Lung Anatomy, Histology, and Development

Question 1

vertebrosternal ribs

Answer 1

ribs 1-7

Question 2

vertebrocostal ribs

Answer 2

ribs 8-10

Question 3

vertebral (floating) ribs

Answer 3

ribs 11-12

Question 4

costodiaphragmatic recess

Answer 4

a region of parietal plerua that extends two ribs below the lung margins and is a site where fluid/blood can accumulate and be sampled

extends to the 12th rib posteriorly and 9th rib anterolaterally

Question 5

structure of the right lung

Answer 5

three lobes - superior (upper), middle, and inferior (lower)

horizontal fissure separtes superior and middle lobes

oblique fissure separates middle and lower lobes

Question 6

structure of the left lung

Answer 6

two lobes, superior and inferior separated by an oblique fissure

upper lobe has a “tongue-shaped” lingula that lies against the heart

Question 7

components of the mediastinum

Answer 7

primary bronchus

pulmonary artery

pulonary veins

bronchial arteries off the descending aorta

autonomic plexus

lymphatic vessels and nodules

Question 8

bronchial vs. pulmonary artery circulation

Answer 8

bronchial arteries come off of the descending aorta and supplies blood to the bronchi - drains into the pulmonary veins and some into the azygous system

pulmonary artery circulation is for alveoli and gas exchange

Question 9

components of the autonomic plexus on the bronchi and pulmonary arteries

Answer 9

parasympathetics from the vagus nerve

postsynaptic sympthetics from the upper thoracic (T1-5) cardiopulmonary splanchnic nerves

reflex afferents in vagus (pain fibers in splanchnics)

Question 10

Which side of the lung is aspirated material likely to go into?

Answer 10

right - right primary bronchus is shorter and more in line with the trachea than the left

Question 11

carina

Answer 11

the internal crest at the bifurcation of the trachea

Question 12

eparterial bronchus

Answer 12

secondary (lobar) bronchi - right upper lobar artery

Question 13

tertiary (segmental) bronchi

Answer 13

supply bronchopulmonary segments that are defined by the tertiary bronchi and the arteries that run with them

smallest lung units that can be surgically resected

Question 14

Kerley B lines

Answer 14

radiologic descriptions of dilated lymphatics in interlobular septa at the periphery of the lung lower lobes

Question 15

muscles used for inspiration

Answer 15

diaphragm

external oblique

accessory - scalenes, pectoralis minor, pectoralis major

serratous anterior

Question 16

muscles used for expiration

Answer 16

internal oblique

abdominal muscles (rectus abdominus)

Question 17

How many generations of branching of the airway are there?

Answer 17

23 generations

Question 18

conducting portion of the airway

Answer 18

moves air into and out of the respiratory part

first 16 generations of branches away from the trachea

Question 19

respiratory part of the airway

Answer 19

7 distal generation os branching that contains alveoli for gas exchange

Question 20

branching sequence of the airway

Answer 20

trachea -> bronchi -> bronchioles -> respiratory bronchioles -> alveolar ducts -> alveolar sacs -> alveoli

Question 21

cells of the conducting part of the airway from trachea through bronchi

Answer 21

pseudostratified columnar (respiratory) epithelium with cilia and mucous-secreting globlet cells

Question 22

silhouette sign

Answer 22

the similar densities of pneumonia and the heart obscure the heart borders

Question 23

C-shaped rings

Answer 23

strcutres that make up the trachea

entirely made up of hyaline cartilage

surrounds the lamina propria of loose connective tissue and submucosa of denser CT with mucous glands

no continuous muscle layer

elastic membrane between mucosa and submucosa

ends of the rings are united by a fibroelastic membrane and trachealis muscle

Question 24

structure of the bronchi

Answer 24

cartilage plates rather than rings

continuous layer of smooth muscle under the cartilage plates

epithelium is the same, and goblet cells are present

Question 25

structure of the bronchioles

Answer 25

lack of cartilage plates and glands (some cartilage may be present at branch points) smooth muscle layer that is relatively thick

Question 26

What happens to the epithelium during the transition from the largest bronchioles to the terminal bronchioles?

