Lecture 21: Macro- and Micro-Structure of the Lungs Flashcards Preview

Structures (ASV) > Lecture 21: Macro- and Micro-Structure of the Lungs > Flashcards

Flashcards in Lecture 21: Macro- and Micro-Structure of the Lungs Deck (92):
1

lobes of lungs

right upper, middle lower

left upper, lower

2

fissures of lungs

oblique fissures (2) - separate L/R upper/lower lobes

horizontal fissure - RIGHT only; divides R middle lobe

3

why no left middle lobe of lungs?

because need space for the heart

4

lung lymphatics

lymphatic channels, appear as little white lines, unless have carbon pigment within visceral pleural lymphatic channels, then appear black

channel lymph fluid through lungs, towards hilum (root of lung) and to mediastinal lymph nodes (toward midline of body)

5

pleura

single layer of mesothelial cells

6

visceral layer of pleura

layer of connective tissue over surface of lung

7

parietal layer of pleura

layer of connective tissue against thoracic wall

8

neumothroax/hemothorax

when visceral and parietal layers dissociate because of air/blood entry into lungs

9

does lung feel a puncture from inside?

no

10

if tear parietal pleura, nerve that detects pain/causes action?

intercostal and phrenic afferent nerves perceive pain

GSA pain results

11

if tear visceral pleura, nerve that detects pain/causes action?

vagus and sympathetics perceive pain

little/no GVA pain results

12

what does vagus nerve control innervation for in lungs?

changes in:
smooth muscle (stretch); muscosa of trachea and bronchi (irritation); C pain fibers in alveoli and bronchi (inflammation); pulmonary veins, cardiac plexus (chemical); aortic arch and wall, pulmonary arteries (pressure)

13

where does vagus nerve run re: T-E?

posterior to hilum of lung; on either side of esophagus and trachea

14

hilum

root of lung, where structures (bronchus, artery, vein) enter/leave

15

what type of fibers do phrenic nerves carry to diaphragm?

GSE fibers

16

where does phrenic nerve run?

anterior to hilum of lung

17

what kind of blood does pulmonary artery carry?

deoxygenated blood

originate from pulmonary trunk, go to lungs from R ventricle of heart

18

what kind of blood does pulmonary vein carry?

oxygenated blood

19

where does pulmonary trunk bifurcation occur?

to left of midline, just inferior to vertebral level TIV/V

20

what is longer- right or left pulmonary artery?

right

21

order of bronchus/artery/vein at hilum of lung

left: are brides vain? - artery, bronchus, vein

right: brides are vein - bronchus, artery, vein

22

bronchial arteries

part of lung's dual blood supply system

arise from aorta, intercostal arteries, or subclavian arteries

enter lungs at hilum

are nutrient arteries supplying oxygenated blood to tissue

23

pulmonary arteries

follow bronchial tree to form capillaries around alveoli

provide deoxygenated blood to lungs

24

2 types of arteries that supply blood to lungs

bronchial arteries, pulmonary arteries

25

where bronchial veins drain

pulmonary veins or left atrium, and into azygos vein on R and superior intercostal vein/meiazygos vein on L

26

tracheobroncial tree divisions

trachea >
intrapulmonary brunchs >
main (primary >
lobar (secondary) >
segmental (tertiary) >
bronchioles

27

divisions smaller than bronchioles bronchioles

terminal bronchiole, respiratory bronchiole, alveolar duct, alveolar sac, alveolus

28

bronchogram

old image of bronchiole tree, taken by having pt ingest metal dust

29

carina

cartilaginous ridge within trachea, runs between the 2 primary bronchi of the trachea where they bifurcate

30

bronchoscopy

image down trachea into 2 main bronchi

31

cell type in trachea

pseudo stratified ciliated columnar

32

layers from out > in of the trachea

adventitia, C-shaped rings, trachealis and longitudinal muscles, submucosa, mucosa

33

adventitia

connective tissue on outside of trachea

34

c-shaped rings of trachea

hyaline cartilage that's incomplete dorsally

35

tracheal is and longitudinal

smooth muscles of trachea

36

submucosa

mucous and serous glands of trachea

37

mucosa of trachea

made of epithelium and lamina propria

38

epithelium of trachea

pseudo stratified ciliated columnar & goblet cells (produce mucus)

39

lamina propria of trachea

connective tissue, elastic fibers

40

how many layers of respiratory epithelium in trachea?

1! just appears to be more because pseudo stratified

41

cilia function in trachea

bring fluid from lungs to trachea, so can get rid of bacteria/other particles not desired in the lungs

42

2 other cell types of respiratory epithelium

endocrine (kulchisky) cells- secrete serotonin, regulate airway reflexes; basal cells (not columnar)- will give rise to epithelia

43

orientations of mainstem bronchi

right is more vertical than left; inhaled objects thus tend to lodge in right mainstem bronchus

44

intrapulmonary bronchus

usually next to branch of pulmonary artery, irregular cartilage plates, smooth muscle, goblet cells, ciliated pseudo stratified columnar epithelium, transitions to ciliated simple columnar as bronchi get smaller

45

broncho-pulmonary segment

area of lung supplied by a segmental bronchus and its accompanying pulmonary artery branch

smallest functionally independent region of a lung and smallest area of lung that can be isolated/removed without affect adjacent regions

secondary/tertiary bronchi travel alongside, and branch in parallel with, pulmonary arteries/arterioles

