Resp Quiz Flashcards
Rhinitis needs one or more of the following to qualify as such…
- Sneezing
- Rhinorrhea
- Nasal congestion
- Nasal itching
Commonly associated symptoms with rhinitis
- Fatigue
- Headache
- Cognitive impairment
- Sleep disturbance
What are the functions of the lungs?
- Gas exchange
- Metabolism
- Regulation of blood pH
- Defense against microbes
Oxygen consumed at rest
250 mL/min
Carbon dioxide produced at rest
200 mL/min
Ventilation at rest
7,000 mL/min
Cardiac output at rest
5,000 mL/min
Two stages of respiration
- Gas exchange
2. Cell respiration
3 processes of respiration
- Ventilation
- Diffusion
- Perfusion
What is ventilation?
Air intake and output
What is diffusion?
Gas exchange
What is perfusion?
Movement of gas within the blood
What is the conduction zone of the airways?
Trachea»bronchi»bronchioles»terminal bronchioles
What is the respiratory zone of the airways?
Respiratory bronchioles»alveolar ducts»alveolar sacs
Where do you lose cartilage down the respiratory tract?
Bronchioles
Type II epithelial cells
Release surfactant
Type I epithelial cells
Structure
What is the function of the cartilage in the upper respiratory tract?
Prevent collapse of smooth muscle in trachea and bronchus
Why is a thin blood-gas interface very important?
Diffusion
Why is a large blood-gas interface very important?
A larger surface area allows for more diffusion
Fick’s law of diffusion
Vgas = A/T * D * (P1-P2)
Diffusion constant for any given gas is dependent on…
- Solubility of the gas in the membrane
2. Inverse of the square root of the molecular weight
Body’s supply of oxygen depends on…
- Concentration of gases in ambient air
2. Partial pressure
Pb (barometric pressure) @ sea level
760 mmHg
Po2 @ sea level
159 mmHg
Pco2 @ sea level
0.3 mmHg
Pn2 @ sea level
600 mmHg
Dalton’s law
Pb = Po2 + Pco2 + Pn2
What happens to the trachea air in relation to partial pressures?
Partial pressure of nitrogen goes down
What happens to the alveoli in terms of partial pressures?
Carbon dioxide partial pressure goes up
Partial pressure of H2O @ 37 C
47 mmHg
Henry’s Law
Mass of a gas that dissolves in a fluid at a given temperature varies in direct proportion to pressure of the gas over the liquid
Two factors that govern the rate of diffusion into a fluid…
- Pressure gradient between gas above the fluid and gas dissolved in the fluid
- solubility of gas in the fluid
Joints of the thorax
- Costovertebral
- Costotransverse
- Sternocostal
- Costochondral
- Sternoclavicular
- Manubriosternal
- Xiphisternal
Regions of parietal pleura
- Cervical
- Costal
- Diaphragmatic
- Mediastinal
What innervates the visceral pleura and what does this mean?
Viscerosensory innervation; leaves lungs relatively insensitive to painful stimuli (dull, non-localized pain)
What innervates parietal pleura and what does this mean?
Somatosensory nerves, making the parietal pleura sensitive to pain (sharp and well-localized pain)
What nerve innervates the pericardium, mediastinal parietal pleura, and diaphragmatic parietal pleura?
Phrenic n.
What dermatomes do pain inputs from phrenic n. refer to?
C3-5
What primary muscles are involved during quiet and forceful inspiration and what are their innervations?
- Diaphragm (phrenic n.)
- External intercostals (intercostal nn.)
What secondary muscles are involved during forceful inspiration and what are their innervations?
- Scalene mm. (cervical spinal nn.)
- Sternocleidomastoid (CN XI - accessory n.)
- Internal intercostals (intercostal nn.)
Where does the diaphragm go when it contracts during inspiration?
Down
Where does the diaphragm go when it relaxes during exhalation?
Up
Which ribs move along the A-P axis?
2-6
Which ribs move along the transverse axis?
7-10
What is expiration mostly due to?
Elastic recoil of the lungs
Relaxation of the inspiratory muscles ________ the volume of the thoracic cavity
Decreases
What are the muscles involved during forced expiration?
- Abdominal muscles (rectus abdominus, external and internal obliques, transversus abdominus) - increases intra-abdominal pressure, forcing organs up and thereby forcing the diaphragm up
- internal intercostals
- innermost intercostals
- transversus thoracis
What innervates the muscles involved during forced expiration?
Intercostal nn. T7-11
What accessory muscles are involved during expiration and what are their functions?
- Scalenes - elevate 1/2 ribs
- Pec minor and major - elevate ribcage if arms abducted and scapula fixed
- Serratus anterior - elevates lateral ribcage if scapula fixed
- Trapezius, levator scapulae, rhomboids - stabilize the scapula so the other muscles can work on the ribcage
What diseases are associated with abnormal hypertrophy of accessory muscles of expiration?
COPD, emphysema
Boyle’s Law
If temp is constant, pressure and volume are inversely related
What is the basis for atelectasis?
If the alveoli collapse, the lung cavity cannot maintain the negative pressure required for normal conditions so air leaves the lung and enters the space between the viscera and the parietal pleura compressing the lung causing it to collapse
What is the sequence of inspiration?
- Inspiratory muscles contract
- Thoracic cavity expands
- Pleural pressure becomes more negative
- Transpulmonary pressure increases
- Lungs inflate
- Alveolar pressure becomes subatmospheric
- Air flows into the lungs until alveolar pressure equals atmospheric pressure (@ max volume here)