Chapter 6.1 Flashcards
Where is the pharynx? What is it used for?
- it is behind the nasal cavity
- > at the back of the mouth
-it is used for both air destined for the lungs and food destined for the esophagus
Where is the larynx? What is its function
- it is below the pharynx
- >its only pathway is for air
Do the brochi and trachea contain cilia? Why?
- to ensure to catch material
- >that has made it past the mucous membrane in the nose and the mouth
Describe the movement of air starting when you take a deep breath
1) Nasal cavity
- >passes through the nasal cavity
- >filtered by mucous membranes/nasal hairs
2) Air passes into larynx and pharynx
3) From the larynx, the air goes to the trachea
4) Then from the trachea it goes to the bronchi
5) Bronchi divide again into the bronchioles
- >which divide further into the alveoli
6) Each alveoli is further coated with surfactant
- >surfactant lowers surface tension and prevents the alveoli from collapsing onto itself
What is the opening of the larynx referred to as?
- it is the glottis
- >the glottis is covered by the epiglottis to prevent food from entering
What membrane surrounds the lungs?
- the pleurae surrounds each lung
- surface adjacent to the lung is the the visceral pleura and the outer part is the parietal pleura
- the fluid within the pleural sac is referred to as the intrapleural sac
- > the fluid layer is thin
- > it helps to lubricate the two pleural surfaces
Do lungs fill passively? If not, then how do they fill
- no inhalation is not passive
- > they require skeletal muscle to generate the negative pressure for expansion
- > most important of these muscles is the diaphragm
What two structures does the diaphragm divide? What control is it under?
- it divides the thoracic(chest cavity) from the abdominal cavity
- it is under somatic control
What ultimately drives breathing
-the pressure differential between the pleura ultimately drive the breathing
What muscles do we use during inhalation? Also describe the process, referring to pressure changes and volume changes that occur.
- we use our diaphragm as well as the external intercostal muscles
- > to expand the thoracic cavity
- > the intrathoracic volume increases
- > the intrapleural volume increases as well
- > intrapleural pressure decreases
- at this point
- > lungs expand into the intrapleural space
- > pressure in the lungs drop
- > air is sucked into the intrapleural space
- note this mechanism is referred to as negative-pressure breathing mechanism
- > because the driving force is the lower pressur ein the intrapleural space
What happens to diaphragm and external intercostal muscles during exhalation
- the diaphragm and external intercostals relax
- > the chest cavity decreases in volume
- > it increases in pressure and air is pushed out into the atmosphere
What is meant by the term total lung capacity
- the maximum volume of air in the lungs
- > when one inhales completely
- > usually 6-7 liters
What is residual volume
-the minimum volume of air in the lungs when one exhales completely
What is vital capacity
- difference between the minimum and maximum volume of air in the lungs
- > TLC- RV
What is tidal volume
-the volume of air inhaled or exhaled in a normal breath
