21-1: Respiratory Organs Flashcards
What is the major function of the respiratory system?
supply body’s cells c O2 and remove CO2
cellular respiration
cells need a continous supply of O2 to convert food to ATP. CO2 is released, which is lethal to cells, so it must be removed quickly before it turns into carbonic acid
What two systems are involved in respiration?
respiratory (organs that exchange gasses between the atmosphere and blood)
circulatory (blood carries O2 to tissues and removes CO2)
respiration
overall exchange of gasses between the atomosphere, the blood, and the cells
What are the three processes involved in respiration?
pulmonary ventilation: atmosphere <> alveoli
external respiration: alveoli <> “blood” (pulmonary capillaries)
internal respiration: blood <> “tissues” (systemic capillaries)
In which respiration process are gasses first crossing a cell membrane?
external respiration
What is the external nose anatomy?
nasal bones form bridge and hyaline cartilage forms tip; covered with skin and lined with mucus membrane
external nares
2 openings on the inferior surface of the nose
What bones make up the nasal septum?
vomer and perpendicular plate of ethmoid bone
What bones make up the roof of the internal nasal cavity?
ethmoid and sphenoid (separates from cranial cavity)
What makes up the floor of the internal nasal cavity?
palate (separates from oral cavity)
internal nares
connect the internal nose posteriorly with the nasopharynx
What structures in the nose are involved in filtering incoming air?
vibrissae - coarse “hairs” lining anterior nasal cavity (filter large dust particles)
mucosa (traps dust, bacteria, and debris)
cilia (sweep mucus back into the pharynxfor swallowing)
What are four functions of the nose?
- FILTERS incoming air with vibrissae, mucosa, and cilia
- capillaries in the nasal mucosa WARM incoming air
- HUMIDIFIES - mucus-secreting epithelium lines cavity and moistens incoming air
- SMELL - olfactory receptors lie in epithelium lining roof of nasal cavity and send signals via cranial nerve I to olfactory area in the brain
Pharynx
5-inch long funnel shaped muscular tube that extends from teh internal nares to the voice box, has three sections (nasopharynx, oropharynx, laryngopharynx)
nasopharynx
uppermost region that runs from internal nares (behind nasal cavity) to roof of mouth. Passageway for air only. Has 2 openings into the Eustachian tube that connect throat to middle ear. 2 pharyngeal tonsils (adenoids) on posterior wall to trap and destroy pathogens entering in the air
oropharynx
middle region behind the mouth, from the soft palate to the epiglottis. contains palatine and lingual tonsils
Fauces
archway between oropharynx and the mouth
Laryngopharynx
lowest region from epiglottis to larynx (anteriorly) and esophagus (inferiorly)
Larynx
short passageway connecting parynx with trachea; in the middle neck, anterior to vertebrae C4 to C6. Walls are made of cartilage
thyroid cartilage
most prominant anterior wall of larynx (aka Adams apple)
cricoid cartilage
cartilage forming inferior wall, attaching larynx to trachea
epiglottis
leaf-shaped piece of elastic cartilage lying on top of hte larynx, moves up and down to prevent food from entering the trachea during swallowing
During breathing, is the epiglottis open or closed?
open to let air pass into trachea
During swalling, is the epiglottis open or closed?
closed (reflex) to have solids and liquids pass into esophagus
What happens if the epiglottis remains open during swallowing?
cough reflex (if anything other than air gets past)
What is the function of the larynx?
voice production (also routes food and air into proper channels) - exhaled air from lungs causes the true vocal cords to vibrate, generating sound waves
What kind of muscle is attached to true vocal cords?
skeletal muscle, used to change pitch
Muscles in the _ form vowels and muscles in the _ form consonates.
pharnyx; face, tongue and lips
laryngitis
inflammation of the larynx caused by viral/bacterial infection, smoke, or overuse
trachea
4-inch tubular passageway for air anterior to the esophagus in the neck; runs from larynx to mid-thorax where it divides into the right and left primary bronchus
carina
spar of cartilage marking end of trachea - very sensitive
What tissues make up the trachea?
16-20 C-shaped rings of hyaline cartilage encircling smooth muscle walls to give rigid support (so it doesn’t collapse and obstruct airways). The open part of the ring faces the esophagus allowing it to expand when swallowing food
Heimlich maneuver
procedure in which air in the lungs is used to expel an obstruction in the trachea
The smooth muscle walls of the trachea are innervated by the ___. Under stress, the _ branch causes the trachea to ___; when resting, the __ branch causes the trachea to __.
autonomic nervous system; sympathetic; dilate; parasympathetic; constrict
hilum
notch on the medial surface of the lung where R&L primary bronchus run
bronchi
at the level of T7, the trachea divides into a right and left primary bronchus
How many secondary bronchi are there?
one for each lobe of the lung - 3 on the right and 2 on the left
What are the branching levels of bronchi?
trachea right and left primary bronchus secondary (lobar) bronchi (one for each lobe) tertiary (segmental) bronchi continue dividing until... bronchiole (smallest branches)
The bronchi are lined with ___ and reinforced with ___. They are also lined with ___, which serve to ___.
ciliated epithelium; smooth muscle reinforced by hyaline cartilage
cilia; push dirt-laden mucus up to pharynx for swallowing
bronchiole
smallest branches; lacking cartilage and cilia; debris destroyed by macrophages in alveoli; smooth muscle walls constrict during an asthma attack
alveoli
little air sacs clustered in bunches around the ends of the bronchioles; account for most of the lung volume and provide a huge surface area for gas exchange
What is the function of the alveoli?
sites of gas exchange between inhaled air and blood of pulmonary capillaries
