Respiratory Tract

Question 1

What is the name of the epithelium that lines most of the respiratory system

Answer 1

Respiratory epithelium

Question 2

What is sense of taste primarily

Answer 2

Sense of taste

Question 3

What does reparatory epithelium line

Answer 3

Tubular portion of the respiratory system

Question 4

What type of epithelium is respiratory epithelium

Answer 4

Pseudostratified columnar ciliated epithelium interspersed with goblet cells

Question 5

What is not usually seen on H&E with light microscopy

Answer 5

Basement membrane of respiratory epithelium

Question 6

What are the two type of epithelial cells present in respiratory epithelium

Answer 6

Ciliated epithelial cells

Goblet cells

Question 7

What type of epithelium is the first part of the nostrils

Answer 7

Keratinised stratified squamous epithelium

Question 8

What type of epithelium is the second part of the nostrils (where you cannot stick your finger in)

Answer 8

Non-keratinised stratified squamous epithelium

Question 9

What is the nasal cavity lined by

Answer 9

Respiratory epithelium

Question 10

Describe the connective tissue underneath the respiratory epithelium

Answer 10

Loose fibrous connective tissue contain seromucin glands and rich network of blood vessels

Question 11

What do seromucin glands in the nasal cavity produce

Answer 11

Catarrah (snot)

Question 12

What epithelium lines the roof of the nasal cavity, extending down septum and lateral wall

Answer 12

Olfactory epithelium

Question 13

What type of epithelium is olfactory epithelium

Answer 13

Pseudostratified columnar ciliated epithelium

No goblet cells

No moving cilia

Contains basal cells and penetrating nerve fibres

Question 14

How can you tell the difference between olfactory and respiratory epithelium

Answer 14

Look at the connective tissue

Olfactory has a rich network of serous glands of Bowman and large number of nerves

Question 15

What do the serous glands of Bowmans secrete

Answer 15

Watery fluid which helps to wash the surface clean

Question 16

What stain would be needed to highlight bipolar nerves on olfactory epithelium

Answer 16

Silver stain

Question 17

Describe olfactory receptor cells

Answer 17

Bipolar neurons - dendrite extends to surface to become club-shaped ciliated olfactory vesicle

Question 18

What is the nasopharynx lined by

Answer 18

Respiratory epithelium

Question 19

What are the three functions of the nasal sinuses

Answer 19

Lower the weight of the skull

Add resonance to the voice

Humidify and warm inspired air

Question 20

What is the nasal sinuses lined by

Answer 20

Respiratory epithelium

Question 21

What is the larynx compromised of

Answer 21

Cartilaginous box - almost entirely hyaline cartilage

Hold larynx open in negative pressure of inspiration

Question 22

What is the epiglottis formed of

Answer 22

Elastic cartilage

Question 23

What is the larynx (expect the vocal cords) lined by

Answer 23

Respiratory epithelium

With loose fibro collagenous stroma with seromucous glands

Question 24

What is the epithelium in the vocal cords

Answer 24

Thin stratified squamous epithelium overlying loose irregular fibrous tissue (Reinke’s space)

Reinke’s space - some blood vessels but almost no lymphatics

Question 25

What is the tracheas supported by

Answer 25

Hyaline cartilage arranged in a series of c-shaped rings

Question 26

What is the epithelium of the trachea

Answer 26

Respiratory epithelium Seromucinous glands in submucosa

Question 27

What is found at the posterior of the C-shaped cartilaginous rings in trachea

Answer 27

Trachealis muscle

Question 28

What do Trachea Main bronchi Lobar bronchi Segmental bronchi all contain

Answer 28

Smooth muscle Partial cartilaginous rings Respiratory epithelium Some basal neuroendocrine cells Seromucinous glands and goblet cells

Question 29

What do bronchioles contain

Answer 29

Smooth muscle Ciliated columnar epithelium Some basal neuroendocrine cells Few goblet cells - Clara cells

Question 30

Describe clara cells

Answer 30

Terminal bronchioles Cuboidal Pale staining cytoplasm Contain abundant mitochondria and smooth muscle No cilia Secretory granules

Question 31

What comes after terminal bronchioles

Answer 31

Respiratory bronchioles

Question 32

What is the first part of the distal respiratory tract

Answer 32

Respiratory bronchioles

Question 33

What are the features of respiratory bronchioles

Answer 33

Cuboidal ciliated epithelium Spirally-arranged smooth muscle No cartilage

Question 34

Describe alveoli

Answer 34

150-400 million/lung 250um in diameter Gas exchange

Question 35

Describe type 1 pneumocytes

Answer 35

40% cell population 90% of surface area Flattened cells, flattened nucleus, few organelles Provide part of blood air barrier

Question 36

Describe type 2 pneumocytes

Answer 36

Cuboidal/columnar 60% of cell population 5-10 of SA Rounded cell, round nucleus, rich in mitochondria, smooth and rough ER, spherical bodies Produce surfactant

Question 37

Describe alveolar macrophages

Answer 37

Luminal cells - also present in interstitium Phagocytes particulates including dusts and bacteria Enter lymphatics or leave via mucocillary escalator

Question 38

Describe the blood air barrier

Answer 38

Type 1 pneumocyte on a basement membrane shared with capillary Vascular endothelial cell 200-800nm thick

Question 39

How many layers are there in the blood air barrier

Answer 39

Can be 3 - type 1 pneumocyte, basement membrane, vascular endothelial cell 4 - add surfactant layer Or add cytoplasm and membrane

Question 40

Describe alveoli interstitium

Answer 40

Where endothelial cells are not in direct contact with pneumocytes Collagen and elastin fibres Macrophages Pores of Kohn

Question 41

Describe pores of Kohn

Answer 41

Holes in alveoli walls Help equalise pressure between adjacent alveoli Lungs expand equally Facilitate spread of infection