Respiratory system

Question 1

56. Epiglottis (HE)

Answer 1

• epithelium: stratified squamous non-keratinized
• laryngeal surface:
  
  • epithelium is narrower
  • epithelium transforms into ciliated pseudostratified columnar epithelium
  • taste buds
• lingual surface:
  
  • CT papilla
• lamina propria: lymphocytes
• submucosa: sero-mucous glands
• fibro-elastric cartilage + small mucous glands

Question 2

17. Larynx (HE)

Answer 2

• thyroid cartilage (+ cricoid)
• folds: vestibular + vocal
• spaces: laryngeal vestibule + laryngeal sinus + cavum subglotticum
• muscles: thyroarytenoid + thyroepiglottic + vocalis
• epithelium: ciliated pseudo stratified columnar (exept vocal folds⇒non-keratinized stratified squamous)
• lamina propria: thin, loose, cellular highly vascular CT
• submucosa: loose CT + sero-mucous glands
• membranes: quadrangular + conus elasticus

Question 3

57. Trachea (HE)

Answer 3

• cartilagineus part: Hyaline
• membranous part: fibroelastic ligament + smooth muscle
• epithelium: pseudo stratified ciliated columnar (+goblet cells)
• lamina propria: loose, highly cellular + vascular CT + elastic fibers
• submucosa: loose CT + sero-mucous glands + smooth muscle(trachealis muscle)
• adventitia: CT + blood vessels, nerves, lymphatics

Question 4

58. Lung (HE)

Answer 4

• bronchi have cartilage, bronchioles do not
• primary bronchi ⇒ terminal bronchi ⇒ bronchiole ⇒ terminal bronchiole ⇒ respiratory bronchiole ⇒ alveolar duct ⇒ alveolar sac
• pulmonary artery branches parallel with air ways
• pulmonary artery and vein have thinner walls

Question 5

Segmental bronchus

Answer 5

• arise from secondary bronchi
• epithelium: pseudo stratified ciliated columnar + goblet cells
• lamina propria: thin
• mucosal-submucosal boundary: smooth muscle layer
• submucosa: loose CT + sero-mucous glands + cartilage
• adventitia: outermost CT

Question 6

Bronchiole

Answer 6

• arise from segmental bronchi
• no cartilage
• devoid of glands
• epithelium: simple ciliated columnar
• lamina propria: smooth muscle + elastic fibers
• after death ⇒ star shaped lumen

Question 7

Respiratory bronchiole

Answer 7

• arise from terminal bronchioles
• epithelium: simple cuboidal
• lamina propria: CT + smooth muscle

Question 8

Alveolar ducts

Answer 8

• long passage that open into alveolar sac

- small aggregation of smooth muscle cells

Question 9

Pneumocytes

Answer 9

TYPE 1 PNEUMOCYTE:
- highly attenuated cytoplasm covering most of alveolar surface
- nuclear region not visible
TYPE 2 PNEUMOCYTE:
- round cells, large nuclei, vacuolated cytoplasm
- foamy cytoplasm
- secrete pulmonary surfactant

Question 10

ALveolar macrophages

Answer 10

• interalveolar septa or luminal surface of pneumocytes
• irregular shape and large size
• dark due to dust and carbon

Question 11

59. Lung (Resorcin fuchsin)

Answer 11

• elastic fibers: blue
• elastic fibers under epithelium
• rich elastic network in alveolar wall
• large pulmonary arteries: internal elastic membrane + external elastic membrane

Question 12

61. Fetal lung (HE)

Answer 12

• early alveolar phase (7th month)
• glandular appearance
• hyaline cartilage
• pulmonary artery has thick muscular wall
• alveolar epithelial cells do not differentiate until late pregnancy
• secretion of surfactant in 7th month⇒ reduces tension in lungs