Respiratory Histology

Question 1

What is the function of the turbinate bones?

Answer 1

To moisturise and heat the air that you breath in

Question 2

Where are the sensory nerve endings for smell?

Answer 2

The olfactory epithelium

Question 3

What is the function of the epiglottis?

Answer 3

To divert food from the airway

Question 4

What is the function of the larynx?

Answer 4

Keeps fluid from getting into airways and also for phonation

Question 5

What type of epithelium is respiratory epithelium?

Answer 5

Pseudostratified epithelium

Question 6

What kinds of cells are present in the respiratory epithelium?

Answer 6

Ciliated cells, goblet cells, basal stem cells, brush cells, serous cells, small granule cells

Question 7

What is the function of ciliated cells?

Answer 7

They make up about 30% of the epithelium and have cilia that can be controlled and move to move mucous up the airways

Question 8

What is the function of goblet cells?

Answer 8

They make up about 30% of the epithelium and secrete mucous

Question 9

What is the function of basal stem cells?

Answer 9

They make up another 30% and are stem cells which continually divide to produce new ciliated cells and goblet cells

Question 10

What is the function of brush cells?

Answer 10

Brush cells are very few cells of the epithelium and have a brush layer rather than cilia - may have a sensory role

Question 11

What is the function of serous cells?

Answer 11

Very few cells of the epithelium - have an unknown secretory role

Question 12

What is the function of the small granule cells?

Answer 12

Very few cells of the epithelium - have an endocrine role and may also be sensory

Question 13

What protective mechanisms do the airways have against dust and fungal and bacterial spores?

Answer 13

Mucous covered walls, cilia, intra-alveolar macrophages

Question 14

What are the three layers of the trachea?

Answer 14

Mucosa, submucosa, adventitia

Question 15

What makes up the mucosa?

Answer 15

The respiratory epithelium and the lamina propria

Question 16

What makes up the submucosa?

Answer 16

connective tissue with serous and mucous glands

Question 17

What makes up the adventitia?

Answer 17

Cartilage and a thin layer of connective tissue

Question 18

How many orders of branching are there between the trachea and the alveoli?

Answer 18

23

Question 19

What is the structure of the bronchus?

Answer 19

Initially similar to the trachea but changes as it gets smaller

Question 20

When is the bronchus called the intrapulmonary bronchi?

Answer 20

When the cartilage rings become cartilage plates

Question 21

Where does the smooth muscle run when the cartilage becomes plates?

Answer 21

Between the lamina propria and the submucosa (technically part of the submucosa)

Question 22

When does the airway become classified as a bronchiole?

Answer 22

When there is no more cartilage - at approximately 1mm in diameter

Question 23

At what stage of the branching is the bronchiole?

Answer 23

15 of 23

Question 24

How do the cells change as you get further down the airways?

Answer 24

There are fewer goblet cells and fewer ciliated columnar cells and get more Clara cells

Question 25

What are Clara cells?

Answer 25

Columnar to cuboidal cellos which have microvilli and secrete surfactant

Question 26

What is surfactant?

Answer 26

A glycoprotein which breaks surface tension to resist the collapse of fine tubes

Question 27

When is the airway classified as a terminal bronchiole?

Answer 27

At the final level of the conducting system when there are no goblet cells - only Clara cells with a few cuboidal epithelial cells with cilia and one or two layers of smooth muscle

Question 28

What do the terminal bronchioles give rise to?

Answer 28

Respiratory bronchioles

Question 29

What are the features of respiratory bronchioles?

Answer 29

Cuboidal to squamous epithelium that gives rise to alveolar ducts

Question 30

What is the structure of the alveoli?

Answer 30

200 micrometer holes separated by inter alveolar septa lined with simple squamous epithelium

Question 31

What are the inter alveolar septum made of?

Answer 31

Reticular fibres, elastin fibres, pores and contains pulmonary capillaries

Question 32

What prevents the alveoli from collapsing?

Answer 32

The radial arrangement of the connective tissue

Question 33

What are the two types of cells in alveolar epithelium?

Answer 33

Type I and type II pneumocytes

Question 34

What are type I pneumocytes?

Answer 34

The epithelial cells between the air and the capillary - have a thick basal lamina and tight junctions to prevent fluid leaking

Question 35

What are type II pneumocytes?

Answer 35

The cuboidal cells at the junctions of the inter alveolar septum whose role it is to secrete surfactant and they are also stem cells

Question 36

What makes up the blood gas barrier?

Answer 36

Type I pneumocyte, basal lamina, connective tissue, basal lamina, endothelial cell, plasma

Question 37

What are the two fates of intra-alveolar macrophages?

Answer 37

Go up airway to ciliated part to get pushed back up and then down to the stomach or take up permanent residence in the alveolar wall

Question 38

What type of cells make up the surface of pleura?

Answer 38

Squamous epithelium