Lecture 17 Respiratory System Flashcards
Breathe in
What are the 4 functions of respiration?
- Pulmonary ventilation
- External respiration
- Transport of respiratory gases
- Internal respiration
Describe External Respiration
The movement of oxygen from the alveoli to the pulmonary capillaries and CO2 from the pulmonary capillaries to the alveoli.
Describe Pulmonary Ventilation
Air must be moved in and out of lungs to continually replace gases in lung alveoli
Describe Transport of Respiratory Gases
Transport of O2 and CO2 between lungs and cells of body via cardiovascular system
Describe Internal Respiration
Gas exchange between systemic capillaries and cells
(O2 leaves blood in systemic capillaries and enters surrounding tissues and then cells while CO2 is opposite)
In lecture (slide 12)
1 6
3 4
2 5
a b
External respiration
Internal respiration
Transport of gases
Pulmonary ventilation
Name the 3 components of the respiratory membrane
- Type 1 alveolar cells
- Pulmonary capillary endothelial cells
- Basal Lamina
How many layers of plasma membrane does O2 need to pass through in order to get into the RBC?
5
What are the first 3 steps of gas exchange and transport?
- Oxygen enters blood at alveolar capillary interface
- Oxygen is transported in blood dissolved in plasma or bound to hemoglobin inside RBCs
- Oxygen diffuses into cells
What are the last 3 steps of gas exchange and transport?
- CO2 diffuses out of cells
- CO2 is transported dissolved in plasma, bound to hemoglobin or as HCO3-
- CO2 enters alveoli at alveolar-capillary interface
What is the pathway of air in the respiratory system?
nose > pharynx > larynx > trachea > primary bronchi > 2 > 3 > 4 > 5th bronchi > bronchioles > terminal bronchioles > respiratory bronchioles > alveoli
True or False: Gas exchange occurs ONLY in respiratory bronchioles to alveoli
TRUE: all other structures constitute the conducting zone
Which is NOT part of the conducting zone?
Nose, pharynx, larynx, trachea, alveoli, most of bronchial passageways
Alveoli (part of respiratory zone along with respiratory bronchioles)
In what ways does the conducting zone passageway perform conditioning of air?
Warming (through BVs in lamina propria), humidifying (through water secretions), and filtering inspired air (breathing in cold air HURTS we need to warm it up)
What is the function of mucus secreted by goblet cells?
To trap foreign pathogens and dust particles
What are alveoli covered in a “cobweb” of?
What are they surrounded by which enable stretch and recoil during inhalation and exhalation?
- Pulmonary capillaries
- Elastic fibers
What is the alveolar layer of the respiratory zone made up of?
A single layer of squamous epithelial cells (type I cells) surrounded by basal lamina
What is the second half of the respiratory zone made up of?
Capillary endothelial cell layer
What is surfactant?
What does it do?
It is a fluid secreted by type II cells
It coats the internal alveolar surfaces and prevents alveoli from collapsing on themselves by reducing surface tension
How is passage of air allowed between alveoli?
They have pores within the alveolar walls that allow air to slip through
Why does quiet respiration occur and what is it due to?
Occurs because diaphragm contracts, increasing thoracic volume vertically
Due to passive recoil
What is Boyle’s law?
Relationship between volume and pressure is inversely proportional
How does intrapulmonary pressure (IPP) occur and what does the increase/decrease of it cause?
Occurs as a result of changes in lung volume
Increase in IPP causes expiration (lung volume -)
Decrease in IPP causes inspiration (lung volume +)
Atmospheric pressure is 760 mmHg. What is the intrapulmonary pressure of the lungs at rest, during inspiration and during expiration?
Rest: 760 mmHg
Inspiration: 757 mmHg
Expiration: 763 mmHg
STUDY QUIZ FLASHCARDS TOO OKAY????!?!!!!?!!?!?!?!!??!!!
okay :)
Ventilation is affected mostly by what two factors?
- Compliance (stretchability) of lungs
- Resistance of airways to airflow
What is the effect of surface tension on alveoli, resistance to stretch, and compliance?
- Raises pressure in alveoli
- Increases resistance
- Decreases compliance
How is surface tension created?
Why is there so much ST in alveoli?
Created by intermolecular forces within fluid molecules that attract molecules to each other.
High in alveoli because of hydrogen bonding of fluid secreted by the lungs
Sympathetic activation results in _________ which _______ resistance whereas parasympathetic activation results in _________ which _______ resistance
BRONCHODILATION, DECREASES
BRONCHOCONSTRICTION, INCREASES
What are two additional factors that can increase resistance of the brochial tube? (bronchoconstrictor)
Histamine and accumulation of mucus
