more effectively
41
How does pH, temp and PCO2 effect hemoglobin saturation
when pH is lower, the curve shifts to the right → lower saturation when higher temperature the curve shifts to the right → lower saturation when PCO2 is higher (e.g. during excersize) the curve shifts to the right → Lower saturation
42
What is the function of 2,3-DPG in mothers?
It lowers the hemoglobin affinity in mothers Allows more oxygen exchange to happen to the fetus
43
What is the reason why fetus have greater oxygen uptake?
1. Uptake is caused by production of fetal hemoglobin 2. Composed of 2 alpha and 2 gamma chains 3. This special form of hemoglobin has a higher affinity for oxygen than their maternal counterparts
44
How is CO2 transfered in the blood?
1. Dissolved in plasma (very small amount) 2. Turned into carbonic acid, then into bicarbonate in plasma majority 3. H+ ion produced, then H+ ion binds to hemoglobin
45
What is the Haldane effect?
As the PO2 increased, amount of CO2 carried decreases
46
Where are the different types of chemoreceptors located inside the body?
1. One is in the medulla oblangata, this is the central chemoreceptor 2. 2 are in the peripheral (carotid and aortic) chemoreceptors
47
How do chemoreceptors influence ventilation
Changes in PO2 (for peripheral) and H+ (For central) → Sends signal to medulla and pons → Motor nuerons responsible for both inspiration and expiration
48
How do central chemoreceptors work?
As PCO2 increases, CO2 is carries across the BBB When CO2 dissociates into bicarbonate and H+ ion, the receptor detects the H+ ions if H+ conc increased → Then ventilation is increased
49
How is peripheral chemoreceptors activated?
When PO2 falls, it gets stimulated and increases ventilation rate
50
How does the body fix acidosis?
1. Shifts the equilibirum to the left → More carbonic acid is formed Allows greater exhalation of CO2 out of lungs 2. Excretion through renal pathways (but this uses bicarbonate) 3. Other buffers in the body
51
How does the body deal with alkalosis?
1. Shifts equilibrium to the right, more breakdown of carbonic acid into H+ and bicarb → Reduced CO2 exhalation 2. Decreased H+ excretion through regeneration of H+ ions
52
Where is the motorneuron that control respiratory system found
Diaphragm motor neuron (Phrenic nerve) → Found in C3, C4, C5 cervical spinal cord Intercostal muscles found in throacic spinal cord T1~T12
53
What are the 4 areas of brain that control breathing?
PRG → Gets emotional information, VRG → Contains the pre-Botzinger complex DRG → Receieves motion information NTS
54
What is the function of pre-Botzinger complex
It is important for the overall control of the respiratory muscles
55
What receptors tell the brain about breathing?
1. RAR (Phasic) and SAR (Tonic) 2. Irritant receptors (C-fiber)
56
RAR, SAR, baroreceptor activity, heart tate change in normal breathing
RAR is activated SAR is barely activated Baroreceptor is activated due to slightly increased BP 4 BPM change in both inhalation and exhalation
57
stretch receptor when slow, deep breathing
1. Way more SAR activity 2. Way more Baroreceptor 3. 8 BPM inhalation, 5 BPM exhalation
58
Water storage places (same as pcl)
Intracellular fluid, (2/3) Extracellular (1/3) → Within ECF, there is Interstitial and intervascular
59
How many L's does glomerulus filter?
144L per day
60
What are the tiny arteries in the kidney called?
Interlobular artery → Arcuate artery
61
What is oncotic pressure
Pressure produced by albumin → Keeps water in the vasculature (where albumin is)
62
What is the ultrafiltration coefficient
Coefficient that takes into account the surface area of diffusion and the permeability of substrate for diffusion In the kidneys, the capilarries are very pearmeable → Any tiny change produces huge movements of water in and out
63
What is the most important determinant of GFR
renal blood flow (plasma flow)
64
What happens to afferent arteriole when aterial pressure increases
Vasoconstriction, vice versa
65
Tubuloglomerular feedback
If too much sodium is in the nephron → adenosine is released from the MD cells The afferent arterioles detect this adenosine and vasoconstrict This decreases the blood flow and reduces GFR
66
Function of angiotensin II
Vasoconstricts the efferent arteriole, therefore increased GFR
67
What is convection
The movement of small solutes with the water flow
68
How does the charge of the macromolecule affect its permeability
The membrane is - charged so more + charged things will move readily
69
How does inulin help to figure out GFR
Inulin is not reabsorbed back into the vasculature → Can detect concentration in urine to figure out GFR
70
What % of water is reabsorbed every day?
