Respiratory Lecture 1: Structure & Function Flashcards
the main function of the respiratory system is to ___
supply tissues with O2 and get rid of CO2 from cell respiration
cellular respiration
the utilization of oxygen in the metabolism of organic molecules
external respiration
exchange of oxygen and carbon dioxide between lungs and the blood
internal respiration
exchange of O2 and Co2 between bloodstream and tissues / cells
most of the energy generated by our tissues is the result of ____ of food substrates
oxidation
the by-product of oxidative metabolism is __
cO2
accumulation of CO2 would result in ___ of bodily fluid
acidification
what are the 7 functions of the respiratory system?
- provide oxygen
- eliminate Co2
- acid-base regulation (with the kidneys)
- phonation (speech sounds)
- host defence
- alterations in arterial chemical messengers, either by removal or inactivation or by activating / producing
- trap and dissolve blood clots
what is one activation of arterial chemical messenger caused by the respiratory system? How is it done?
conversion of AT 1 to AT 2 (vasoconstrictor). Done by activity in the pulmonary angiotensin converting enzyme (ACE) in pulmonary capillaries
describe the structure of the pharynx
hollow muscular tube, about 12 cm long
location of pharynx and what it joins to
behind nose and mouth, joins the larynx
the trachea is surrounded by what type of rings? what is their purpose?
c-shaped cartilage rings; help prevent collapse of airway sand allow for easy, low resistance air movement
the larynx is also called the
voice box
the larynx spits into what two tubes?
trachea and the esophagus
what is the epiglottis and its purpose?
skin flap that covers the trachea during swallowing to prevent aspiration of food/water etc
there are ~___ divisions of the airways after the trachea
23
what is included in the upper airway?
everything above the trachea
what is included in the lower airway?
the trachea and everything below it
what is the most important muscle involved in inspiration?
diaphragm
every time an airway divides, a ___ divides with it
blood vessel
in order for good respiration, what 2 components must be well-matched?
- good blood supply
2. ventilation
a dense network of pulmonary capillaries around alveoli is vitally important to ___
difusion of O2 and Co2
the ___ is the final part of the conducting zone
terminal bronchiole
what structures are located at the end of the airway/
alveoli
___ are the site of gas exchange
alveoli
t/f there are no alveoli in the conducting zone
true
what is an alveolar sac?
collection of many alveoli
___ are tiny hollow sacs with open ends to the lumen of the airways
alveoli
most of the air-facing surfaces go an alveoli are lined by a continuous one-cell thick layer of ____- cells that are deemed type ___ alveolar cells
flat (squamous) epithelial cells; type 1
type ___ alveolar cells produce detergent-like substance called surfactant
2
total alveolar surface area is very ___ and permits ___ gas exchange of large quantities of O2 and Co2 diffusion
large; rapid
alveolar ___ are responsible for host defence
macrophages
foreign material that is ingested by the alveoli macrophages is either ___or ____
killed or carried to the lymphatics
what is the function of the epithelial cell lining of the alveoli?
provides structural support and thin barrier for easy gas exchange
what are the two pleural membranes?
parietal an visceral
pressure within the intrapleural space is ___ than atmospheric pressure
less
the parietal pleura covers the __ and ___
thoracic cavity and superior face of the diaphragm
visceral pleura covers the ___
external surface of the lung
pleura secrete fluid that remains in the pleural cavity and acts to ____ and prevent ___ when breathing
lubricate the lung; friction
what is pleurisy?
infection / inflammation of the pleura often caused by pneumonia and results in roughening of pleura and friction / sobbing pain with each breath
as pleurisy advances, there is a build up of __ that makes it hard to breathe
fluid
why is the pressure in the intrapleural space below atmospheric pressure?
the lung tissue and tissue of the chest wall are very elastic and pull in opposing directions resulting in a slight pressure decrease
the pressure in the intrapleural space is typically ~ ___ mmHg below atmospheric pressure
3/4
normal quit breathing is also called
tidal breathing
what muscles are involved in tidal breathing?
diaphragm and the external intercostal s
the diaphragm receives input from the __ nerve
phrenic
during exercise, what accessory muscles are required for inspiration?
scalene and the sternomastoids
normal quiet expiration is ___
passive
during expiration, the inspiration muscles are__
relaxed
during exercise, what muscles are used for expiration?
internal intercostals and abdominals
when the diaphragm contracts it moves ___ and ___
down and flattens
the abdomen moves out a bit during inspiration to ___
increase the negative pressure around the lung
the pulmonary circulation consists of ___ that carry blood from the ___ to the ___ and then back to the ___
blood; heart; alveoli, heart
the total blood volume in the pulmonary circuit is ~ ___mL or ___ % of total circulating blood volume
500; 10
__mL of blood is present in the areolar capillary network at nay given time
75b
the amount of blood in the pulmonary alveolar capillary network can be increased during exercise to ___ ML. How is this increase possible?
150-200. recruitment of previously vacant capillaries
mean pressure in the min pulmonary artery is about ___ mmHg, with systolic and diastolic pressures of ___ and ___ respectively
14; 24; 9
the mean pressure in the aorta is __mmHg
90
the driving pressure in the pulmonary circuit is very very ___
low
the pulmonary circulation exists in parallel to
the systemic circulation
pulmonary arteries carry __ blood
de-oxygenated (opposite of systemic circuit)
what are the 4 functions of the conducting zone of the respiratory tract?
- low resistance pathway for air
- host defence
- warms / moistens air
- phonation
the conductive system assures that air is at what temperature and what level of moisture?
37 C and fully saturated
what is the 1 function of the respiratory zone?
gas exchange
how does impaction prevent entry of foreign objects?
largest particles can’t turn the corners of the respiratory system, so they hit the wet surface and stick and will then be destroyed or physically removed
95% of particles greater than ___Um are filtered by the nose
5
how does sedimentation prevent entry of foreign materials?
gradual settling of particles due to their weight, then mucosillary system will cough them up
sedimentation predominates in the ___ airways
small
what is the diffusion method of preventing entry of foreign materials?
random movement of particles as a result of their continuous bombardment by gas molecules
the diffusion method only occurs for the particles of less than ___ um
0.1
what are the 2 main host defence mechanisms and theoir location?
- mucocilliary system located in the conduction zone
2. alveolar macrophages in respiratory zone
macrophage activity is impaired by
cigarette smoke, alcohol, alveolar hypoxia, ozone, radiation
inspired air moves down the terminal bronchioles by ___
bulk flow
once in the respiratory zone, the surface area is so large that __ takes over
difusion
conducting zone is ___mL volume or __% of a normal breath
150, 30
the total surface area of the respiratory zone
70 m2
