Respiratory system

Question 1

Dvisions of respiratory system

Answer 1

conduction, respiratory

Question 2

Funtions and features of conducting division of respiratory system

Answer 2

Fxn: warm, moisten, filter air

features: mucous and serous glands, ciliary movement
Extrapulmonary: nasal cavity, pharynx, larynx, trachea, 1º bronchus
Intra pulmonary: bronchial tree

Question 3

Function and parts of respiratory division of respiratory system

Answer 3

Fxn: gaseous exchange
Parts: respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli

Question 4

regions of nasal cavity

Answer 4

vestibular, olfactory, respiratory

Question 5

Vestibule of nasal cavity

Answer 5

Epithelium: stratified squamous (skin) with sebaceous glands and vibrissae (short firm hairs)

Lamina propria: Glands and vibrissae trap large particulate material in inspired air

Cartilate framework (hyaline cartilage with some elastic fibers)

Question 6

Olfactory region of nasal cavity

Answer 6

neuroepithelium: pseudostratified columnar with 4 cell types:
olfactory-Bipolar neuron, dendrites form olfactory vesicles, axons at basal surface, long non-motile cilia
supporting cells-numerous; columnar with microvilli, abundant mitochondria, lipofuscian granules, and sER, adherent jxns with olfactory receptors, apical ovoid nucleus; support like neuroglia, secrete ordor binding protein,
brush cells-columnar with mircorvilli, synapses with CNV; probably has sensory function
basal cells-small and close to basal lamina; stem cell

Lamina propria: continuous with periostium of ethmoid bone, highly vascular, abundant nerve endings

Bowman’s (olfactory) Gland-seromucous

Question 7

Bowman’s Gland

Answer 7

Olfactory gland
seromucous gland in olfactory mucosa; mostly serous with short ducts; helps to dissolve odoriferous substances; lipofucin granules in ducts and secretory units; helps clear away odoriferous substances

Question 8

Respiratory regoin of nasal cavity

Answer 8

Respiratory epithelium (pseudostratified columnar with cilia and globlet cells)
Lamina propria: highly vascularized: bloo vessels parallel to air flow to wairm air (become engorged and leaky in allergic reactions and viral infections–>distension of LP and trouble breathing); seromucous glands
Conchae (aka turbinae) increase surface area ∴ increase filtration and warming

Question 9

Pharynx

Answer 9

between oropharynx and trachea
fxn: air conduction, phonation
Vestibular fold (false vocal fold): loose connective tissue with glands and lympoid aggregations (respiratory epithelium)
True vocal cords: vocalis muscle (skeletal); vocal ligament (elastic fibers); stratified squamous non-keritinized

Question 10

Trachea

Answer 10

Derived from forgut
Layers resemble GIT: mucosa, submucosa, cartilaginous layer (replaces muscularis externa), adventitia
C-shaped cartilage rings (hyaline cartilage)

Question 11

Trachea Mucosa

Answer 11

Respiratory epithelium:
Ciliated columnar cells: numerous and full thickness; aggregated basal bodies–> dark line at apical surface
Muucus cells: similar to goblet cells, interspaced among ciliated cells, full thickness, increased in chronic inflammation
Basal cells: reserve/stem cells
Small granule cells (Enteroendocrine): many small granules near basal cytoplasm–>local effect on nearby structures, peptide hormones
Brush Cells: columnar with blunt microvilli, probably sensory, synapses with afferent nerve at base

very thick basement membrane

Lamina Propria: Loose CT with lymphatic tussue, lots of elastic fibers arrainged longitudinally at mucosa/submucosa boudry

Question 12

Tracheal submucosa

Answer 12

loose CT, very similar to LP, seromucous glands (mucous acini with serous demilunes, secrete glycoprotein; especially numerous in posterier aspect where there is no cartilage)

Question 13

Tracheal cartilage and advantitia

Answer 13

16-20 C shaped rings of hyaline cartilage, fibroelastic membrane containting trachealis muscle spans gap in cartilage

Advantitia: dense CT, large blood vessels and lymphatic tissue

Question 14

1º Bronchi

Answer 14

histologically identical to trachea without trachealis muscle; Extra pulmonary bronchi

