Respiratory Tract Flashcards
which part of the respiratory system does respiration begin to occur?
respiratory bronchioles
what is included in the upper respiratory system?
- nasal cavity
- pharynx
- larynx
what is included in the lower respiratory system?
- trachea
- bronchi
- bronchioles
- terminal bronchioles
what is included in the respiratory portion?
- respiratory bronchioles
- alveolar ducts
- alveoli
what is phonation?
phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration
what is the function of the turbinate?
it humidifies and cleanses the air breathed in
what is the vestibule? what is the structure of it?
it is the nose opening leading into the nasal cavity. It has a cartilage framework and short firm hairs.
what cells is the vestibular composed of?
stratified squamous epithelium
what cells is the respiratory region composed of?
respiratory epithelium. This is ciliated pseudostratified columnar epithelium
how are the capillaries arranged in the nasal respiratory region?
they are lined up perpendicular to the airflow which warms the air
what cells is the olfactory region composed of?
it is lined by pseudostratified columnar epithelium with four types of cells
where is the olfactory region located?
it is found at the roof of nasal cavity and the superior nasal conchae
what happens to the turbinates during infection?
they inflame
what is rhinitis/coryza? how is it caused?
inflammation of the mucous membrane, it can be caused by allergic reactions or viral infections
what is the pathophysiology of rhinitis?
*Capillaries that reside near the surface of the lamina propria become engorged
*Lamina propria becomes distended with fluid *Marked swelling of the mucous membrane *Restriction of the air passage
*Breathing difficult
what are the olfactory (Bowman’s) glands?
these glands produce a serous fluid that bathes the olfactory cilia and serves as a solvent to dissolve the odour molecules for detection by the olfactory cells
what is in the serous secretion of the olfactory glands?
lysozyme and IgA
what 4 types of cells is the olfactory epithelium made up of?
1.Olfactory receptor cells
2.Supportive
3.Brush cells
4.Basal cells
what 5 types of cells is the respiratory epithelium made of?
1.Ciliated columnar cells
2.Mucus cells
3.Brush cells
4.Small granule
5.Basal cells
what does the lysozyme of the serous secretion of the olfactory glands do?
it breaks the particles into smaller particles and are then taken by olfactory receptor cells that are connected to axons.
what is the function of basal cells?
stem cells that regenerate all other cell types
what is the function of goblet/mucous cells?
to secrete mucin granules to create a protective mucus barrier
what is the function of ciliated columnar cells?
sweeping motion helps expel particles trapped in the mucus
what is the function of small granule cells?
enteroendocrine cells secrete catecholamines
what is the function of brush cells?
synapse with afferent nerves for sensory function
what is Kartagener syndrome also known as?
ciliary dyskinesia
what is Kartagener syndrome?
a genetic disorder involving the mutation in genes that code for ciliary protein dynein and results in situs inversus, and recurrent sinus and pulmonary infections.
what is situs inversus
Situs inversus is a rare genetic condition in which the organs in your chest and abdomen are positioned in a mirror image of normal human anatomy. This organ reversal is a result of faulty migration during embryogenesis.
why does dyskinesia result in recurrent sinus and pulmonary infections?
cilia does not work properly and mucus is accumulated which could contain pathogens
what is the larynx?
the tubular region between the pharynx and trachea
what type of cartilage is the larynx made of?
hyaline cartilage and elastic cartilage
what is the function of the larynx?
air conduction and phonation
what are the 2 types of folds that make up the structure of the larynx?
the vestibular and vocal folds
what is the function of vocal folds?
to produce sound
what cells make up the vocal folds? Why are there many layers?
stratified squamous cells and muscle. There are many layers because there is a lot of friction with air
what cells make up the vestibular folds?
respiratory epithelium
what is lamina propria?
loose connective tissue
what four layers make up the trachea?
- mucosa
- submucosa
- cartilaginous layer
- adventitia
what makes up the mucosa of the trachea?
