Lecture 24- respiration Flashcards
the upper respiratory tract contains
nasal cavity
pharynx
larynx
site of gas exchange
alveoli
common passageway shared by respiratory and digestive system
pharynx
why is the surface of the lungs moist?
thin layer of fluid for oxygen to dissolve into before it can diffuse across the alveolar and capillary endothelium
why does the trachea have rings?
to prevent collapse from pressure changes
why does air move into the lungs?
the gas pressure in the lungs is less than atmospheric pressure
why does air move out of the lungs?
gas pressure in lungs is more than atmospheric pressure
(pressure moves to region of lower pressure)
our respiratory system is optimized to take advantage of
bulk flow and diffusion
distance between alveolar airspace and capillary endothelium is —-, allowing gases to diffuse —- between them
short, rapidly
how many cell membranes does a molecule of O2 need to cross to get from the inside of an alveolus into blood?
4 cell membranes
(2 cells)
lower respiratory system
trachea
primary bronchi (R, L)
many smaller bronchi
bronchioles
alveoli
functions of the respiratory system
- Gas exchange: O2 uptake and CO2 release
- Regulating body pH (homeostasis)
- Conditioning of inspired air
- Protection: filtering and clearing foreign particles
- Vocalization
External respiration
= movement of gases between internal environment of body and external environment
inspiration and expiration
describe the 3 types of exchange
exchange 1: atmosphere to lungs (ventilation)
exchange 2: lungs to blood
exchange 3: blood to cells
muscles used for ventilation
external intercostals and diaphragm
for forceful breathing, sternocleidomastoids and scalenes are recruited
