Thorax 3: Microanatomy and Development

Question 1

describe the muscosa of the trachea

Answer 1

ciliated, pseudostratified epithelium and an elastic, fiber rich lamina propria

Question 2

describe the submucosa of the trachea

Answer 2

denser connective tissue than the lamina propria (still loose CT)

Question 3

describe the cartilaginous layer of the trachea

Answer 3

C-shaped hyaline cartilage

Question 4

describe the adventitia of the trachea

Answer 4

connective tissue that binds the trachea to adjacent structures

Question 5

what are the 3 main types of epithelium in the trachea

Answer 5

1) goblet cells
2) ciliated cells
3) basal cells

Question 6

describe goblet cells

Answer 6

produce the mucous coat, contain mucinogen granules

Question 7

describe ciliated cells

Answer 7

the most numerous type, provide a coordinated swiping motion of the mucous coat from the farthest passages to the larynx

Question 8

describe basal cells

Answer 8

stem cells that differentiate to replace goblet and ciliated cells

Question 9

describe the basement membrane of the trachea

Answer 9

thick, characteristic of the tracheal epithelium

densely packed collagen fibers

Question 10

describe the lamina propria of the trachea

Answer 10

loose CT

very cellular: lymphocytes, plasma cells, mast cells, eosinophils, fibroblasts

associated lymphatic tissue

Question 11

describe the submucosa of the trachea

Answer 11

-relatively loose CT of similar in appearance to the lamina propria
-diffuse lymphatic tissue and lymphatic nodules that extends from the lamina propria
-contains large distributing vessels
-contains submucosal glands composed of mucous secreting acinus

Question 12

describe the cartilage of the trachea

Answer 12

-made of C shaped cartilages
-provide flexibility to the tracheal pipe and maintain the potency of the lumen

Question 13

what is the bronchopulmonary segment?

Answer 13

segmental bronchus + supplied parenchyma

Question 14

describe the makeup of the secondary and tertiary bronchi

Answer 14

epithelium
lamina propria
smooth muscle
submucosa
cartilage

Question 15

describe the terminal bronchioles

Answer 15

most distal of the conducting portion

do not engage in gas exchange

Question 16

describe the respiratory bronchioles

Answer 16

engage in gas exchange and are the beginning of the respiratory portion

Question 17

describe the alveolar ducts

Answer 17

elongated airways with almost no walls

alveoli surrounds the duct space

Question 18

describe the alveolar sacs

Answer 18

spaces that are at the terminatino of alveolar ducts

Question 19

describe alveoli

Answer 19

terminal air spaces

increase area for gas exchange

Question 20

describe pneumocytes type 1 (alveoli)

Answer 20

-extremely thin
-line most of the alveoli surface
-form an effective barrier between the air space and the septal wall

Question 21

describe pneumocytes type 2 (alveoli)

Answer 21

-cuboidal cells
-line 5% of the alveoli surface
-interspersed among P1
-secrete surfactant

Question 22

describe surfactant

Answer 22

phospholipids and hydrophobic proteins that reduce the surface tension at the air-epithelium interface

Question 23

describe the thick region of the alveoli

Answer 23

contain connective tissue and macrophages

Question 24

describe the thin region of the alveoli

Answer 24

form the air-blood barrier and is responsible for most of the gas exchange

Question 25

what makes up the air-blood barrier?

Answer 25

surfactant + P1 + endothelium

Question 25

what makes up the air-blood barrier?

Answer 25

surfactant + P1 + endothelium