Nasal Cavity, Pharynx, Larynx, Trachea, and Lungs

Question 1

understand airflow from nares to alveoli

Answer 1

1. nares: air enters here (nostrils, nasal cartilages give rigidity)
   1a. nasal diverticulum: in equine only!!! a blind sac that is opened by the facial muscles to funnel more air in during exercise
2. nasal cavity: nasal septum divides into right and left sides, contains dorsal meatus, dorsal/ethmoid concha, middle meatus, ventral meatus, ventral/maxillary concha, maxilla bones on either side, vomer bone caudally, all this shit to swirl and warm and moisten air before it goes farther
3. tonsils: filtering gates against pathogens from air and food; palatine, lingual, pharyngeal, and tubal tonsils (tubal tonsils are prominent in large animals)
4. pharynx/larynx intersection: larynx for food, pharynx for air (supposedly but these bitties cross paths and the epiglottis sometimes sucks at its job and we can all choke pretty easily)
5. larynx: rigid due to laryngeal cartilages (arytenoid and cricoid); has both respiratory and vocal functions (vocal due to rima glottidis: narrowed edges of larynx/vocal folds)
6. trachea: uneventful vacuum hose; rigidity from cartilage that is NOT arranged in rings, but a U shape that opens dorsally and is encircled by tracheal muscle
7. lungs: enter principle bronchi first, principle bronchi branch into specific lung lobes, where secondary and then tertiary bronchi branch off

Question 2

describe lungs in each species

Answer 2

horse:
left: left cranial and left caudal lobes
right: right cranial lobe (contains cardiac notch), accessory lobe, right caudal lobe

cow:
left: cranial part of left cranial lobe, caudal part of left cranial lobe, left caudal lobe
right: cranial part of right caudal lobe (contains cardiac notch and tracheal bronchus), caudal part of right cranial lobe(also cardiac notch and tracheal bronchus), middle lobe, accessory lobe, right caudal lobe

cat and dog:
left: cranial part of left cranial lobe, caudal part of left cranial lobe, left caudal lobe
right: right cranial lobe, middle lobe, accessory lobe, right caudal lobe

Question 3

identify and name nose, pharynx, larynx, trachea, and lungs

Answer 3

see pictures

Question 4

identify and name pleural space including visceral and parietal pleura, internal and external intercostals, and diaphragm

Answer 4

see pictures

Question 5

describe lower respiratory anatomy, including tracheal branching and lung lobation

Answer 5

trachea branches into L and R principle bronchi, which branch into secondary bronchi, which branch into segmental bronchi that enter each lung lobe and branch into terminal bronchioles that become respiratory bronchioles and enter alveoli for gas exchange

dog and cat lung lobes:
left side: cranial part of left cranial lobe, caudal part of left cranial lobe, left caudal lobe
right side: right cranial lobe, middle lobe, accessory lobe, right caudal lobe

cow:
left side: cranial part of left cranial lobe, caudal part of left cranial lobe, left caudal lobe
right side: cranial part of right cranial lobe (supplied by tracheal bronchus; cardiac notch), caudal part of right cranial lobe (supplied by tracheal bronchus), middle lobe, accessory lobe, right caudal lobe

horse:
left side: left cranial lobe, left caudal lobe
right side: right cranial lobe (cardiac notch), accessory lobe, right caudal lobe