LEC 21: Lungs - 08.29.14 Flashcards Preview

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Flashcards in LEC 21: Lungs - 08.29.14 Deck (75):
1

Gross Anatomy of the Lungs (Right, Left)

RIGHT:

  • 3 lobes
  • Right Upper [horizontal fissure], Right Middle [oblique fissure], Right Lower

LEFT:

  • 2 lobes
  • Left Upper [oblique fissure], Left Lower

NB: oblique fissure = major fissure

2

Front View of Lungs 

(what is palpated with stethoscope)

RIGHT: 

  • Right Upper and Right Middle equally apparent
  • Right Lower very small

LEFT: 

  • Majority is Left Upper
  • Very small portion of Left Lower

3

Right Lateral View of Lungs

(what can you palpate)

RIGHT:

  • Right Upper (~1/3)
  • small portion of Right Middle
  • Significant portion of Right Lower

4

Left Lateral View of Lungs

(what can you palpate)

LEFT:

  • Left Upper
  • Left Lower

5

Back View of Lungs

RIGHT:

  • mostly Right Lower
  • small portion of Right Upper

LEFT:

  • mostly Left Lower
  • small portion of Left Upper

6

Describe this image from the lung

Lung lymphatics

  • white lines under shiny visceral surface
  • channel lymph toward hilum and to mediastinal lymph nodes
  • carbon (turns black) within visceral pleural lymphatic channels

7

What layer of pleura covers the lung

Visceral pleura

8

What is the layer of pleura against chest wall

Parietal pleura

9

What is the cellular composition of the pleura

  • single layer of mesothelial cells

 

  • mesothelial cells are a form of simple squamous epithelium

 

10

pleural cavity

Space between parietal and visceral layers of lungs = pleural cavity;

should not have anything between these layers except for a small amount of lubricating fluid

11

hemothorax

collection of blood in the space between the chest wall and the lung (the pleural cavity)

12

pneumothorax

collection of air in the space between the chest wall and the lung (the pleural cavity)

13

What is the result if there is a tear/puncture in the parietal pleura

AFFERENT NERVE: intercostal and phrenic

RESULT: GSA pain

14

What is the result if there is a tear/puncture in the visceral pleura

AFFERENT NERVE: vagus and sympathetics

RESULT: little/no pain

 

Gray's: visceral pleura is innervated by visceral afferent nerves that accompany bronchial vessels, pain is generally not elicited from this tissue

15

What nerve senses everything but tear/puncture in the lung

the vagus nerve (CN X - cranial nerve 10)

 

16

Location of vagus nerve in the lung

vagus nerve runs posterior to hilum of lung

17

Location and function of phrenic nerve in the lung 

Phrenic nerve (C3-C5) runs anterior to hilum of lung;

Phrenic nerves carry motor (GSE) fibers to diaphragm

18

hilum

also known as the root of the lung;

formed by bronchus, pulmonary artery, pulmonary vein, bronchial artiers/veins, pulmonary plexus of nerves, lymphatic vessels, bronchial lymph glands, and areolar tissue

hilum is also where the viseral and parietal pleura meet

19

Order of arteries/bronchus/veins in hilum of lung (Left/Right)

LEFT: (Are Brides Vain)

  • Artery, Bronchus, Vein

RIGHT: (Bride Are Vain)

  • Bronchus, Artery, Vein

20

Where do the visceral and parietal pleura meet (reflection of the pleura)

root of the lung (hilum)

21

Pulmonary arteries

Carry deoxygenated blood away from the heart to the lungs (where blood gets oxygenated)

 

NB: these arteries do not "supply" the lungs -- the material they carry is not beneficial; lungs are supplied by bronchial arteries/intercostal arteries (aorta) or subclavian arteries

22

Pulmonary veins

carry oxygenated blood from the lungs back to the heart; blood enters at left atrium, flows to left ventricle where it will be circulated (aorta)

 

 

23

Impressions on the Left Lung

LEFT:

  • Left Subclavian Artery
  • Arch of Aorta
  • Brachiocephalic Vein
  • Left Ventricle

"LABL"

24

Impressions on the Right Lung

RIGHT:

  • Superior Vena Cava
  • Inferior Vena Cava
  • Azygos Vein
  • Brachiocephalic Trunk (Artery)
  • Esophagus
  • Right Atrium

