Histology

Question 1

Give 5 functions of the respiratory system

Answer 1

1) Supplies oxygen to the blood for delivery to the cells in the body
2) Removes carbon dioxide that has been accumulated in the blood from tissue in the body
3) Phonation- speaking, singing
4) Olfaction- smelling
5) Blood pressure control via the RAAS system

Question 2

The nasal cavity provides an area for warming, moistening and filtering inspired air. What assits this process?

Answer 2

Turbinates which produce turbulence to further warm and moisten air

Question 3

What filters the air inspired through the nose?

Answer 3

Nasal hairs within the vestibule

Question 4

What cells within the nasal cavity allow us to smell?

Answer 4

Olfactory epithilium on the roof of the cavity

Question 5

What is respiratory epithilium?

Answer 5

Pseudostratified cilliated columnar epithilium with goblet cells

Question 6

What cells is the vestibule made up from?

Answer 6

Keritenised stratified squamous epithilium

Question 7

Where in the nasal cavity does respiratory epithilium begin?

Answer 7

Anterior margins of the turbinate bones

Question 8

What is mucosa?

Answer 8

Mucus membrane

Question 9

Where is olfactory mucosa found?

Answer 9

On the roof of the nasal cavity, inferior to the olfactory bulb

Question 10

What lies beneath respiratory epithilium in the nasal cavity?

Answer 10

The lamina propria which is a band of connective tissue with seromucus glands and a rich venous plexus that can engorge with blood to block the nose (especially in allergic reactions)

Question 11

What cells line the oropharynx and why?

Answer 11

Non- keratinised stratified squamous epithilium. It carries air and food so must resist abrasion

Question 12

What lines the epiglotis on its anterior and posterior surface

Answer 12

Anterior-stratified squamous epithilium

Posterior- respiratory epithilium

Question 13

What comprises the conducting airway?

Answer 13

Trachea to terminal bronchioles

Question 14

What comprises the respiratory airway?

Answer 14

Respiratory bronchioles to alviolar sacs

Question 15

What is the larynx and where is it found?

Answer 15

The most supirior part of the trachea containing the vocal folds.

Question 16

What are the walls of the larynx made from and what cells line the surface?

Answer 16

Respiratory epithilium lines the surface and the walls are made from muscle and cartilage

Question 17

What cells line the vocal folds?

Answer 17

Stratified squamous epithilium

Question 18

Where does the trachea terminate?

Answer 18

Carina where it bifurcates to form the right and left main bronchi

Question 19

What type of cartilage is found in the trachea and what shape is it?

Answer 19

Hyaline cartilage. Its C shaped.

Question 20

What spans the open side of the C shaped cartilage in the trachea?

Answer 20

Fibroelastic tissue and smooth muscle called the trachealis muscle

Question 21

List the layers of the trachea from the inside out.

Answer 21

Respiratory epithilium, Basal lamina, Lamina propria, Submucosa (with seromucus glands), Hyaline cartilage, Adventicia

Question 22

Do the bronchi have cartilage in their walls?

Answer 22

Yes, They are not C shaped but spiral shaped cartilage plates

Question 23

List the layers of the bronchi from the inside out.

Answer 23

Respiratory epithilium, basal lamina, lamina propria, muscularis, sub mucosa, cartilage

Question 24

What happens to the cartilage as you go further down the bronchial tree?

Answer 24

It becomes more discontinuous

Question 25

When is the hyalinie cartilage lost from the airway walls?

Answer 25

When the diameter of the airway is <1mm. We now refer to the airway a bronchioles

Question 26

What happens to the depth of the columnar epithilium as you go down the bronchial tree?

Answer 26

It decreases. Transforms from columnar to cuboidal epithilium

Question 27

Do goblet cells and cillia exist at the level of the bronchioles and below?

Answer 27

Goblet cells = No
Cillia = Yes

Question 28

How can you distinguish between terminal and respiratory bronchioles?

Answer 28

Terminal bronchioles do NOT have any gas exchange function, whereas respiratory bronchioles do.

Question 29

What type of cells line the terminal bronchioles

Answer 29

Cuboidal cilliated epithilium and non-cilliated club cells.

Question 30

What are the functions of club cells?

Answer 30

Stem cells to replace epithilium, detoxification, immune modulation and they produce a small amount of surfactant

Question 31

Do alvioli interupt the continuity of respiratory bronchioles?

Answer 31

Yes

Question 32

What lines the respiratory bronchioles?

Answer 32

Discontinuous squamous type 1 pneumocytes

Question 33

Which cells make up the alviolar epithilium?

Answer 33

Type 1 and 2 pneumocytes

Question 34

What is the function of type 1 pneumocytes?

Answer 34

They line up to 90% of the alveolar surface and they are simple squamous epithilium that is thin and permeable to gasses for exchange.

Question 35

What is the function of type 2 pneumocytes?

Answer 35

Polygonal shape and the surface has microvilli. The cytoplasm contains laminar bodies that contain surfactant. This is released by exocytosis and reduces alveolar surface tension at the air/fluid interface. This reduces tendency for alveolar collapse at the end of expiration

Question 36

What is the function of alveolar macrophages?

Answer 36

Phagocytose inhailed particles that have escaped entrapment by mucus. They can then migrate up the mucocillary escalator or remain in the septal connective tissue

Question 37

Where are alveolar macrophages found?

Answer 37

Free cells either in the septa or migrating over the luminal surfaces of alveolar.

Question 38

Where are the capilaries found in the lungs?

Answer 38

The septa between the alvioli

Question 39

What is the function of alviolar pores?

Answer 39

To equilibriate the pressure between the alvioli

Question 40

What makes up the visceral pleura?

Answer 40

Mesothilium backed by layers of fibrous, elastic and connective tissue