Respiratory #1 Flashcards
Eupnea:
Tachypnea:
Eu-Normal rhythmic breathing
tach–Increased frequency of breathing.
Hyperpnea:
Hyperventilation:
Hypoventilation:
hyperpnea- Increased breathing, usually increased tidal volume with/without increased frequency
hypervent-Increased alveolar ventilation relative to metabolic rate (arterial CO2 tension usually less than 37 mm Hg).
- Hypoventilation: Decreased alveolar ventilation relative to metabolic rate (arterial CO2 tension usually above 43 mm Hg).
Apnea:
Apneusis
Apneustic pattern
Apnea: Cease breathing in resting expiratory position.
* Apneusis: Cease breathing in inspiration.
- Apneustic pattern: Apneusis interrupted periodically by exhalation; may be rhythmic.
- Gasping:
Spasmodic inspiratory effort, usually maximal, brief, and terminating abruptly;
may be rhythmic or irregular; may be involuntary
(e.g. when frightened) or voluntary (e.g. when singing or swimming).
Dalton’s Law of Partial Pressures –
Dalton’s Law of Partial Pressures –
Total pressure (PT) of a gas mixture is a sum of the fractional pressures exerted by its
individual component gases (i.e., partial pressures). T
Normal atmospheric fractional concentration of O2
0.21; 21%
value is altitude independent
KNOW THIS
tension
The “partial pressure” of a gas
“tension“.
Water Vapor Pressure in lungs of humans and vet
when temp is 37 and humidity is 100%
Water vapor (partial) pressure in lungs at 37◦C & 100% relative humidity
Human is 47mmHg.
Vet medicine is 50 mm Hg
KNOW BOTH VALUES!!
Used to correct for P02 in inspired air.
Boyle’s Law
Volume is inversely proportional to pressure at constant temperature:
V1/V2 = P2/P1
Boyle’s Law example
At constant temperature, a fixed number of gaseous molecules will exert less pressure
the larger the volume of their container.
Mechanics of breathing–Ventilation
getting the gas to in the lungs to the vessel
Gas exchange
Perfusion
Ventilation must match
Perfusion
What is symbolized with a capital letter?
Primary variables
What is symbolized by a “dot” over the variable
A dot over the variable indicates a rate
What do modifiers in small capital letters indicate?
Gas phase
What do modifiers in lower case letters indicate?
Gas dissolved in liquid or tissues
Example: Pa = partial pressure of a gas dissolved in arterial blood
Describe the respiratory process (summarize)
Brain drives lung ventilation (gas exchange)
Oxygenated blood is perfused from the lungs to the heart, deoxygenated blood is returned to the lungs from the heart.
O2 blood from the heart can continue onto the muscles
then exchanged for deoxygenated blood which the will be returned to the lungs.
Some oxygenated blood from the heart will provide feedback to the brain which can influence the rhythm and depth of breathing.
What are the 3 main components of the respiratory system?
Respiratory controller
Ventilatory pump
Gas exchanger
What are the 2 contributors to the respiratory controller (the control center)?
Cortex - behavioral control
Brainstem - automatic control
What contributes to the ventilatory pump
(where we take air in and push air out)?
Chest wall muscles & skeleton, chest wall connective tissue,
airways, pleura,
spinal cord and peripheral nerves
What are the contributors to the gas exchanger?
Alveoli
Pulmonary capillaries
Arterial supply via pulmonary artery
Venous return via pulmonary vein
6 examples of non-respiratory air movements
Cough
Sneeze
Crying
Laughing
Hiccups
Yawn
What is Valsalva’s maneuver?
expire against closed glottis and increase abdominal pressure
What structures are conducting zone?
Transitional zone?
Respiratory zone?
Conducting: trachea, bronchi, bronchioles, terminal bronchioles
Transitional: respiratory bronchioles
Respiratory: alveolar ducts, alveolar sacs
What structure of the airway has largest cross-sectional area?
Alveolar sacs
How is cross-sectional area and resistance to air flow related?
Bigger the area, lower the resistance to air flow
Is dead space involved in gas exchange?
No
How much dead space is there?
Most species?
cattle/horses?
33% in most
50-70 in large animals
Functional unit of gas exchange
(a sac gland present on the alveolar sacs)
Acinus
