Histology Of The Respiratory Tract

Question 1

What are the two types of membranes contained in the respiratory tract?

Answer 1

A mucous membrane which lines the conducting portion and a serous membrane which lines the pleural sacs that envelope each lung

Question 2

What are the two regions of the nasal cavities?

Answer 2

The ofactory regions and the non-olfactory regions

Question 3

What is the histology of the non olfactory negion of the nasal cavity>

Answer 3

Psuedostrafied ciliated epithelium, with mucous glands and venous sinuses in the lamina propria.

Question 4

What is the importance of the venous plexuses in the non-olfactory region of the nasal cavity?

Answer 4

Swell every 20-30 minutes, alternating blood flow from side to side and preenting aterial blood flow issues, and patency is maintained by the surrounding tissues

Question 5

What is the histology of the olfactory region?

Answer 5

Pseufostratified epithelium that is particulay thick in this region, with no mucous secreting goblet cells, and mircovili, and contains oflfactory cells that are also known as bipolar neurones, and the lamina propria blends with the submucosa

Question 6

What are olfactory cells/ bipolar neurones?

Answer 6

One dendrite extends to the surface to form a connection with the non-motile cillia, and parallel to the surface- increases the surface area and responds to different odurs

Question 7

What is the histology of the larynx?

Answer 7

The ventricular folds are lined by pseudostratifed epithelium, nad contain mucus glands and numerous lymph node nodules, and the venrticulaes together with the ventricular folds contribute to the resonance of the larnyx,

Question 8

What are some of the features of the vocal cords?

Answer 8

Is lined by a stratified squamous epithelium, and contains a vocal ligament, that is a large bundle of elastic fibres running from front to back, and a vocals muscle, which is a bundle of skeletal muscle

Question 9

Name some of the features of the histology of the trachea.

Answer 9

The cartilage rings and the spinal muscle completly encircle the lumen, and a fibroelastic membrane contains the tracelais muscle

Question 10

What are the layers of the tracheal walls?

Answer 10

The lamina propria, the submucosa with the seromucous galnds, and the c shaped cartilage ring

Question 11

What are some of the features of the walls of the secondary and the teritary brochi?

Answer 11

Epithelium, then a layer of smooth muscle, and glands in the submucous annad caritalge

Question 12

What are some of the features of the histology of the alevoli?

Answer 12

Type 1 cells are simple squamous and then used for gas exchange, whereas type II cells are cuboidal and cover 10% of the surface area and produce surfactant, and there are numerous marcophages that line the alveolar surface

Question 13

What occurs during empysema?

Answer 13

Destruction of the alveolar wals and permant enalrgement of the air spaces, whcih can result from smoking or a alpha 1 deficency, and the alveolar walls normally help to keep the bronchioles open, and when these are damaged the brochiloes collapse, making it difficult for the lungs to empty

Question 14

What happens in penumonia?

Answer 14

Inflammation of the lungs caused by bacteria, the lung consolidates as the alveoli fill with inflammatory cells, and the most common cause is streptococcus pneumonaie

Question 15

What are some of the histological features of a brochioel?

Answer 15

No subepitheal cartilage or glands, surrounding alevloi keep them open, and the epitheailu goes from pesudostrailied, to simple columnar epithelia to cubodial

Question 16

What is the relationship between the brochioles and asthma?

Answer 16

The absence of cartilage is problematic because it allows these air passages to constrict, and almost close down when the smooth muscle contraction becomes excessive, and this can cause more difficuty with epxiration then with inspiration

Question 17

What is a clara cell?

Answer 17

as the brochioles get smaller, goblet cells give way to the clara cells interspersed between the ciliated cuboidal epithelium, these secrete a surfactant lipoprotein, which prevents the walls of the bronchioles sticking together during expiration

Question 18

Why are gobelt cells absent in the small brochioles?

Answer 18

To prevent the airways from becoming blocked by mucus

Question 19

What are the different passageways that could open into the alevoli?

Answer 19

No alevolar openings in the terminal brohcioles, the brociole opens onto some alevoli this is a respiratory brohciole,

Question 20

What are some of the features of the alevolar walls?

Answer 20

Have abundant capillaries, are supported by a basketwork of the collagen or reticular fibres, and have a covering composed of type 1 pneumocytes, and air in the alveoli is as close as 0.2 um to the bloodstream