10 in each lung

46

bronchiole

really thin epithelium so can have gas exchange with alveoli

characterized by no cartilage, smooth muscle, very few/no goblet cells, and epithelium transfers from ciliated simple columnar to ciliated simple cuboidal

47

4 F's of sympathetic innervation

fright, flight, fight, fornicate

48

autonomic innervation of bronchial glands

sympathetic: inhibitory - make lumens BIG

parasympathetic (vagus): secretomotor

49

autonomic innervation of bronchial smooth muscle

sympathetic: bronchodilation

parasympathetic (vagus): bronchoconstriction

50

autonomic innervation of bronchial vasculature

sympathetic: vasoconstriction

parasympathetic: vasodialation

51

why is it good to have a large diameter lumen in the bronchi/bronchioles?

no gas exchange

52

autonomic innervation to alveolar vasculature

none! they are capillaries, controlled by locally circulating factors like histamine, not by nervous system

53

sympathetics control in lungs

secretory inhibition, bronchodilation, vasoconstriction

54

parasympathetics control in lungs

secretomotor, bronchoconstriction, vasodilation

55

COPD and asthma

chronic obstructive pulmonary disease and asthma

may have abnormally high parasympathetic discharge and flow of air through bronchi, and inflammation

56

L/R vagus orientations re: esophagus

left: anterior
right: posterior

57

posterior pulmonary plexus

come off of vagus; sit on top of esophagus; eventually provide PARASYMPATHETIC innervation to lungs

58

where does parasympathetic innervation to the lungs come from?

pulmonary plexus

59

where does sympathetic innervation to the lungs come from?

sympathetic chain

60

terminal bronchiole characteristics

biggest of microstructures
surrounded by layer of smooth muscle, no goblet cells, ciliated simple cuboidal epithelium, clara cells

61

clara cells

precursors of bronchiolar epithelial cells

detoxify carcinogens, synthesize a surfactant-like protein, secrete alpha-1-antitrypsin which inhibits digestion of elastin

have secretory vesicles, no cilia

62

emphysema

caused by elastic tissue breakdown

can be caused by breakdown of clara cells

63

what does alveolar wall contain?

elastic tissue (elastin)

64

acinus (pl=acini)

functional subunit of the lung supplied by a single respiratory bronchiole

65

subdivisions from bronchus to alveolus

bronchus,
respiratory bronchiole,
alveolar duct,
alveolar sac,
alveolus

66

respiratory bronchiole characteristics

simple cuboidal epithelium, wall punctuated by alveoli and smooth muscle; isn't smooth anymore, has potholes in it with lumps of smooth muscle

67

alveolar duct characteristics

wall punctuated by alveolar sacs and alveoli

68

alveolar sac characteristics

terminal part of alveolar duct, alveolar clusters = alveolar sac

69

alveolar capillaries

seen inside of alveolar sac
can fit 1 RBC through

70

cell types in capillary walls / function

function: more surface area for gas exchange

cells:
type I alveolar cell, capillary endothelial cell

71

blood-air barrier for gas exchange made of

simple squamous epithelium

direct exchange from endothelial cell to alveolar cell

72

cell types in alveolar wall cells

endothelial cells,
type I pneumocytes,
type II pneumocytes

73

characteristics of endothelial cells in alveolar wall cells

thin, flat
do gas exchange

74

characteristics of type I pneumocyte cells in alveolar wall cells

thin, flat
do gas exchange
only 40% of alveolar cells
cover 90% surface of alveoli

75

characteristics of type II pneumocyte cells in alveolar wall cells

thick, protruding, "foamy"
no gas exchange
60% alveolar cells
replace damaged type I cells
secrete surfactant

76

what type of cell secretes surfactant?

type II pneumocyte

77

what is alveolar surface area equal to?

tennis court!

78

lamellar bodies

secretory vesicles that produce surfactant in type II pneumocytes

produce it in form of tubular myelin weaves

look like little jupiters

79

surfactant characteristics

phospholipids, cholesterol, carbs, proteins

decreases alveolar surface tension

keeps cell surface water layer thin, so increases gas exchange

increases stretchability (compliance)

prevents alveolar collapse

reduces fluid flow from capillaries into airways

80

what does low surfactant levels cause?

respiratory distress syndrome

ie in premature babies

81

pore of kohn

alveolar pores

allow equalization of pressure between alveoli, facilitate flow between acini when bronchioles are blocked

82

is it good to have surfactant in alveolar pores?

no; blocks communication between alveoli

83

alveolar macrophages

phagocytyze extra surfactant

aka "dust cells" because ingest inhaled particulate matter

84

what is rate that lungs can recruit alveolar macrophages?

1 million macrophages/hr!

85

characteristics of smoker's lungs

excess carbon particles (trapped in macrophages)

chronic bronchitis (excess mucus from goblet cells)

increased pneumonia risk

loss of elasticity (emphysema, fibrosis)

metaplasia (bronchi epithelium changes to stratified squamous), interstitial disease (thickened alveolar walls)

cancer

86

cell type of trachea and mainstem bronchus

ciliated pseudo stratified columnar

87

cell type of intrapulmonary bronchus

transitions

88

cell type of broncho-pulmonary segment

ciliated simple columnar

89

cell type of bronchiole

transitions

90

cell type of terminal bronchiole

ciliated simple cuboidal

91

cell type of respiratory bronchiole

simple cuboidal

92

cell type of alveolus

simple squamous