Exam 1

• 
• presure and volume vary directly (temperature is constant)

• 
• volume and temperature vary directly (pressure is constant)

Force exerted on the earth’s surface by the atmospheric pressure

P_AO₂ = (P_B – P_H2O)FiO₂ – P_aCO₂(1.25)


Partial pressure in the alveolar = (bariometric pressure – partial pressure of water) – fractional inspired O2 – partial pressure of arterial blood gas (1.25)

• Respiratory exchange ratio is the
• 1.25 in the equation

Movement of gas from an area of high concentration to an area of low concentration until equilibrium is reached

• Rate of gas transfer is directly proportional to surface area of tissue
• (A), and difference in partial pressure of gas between two sides of tissue (P1, P2)

Transfer of gas across alveolar wall is a function of the amount of blood that flows past the alveoli

Movement of gas across alveolar wall is a function of integrity of alveolar-capillary membrane

Work of Breathing, it is the work put into moving into and out of the lungs

Pressure difference between two points

• Pressure difference between mouth pressure (P_m) and
• alveolar pressure (P_alv)

Pressure difference across the airway walls

• Difference between the alveolar pressure
• (Palv) and the pleural pressure

Difference between the alveolar pressure(Palv) and the body surface pressure

• Inspiration (active): Diaphragm contracts to enlarge chest cavity, pressure drops moving air into lungs
• Expiration (passive): Diaphragm relaxes to decrease chest cavity, pressure increases forcing gas out of lungs

The amount of air that the lungs will accept for each cmH₂O pressure change

• Change in volume (L) per unit pressure (cmH₂O)
• ΔV / ΔP

Movement of a specific volume of fluid in a particular period of time

If liquid flows through a ridgid pipe, the mass of the fluid entering a tube must equal the mass leaving the tube

Describes elastance : the ability of matter to return to its natural shape afte external force is removed

Change in pressure per change in volume

ΔP / ΔV

Cohesive force of luquid molecules at a liquid-gas interface

Pressure and radius are inversely related

• Film that lines alveoli
• Decreases alveolar surface tension
• produced and stored in type II alveoli cells
• Keeps alveoli from collapsing

• Elastic properties of the lung
• Surface tension of the liquid film that lines the alveoli

The movement of gas in and out of the lungs and pressure changes required to do so

• During normal inspiration, bronchial airways get longer and wider
• During exhalation, bronchial airways get shorter and more narrow
• 
• V (with dot) =flow, P=pressure, r=radius

Pressure difference between the mouth and the alveoli

Streamlined, orderly flow

Molecules move in a random manner, jumbled mixture of velocities

• Occurs in areas where airways branch
• May be laminar or turbulent

• Pneumotachometer^*
• Fixed orifice meter
• Thermal meter
• Ultrasonic meter
• Rotating vane anemometer (Wright respirometer)

Anatomic and alveolar

respiratory rate (12-20)

Volume of air going in and out durign one quiet breath (about 500mL)

Nasal cavity, paranasal sinus, pharynx, tongue, epiglottis, soft and hard palates, oral cavities, laryngopharynx, larynx (true vocial cords)

Tracheobronchial tree (including the alveoli)

The path for gas to move in and out of the lung (no gas exchange takes place)

Trachea, mainstem bronchi, bronchioles, terminal bronchioles

Generations 0-19

Conduct air from the outside environment into the body

Heat/cool and humidify air to body temperature

Filter out particles from environment

Smell

Speech

Passageway between pharynx and trachea

Protects against aspiration

Generates sound for speech

(also used in valsalva maneuver)

• Trachea 0
• Main stem bronchi 1
• Lobar bronchi 2
• Segmental bronchi 3
• Subsegmental bronchi 4-9
• Bronchioles 10-15
• Terminal bronchioles 16-19

• Respiratory bronchioles 20-23
• Alveolar ducts 24-27
• Alveolar sacs 28

Trachea, main stem bronchi, lobar bronchi, segmental bronchi, subsegmental bronchi

only conduct air)

Bronchioles, terminal bronchioles

(conduct air and gas exchange)

• True 1-7
• False ribs 8-10
• Floating ribs 11-12

–Scalenus muscles

–Sternocleidomastoid muscles

–Pectoralis major muscles

–Trapezius muscles

–External intercostal muscles

–Rectus abdominis muscles

–External abdominis obliquus muscles

–Internal abdominis obliquus muscles

–Transversus abdominis muscles

–Internal intercostal muscles

–raise HR

–Relax bronchial smooth muscle

–lower secretions

–Pupils widen

–lower HR

–Bronchial smooth muscle constricts

–raise secretions

–Pupils constrict