7. Respiratory system

Question 1

what type of tissue holds open the larynx and trachea

Answer 1

Hyaline cartilage

Question 2

what tissue bridges the gap between the free ends of C-shaped cartilages in the trachea?

Answer 2

smooth muscle

Question 3

what is present within the walls of bronchi but not bronchioles?

Answer 3

cartilage

Question 4

where is Reinke’s space?

Answer 4

in the vocal cords

Question 5

which cells secrete surfactant?

Answer 5

type II pneumocytes

Question 6

what cells are phagocytes

Answer 6

alveolar macrophages

Question 7

how many cell layers are there in the air blood barrier

Answer 7

2

Question 8

how thick is the air-blood barrier

Answer 8

600nm

Question 9

where are the pores of Kohn

Answer 9

alveolar walls

Question 10

respiratory epithelium

Answer 10

lines tubular portion of the respiratory
Pseudostratified
ciliated
interspaced goblet cells

Question 11

the nose

Answer 11

filtration, humidification, warming, olfaction
keratinising and non-keratinising squamous epithelium
respiratory epithelium
richly vascular lamina propria containing seromucinous glands

Question 12

the nose - olfaction

Answer 12

roof of nasal cavity, extending down septum and lateral wall
Pseudostratified columnar epithelium of olfactory receptor cells with supporting sustentacular cells and basal cells
serous glands of Bowman
Non-motile cilia
olfactory receptor cells
bipolar neurones - dendrite extends to surface to become club-shaped ciliated olfactory vesicle

Question 13

nasopharynx

Answer 13

gas transport, humidification, warming, olfaction, lined by respiratory epithelium

Question 14

nasal sinuses

Answer 14

lower the weight of the skull, add resonance to the voice, humidify and warm inspired air, lined by respiratory epithelium

Question 15

the larynx

Answer 15

cartilaginous box (hyaline), voice production, respiratory epithelium, loose fibrocollagenous stroma with seromucinous glands, lymphatics and blood vessels common

Question 16

the vocal cords

Answer 16

voice production
stratified squamous epithelium overlying irregular fibrous tissue (Reinke’s space)
almost no lymphatics

Question 17

tranchea

Answer 17

respiratory epithelium
seromucinous glands in submucosa
trachealis muscle posteriorly
C-shaped (hyaline) cartilagenous rings

Question 18

clara cells

Answer 18

most numerous in terminal bronchioles
mitochondria, smooth ER, secretary granules
no cilia; vesicular cytoplasm
precise purpose is uncertain, think they produce and eliminate surfactant and oxidise inhaled toxins

Question 19

respiratory bronchioles

Answer 19

first part of distal respiratory tract 
link terminal bronchioles and alveolar ducts
cuboidal ciliated epithelium 
spirally arranged smooth muscle
no cartilage

Question 20

alveoli

Answer 20

150-400 million/lung

250 um in diameter

Question 21

type I pneumocytes

Answer 21

40% of cell population
90% of surface area
flattened cells, flattened nucleus, few organelles

Question 22

type II pneumocytes

Answer 22

60% of cell population
5-10% of surface area
rounded cells, rounded nucleus, rich in mitochondra, smooth and rough ER, spherical bodies
produce surfactant

Question 23

alveolar macrophages

Answer 23

luminal cells, also present in the interstitium
phagocytose particles including dusts and bacteria
enter lymphatics or leave via mucocilary esculator

Question 24

blood-air barrier

Answer 24

type I pneumocyte
fused basement membrane of penumocyte and capillary
vascular endothelial cell
200-800nm thick

Question 25

interstitium

Answer 25

``` where endothelial cells are not in direct contact with pneumocytes collagen and alastin fibres fibroblasts macrophages (pore of Kohn) ```

Question 26

Visceral pleura

Answer 26

``` flat mesothelial cells loose fibrocollagenous connective tissue irregular external elastic layer interstitial fibrocollagenous layer irregular internal elastic layer ```