Intro- pulm anatomy, histology, etc Flashcards
pg 1-20 (44 cards)
Lung lobes and segments
Right Upper Lobe: apical, posterior, anterior
Right middle lobe: medial, lateral
Right lower lobe: superior, anterior basal, medial basal, lateral basal, posterior basal
Left Upper Lobe:
(Upper division): apical-posterior, anterior
(Lingula): superior, inferior
Left lower lobe: superior, antero-medial basal, lateral basal, posterior basal
Cartilage shape in trachea and bronchi
trachea + mainstem bronchi: C-shaped rings
Segmental and lower bronchi: plates of cartilage
Kartagener’s syndrome
Primary ciliary dyskinesia
Often have mirror image of a normal chest
with dextrocardia and reversal of the normal branching pattern of the lungs (with a “left middle lobe” and a “right ligula”
Aspirated foreign bodies usually lodge where?
In the right lung
Left mainstem bronchus is longer than the right and more actuely angled at the trachea
Conducting airways
Airways without alveoli directly attached
How do you distinguish bronchi from bronchioles?
Bronchioles have no cartilage in their walls
Respiratory bronchioles
Arise from the terminal bronchioles (~generation 16)
Have alveoli budding directly off their walls
Alveolar ducts
Make up the final 3 or so generations of airways.
Made up of alveoli with BANDS OF SMOOTH MUSCLE in their walls.
Acinus
Comprised of a respiratory bronchiole and all of its branches and alveoli
Epithelial cell type in the trachea, bronchi, bronchioled, alveoli
Trachea and bronchi: Pseudostratified Columnar
Bronchioles: Cuboidal
Alveoli: Squamous
Where are these found:
- Cilia
- Sub-mucosal glands
- Goblet Cells
Cilia: between the bronchioles and trachea
Sub-mucosal glands: in the trachea and bronchii
Goblet cells: in all airway levels down to the terminal bronchiole
Cells on the alveolar surface
93% Type I epithelial cells (squamous pneumocytes)
-terminally differentiated
7% Type II (granular pneumocytes)
- more numerous, but rounded shape, take up less surface area.
- can differentiated into Type I cells in cases of lung injury
- produce surfactant
Capillary endothelium metabolic activities
- Converts Angiotensin I to angiotensin II
- Produces factor 8
- Inactivates prostaglandins E2 and F2a, leukotriene, and serotonin
- Principal site of liquid and solute filtration with net outward flow of 10-20 ml/hr in adults (fluid removed via pulmonary lymphatics)
In order to get to a rbc in the capillary, a molecule of O2 must traverse:
Surfactant Type 1 pneumocyte Fused basement membrane Endothelial Cell Plasma
Lung Blood Supply
Two separate blood supplies:
- Pulmonary arteries (carry desaturated blood to capillary bed for reoxygenation)
- Bronchial arteries (carry arterial blood to nourish the bronchi)
Pulmonary lymphatics
Drains into mediastinal lymph nodes.
Lymph flow ~20 ml/hr
Pulmonary Interstitium
Portion of the lung btw the alveolar epithelium and capillary endothelium
Composed of non-cellular components (collagen and elastin), some fibroblasts and macrophages
Respiratory muscles
Main muscle of inspiration: diaphragm Accessory muscles of inspiration: -external intercostals -scalene muscles -sternomastoid muscles
Accessory muscles of expiration:
- Rectus abdominus
- Obliques
- Transverse abdominal muscles
- Internal intercostals
Respiratory System innervation
Motor:
Diaphragm: phrenic nerves (C3, C4, C5)
Intercostals: intercostal nerves (thoracic segmental nerves)
Autonomic:
Sympathetic- (upper thoracic ganglia) Stim results in bronchodilation, constriction of pulmonary blood vessels, inhibition of glandular secretion
Parasympathetic- (vagus nerve) Stim results in
airway constriction, dilatation of pulmonary circulation, increased glandular secretion
Non-adrenergic, non-cholinergic pathway: (NANC) possibly mediated via NO
Receptor types
Pulmonary stretch receptors (slowly adapting)
-assoc. w/smooth muscle of intra-pulmonary airways. React to lung inflation and increased transpulmonary pressure.
Irritant, rapidly adapting. Epithelial, larynx and intrapulmonary. React to irritants, mechanical stim, etc.
C-fiber receptors:
- Pulmonary C-fiber receptors:
- found in alveolar wall
- sense increased pulmonary interstitial congestion, chemical injury, microembolism - Bronchial C-fiber receptors.
- Stim results in bronchoconstriction
C-fibers responsible for sensation of dyspnea in many pulmonary diseases.
Conducting Airways
nasal cavities, pharynx, larynx, trachea, bronchi, bronchioles
Respiratory airways
respiratory bronchioles, alveolar ducts, alveolar sacs
As air moves distally into the lung, what happens to air flow, air turbulence, humity & warmth?
Cross-sectional area increases
Air flow velocity decreases
Air turbulence increases
Humidity & warmth increase
Four layers that form the Trachea through bronchioles
Mucosa
Submucosa
Muscularis and/or cartilage
Adventitia