Histology

Question 1

What is the function of mucous?

Answer 1

• prevents dehydration of the epithelia

- traps particulate matter

Question 2

What respiratory epithelia lines the nose?

Answer 2

Simple

Question 3

What is the function of the rich plexus of thin-walled arterioles and venules in the connective tissue of the nose?

Answer 3

Warm and humidify air

Question 4

What is the epithelium of the larynx vs the vocal folds?

Answer 4

respiratory epithelium vs stratified squamous (can withstand vibrations)

Question 5

What is the cartilage in the larynx?

Answer 5

Hyaline (imagine someone singing… a high line!)

Question 6

Histological parts of larynx?

Answer 6

Hyaline + striated muscle embedded in fibrous connective tissue

Question 7

Histological/anatomical parts of trachea?

Answer 7

• Respiratory epithelium
• Deep to epithelium are numerous sero-mucous (mixed) glands and lymph nodules
• 12-15 incomplete rings of hyaline cartilage
• Rings of cartilage are joined posteriorly by trachealis muscle (involuntary smooth muscle)

Question 8

What is the diameter of a bronchiole?

Answer 8

Less than 1mm

Question 9

What is the epithelium of a bronchiole?

Answer 9

Simple ciliated columnar epithelium

Question 10

Histological parts of bronchioles?

Answer 10

• Prominent band of smooth muscle
• Lymph nodules in connective tissue
• Pulmonary arteries and veins close by

Question 11

What is the epithelia of terminal and respiratory bronchioles?

Answer 11

Simple cuboidal; sparsely ciliated; clara cells (Clara has square head… Clara… I’m down here!!)

Question 12

Histological parts of terminal vs respiratory bronchioles

Answer 12

• Spincter like ring of smooth muscle (regulate ventilation of alveoli) vs none
• smaller in diameter vs larger (ahh I can breathe!)

Question 13

What are the 5 layers oxygen and carbon dioxide diffuse across?

Answer 13

Surfactant, alveolar cell, basement membrane, capillary endothelium and red cell membrane

Question 14

What is the function of surfactant?

Answer 14

• Reduce surface tension (= better expansion and collapse)

- prevents desiccation of air sacs (due to lipid-like insulating layer)

Question 15

Histological parts of pulmonary and bronchial vessels

Answer 15

• Large pulmonary arteries have longitudinally running elastic fibres in their walls (boingy, boingy on our way to be oxygenated)
• Large pulmonary veins: medial layer = muscle, elastic fibres, internal elastic lamina
• Smaller pulmonary veins and arteries have similar amounts of smooth muscle in walls