respiratory system Flashcards
pulmonary ventilation
movement of air in and out of lungs
external respiration
exchange of O2 and CO2 in lungs and blood
internal respiration
exchange of O2 and CO2 in systemic blood vessels and tissue
functions of nose & nasal cavity
- filters and cleans air
- provides an airway for respiration
- moistens and warms entering air
- serves ad resonating chamber for speech
- houses olfactory receptors
three regions of the pharynx
- nasopharynx
- oropharynx
- laryngopharynx
epiglottis
elastic cartilage, open for breathing
glottis
opening between vocal folds
thyroid & cricoid cartilage
shield, can affect the level of tension affecting the vocal cords
arytenoid cartilage
production of vocal sound
vocal folds
folds vibrate to produce sound as air rushes up from lungs
how do vocal cords differ in men and women
the opening is wider for men than in women making the sound deeper
describe the trachea & bronchial tree
trachea - windpipe extends from larynx into mediastinum, where it divides into two main bronchi
bronchial tree - air passages undergo 23 orders of branching
how is the right lung different from the left
three lobes on the right and two on the left
what type of tissue is alveoli composed of
simple squamous epithelium
what are its functions
allows gas exchange across membrane by simple diffusion
why is surfactant important ?
keeps the alveoli inflated that is essential.
what causes respiratory distress syndrome
insufficient quantity of surfactant in premature infants
- fetal lungs do not produce adequate amounts of surfactant until last two months of development
describe respiratory membrane
blood- air barrier that consists of alveolar and capillary walls along with their fused basement membranes, very thin
which blood vessels carry deoxygenated blood to the lungs? oxygenated lungs?
pulmonary arteries - deoxygenated
pulmonary veins - oxygenated
what is atmospheric pressure?
760 mm hg
intrapulmonary pressure
pressure in alveoli
- fluctuates with breathing
intrapleural pressure
pressure in pleural cavity
- always a negative number
intrapleural pressure during inspiration
cavity pressure becomes more negative
intrapulmonary pressure during inspiration
lungs are stretched then pressure drops by 1 mm Hg, air flows into lungs, down its pressure gradient
intrapleural pressure in expiration
returns to inital value as chest wall recoils
intrapulmonary pressure
pressure increases during expiration
atelectasis
lung collapse due to plugged bronchioles, causes collapse of aveoli
pneumothorax
air in pleural cavity
tidal volume
amount of air moved into and out of lung with each breath
inspiratory reserve volume
amount of air that can be inspired forcibly beyond the tidal volume
expiratory reserve volume
amount of air that can be forcibly expelled from lungs
residual volume
amount of air that remains in lungs
vital capacity
tv + irv + erv
total lung capacity
sum of all lung volumes
partial pressure
pressure exerted by each gas in mixture
directly proportional to its percentage in mixture
what happens to the partial pressure in high altitude
partial pressure declines
external respiration
involves the exchange of O2 and CO2 across respiratory membranes
- partial pressure gradients and gas solubilities
- ventilation perfusion coupling
alveolar O2 high = arterioles dilate
alveolar O2 low = arterioles constrict
alveolar CO2 high = bronchioles dilate
alveolar CO2 low = bronchioles constrict
internal respiration
involves gas exchange in body tissues
- partial pressures and diffusion gradients are reversed
-tissue po2 is always lower so oxygen moves from blood to tissues
- tissue pco2 is always higher than arterial blood so co2 moves from tissue to blood
how is oxygen transported to the blood?
each hemoglobin can transport 4 oxygen molecules
hemoglobin
found in a red blood cell
- carries oxygen
which blood vessels carry deoxygenated blood to the lungs??
CO2 is bound to the globin part of hemoglobin
hypoxia
inadequate O2 delivery to tissue
what does the oxyhemoglobin dissociation curve tell us
temperature
blood pH
DPG
Pco2
how is carbon dioxide transported into the blood
CO2 binds to the globin part of the hemoglobin reffered to carbaminohemoglobin
bicarbonic ions
combining CO2 with water to form carbonic acid, which quickly dissociated into bicarbinate and H-
respiratory centers in the medulla & pons
ventral respiratory group
- its inspiratory neurons excite inspiratory muscles via phrenic and intercostal nerves
dorsal respiratory group
- integrates input from peripheral stretch and chemoreceptors
aortic & carotid bodies
peripheral chemoreceptors sense arterial O2 levels
hypothalamic controls
act through limbic system to modify rate and depth of respiration
Chronic obstructive pulmonary disease
irreversible decrease in ability to force air out of lungs
chronic bronchitis
mucosae of lower respiratory passageways become inflamed and fibrosed
asthma
active inflammation of airways precedes bronchospasms
tuberculosis
infectious disease cause by bacterium mycobacterium tuberculosis that leads to tubercules in the lung diseases
cystic fibrosis
abnormal, viscous mucus clogs passageways, which can lead to bacterial infections
hyperventilation
increased depth and rate of breathing that exceeds bodys need to remove CO2
