Respiratory Histology Flashcards by Emily Prazak

What are the components of the conducting division of the respiratory system?

nasal cavity, mouth, nasopharynx, pharynx, larynx, trachea, primary, secondary and tertiary bronchi, bronchioles and terminal bronhcioles

How well did you know this?

Not at all

Perfectly

WHat are the functions of the conducting division?

warm, moisten and filter air

deliver air to respiratory division

How well did you know this?

Not at all

Perfectly

What happens to total cross sectional area and air velocity as you descend further into the conducting division?

cross sectional area increases

air flow velocity decreases

How well did you know this?

Not at all

Perfectly

What are the components of the respiratory division?

respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli

How well did you know this?

Not at all

Perfectly

The anterior portion of the nasal cavity (vestibule) contains what?

skin, vibrissae, sebaceous and sweat glands

How well did you know this?

Not at all

Perfectly

The posterior portion of the nasal cavity is covered by MOSTLY what epithelium?

respiratory epithelium mainly, but some olfactory epithelium

How well did you know this?

Not at all

Perfectly

What kind of epithelium is respiratory epitheilum?

pseudostratified ciliated columnar epithelium

How well did you know this?

Not at all

Perfectly

What glands are associated with the respiratory epithelium? What layer are they in mostly?

seromucous glands - mainly in the submucosa, but some in the lamina propria

How well did you know this?

Not at all

Perfectly

Where is the olfactory region of the nasal cavity?

the roof of the nasal cavity, superior aspect of the nasal septum and superior concha

How well did you know this?

Not at all

Perfectly

What are the three main cell types in the olfactory epithelium?

olfactory cells
sustentactular cells
basal cells

How well did you know this?

Not at all

Perfectly

What kind of neurons are the olfactory cells? Describe their orientation?

bipolar neurons

have an olfactory vesicle the protrudes above the epithelial surface with non-motile cilia from each vesicle extending along the epithelial surface embedded in mucous

How well did you know this?

Not at all

Perfectly

Axons from these bipolar neurons pass through what to get to the brain?

the cribriform plate

How well did you know this?

Not at all

Perfectly

What do the sustentacular cells do?

provide physical support, nourishment and electrical insulation for the olfactory cells

How well did you know this?

Not at all

Perfectly

Where are the basal cells?

they are pyramidal cells that don’t reach the epithelial surface - just along the basal lamina

How well did you know this?

Not at all

Perfectly

What do the basal cells do?

they serve as a reservoir for replacing both the olfactory cells and sustentacular cells (which only life less than a year)

How well did you know this?

Not at all

Perfectly

What gland produces the mucous in which the cilia of the bipolar olfactory cells lie? WHere is it?

Bowman’s gland in the lamina propria CT

How well did you know this?

Not at all

Perfectly

Describe the layering and serous fluid in the nasal cavity.

the mucus lies above a more fluid-serous layer in which the tips of the cilia terminate

How well did you know this?

Not at all

Perfectly

Which direction do the cilia beat in the nasal cavity?

the cilia beat towards the back of the naso pharynx such that the serous fluid layer will move and drag the mucous layer along with it - so the mucous with trapped particles can be swallowed or expectorated

How well did you know this?

Not at all

Perfectly

What are the two main immunoglobulins located in the nasal cavity and what do they do?

secretory IgA and IgE produced by the plasma cells

they will bind to specific antigen or allergens that get embedded in the mucous

How well did you know this?

Not at all

Perfectly

What are the 4 paranasal sinuses?

ethmoid
sphenoid
frontal
maxilla

How well did you know this?

Not at all

Perfectly

What epithelium lines the paranasal sinuses?

respiratory epithelium

How well did you know this?

Not at all

Perfectly

What part of the conducting system lies posterior to the choana and extends to the opening of the larynx?

the pharynx

How well did you know this?

Not at all

Perfectly

What are the three parts of the pharynx?

nasopharynx, oropharynx, laryngeal pharynx

How well did you know this?

Not at all

Perfectly

What kind of epithelium is in the nasopharynx? the oroharynx/ laryngeal pharynx?

naso = respiratory
oropharynx = stratified squamous epithelium
laryngeal pharynx = stratified squamous epithelium

How well did you know this?

Not at all

Perfectly

What regions lies between the pharynx and the trachea?

the larynx

WHat is the wall of the larynx reinforced by?

numerous carilages: hyaline cartilages: thyroid and cricoid cartilages and inferior aspect of paired arytenoids elastic cartilages: unpaired epiglottis cartilage, paired corniculate and cuneiform cartilages, superior aspect of arytenoids

What are the main anatomical objects of interest in the larynx?

the vocal folds - ventricular above and true vocal folds below

What are the vestibular folds made of? What are the vocal folds made of?

vestibular are pseudostratified ciliated columnar epithelium covering loose connective tissue with adipose cells, seomucous glands and lymphoid elements vocal are dense, regular elastic connective tissue covered with stratified squamous epithelium, otherwise pseudostratified ciliated columnar

The epiglottis has a core made of what? What's the superior surface coverd by? How about the inferior surface?

core of elastic cartilage superior surface - stratified squamous inferior surface - pseudostratified ciliated columnar

What comes after the larynx?

the trachea

What is the wall of the trachea reinforced by?