Answer 26

epithelium goes from ciliated, pseudostratified columnar in the largest bronchioles to simple cuboidal in the terminal bronchiole

Question 27

acinus

Answer 27

the functional unit of the lung that contains all of the components of the alveoli

Question 28

Clara cells

Answer 28

simple cuboidal cells that replace goblet cells and secrete a surfce active lipoprotein that keeps the wall sfrom sticking to each other

Question 29

CC16

Answer 29

an airway fluid marker of pulmonary disease (Clara cell injury)

Question 30

respiratory bronchioles

Answer 30

the first part of the airway where gas exchange occurs alveoli start to line the walls also ciliated and Clara cells (mostly Clara cells)

Question 31

Describe gas molecule movement through the lungs.

Answer 31

velocity goes down corresponding to drastic opening of airways air velocity increases a little with the first few generations of branching in the lungs, the secondary and tertiary bronchi cross-sectional area is smaller helps facilitate a cough, moves air faster through the big airways

Question 32

type I alveolar cells (pneumocytes)

Answer 32

make up 40% of alveolar cells but 95% of the alveolar surface area because of their thin shape lined by surfactant that prevents their collapse by reducing surface tension

Question 33

alveolar septum (pulmonary membrane or air-blood barrier)

Answer 33

gas exchange happens here consists of thin type I cell with its coating of usrfactant, the blood capillary endothelium, and a basal lamina shared by the two walls very thin, 0.15-0.50 microns between air and blood

Question 34

type II alveolar cells

Answer 34

comprise 60% of alveolar cells, but only 5% of the surface area comprise the thick wall of the alveolar septum along with collagen fibrils, elastic fibers, fibroblasts, and macrophages secrete phospholipid DPPC for reducing surface tension secrete surfactant proteins that regulate the synthesis, secretion, and spreading of surfactant and modulate immune and allergic responses

Question 35

alveolar ducts

Answer 35

the progression of respiratory bronchioles that consists of only rows of alveoli

Question 36

alveolar sacs

Answer 36

the end of alveolar ducts with a cluster of alveoli opening into a central space alveolar sacs may occur along the walls of alveolar ducts as well

Question 37

elastic fibers

Answer 37

important for pulmonary stroma, oriented in all directions and help the lungs dilate

Question 38

atelectasis

Answer 38

the obstruction of a bronchus

Question 39

Where does the larnx, trachea, and lungs develop from?

Answer 39

laryngotracheal (lung bud) diverticulum of splanchnopleure that grows ventrally off the foregut

Question 40

What gives rise to the carilage, smooth muscle, connective tissue, and visceral pleura?

Answer 40

splanchnic mesoderm

Question 41

embryonic period of lung development

Answer 41

branching of the bronchi the epithelim is undifferentiated simple cuboidal epithelium

Question 42

pseudoglandular period

Answer 42

6 to 16 weeks the airway resembles and exocrine gland branching vessels to the level of terminal bronchioles, but no air exchange segments epithelium begins to differentiate blood vessels elaborate but are not closely applied to the airway

Question 43

canalicular stage

Answer 43

16 to 26 weeks branching down to primordial alveolar ducts surrounded by a rich vascular network epithelium is thinning at the location of alveoli breathing is possible, but surfactant is not yet produced type I cells differentiate

Question 44

saccular (terminal sac) stage

Answer 44

26 weeks to birth elaboration of primordial alveoli with the differentation of Type I and Type II alveolar cells surfactant is being produced, and preterm viability is possible

Question 45

alveolar stage

Answer 45

32 weeks to 8 years alveoli and acini continue to develop, and more generations of airway branching continue after birth only about half the number of adult alveoli are present at birth