FINAL EXAM Flashcards
Three main functions of respiratory system
Gas Exchange
Acid-base balance
Heat Loss
Major structures of the respiratory system
Upper airway and
respiratory tract (Conducting Zone and Respiratory Zone) All passages from pharynx to lungs.
Parts of Upper Airway
Nasal and Oral Cavity
Pharynx
Parts of Respiratory tract
Conducting Zone (Larynx, bronchi, bronchioles, and terminal bronchioles)
- Air is humidified and heated/cooled to body temperature
- Considered dead space
Respiratory Zone (Respiratory bronchioles to alveoli) -Where gas exchange occurs
Different Pulmonary pressures
- Intra-alveolar pressure
- Intra-pleural pressure
- Trans-pulmonary pressure
Describe Intra-alveolar pressure (Palv)
- pressure within the alveoli
- At the end of a normal inspiration, alveoli pressure (Palv) =Atmospheric Pressure (Patm)
- Gradient between Palv and Patm allows for air flow into/out of the lungs
Air flows into the lungs when what is true with pressure
Palv (Alveoli pressure) < Patm (atmospheric pressure)
Intra-pleural pressure (Pip)
-pressure within the pleural space
-At the end of normal inspiration Pip = -4
(the forces between the chest wall and ribcage pull the two parts of the pleura apart)
Ribcage vs. Lungs
- Ribs want to expands
- lungs want to collapse
- The pleura opposes these two forces
- If the pleura isn’t airtight, the lung collapses and pneumothorax occurs
Trans-pulmonary pressure
- Difference in pressure between the intra-pleural and intra-alveolar pressure
- pressure across the wall between the alveoli and the pleura
- Increased trans-pulmonary pressure leads to lung expansion
Inspiration
- Diaphragm contracts
- Chest wall expands
- Thoracic cavity volume increases
- decreases intra-pleural pressure
- lungs fill up with air
Expiration
- Diaphragm relaxes
- Chest wall contracts
- Thoracic cavity volume decreases
- Intra-pleural pressure increases
- Air leaves lungs
- **Normally expiration is a passive process
Compliance
- The ability of a vessel to stretch as it fills
* Large compliance means a large change in volume only needs a small change in pressure
Surface Tension
-Measure of the work required to increase the surface area of a liquid by a given amount
-High surface tension means more work is required
-Decreases compliance
-SURFACANT decreases surface tension
(surfacant is found in alveoli)
How do you calculate flow?
Flow=pressure gradient/resistance
What could be changed in an attempt to maintain flow when resistance is increased?
Increase pressure gradient by increasing expiratory muscular effort
Tidal Volume (TV)
Amount of air that moves in/out of lungs during a normal breath
Inspiratory Reserve Volume (IRV)
Maximum volume of air that can be taken into the lungs AFTER a normal inspiration
Expiratory Reserve Volume (ERV)
Volume of air remaining in the lungs AFTER a normal expiration
Residual Volume (RV)
The amount of air remaining in the lungs AFTER a maximal exhalation
Inspiratory Capacity (IC)
Maximal amt of air that can be inspired AFTER a normal inspiration
Functional Reserve Capacity (FRC)
Max amt of air that can be exhaled AFTER a normal expiration
vital capacity (VC)
Maximal amt of air that can be moved into and out of the lungs
Total Lung Capacity (TLC)
Amt of air in the lungs after a maximal inspiration
What is Obstructive lung pathology
- Increases airway resistance
- Overinflates lungs
- Increases TLC and FRC
- COPD, asthma, emphysema or chronic bronchitis
What is Restrictive lung pathology
- Decreases pulmonary compliance
- Decreases TLC and VC
- Pulmonary Fibrosis
Calculate how much air we breathe
Frequency=Respiratory rate (RR)
Breathe size = Tidal Volume (Vt)
Minute ventilation (Ve) = RR X Vt
How do you calculate Resistance
Resistance = Pressure/Flow
Flow of blood through pulmonary circulation
Right side of heart Pulmonary artery Pulmonary capillaries Pulmonary vein Left side of heart Systemic artery Systemic capillaries Systemic vein
Dalton’s Law
Pressure exerted by each component in a gaseous mixture is independent of other gases in the mixture
Partial Pressures of O2 and CO2
O2–
Alveolar–100 mm HG
arterial –100 mm HG
venous–40 mm HG
CO2–Alveolar–40 mm HG
arterial– 40 mm HG
venous–46 mm HG
3 main factors that affect alveolar pp of O2 and CO2
1-The PO2 and PCO2 of the inspired air
2-Rate of alveolar ventilation
3-Rate of of O2 consumption and CO2 production
What will happen to PAO2 and PACO2 if you climb to top of a mountain?
Nothing–Assuming ventilation remains constant, since there is essentially no CO2 in the atmosphere, your PACO2 won’t change
Hyperpnea
An increase in ventilation to meet metabolic demand
Hyperventilation
An increase in ventilation beyond what is needed for metabolic demand
Dyspnea
labored or difficult breathing
Tachypnea
rapid, shallow breathing
Apnea
temporary cessation of breathing
Hypoventilation
ventilation is insufficient to meet the metabolic demands of the body
Hypoxia
deficiency of oxygen in the tissues
Hypoxemia
deficiency of oxygen in the blood
hypercapnia
excess of carbon dioxide in the blood
hypocapnia
deficiency of carbon dioxide in the blood
How is oxygen transported in blood
97% bound to hemoglobin
3% dissolved in plasma
Blood O2 content =
Amt of O2 bound to hemoglobin +
Amt of CO02 dissolved in plasmaOxyhemoglobin curve to LEFT
- decreased acidity (increased PH)
- decreased carbon dioxide
- decreased temp
- decreased 2,3 DPG
*Increases infinity of O2 and hemoglobin (easier to load)
Oxyhemoglobin curve to RIGHT
- increased acidity (decreased PH)
- increased carbon dioxide
- increased temperature
- increased 2,3 DPG
*decreases affinity of O2 and hemoglobin (easier to unload)
How is CO2 transported in the blood
bicarbonate (89.6%)
dissolved in plasma (5.5%)
bound to hemoglobin (4.9%)
Name 2 types of pulmonary chemoreceptors
Central and Peripheral
Central chemoreceptors
*located in Medulla
Which chemical factors involved?
*H+ (directly) and CO2 (indirectly
H+ cannot pass blood brain barrier)
Peripheral chemoreceptors
*located in cartoid sinus and aortic arch
Which chemical factors involved?
- H+, CO2 & O2
- Oxygen has biggest influence
- **They stimulate the carotid and aortic chemoreceptors
At sea level what drives us to breathe
increased CO2
Normal PH of arterial blood
7.4%
Arterial blood PH
*normal value is 7.4
*Maintained between 7.38 - 7.42(below 6.8
or above 8.0 can be fatal)
*acidosis – PH below 7.35
*Alkalosis – PH above 7.45
How to counteract Carbon dioxide - acidosis
-Increase ventilation (blow off CO2)
-Convert CO2 to bicarbonate (alkaline)
-Retain bicarbonate
(increase in CO2 we become acidotic)
How to counteract Bicarbonate - alkalosis
-Decrease ventilation (retain CO2)
-Convert bicarbonate to CO2 (acidotic)
-Excrete bicarbonate in the urine
(Buildup of bicarbonate we become alkalotic)
Structure of ATP
3-phosphate groups
1-molecule of adenosine
Define metabolism
the sum total of all chemical reactions that occur in cells
How we use ATP to generate energy
Energy released when ATP broken down to ADP
