Respiratory system

Question 1

Adaptations of the upper respiratory system

Answer 1

Airways always kept open by bony or cartilaginous scaffolds
Turbinate bones increase SA:V of paranasal sinuses
Hairs preven large particles from entering

Question 2

Label the upper respiratory system

Answer 2

Question 3

Name the 3 component of the lower respiratory system

Answer 3

Airways
Alveoli
Interstitium (connective tissue)

Question 4

Describe the different layers of the large airways

Answer 4

Respiratory epithelium - pseudostratified columnar ciliates + BM

Lamina propria - contains connective tissue, blood and lymph

Smooth muscle - fibroelastic tissue below the Lamina propria ; becomes more prominent as tubes get smaller, eventually replacing cartilage

Submucosa - seromucus glands , smooth muscle and elastin fibres

Cartilage - hyaline cartilage , disappear as alveoli are approached

Question 5

Describe the components of the respiratory epithelium

Answer 5

Basal cells (stem cells)

goblet cells produce mucus

neuroendocrine cells

club cells found at terminal bronchioles only (involved in detoxifying harmful substances)

all these components give the pseudostratified appearance

Question 6

Metaplasia of respiratory epithelium

Answer 6

Survival mechanism in response to injury

Specialised function is lost

Change in type of epithelium to stratified squamous

Question 7

Variation in airway structure

Answer 7

As you descend to the alveoli, less cartilage and more smooth muscles, fewer glands, flatter cells

Question 8

Describe the alveoli epithelium

Answer 8

Type 1 pneumocytes - flattened squamous epithelial cell ; BM is fused with capillary BM

Type 2 pneumocytes - rounded cells with prominent secretory granules for production and secretion of surfactant (reduces surface tension allowing full expansion of lungs )

Question 9

Describe the structure of intersitium

Answer 9

CT with little type 1 collagen

Blood vessels

Macrophages

Fibroblasts

Question 10

Scar tissue is made from which type of collagen

Answer 10

Type 1 - tough and strong

Question 11

Host defence mechanisms of upper and lower respiratory tract

Answer 11

Mucocillia

sloughing of epithelial cell

Cough

epiglottic reflex

sharp angle branching or airways ensures hair hits mucosal surfaces

alveolar Lining fluid (surfactant, Ig, complement )

cytokines

macrophages and neutrophils