lecture 24: the resp sys Flashcards
air passage
- nasal or oral cavity
- pharynx
- larynx
- trachea
- bronchi - 1st, 2nd, 3rd
- terminal bronchioles
- resp bronchioles
- alveoli
conducting zone
- air passage
- nose, nasal cavity, pharynx
- larynx, trachea, primary, secondary, tertiary bronchi, and terminal bronchioles
resp zone
- gas exchange
- resp bronchioles
- alveolar duct and sacs
- pulmonary alveoli
thoracic cavity
- lung sit within the thoracic cavity
- rib cage protects lungs
- vacuum inside your chest cavity
the conducting zone includes the trachea, primary, secondary, and tertiary bronchi
true
left lung has 3 lobes while the right has 2
false
pulmonary ventilation
- breathing
- the physical movement of air into and out of the lungs; inhalation and exhalation
- function: continuous supply supply of oxygen and release of carbon dioxide
rules of ventilation
- volume and pressure and inversely related
- volume of the lungs is dependent on the volume of the thoracic cavity
- the thoracic cavity volume is dictated by the muscles of inspiration and expiration
increased volume = decrease pressure
decreased volume = increased pressure
- gases move from an area of high to low pressure
- at rest: atmospheric pressure = pressure in lungs
- inspiration: atmospheric pressure > pressure in lungs
- expiration: atmospheric pressure < pressure in the lungs
volume and pressure
pressure and volume are inversely related
- inspiration
- expiration
changes in pressure
gases go from high to low pressure
- inspiration
- expiration
inspiration
- increase in thoracic volume
- decrease in lung pressure, pulling in air
- two types: quiet, deep
expiration
- decrease in thoracic volume
- increase in lung pressure, air expelled
- two types: passive, active
primary musculature
diaphragm
- boundary between thoracic and abdominal cavity
- action during quiet and deep inspiration: contracts to increase volume of the thoracic cavity and expands lungs
additional musculature
external intercostals
scaleness
- most superficial muscle in between the ribs
- fibers run towards pockets
- action during deep inspiration: elevates the rib cage and sternum to increase volume of the thoracic cavity
passive expiration
- no muscle contraction involved
- muscles of inspiration return to resting position
- recoil of lungs forces air out
abdominal muscles
- external oblique
- internal oblique
- transverse abdominis
- rectus abdominis
- action during forced expiration: abdominal muscles will move the diaphragm up and depress the rib cage to decrease volume of thoracic cavity
- diaphragm returns to dome shape
internal intercostals
- deep to external intercostals
- fibers run towards opposite shoulder
- action during forced expiration: depresses the rib cage and sternum to decrease volume of the thoracic cavity
respiratory summary
- inspiratory muscles contract
- thoracic volume increases
- lungs expand
- intrapulmonary pressure drops
- pressure in lungs < atmospheric
- air flows in
- pressure in lungs will reach zero
- triggers expiration
- lungs recoil
- diaphragm and chest wall relaxes
- thoracic volume decreases
- intrapulmonary pressure rises
- pressure in lungs > atmosphere
- air is forced out of lungs
the rib cage and sternum elevate to increase the volume of the thoracic cavity during this action
inspiration
during forced expiration, the abdominal muscles will pull the diaphragm down and depress the rib cage to decrease the volume of the thoracic cavity
false
bronchiole tree
- primary bronchus
- secondary bronchus
- tertiary bronchus
- bronchioles: respiratory bronchiole, alveolar sacs
respiratory portion: alveoli
primary site of gas exchange:
- o2 into bloodstream
- carbon dioxide out of blood stream
capillary network surrounding alveolus
large surface area and thin membrane allow for max gas exchange
alveoli
type 1 pneumocytes:
- simple squamous epithelium of alveoli
- thin walls allow for gas exchange
elastic fibers:
- allow the alveoli to stretch and recoil
type 2 pneumocytes:
- “septal cells”
- produce surfactant: oily substance secreted over alveoli to reduce surface tension
- prevents collapse of alveoli
alveolar macrophage
- “dust cells”
- phagocytose particles
what cell produces surfactant
type 2 pneumocyte
the resp portion includes resp bronchioles, alveolar ducts, and pulmonary alveoli
true/false
true
the respiratory membrane
- aspects of the respiratory membrane:
1. capillary endothelium
2. fused basement membranes
3. alveolar epithelium (type 1 pneumocytes)
gas exchange occurs across this membrane!
respiratory membrane: capillary wall, fused basement membrane, wall of alveoli, surfactant
external respiration (pulmonary)
- exchange btwn the body’s fluids and the external environment; gas exchange btwm the pulmonary circuit and alveoli
- o2 enters blood from alveoli via inhalation
- co2 exits blood into alveoli via exhalation
- blood gains o2 and loses co2
internal respiration (tissue)
- gas exchange btwn the systemic circuit and cells of the body
- o2 exits blood from capillary to tissue in need
- co2 dioxide exits tissue into capillary
- blood loses o2 and gains co2
during external resp, there is gas exchange btwn the pulmonary circuit and alveoli. what changes happen to the blood?
gains o2 and loses co2
blood supply
circulatory system
1. systemic circuit: btwn heart and body
2. pulmonary circuit: btwn heart and lungs
systemic circuit
- blood becomes deoxygenated (co2) at body tissues (ex. muscle)
- deoxygenated blood returned to the heart through the SVC and IVC
- oxygenated blood exits the heart through the aorta
- travels to body tissue in need of o2
pulmonary circuit
pulmonary artery:
- carries deoxygenated blood (rich in co2) from the heart to the lungs
- exhale co2 at the lungs
pulmonary vein:
- carried oxygenated blood from the lungs to the heart
circulatory sys review
- tissue uses up oxygen
- deoxygenated blood through vena cava to right atrium
- right ventricle
- pulmonary artery
- blood travels back to the heart via the pulmonary vein
- enters left atrium
- left ventricle
- exits heart at aorta
- oxygenated blood to tissues
pulmonary artery carries oxygenated blood from the lungs to heart
true or false
false
deoxygenated blood in the vena cava enters into which region of the heart
right atrium
