Block 1 - Asthma + COPD Physiology Flashcards
Physiology
Respiration is responsible for ___
Gas exchange
Physiology
Ventilation is responsible for ___
Moving air in and out of the lungs
Physiology
What are the functions of the diaphragm?
- Seperates the chest from the abdomin
- Creates a suction from moving downward and expanding the lungs by drawing air
- Aids in breathing
Physiology
Where are intercostal muscles located?
Between ribs forming the chest wall
Physiology
What is the difference between external and internal intercostal muscles?
External: quiet and forced inhalation
Internal: forced expiration
Quiet expiration = passive process
Respiration
What is dyspnea?
Difficult or labored breathing
Respiration
What is apnea?
Absence of breathing
Respiration
What is tachypnea?
Increased frequency of respiratory rate
Respiration
What is orthopnea?
dyspnea when recumbent, relieved when placed upright (CHF, asthma, lung failure)
Respiration
What is the purpose of the main entrance of the nasal cavity?
- Warms and saturates inspired air
- Removes bacteria and debris
- Converes heat and moisture from expired air
Respiration
What is the purpose of nasal hair?
Purify and filter air
Respiration
What are the routes of air entry?
nasal and oral
Respiration
Describe the function of the pharynx
Collects incoming air from the nose and passes it down (part of digestive and respiratory)
Respiration
Describe the function of the epiglottis
guards the entrance to the trachea
Respiration
What happens when the epiglottis is at rest vs swallowing?
Rest: upright allowing air to pass to larynx
Swallowing: folds back to cover entrance, preventing food and drinks to enter the trachea
Respiration
Describe the function of the larynx
contains vocal cords, used to create sound
Respiration
What are the components of the upper respiratory tract?
- Pharynx
- Epiglottis
- Larynx
- Nasal/Oral Cavity
Respiration
What are the components of the lower resp tract?
- Bronchi
- Bronchioles
- Alveloli
- Capillaries
Respiration
Describe cells associated with bronchi?
Ciliated epithelial columnar: carries mucus, phlegm, liquid upward and out into the throat to be coughed up or swallowed
Goblet: Secretes mucus
Respiration
Describe the structure of bronchioles
Lined by smooth muscle and under autonomic control
Respiration
Describe the function of alveoli
Site of gas exchange with blood
Respiration
Describe the function of the capillaries in the lower resp tract
Region of gas diffusion down its concentration gradient
Respiration
What is pulmonary surface tension?
The attraction of water molecules along alveolar walls over air
Respiration
What is the function surfactant?
Limit surface tension in alveoli, preventing its collapse during inhalation
Respiration
What is the composition of pulmonary surfactant?
In order to create a water-air interface, surfactant is composed of phospholipids and apoproteins that creates a barrier between alveoli and air
Respiration
What cell secretes surfactant?
Type 2 alveolar epithelial cells lining alveoli and respiratory bronchioles
Respiration
Explain why premature infants are suceptible to respiratory distress?
Surfactant forms later in the fetus’s life
Respiration
What cells secrete mucous in the bronchi?
goblet cells
Pulmonary Circulation
What is the standard pulmonary arterial pressure?
25/8
Pulmonary Circulation
Describe the gas exchange in process in the alveoli
Exchange occurs passively based on gas pressure gradient
Pulmonary Circulation
What is the normal transit time through pulmonary capillaries?
Pulmonary Circulation
At rest, when is the blood fully oxygenated?
0.8 sec
Pulmonary Circulation
under high cardiac output, what is the transit time for full oxygenation?
0.3 sec
Pulmonary Circulation
What’s the difference between perfusion and diffusion limited?
Perfusion limited: occurs at normal states where a partial pressure gradient is maintained and equilibrium can be met
Diffusion limited: incomplete equilibrium from fibrotic disease states that alter the membrane
Pulmonary Circulation
What is primarily carried in plasma?
Bicarbonate
Pulmonary Circulation
How is HCO3 carried throughout the body?
- Bicarbonate in plasma (70%)
- CO2 bound to Hb (30%)
- Dissolved CO2 in plasma (10%)
Pulmonary Circulation
What is an excess of HCO3?
Hypercapnia
What are CNS chemoreceptors in the respiratory centers?
Monitor [H+] to control rate of respiration
Sensitive to changes in the CSF
What are periphery chemoreceptors?
Locates in aortic bodies and monitors oxygen by oxygen sensitive K+ channels
What is the lethal range of carbon monoxide?
0.6 mmHG
What makes carbon monoxide dangerous?
250x greater affinity for Hb than O2
What is spirometry?
Tests lung function, full inspiration followed by maximal forced expiration (3 times)
What is tidal volume?
500 mL, air moved in and out by normal breathing