Respiratory epithelium:
Ciliated columnar cells: numerous and full thickness; aggregated basal bodies–> dark line at apical surface
Mucus cells: similar to goblet cells, interspaced among ciliated cells, full thickness, increased in chronic inflammation
Basal cells: reserve/stem cells
Small granule cells (Enteroendocrine): many small granules near basal cytoplasm–>local effect on nearby structures, peptide hormones
Brush Cells: columnar with blunt microvilli, probably sensory, synapses with afferent nerve at base

very thick basement membrane

Lamina Propria: Loose CT with lymphatic tussue, lots of elastic fibers arrainged longitudinally at mucosa/submucosa boudry

loose CT, very similar to LP, seromucous glands (mucous acini with serous demilunes, secrete glycoprotein; especially numerous in posterier aspect where there is no cartilage)

Question 15

Intrapulmonary bronchi

Answer 15

respiratory epithelium with lower cell height; reduced basement
muscularis- spiral oriented smooth muscle regulates airway diameter (replaces elastic lamina; increase to provide support as there is less cartilage)
submucosa-loose CT with glands (larger bronchi)
cartilage-discontinuous cartilage plates, linear pattern (gets smaller as you get deeper and brochi get smaller)
Advantitia-continuous with lung tissue

Question 16

Bronchioles

Answer 16

air donducting ducts that supply each pulmonary lobule, no glands

epithelium-simple columnar to simpule cuboidal, ciliated, goblet cells in larger bronchioles, clara cells, smooth muscles

Question 17

terminal brochiole

Answer 17

circumferential smooth muscle, simple cuboidal epithelium, some cilia, clara cells, >.5 nm, sparse

Question 18

Clara cells

Answer 18

replace goblet cells in bronchioles

cuboidal with domed shaped apical surface, well developed rER, also sER, golgi, and secretory granules

Secretes: surface active agent (liproprotein that prevents adhesion); Clara Cell Protein (CC16, diagnostic marker)

Question 19

CC16

Answer 19

clara cell protein
diagnostic marker for chronic lung diseases like COPD and Asthma–>leaks across blood/gas barrier and elevated in serum; decreases in bronchoalveolar lavage

Question 20

Respiratory Bronchiole

Answer 20

Transition airway–>respiration adn conduction
simple cuboidal ciliated epithelium with clara cells proximal to terminal bronchiole, mostly clara cells distally; walls interrupted by alveoli, small amount of smooth muscle

Question 21

Alvolar ducts

Answer 21

from RB as alvolar out-pouchings increase–>numerous alveoli

“drumsticks” of smooth muslce–>bundles b/w alvolar out-pocketing (nteralvolar septum)

Question 22

Alvolar sac

Answer 22

end of alvolar duct, several alveoli

Question 23

Alveoli

Answer 23

thin walled polyhedral terminal sacs where gaseous exhange takes place; separated by interalveolar septum; continuous capillaries with lots of pinocytotic vesicles for gas exchange

Question 24

Alveolar cells

Answer 24

Type 1-simple squamous, gas exchange, not capapble of mitosis, covered by surfactant, tight jxns
Type 2 (septal cells)-cuboidal secretory cells mostly at septal junctions, regenrate both types of pneumocytes, secrete surfactant, rounded nucleus, lamellar (secretory, prallel membrane stacks, contain phospholipids, neutral lipids and proteins) bodies in apical cytoplasm, well developed sER.
Alveolar macrophages-move freely b/w septum and surface, clean shit up, may be swept up bronchial tree, can be marker of heart failure or other things

Question 25

Surfactant

Answer 25

dipalmitoylphosphotidylcholine (DPPC)
Sp-A: regulates synthesis and secretion of surfactant, modulates immune response
SP-B&C: surfactant organizing protein
SP-D: binds microorganisms and lymphocytes, involved in acute inflammatory response
Adequate amout @ 35th week
regulated by cortisol, insulin, thyroxin, prolactin

Question 26

Interalveolar septum

Answer 26

type I and II cells, collagen (reticular) fibrils and elastic fibers; blood air barrier; thin layer of connective tissue

Question 27

Strongest point of blood/air barrier

Answer 27

where type I and enothelial cells fuse (think portion of interalveolar septum)

Question 28

Thin portion of blood-gas barrier

Answer 28

1. surfactant 2. type I pneumocyte 3. fused basal lamia of type I and endothelium 4. endothelial cells

most effective barrier

Question 29

This protion of blood-gas barrier

Answer 29

1. surfactant 2. P1 3. basal lamina of P1 4. connective tissue elements (cells, elastic an collagen) 5. basal lamina of endothelium 6. endothelial cells

Question 30

Pores of kohn

Answer 30

Alveolar pores–>allow collateral air circulation b/w alveoli, facilitate spred of infection b/w lobules