0.99
71
Where is the sodium potassium pump located in the polarised cell of nephrons?
Basolateral side → It ejects sodium outside of the cell into interstitial fluid
72
Function of the sodium hydrogen exchanger
1. Move Na+ into cell down conc gradient 2. Move H+ out of cell against conc gradient 3. This is on the luminal side
73
What are the transporters on luminal and baso lateral side in nephron?
Luminal: Antiporters (NaH exchangers) Co-transporters (Sodium glucose) Sodium channel Basolateral: Na+/K+ ATP-ase
74
Proximal tubule function
Most water, sodium, chloride, potassium and bicarb is reabsorbed here Most important exchanger is NaH exchanger
75
Thick Ascending limb of loop of henle function
Very impermeable to water Reabsorbs sodium through the Na-K-Cl protein Fluid leaving the ascending limb is hypotonic than plasma
76
Distal tubule function
reabsorbs 5~10% of sodium and water Most common sodium transporter is sodium chloride co-transporter
77
Collecting duct function
Reabsorbs 1~3% of sodium Most common channel is epithelial sodium channel
78
Function of aldosterone
Increases # and probability of Na+ channels to increase sodium reabsorption
79
ADh function
Increases water reabsorption by increasing aqua porin 2 receptors
80
2 types of sodium glucose transporters
1 is high affinity low capacity 1 is low afinity high capacity
81
How does the body sense sodium levels?
1. Arterial baroreceptors (Carotid and Aortic) 2. Afferent arterioles of kidneys 3. Heart stretch receptors
82
How does baroreceptor change the blood pressure?
Baroreceptors send signal to medulla oblangata by the 9th cranial nerve This signal is inhibitory to the sympathetic nervous system So if theres an increase in the volume detected by the receptor → Decreased sympathetic nervous system activity vice versa
83
How does increased sympathetic nervous system increase blood pressure?
1. Sympathetic nervous system activates renin 2. Renin converts angiotensinogen to Angiotensin I (10 peptide long chain) 3. ACE enzyme then cleaves to form Angiotensin II 4. Increased sodium reabsorption
84
Angiotensin II activity in the proximal tubule
1. Norepinephrine and Angiotensin II makes Na/H+ exchanger work more 2. Increased sodium intake
85
Angiotensin II affect on distal convoluted tubule
1. Increases the NA+ Cl- co-transporter activitiy 2. Increased sodium intake
86
Angiotensin II effect on efferent arteriole (2 consequences)
1. Efferent arteriole constricts 2. This increases GFR into the glomerulus 3. This also reduces pressure on the preitubular capillaries, decreaseing hydrostatic and increasing oncotic pressure 4. This makes water and sodium easier to escape into the capillaries
87
Angiotensin II effect on aldosterone and collecting duct
1. Angiotensin II increases production of aldosterone 2. This makes the ENaC (Epithelium sodium channels) in the collecting duct to open more 3. Increases sodium reabsorption
88
What happens to ECF volume and eventually to angio tensin system when sitting in a hottub
1. Increased pressure outside pushes fluid from ICF to ECF, increasing baroreceptor activity 2. This reduces the sympathetic nervous system 3. Decreases the renin-angiotensin activity
89
How does cardiac stretch signal for more urine production
1. Increase in vascular volume due to being in hottub causes cardial stretch 2. Increased production of ANP 3. Aldosterone inhibition, Renin inhibition, More urine
90
What compartment of the water does the body detect?
Intracellular fluid
91
How does the hypothalamic osmoreceptors work?
1. In a more hypertonic solution, the cells will shrink 2. This causes ion channels to open, depolarising the cell 3. This generates an action potential 4. Leading to more AVP release and thirst increase