10-12 C-shaped cartilaginous rings

What are these cartilginous rings made of?

hyaline cartilage

What way does the open end of these cartilages face?

open end faces posteriorly where it's joined by the trachealis muscle (smooth muscle) so the front is really protected by cartilage - makes sense

What does contraction of the trachealis muscle cause?

decreased diameter of the tracheal lumen, resulting in faster air flow

What are the three layers of the trachea?

mucosa submucosa adventitia

What are the 6 cell types of the respiratory epithelium in the mucosa of the trachea?

1. ciliated columnar cells >30% 2. goblet cells <30% 3. basal cells 30% 4. brush cells 3% 5. serous cells 3% 6. Cells of the diffuse neuroendocrine system 3-4%

Is the basement membrane thick or thin in the trachea?

very thick

What is contained by the lamina propria in the trachea? WHat separats it from the underlying submucosa

loose fibroelastic tissue, lymphoid elements, mucous and seromucous glands with short ducts separated from underlying submucosa with elastic lamina

What layer contains the C-shaped hyaline cartilages?

the adventitia

What does the trachea bifurcate into? What's the order of airways afte rthat?

right and left primary bronchi (extrapulmonary bronchi) then intrapulmoarny bronchi: secondary (lobar) and tertiary (segmental) bronchioles terminal bronchioles respiratory bronchioles

What tissues decrease as you progress down the airways and what increases?

decreases: cartilage, glands, goblets, epithelial height increases: smooth muscle and elastic tissue

How do the right and left primary bronchi differ?

right trifurcates to the three lobes | left bifurcates to the two lobes

How does the cartilage of the lobar bronchi differ from that of the primary bronchi?

the C shaped cartilage rings are replaced by irregular plates of hyaline cartilage

Describe how the epithelium of larger bronchioles differs from that of smaller bronchioles?

larger - ciliated simple columnar with occasional goblets | smaller - simple cuboidal with some cilia with occasional clara cells and no goblet cells

Describe a clara cell.

it's a columnar cell with a dome-shaped apices with hsor mticrovilli. the apical cytoplasm contains numerous secretory granules containing glycoprotein

What do we think that glycoprotein is for?

believed to line and protect the bronchiolar epithelium

How do the clara cells degrade inhaled toxins?

cytochrome p-450 enzymes in the membranes of their smooth endoplasmic reticulum

Respiratory bronchioles are similar in structure to terminal bronchioles with what one important exception?

the wall is interrupted by occasional alveoli where gas can be exchanged

What are the walls of the alveolar ducts?

don't really have walls - just linear arrangements of alveoli

What reinforce the alveolar ducts then if they don't have walls?

interalveolar septa - connective tissue

Opening of each alveolus is controlled by what?

a single smooth muscle cell - knob - that forms a delicate sphincter that regulates the diamter of the alveolar opening

WHat type of fibers surround the alveolar ducts and sacs?

fine elastic fibers

Each cluster of alveoli is known as what?

an alveolar sac

How many alveoli are present in the lungs?

about 300 million

THe interalveolar septum between adjacent alveoli contains just continous capillary and basal lamina in the thin regions, but what in the thicker areas?

``` type 3 collagen elastic fibers macrophages fibroblasts mast cells lymphoid elements ```

What are the two cell types in the alveolar walls? Which icovers 85% of the alveolar surface? Which is more numerous?

type I and type 2 alveolar cells (pneumocytes) 85% of the alveolar surface is type 1 but type 2 are slightly more numerous

The type 1 pneumocytes rest on a basal lamina except where?

at respiratory pores, which are formed by fusion of cell membranes of adjacent type 1 pneumocytes in two distinct alveoli

What sort of jucntions are found between type 1 alveolar cells?

occluding junctions

Describe the shape of the type 2 pneumocytes.

cuboidal in shape with dome-shaped surface that bulges into the alveolar lumen

What form of junctions form between type 1 and type 2 alveolar cells?

tight junctions

THe type 2 pneumocytes contain membrane-bound lamellar bodies in the cytoplasm which contain what?

pulmonary surfactant (dipalmitoyl phosphatidylcholine and phsphatidylglycerol)

What will migrate between the type i pneumocytes into the alveolar lumen to phagocytize particulate matter and surfactant?

alveolar macrophages

branches of what arteries parallel the bronchial tree and bring deoxygenated blood from the right heart?

pulmonary arteries

venous drainage is vessels located where in the lung tissue? Do they travel with the arterial blood supply?

the vessels are located in the septa between lobules of the lung - thus the veins follow a different path than the arteries

What vessels bring osygenated blood to the bronchial tree, interlobular septa and pleural llungs?

the brinchial arteries

where do the bronchial veins drain?

into the azygos system

There is a superficial system of lymphatic drainage in the visceral pleura that eventually drains into what nodes? How about the deep lymphatic system following the pulmonary arteries, pulmonary veins and bronchial tree?

the hilar lymph nodes at the root of each lung

Sympathetic supply to the lung comes from what? Causes what?

thoracic sympathetic chain ganglia - causes bronchodilation

Parasympathetic supply is from what? Cuases what?

from the vagus - causes bronchoconstriction