respiratory system Flashcards
respiratory system functions:
exchange oxygen & carbon dioxide between environment, blood & tissue
oxygen is necessary for . . .
energy production
physiology includes three components:
- ventilation
- gas exchange or respiration
- transport of gases to peripheral tissues
four processes of respiration of respiration:
respiratory system:
ventilation (breathing)
external respiration (gas exchange)
circulatory system:
transport
internal respiration
what is pulmonary ventilation (breathing)
movement of air into and out of lungs
what is external respiration?
exchange of O2 and CO2 between lungs and blood
what is internal respiration?
exchange of O2 and CO2 between systemic blood vessels and tissues
what is thorax and what does it do?
bony thorax covers and protects the major organs of the cardiopulmonary system
what does the sternum consist of?
flat bone consisting of manubrium, body, xiphoid
upper respiratory is made up of . . .
nasal cavity
oral cavity
pharynx
nostril
larynx
trachea
lower respiratory is made up of . . .
carina of trachea
left main (primary) bronchus
right main (primary) bronchus
right lung
Left lung
diaphragm
what is the trachea?
the windpipe that extends from the larynx into the mediastinum, where it divides into two main bronchi
trachea walls are composed of what three layers?
mucosa
submucosa
adventitia
what is the mucosa?
ciliated pseudostratified epithelium with goblet cells
what is the submucosa?
connective tissue with seromucous glands supported by 16-20 C-shaped cartilage cartilage rings that prevent collapse of trachea
what is the adventitia?
outermost layer made of connective tissue
trachea divides to form what . .
right and left main bronchi
each lobar bronchus branches into . . .
segmental (tertiary) bronchi
respiratory zone begins where terminal bronchioles feed into __________________ which leads into ________________ and finally into ________________
respiratory bronchioles
alveolar ducts
alveolar sacs
alveolar sacs contain clusters of . . .
alveoli
respiratory membrane consists of ________ and ________ walls and their fused basement membranes
alveolar
capillary
what is the alveoli wall composed of ?
primarily of a single layer of cells and a flimsy basement
alveoli wall secrete _______ and __________________.
surfactant
antimicrobial proteins
what does the media stinen store?
the heart
two circulations perfuse lungs:
pulmonary circulation
bronchial circulation
pulmonary circulation is made up of . . .
pulmonary arteries
pulmonary veins
what do the pulmonary arteries do?
deliver systemic venous blood from heart to lungs for oxygenation
what do pulmonary veins do?
carry oxygenated blood from respiratory zones back to heart
bronchial circulation is made up of . . .
bronchial arteries
what do bronchial arteries do?
provide oxygenated blood to lung tissue
what are the lungs innervated by?
parasympathetic and sympathetic motor fibers
as well as visceral sensory fibers
in the lungs nerves enter through _________________ on lung root
pulmonary plexus
parasympathetic fibers cause what?
bronchoconstriction
sympathetic fibers cause what?
bronchodilation
what do the pleurae do?
divides thoracic cavity into two pleural compartments and mediastinum
what is the parietal pleura?
membrane on thoracic wall, superior face of diaphragm, around heart, and between lungs
what is the visceral pleura?
membrane on external lung surface
___________ fills the ____________ between two pleurae
pleural fluid
pleural cavity
what is pleurisy?
inflammation of pleurae that often results from pneumonia
other fluids that may accumulate in pleural cavity?
blood
blood filtrate
what is pleural effusion?
fluid accumulation in pleural cavity
volume changes cause __________ changes which cause ____________________
pressure
air to move
intrapleural pressure is always ________ relative to intrapulmonary pressurw
negative
what keeps the lungs from collapsing?
negative pressure
what is atelectasis?
plugged bronchioles, which cause collapse of alveoli
what is pneumothorax? and how can it occur?
air in pleural cavity
can occur from either wound in parietal pleura or rupture of visceral pleura
what does pulmonary ventilation consists?
inspiration and expiration
what is boyle’s law?
the relationship between pressure and volume of a gas
inspiration is an active process involving what muscles?
inspiratory muscles – diaphragm and external intercostals
action of the diaphragm
when dome-shaped diaphragm contracts, it moves inferiorly and flattens out
what does the diaphragm and external intercostal muscles contracting result in?
increase in thoracic volume
action of intercostal muscles
when external intercostals contract, rib cage is lifted up and out
inspiration - sequence of events
- inspiratory muscles contract
- thoracic cavity volume increases
- lungs are stretched; intrapulmonary volume increases
- intrapulmonary pressure drops
- air flows into lungs downs its pressure gradient until intrapulmonary pressure is 0
what muscles do forced expiration use?
an active process that uses oblique and transverse abdominal muscles, as well as internal intercostal
expiration – sequence of events:
- inspiratory muscles relax
- thoracic cavity volume decreases
- elastic lung recoil passively; intrapulmonary volume decreases
- intrapulmonary pressure rises
- air flows out of lungs downs its pressure gradient until intrapulmonary pressure is 0
physical factors influencing ventilation:
airway resistance
alveolar surface tension
lung compliance
restrictive lung disease =
low compliance
obstructive lung disease =
high compliance
what dilates bronchioles?
epinephrine
alveolar surface tension?
the attraction of liquid molecules to one another at a gas-liquid interface
what is surfactant ?
a protein complex that helps reduce surface tension of alveolar fluid
what is surfactant produced by?
type II alveolar cells
what is infant respiratory distress syndrome (IRDS)
increased surface tension results in collapse of alveoli after each breath
what is lung compliance?
measure of change in lung volume that occurs with a given change in transpulmonary pressure
two factors affecting compliance
elasticity
surfactant
compliance can be diminished by:
- nonelastic scar tissue replacing lung tissue
- reduced production of surfactant
- decreased flexibility of thoracic cage
total compliance of the respiratory system is also influenced by compliance of the thoracic wall, which can be decreased by:
- deformities of thorax
- ossification of costal cartilage
- paralysis of intercostal muscles
