Chapter 22: Respiratory System Parts of the Respiratory System Part 2

Trachea “Windpipe” “Windpipe” Descends from the larynx Descends from the larynx Ringed tube of cartilage. Ringed tube of cartilage. –C-rings: tracheal cartilages to help prevent the trachea from collapsing. Ends by dividing into the two main bronchi. Ends by dividing into the two main bronchi. The last tracheal cartilage is called the carina The last tracheal cartilage is called the carina

Tracheostomy Used to reestablish air flow past an obstruction superior to the larynx Used to reestablish air flow past an obstruction superior to the larynx Small incision is made into the trachea and a tube is inserted through the incision Small incision is made into the trachea and a tube is inserted through the incision

Bronchi Starts at the tracheal branch (carina) Starts at the tracheal branch (carina) Right and left main (primary) bronchi are formed at the division of the trachea Right and left main (primary) bronchi are formed at the division of the trachea

Once inside the lungs each main bronchus subdivides into lobar (secondary) bronchi  serves each lobe Once inside the lungs each main bronchus subdivides into lobar (secondary) bronchi  serves each lobe –3 right –2 left Bronchi

The lobar bronchi branch into segmental (tertiary) bronchi, which keep dividing into smaller and smaller branches The lobar bronchi branch into segmental (tertiary) bronchi, which keep dividing into smaller and smaller branches About 23 orders of branching!! About 23 orders of branching!! Bronchi

Often called the bronchial or respiratory tree because of all of the branching Often called the bronchial or respiratory tree because of all of the branching Bronchi

Tissue mimics that of the trachea, but as the conducting tubes become smaller: 1. Cartilage rings are replaced by irregular plates of cartilage (bronchioles no cartilage) 2. Epithelium types changes 3. Amount of smooth muscle increases Bronchi - Changes

Bronchioles Passageways smaller than 1mm are called bronchioles (“little bronchi”) Passageways smaller than 1mm are called bronchioles (“little bronchi”) Tiniest are the terminal bronchioles (<.5mm) Tiniest are the terminal bronchioles (<.5mm)

Bronchioles Respiratory zone begins as the terminal bronchioles feed into the respiratory bronchioles. Respiratory zone begins as the terminal bronchioles feed into the respiratory bronchioles. Protruding from the respiratory bronchioles are the alveoli Protruding from the respiratory bronchioles are the alveoli

Asthma Attack The bronchioles are made of smooth muscle  muscle spasms close off the air ways  air can’t flow through easily  wheezing, coughing, tight chest The bronchioles are made of smooth muscle  muscle spasms close off the air ways  air can’t flow through easily  wheezing, coughing, tight chest Quick relief inhaler  bronchiodilator  quickly open swollen airways Quick relief inhaler  bronchiodilator  quickly open swollen airways

Alveoli Thin-walled air sacs Thin-walled air sacs These are the “air sacs” of the lungs These are the “air sacs” of the lungs

Alveolar sacs – clusters of alveoli Alveolar sacs – clusters of alveoli Like a bunch of grapes Like a bunch of grapes Alveoli About 300 million alveoli in the lungs! About 300 million alveoli in the lungs! Very large surface area for gas exchange! 750ft 2 (Tennis Court) Very large surface area for gas exchange! 750ft 2 (Tennis Court)

Respiratory Zone!! Actual place where gas exchange takes place! Respiratory Zone!! Actual place where gas exchange takes place! What tissue should we expect to find? What tissue should we expect to find? Alveoli

Lungs The bronchi, bronchioles, the alveoli, and all associated capillaries The bronchi, bronchioles, the alveoli, and all associated capillaries Right and left lobes Right and left lobes Right  superior, middle, inferior Right  superior, middle, inferior Left  superior, inferior Left  superior, inferior Where is the missing lobe? Where is the missing lobe?