# Shared Flashcard Set

## Details

Physiology Test 2
N/A
31
Health Care
Undergraduate 3
10/09/2013

## Cards Return to Set Details

Term
 What are the absolute pressures of the lung?
Definition
 Mouth pressure: Pm Alveoloar Pressure: PALV Body surface pressure: Pbs Pleural Pressure: Ppl
Term
 What are the transpressures?
Definition
 Transpulmonary, trans chest wall, transsystem, transairway
Term
 What is the equation for transpulmonary pressure?
Definition
 PL=PALV+Ppl Alveolar + Pleural
Term
 What is the equation for Trans chest wall pressure?
Definition
 Pcw=Ppl-Pbs Pleural pressure - body surface pressure
Term
 What is the equation for trans respiratory system pressure?
Definition
 Prs=PAlv-Pbs Alveolar pressure - body surface pressure
Term
 What is the equation for trans airway pressure?
Definition
 Paw=PAlv - Pm Alveolar pressure - mouth pressure
Term
 When you're blowing out is the transairway pressure negative, positive, or zero?
Definition
 Positive during expiration
Term
 What capacity are you at when transairway pressure is zero?
Definition
 FRC functional residual capacity
Term
 What are the pressures during the breathing cycle?
Definition
 Transpulmonary pressure and transairway pressure. When you exhale transpulmonary pressure is positive, and negative when you inhale.
Term
 What is the equation for compilance?
Definition
 C=change in volume/change in pressure
Term
 What is the golden rule for lung volume and lung pressures?
Definition
 There is only one trans pressure per specific lung volume
Term
 Hooke's Law
Definition
 Lung inflates proportionally to pressure difference. Volume is proportional to pressure (linear until a certain point)
Term
 LaPlace's Law
Definition
 surface tension is proportional to pressure X radius
Term
 If a bubble increases in size, but the amount of surfactant remains the same, what happens to surface tension?
Definition
 Surface tension increases
Term
 What is critical opening pressure? What are normal values?
Definition
 The amount of pressure needed to open a collapsed alveolus.  Normal values: 40-55 cm H2O
Term
 What are the factors that oppose surface tension and stabilize the lung?
Definition
 1.Surfactant: a material made of phospholipids which liines ther surface of the terminal lung units (alveoli, alveolar ducts, and respiratory bronchioles) 2.Polyhedral structure: stable in nature 3.Interdependence: architecture of alveolar units promotes mechanical stability. Alveoli are tethered together in such a way that adjoining units help keep each other open.
Term
 How do you measure normal compliance, system compliance, and chest wall compliance?
Definition
 Normal: C= change in volume/change in pressure System compliance= lung + chest wall compliance 1/total compliance= 1/lung compliance + 1/chest wall compliance
Term
 [image]
Definition
 Which graph has less resistance? What has the bigger endotracheal tube? R1
Term
 Specific Compliance
Definition
 A way of normalizing compliance. Compliance should be the same in each person as long as not diseased. Specific compliance= compliance/FRC
Term
 Why does the apex have a larger FRC is resting position?
Definition
 Because te base is heavier due to weight of the blood and gravity
Term
 What are the 3 types of resistance?
Definition
 Airway: 80% normal breathing, gas work Tissue: 20% can increase if tissue more dense Ineterital: negligible (can cause more resistance closer to death due to lung getting heavier)
Term
 Distribution of Resistance
Definition
 20% nose, pharynx, larynx, trachea 60% airways > 2mm cartilaginous <20% airways <2mm
Term
 Types of Airflow
Definition
 Laminar airflow: friction between tubing wall and gas, driving pressure for laminar flow is influenced by gas viscosity, but not molecular weight or density Turbulent flow: more interaction between gas molecules, requires higher pressure
Term
 Factors that affect Reynold's Number
Definition
 Reynolds #= diameter*velocity*density/viscosity Reynolds # greater than 2000 = turbulent flow Large diameter, large velocity, or large density cause larger # More viscosity= lower reynolds #
Term
 Factors affecting airway resistance.
Definition
 Interdependence, amount of air in lung Smooth muscle tone: 1. local control (histamine, prostaglandin, high CO2=dilation) 2. Innervation; sympathetic: dilation airflow factors: velocity, density, viscosity
Term
 What trans pressure is the elastic recoil pressure?
Definition
 Transpulmonary Pressure
Term
 What are the normal values for resistance?
Definition
 .6-2.4 cm H2O/L/sec
Term
 If you decrease the size of a tube, what happens to resistance?
Definition
 Resistance increases and more pressure is required
Term
 What is the equation for resistance?
Definition
 R= Peak pressure-Plateau pressure/change in volume
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