"BRAISE"

25

What blood vessels supply the lungs

  • bronchial arteries (from aorta)
  • intercostal arteries (from aorta)
  • subclavian arteries

 

NB: These are nutrient arteries that supply oxygenated blood to lung tissue; they enter at the hilum

26

How are capillaries formed

Pulmonary arteries follow bronchial trees to form capillaries around alveoli; pulmonary arteries carry deoxygenated blood

 

27

Bronchopulmonary segments

  • lung sub-units corresponding to bronchial tree
  • no visible lines demarcating individual segments

 

28

Trace the tracheobronchial tree

  • Trachea
  • Intrapulmonary bronchus 
    • Main (1)
    • Lobar (2)
    • Segmental (3)
  • Bronchiole
  • Terminal Bronchiole
  • Respiratory Bronchiole
  • Alveolar Duct
  • Alveolar Sac
  • Alveolus

29

Carina

  • cartilaginous ridge within trachea at site of tracheal bifurcation
  • bifurcation usually at T5 vertebrae, with the angle of Louis
  • lies more toward left side (foreign bodies most often aspirated into right side)

 

30

Histology of Trachea

C = cartilage

M = mucosa

T = trachealis muscle (smooth)

L = longitudinal muscle (smooth)

31

Adventitia

connective tissue on outside of trachea

 

32

C-shaped rings

Trachea made up of C-shaped rings (hyaline cartilage, incomplete dorsally)

33

What are the smooth muscles of the trachea

  • trachealis
  • longitudinal

 

34

What are the mucosal layers of the trachea

  • submucosa
    • mucous and serous glands
  • muscosa
    • epithelium - pseudostratified ciliated columnar cells, goblet cells
    • lamina propria - connective tissue, elastic fibers

35

Label the parts of the slide

A. Mucosa - epithelium

B. Mucosa - lamina propria

C. Submucosa - serous glands

D. Submucosa - mucous glands

E. Perichondrium

F. Hyaline cartilage

36

What type of epithelium is found in the respiratory tract

ciliated, pseudostratified columnar; nuclei are at different heights, but all cells are anchored to the basement membrane

37

Label this epithelium

ciliated, pseudostratified columnar

A. Goblet cell

B. Cilia

38

What other types of cells are present in respiratory epithelium

  • Endocrine (Kulchisky) cells
    • secrete serotonin, etc.
    • regulate airway reflexes (smooth muscle contraction)
  • Basal cells (not columnar)
    • undifferentiated precursors

39

Differences between angles of mainstem bronchi

Right mainstem bronchus is more vertical than left; inhaled objects tend to lodge in the right mainstem bronchus so often

40

Intrapulmonary Bronchus

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

41

Broncho-pulmonary segment

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

42

Bronchiole

  • no cartilage
  • smooth muscle
  • very few goblet cells
  • epithelium transitions from ciliated simple columnar to ciliated simple cuboidal

43

pattern of epithelium as you move down bronchiole tree

TRACHEA (RESPIRATORY EPITHELIUM): ciciliated, pseudostratified columnar 

INTRAPULMONARY BRONCHUS: transitions to ciliated, simple columnar

BRONCHIOLE: transitions to ciliated simple cuboidal

44

Sympathetic Nervous System

4 Fs:

Fight

Flight

Fright

Fuck

45

Autonomic Innervation of Bronchial Glands

Sympathetic = inhibitory (need air passageway high and dry to run away)

Parasympathetic (Vagus nerve) = secretomotor

46

Autonomic Innervation of Bronchial Smooth Muscle

Sympathetic = bronchodilation

Parasympathetic (Vagus nerve) = bronchoconstriction

47

Autonomic Innervation of Bronchial Vasculature

Sympathetic = vasoconstriction

Parasympathetic = vasodilation (? - may have conflicting experimental evidence)

 

NB: No gas exchange in bronchi or bronchioles, thus want large diameter lumen!

48

Autonomic Innervation of Alveolar Vasculature

Sympathetic = no effect

Parasympathetic (Vagus never) = no effect

 

49

Sympathetic Nervous System in Respiratory Tract

  • secretory inhibition
  • bronchodilation
  • vasoconstriction

50

Parasympathetic Nervous System in Respiratory Tract

  • secretomotor
  • bronchoconstriction
  • vasodilation (?)

