Respiratory Tract

Question 1

what is respiratory epithelium?

Answer 1

pseudostratified ciliated columnar epithelium with interspersed goblet cells

Question 2

what are the functions of the nose?

Answer 2

• filtration
• humidification
• warming
• olfaction

Question 3

what is the epithelia of the nose?

Answer 3

near opening:
- keratinising stratified squamous epithelium
further from opening:
- non-keratinising stratified squamous epithelium

• respiratory epithelium

Question 4

what produces snot in the nose and where are they found?

Answer 4

seromucinous glands

- loose fibrous connective tissue beneath epithelia

Question 5

what do the serous glands of Bowman secrete?

Answer 5

watery fluid (to wash surface of nasal cavity clean)

Question 6

what is the epithelium of the roof of the nasal cavity?

Answer 6

respiratory (no goblet cells)

Question 7

what are bipolar neurons and where are they found?

Answer 7

dendrite extends to surface to become club-shaped ciliated olfactory vesicle
- found in roof of nasal cavity

Question 8

what are the functions of the nasopharynx?

Answer 8

• gas transport
• humidification
• warming
• olfaction

Question 9

what is the nasopharynx lined by?

Answer 9

respiratory epithelium

Question 10

what are the nasal sinuses?

Answer 10

air filled spaces within bones of skull and facial skeleton

Question 11

what are the functions of the nasal sinuses?

Answer 11

• lower the weight of the skull
• add resonance to the voice
• humidify and warm inspired air

Question 12

what are the nasal sinuses lined by?

Answer 12

respiratory epithelium

Question 13

describe the structure of the epiglottis

Answer 13

elastic cartilage

Question 14

what is the function of the larynx?

Answer 14

voice production

Question 15

what is the larynx lined by?

Answer 15

respiratory epithelium (except vocal cords)

Question 16

describe the structure of the larynx

Answer 16

• almost entirely hyaline cartilage

- seromucinous glands

Question 17

what is the function of the hyaline cartilage in the larynx?

Answer 17

hold larynx open against negative pressure during inspiration

Question 18

what are the vocal cords lined by?

Answer 18

stratified squamous epithelium

Question 19

describe the structure of the vocal cords

Answer 19

• irregular fibrous connective tissue in Reinke’s space
• vocal ligament
• vocalis muscle

Question 20

what lines the trachea?

Answer 20

respiratory epithelium

Question 21

describe the structure of the trachea

Answer 21

• hyaline cartilage in C-shaped rings
• gap between rings filled by trachealis (vertical smooth muscle)
• submucosa

Question 22

what do the bronchi and bronchioles have in common?

Answer 22

• smooth muscle

- some basal neuroendocrine cells

Question 23

what are the differences in the structure of the bronchi and bronchioles?

Answer 23

bronchi:
- partial cartilaginous rings
- respiratory epithelium
- seromucinous glands
- goblet cells
bronchioles:
- ciliated columnar epithelium
- few goblet cells
- clara cells

Question 24

what are the types of bronchi?

Answer 24

• main
• lobar
• segmental

Question 25

describe the sequence of trachea, bronchi and bronchioles

Answer 25

1. trachea 2. main bronchi 3. lobar bronchi 4. segmental bronchi 5. terminal bronchioles 6. respiratory bronchioles

Question 26

where are clara cells most commonly found?

Answer 26

terminal bronchioles

Question 27

describe the structure of clara cells

Answer 27

- roughly cuboidal | - pale-staining vesicular cytoplasm

Question 28

describe the structure of respiratory bronchioles

Answer 28

- spirally-arranged smooth muscle | - no cartilage

Question 29

what type of epithelia lines the respiratory bronchioles?

Answer 29

cuboidal ciliated

Question 30

what make up 40% of the cell population of the alveoli?

Answer 30

type 1 pneumocytes

Question 31

what makes up 90% of the surface area of the alveoli?

Answer 31

type 1 pneumocytes

Question 32

describe the structure of type 1 pneumocytes

Answer 32

- squamous epithelial cells - flattened nucleus - few organelles

Question 33

how are type 1 pneumocytes adapted to their function?

Answer 33

very thin

Question 34

what makes up 60% of the cell population of the alveoli?

Answer 34

type 2 pneumocytes

Question 35

what makes up 5-10% of the surface area of the alveoli?

Answer 35

type 2 pneumocytes

Question 36

describe the structure of type 2 pneumocytes

Answer 36

- round/cuboidal/columnar - central round nucleus - rich in mitochondria - spherical bodies

Question 37

which cells produce surfactant?

Answer 37

type 2 pneumocytes in alveoli

Question 38

what are alveolar macrophages?

Answer 38

phagocytic cells derived from blood monocytes

Question 39

what is the function of alveolar macrophages?

Answer 39

phagocytose bacteria and particulate matter that have reached the alveolar air spaces

Question 40

how are alveolar macrophages removed from the lungs?

Answer 40

- lymphatics of lungs | - mucociliary escalator

Question 41

where are alveolar macrophages found?

Answer 41

- interstitial connective tissue of alveolar walls | - lumen of alveoli

Question 42

what is the blood-air barrier?

Answer 42

type 1 pneumocyte resting on basement membrane shared by vascular endothelial cell of an adjacent capillary

Question 43

how many layers could you say there are in the blood-air barrier?

Answer 43

2, 3, 4 or 8

Question 44

what is the interstitium?

Answer 44

loose fibrous connective tissue | - where endothelial cells are not in direct contact with pneumocytes

Question 45

what does the interstitium contain?

Answer 45

- collagen and elastin fibres - fibroblasts - macrophages

Question 46

what are the pores of kohn?

Answer 46

holes in alveolar walls

Question 47

what are the functions of the pores of kohn?

Answer 47

- equalise pressure between adjacent alveoli - help lungs to inflate easily and evenly during inspiration - allow pneumonic infection to rapidly spread to multiple alveoli

Question 48

what are the 2 layers of pleura?

Answer 48

(same membrane that reflects itself) - adheres to outer surface of lungs - adheres to inner surface of chest wall

Question 49

what type of epithelia lines the visceral pleura?

Answer 49

flattened squamous mesothelial cells

Question 50

what are the layers of connective tissue in the pleura?

Answer 50

- irregular internal elastic layer - interstitial fibrocollagenous layer - irregular external elastic layer