B27 - Trachea, lungs, blood supply and innervation

Question 1

Trachea

Structures to mention

Answer 1

• Pars cervicalis
• Pars thoracica
• Cartilagines tracheales
• Musculus trachealis (Transverse bands of smooth muscle, muscle it attached inside the cartilage (Ca: outside))
• Ligg. anularia (Connective tissue between the tracheal cartilages)
• Bifurcatio tracheae (Where right and left main bronchi arise)
• Carina tracheae (Crest in the lumen on the caudal side of the bifurcation)

Question 2

Traches

Draw a tansverse section of trachea in:

1. Ca
2. Sus
3. Bo
4. Eq

Answer 2

Question 3

Trachea

From where → to where does the trachea extend?

Answer 3

• From cart. cricoidea → radix pulmonis (root of lunge)
• At the root of the longue it bifucates to bronchus principalis dextra et sinistra

Question 4

Trachea

Pars cervicalis

Answer 4

• Related dorsally to:
  
  • Esophagus
  • M. longus colli
  • M. longus capitis
• Related ventrally and laterally to:
  
  • Muscles which passes from sternum → head
• Related dorsolaterally by:
  
  • A. carotis communis
  • Tr. vagosympatheticus
  • V. jugularis interna

Question 5

Trachea

Pars thoracica

Answer 5

• Dorsal to: vena cava cranialis
• Crosses arcus aorta on the right side
• Divided into two principal bronchi at the level of 4^th - 6^th intercostal space
• Su, ru: cranial to bifucation: bronchus trachealis
  
  • ​Supplies lobus cranialis sinister (right cranial lung lobe)

Question 6

Bronchii

1. Structures to mention
2. Draw the bronchial three

Answer 6

• Arbor bronchalis (Bronchial three)
• Bronchus principalis dext. et sin.
• Bronchi lobares (Each serves one whole lobe)
  
  • Bronchus trachealis (su, Ru) (Bronchus of the right cranial lung lobe)
• Bronchi segmentales (Each serves one whole segmentum bronchopulmonale)
• Bronchuli lobulares
• Bronchuli terminales
• Bronchuli respiratorii (Form terminal subdivision of bronchioles)
  
  • Ductuli alveolares
  • Sacculi alveolares (Bearing alveoli)
  • Alveoli pulmonis (Site of gas exchange)

Question 7

Lungs

1. Structures to mention (ø lobes)
2. Draw the lung

Answer 7

• Basis pulmonis (Caudal part, in contact with the diaphragm)
• Apex pulmonis (Cranial)
• Facies costalis (In contact with the costal pleura)
• Facies medialis
  
  • Impressio cardiaca
  • Impressio aortica
  • Impressio oesophagea
  • Sulcus venae cavae caudalis (Groove for the v. cava caudalis in the right lung between accessory lobe and middle and caudal lobes)
• Facies diaphragmatica
• Facies interlobares (In the fissure between lobes)
• Margo obtusus [=dorsalis] (Thick, dorsal border)
• Margo acutus (Thin border)
  
  • Margo ventralis (Cranial to the tip of the middle lobe of the right lung or along the ventral border of the cranial lobe of the left lung)
  • Margo basalis
• Hilus pulmonis (Area where bronchus and vessels enter)
• Radix pulmonis (Composed of the structures that enters the lung at the hilus)
• Incisura cardiaca pulmonis dexter
• Incisura cardiaca pulmonis sinister
• Lobus pulmonis
• Segmentum pulmonis
• Lobulus pulmonis
• Acinus pulmonis

Question 8

Lung

Give the lung lobes in:

1. Dog
2. Horse
3. Bovine
4. Pig

Answer 8

Dog: (7)

• Sinister:
  
  • Lobus cranialis
    
    • ​Pars cranialis
    • Pars caudalis
  • Lobus caudalis
• Dexter:
  
  • ​Lobus cranialis
  • Lobus medius
  • Lobus caudalis
  • Lobus accessorius

Horse: (5)

• Sinister:
  
  • ​Lobus cranialis
  • ​​Lobus caudalis
• Dexter:
  
  • ​​​Lobus cranialis
  • ​​Lobus caudalis
  • ​​Lobus accessorius

Bovine: (7)

• Sinister:​
  
  • ​​Lobus cranialis
    
    • ​Pars cranialis
    • Pars caudalis
  • ​​Lobus caudalis
• Dexter:
  
  • ​​​Lobus cranialis
    
    • ​Pars cranialis
    • Pars caudalis
  • ​​Lobus medius
  • ​​Lobus caudalis
  • ​​Lobus accessorius

Swine: (7)

• ​​​Sinister:
  
  • ​​​Lobus cranialis
    
    • ​Pars cranialis
    • Pars caudalis
  • ​​Lobus caudalis
• Dexter:​
  
  • ​​​Lobus cranialis
  • ​​Lobus medius
  • ​​Lobus caudalis
  • ​​Lobus accessorius
• Eq: undivided cranial lobes
• Bo: left & right cranial lobes divided
• Bo, sus: Bronchus trachealis to right cranial lobe

Question 9

Lungs

Location

Answer 9

• Pleural sacs - which come together medially to form mediastinum

Question 10

Lungs

What are the lungs covered with?

Answer 10

• Pulmonary pleura
• Pulmonary lig.
• Fill their respective pleural sacs completely, leaving only a capillary space which in healthy animals contains a small amount of serous fluid → frictionless movement of the lungs during respiration

Question 11

Blood supply of the lungs

Answer 11

Functional blood supply:

• Comes from right ventricle → tr. pulmonalis → lung
  
  • ​Enters the lung as venous blood
• Passes through the alveolar capillaries where it is oxygenated
• Leaves: lung → vv. pulmonales → left atrium

Nutritional blood supply:

• Aorta thoracica → a. bronchoesophagea
  
  • Follows as bronchial arteries the ramifications of the broncheal tree, supplying the bronchi proximal to the bronchioles
  • Ca: right & left
  • Others: single
• After leaving the lungs: vv. bronchales → v. azygous

Question 12

Innervation of the lungs

Answer 12

• Sympathetic and parasympathetic
  
  • Sympathetic fibers from ggl. cervicale mediale et caudale → mediastinum
  • Unite with parasympathetic fibers from n. vagus
  • Form plexus cardiaca
  • Delivers fibers for plexus pulmonalis within mediastinum
• Efferent:
  
  • Bronchial glands
  • Musculature
  • Blood vessel
• Afferent:
  
  • Bronchial mucosa
  • Vessels
  • Stretch receptors