51

COPD / Asthma

may involve abnormally high parasympathetic discharge as well as inflammation

 

52

pulmonary plexus

  • sympathetic axons
  • parasympathetic axons and ganglia

53

Name the divisions of the bronchiole

  • terminal bronchiole
  • respiratory bronchiole
  • alveolar duct
  • alveolar sac
  • alveolus

54

Histology of the Terminal Bronchiole

  • surrounded by layer of smooth muscle
  • no goblet cells
  • ciliated simple cuboidal epithelium
  • Clara cells

55

What do the green and purple arrows label (hint: terminal bronchiole)

GREEN: ciliated cuboidal cells

PURPLE: Clara cells

56

Clara cell

  • precursors of bronchiolar epithelial cells
  • detoxifies carcinogens
  • synthesizes a surfactant-like protein
  • secretes alpha-1-antitrypsin that inhibits digestion of elastin

emphysema = elastic tissue breakdown

57

Alveolar Wall (what do arrows point to)

Alveolar Wall contains elastic tissue 

58

Acinus

(plural = Acini)

  • functional subunit of the lung supplied by a single respiratory bronchiole

59

What are the divisions after the terminal bronchiole

  • Terminal Bronchiole
  • Respiratory Bronchiole
  • Alveolar Duct
  • Alveolar Sac
  • Alveolus

60

Histology of the Respiratory Bronchiole

  • simple cuboidal epithelium
  • wall punctuated by alveoli and smooth muscle
  • encircled by smooth muscle, interrupted by alveoli

61

What are A and B in this respiratory bronchiole

Respiratory bronchiole is encircled by smooth muscle, interrupted by alveoli

A. Alveolus

B. Smooth muscle 

62

Histology of the Alveolar Duct

  • wall punctuated by alveolar sacs and alveoli

63

Histology of the Alveolar Sac

terminal part of alveolar duct, alveolar clusters

 

64

Histology of the Alveolar Capillaries

end of tracheobronchial tree

65

What are the features of alveolar capillaries

  • capillary walls protrude into lumen
  • provide more surface area
  • simple squamous epithelium

66

What are the (3) types of cells found in alveolar walls

1. Endothelial cells

  • thin, flat; gas exchange

2. Type I pneumocytes

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

3. Type II pneumocytes

  • thick, protruding, "foamy"
  • 60% of alveolar cells
  • Replace damaged Type I cells
  • Secrete surfactant

67

What are the (3) types of alveolar cells (lining the alveoli)

Endothelial

  • thin, flat cells for gas exchange

Type 1 pneumocytes

  • flat cells

Type 2 pneumocytes

  • round, "foamy" cells

68

Lamellar bodies

  • Type II pneumocytes store surfactant in lamellar bodies
  • gives foamy appearance on light microscopy
  • product surfactant in form of tubular myelin weaves

69

Surfactant

  • found on alveolar surface
  • mix of phospholipids, cholesterol, carbohydrates, proteins
  • acts as detergent to decrease alveolar surface tension
  • keeps cell surface water layer thin, increasing gas exchange
  • increases compliance (stretchability)
  • prevents alveolar collapses

70

clinical sign of low surfactant levels

respiratory distress syndrome

71

Alveolar Pore (of Kohn)

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

72

Alveolar Pores (of Kohn) are sometimes partially obstructed by an accumulation of surfactant; how is extra surfactant removed

  • Alveolar macrophages phagocytose extra surfactant
  • also called "dust cells" because they ingest inhaled particulate matter

73

Alveolar macrophages

  • also called "dust cells"
  • phagocytose extra surfactant
  • ingest inhaled particulate matter

74

What might lots of alveolar macrophages signify

  • infection/irritation
  • lungs can recruit ~1mm macrophages per hour

 

75

Smoker's Lungs

  • excess carbon particles (trapped in macrophages)
  • chronic bronchitis (excess mucus from goblet cells)
  • increased risk of pneumonia
  • loss of elasticity (emphysema, fibrosis)
  • cancer
  • metaplasia (bronchi epithelium changes to stratified squamous)
  • interstitial disease (thickened alveolar walls)