5.1 - Structure and Function of Respiratory System Flashcards
What are the main functions of the respiratory system?
- exchange of gases between atmosphere and blood
- homeostatic regulation of body pH
- Protection from inhaled pathogens and irritating substances
- Vocalization
The process of gas exchange between the atmosphere and the lungs is called? What are its parts?
ventilation or breathing
- inspiration/inhalation: air moves into lungs
- expiration/exhalation: air moves out of lungs
Where does gas exchange take place?
- from lungs to blood
- from blood to cells
- from cells back to blood
- from blood to lungs
What are the 3 structures involved in both ventilation and gas exchange?
conducting system
- airways
exchange surface
- alveoli
pumping system
- bones and muscles of thorax
What is the span of the conducting system or airways?
from the external environment to the exchange surface of the lungs (alveolar interface)
What are the 2 divisions of the respiratory system and their components?
upper respiratory tract
- mouth, nasal cavity, pharynx, larynx
lower respiratory tract
- trachea, bronchi, bronchioles, lungs
On the external view, the right lung is divided into __ lobes, and the left lung is divided into __ lobes
right lung: 3 lobes
left lung: 2 lobes
The trachea branches into __ bronchi, which further divides __ times, terminating into ____
2 bronchi
divides 22 more times
terminates into cluster of alveoli
What are the sites of gas exchange?
the alveoli
What are alveoli? Where are they found?
tiny hollow sacs found at the ends of the terminal bronchiole
How does gas exchange occur between alveoli and capillary?
by diffusion
What makes up the majority of the alveolar surface?
an extensive capillary network covers 80-90% of the alveolar surface
List and define the types of alveoli cells:
type 1 alveolar cells
- large but thin
- rapid gas diffusion
type 2 alveolar cells
- smaller but thicker
- synthesize and secrete surfactants
What do surfactants do?
disrupt cohesive forces that hold water together to prevent lungs from collapsing
Blood vessels of the _______ circulation allow for exchange with alveoli
pulmonary circulation
What is the path taken by low O2 blood exiting the right ventricle of the heart?
- goes into pulmonary arteries via pulmonary trunk
- 2 pulmonary arteries, 1 to each lung
TRUE OR FALSE:
About 10% of the total blood volume is in the pulmonary circulation at any one time
TRUE
Why is the rate of blood flow high in the right ventricle compared to the left ventricle?
right ventricle: all of the output goes to the lungs
left ventricle: output goes towards different parts of body
TRUE OR FALSE:
The right ventricle pumps harder than the left ventricle
FALSE:
left ventricle pumps harder than right ventricle
Why is the blood pressure of the pulmonary circuit low compared to systemic circuit?
blood needs to travel a shorter distance to the lungs, can be at lower pressure than elsewhere
What is the relation of the lungs to the chest wall?
- chest = thorax
- closed compartment
- closed off at top by: neck muscles and connective tissue
- closed off at bottom by: diaphragm
- wall: ribs and intercostal muscles
What are the muscles of expiration and inspiration?
expiration
- abdominal muscles
- internal intercostals
inspiration
- diaphragm
- external intercostals
- sternocleidomastoids
- scalenes
What surrounds the lungs?
pleural sac
- forms double membrane around each lung
What is the pleura?
lubricant fluid
