Respiratory System Flashcards
what is a respiratory surface?
one across which o2 and co2 are exchanged
where does the swim (gas) bladder of fish lie?
above the gut (it develops as outgrowth of gut)
from which part of the gut do the lungs develop?
the foregut
which part of the germ layer does the lung lining come from?
gut endoderm
which part of the germ layer do the surrounding tissues come from?
mesoderm
how many pairs of ribs are there?
12
how are the ribs attached to the sternum?
costal cartilages
what type of cavities is the thorax divided into?
pleural cavities
what separates the pleural cavities?
a central wall of tissue (mediastinum)
what is each lung wrapped in?
pleura
which layer is the visceral pleura?
inner layer
what does the visceral pleura lie against?
the lung
which layer is the parietal pleura?
outer layer
what does the parietal pleura attach to?
the inside of the rib cage
what does the pleural cavity contain?
lubricating fluid
the pressure in the pleural cavity is positive. true or false?
false- it is negative
what is another name for the root of the lungs?
the hilum
the visceral and parietal pleura are continuous with one another at the hilum. true or false?
true
how many lobes does the right lung have?
3 lobes
what are the lobes of the right lung?
upper, middle and lower
how many lobes does the left lung have?
2 lobes
what are the lobes of the left lung?
upper and lower
why is the left lung smaller than the right?
it fits against the cardiac notch
what happens at the root of the lung?
structures enter or leave the lung
what structures enter/leave the lung at the hilum?
one main bronchus, autonomic nerves, 1 pulmonary artery, 2 pulmonary veins.
what supplies the alveoli with blood?
pulmonary artieries
what is emphysema?
the thinning of the alveoli, loss of elastic tissue and collapse of small bronchioles and alveoli, therefore decrease in lung capacity
where does gas exchange occur in an embryo?
placenta
what is surfactant?
a chemical (lipid protein) that is secreted into the lungs and stops the alveoli collapsing
when does most of lung maturation take place?
in the last few weeks of pregnancy
describe the process of breathing in
volume of lungs increases, pressure decreases. therefore atmospheric pressure forces air into lungs. lungs expand until pressure is equal inside and out.
describe the process of breathing out
volume of lungs decrease, pressure increase. therefore air forced out
in what directions can the thoracic cavity expand?
bilaterally, superiorly/inferiorly, anteroposteriorly
describe the movement of the respiratory system during inhalation.
first rib fixed by neck muscles (scalenes). EXTERNAL intercostal muscles pull ribs UPWARDS towards first rib. this action also moves ribs OUT and sternum FORWARDS. diaphragm CONTRACTS and FLATTENS.
describe the movement of the respiratory system during exhalation.
lower rib fixed by abdominal muscles. INTERNAL intercostal muscles pull ribs DOWN. diaphragm RELAXES and returns to domed resting position.
what is the diaphragm made of?
skeletal muscle and tendon
what supplies the diaphragm?
left and right phrenic nerves
how do the phrenic nerves lie in the body?
start in neck, travel through thorax to diaphragm