– RE - Respiratory epithelium
– LP- lamina propria→ loose connective tissue
– Longitudinal elastic fibres in deep LP
what makes up the submucosa of the trachea?
- Loose connective tissue
- Seromucous glands
what makes up the cartilaginous layer of the trachea?
- C-shaped hyaline -open posteriorly “gap” between free cartilage ends is completed by a fibroelastic membrane and trachealis muscle (smooth)
what makes up the adventitia of the trachea?
- Connective tissue- binds trachea to adjacent structures
how many primary bronchi are there?
2
how many secondary bronchi are there?
the right lung has 3 and the left has 2
how many tertiary bronchi are there?
eight tertiary bronchi in the left lung and ten tertiary bronchi in the right
what 5 layers make up the bronchi?
- mucosa
- muscular layer
- submucosa
- cartilage layer
- adventitia
what is metaplasia?
A change of a cell to a form that does not normally occur in the tissue in which it is found.
who is at risk for metaplasia?
smokers
what is dysplasia?
A change of an increased number of cells to a form that does not normally occur in the tissue in which it is found.
Metaplasia leads to dysplasia. What can dysplasia lead to?
neoplasia or squamous cell carcinoma
describe the epithelium of the bronchioles. Large to small.
Larger bronchioles: Ciliated, pseudostratified columnar that transition into simple ciliated columnar (Goblet cells present)Smaller bronchioles (Terminal and Respiratory):simple cuboidal with secretory club.
They become more simple as the structure gets smaller.
is cartilage present in large bronchioles?
yes
is cartilage present in small bronchioles?
no, but may be present slightly at branching points
what is the pathophysiology of bronchial asthma?
Airway obstruction occurs due to
o Increased mucus
o Increased smooth muscle (hypertrophy and hyperplasia)
o Bronchiolar wall inflammation
what are the symptoms of bronchial asthma?
short breath, wheezing and coughing
how is bronchial asthma treated?
albuterol, corticosteroids (anti-inflammatory) and anticholinergic medications which relax smooth muscles
what are 3 typical changes that occur as the respiratory tract descends? (5)
- loss of cartilage
- loss of mucous glands
- loss of goblet cells
- loss of cilia
- cells become progressively flattened
what is included in the respiratory portion?
- Respiratory bronchioles
- Alveolar ducts
- Alveoli
what cells make up the alveolar epithelium?
type I and type II pneumocytes
what are type 1 pneumocytes?
Type I pneumocytes cover 90% of the internal surface of each alveolus.
These cells are thin and squamous, ideal for gas exchange.
They share a basement membrane with pulmonary capillary endothelium, forming the air-blood barrier where gas exchange occurs.
what are type 2 pneumocytes?
Type II pneumocytes are identified as the synthesizing cells of the alveolar surfactant, which has important properties in maintaining alveolar and airway stability.
Lung surfactant can reduce the surface tension and prevent alveolar collapse and the airway walls collapse.
what is alveolar surfactant regulated by?
cortisol , insulin, thyroxin and prolactin
when is an adequate amount of surfactant produced in foetuses?
after 35th week of gestation
what is the interalveolar septum?
The alveolar septum separates adjacent alveoli in lung tissue.
The air blood barrier.
what are the pores of Kohn?
The pores of Kohn are apertures in the alveolar septum, which allow the communication of two adjacent alveoli.
what is neoplasia?
An abnormal mass of tissue that forms when cells grow and divide more than they should or do not die when they should. IRRIVERSIBLE
what is COPD?
Chronic obstructive pulmonary disease (COPD) is the name for a group of lung conditions that cause breathing difficulties.
what is emphysema? What causes it?
Emphysema is a lung condition that causes shortness of breath. Large alveolar airspaces giving reduced functional efficiency
how do neutrophils play a role in the pathophysiology of emphysema?
- Neutrophils release proteases including elastase, which breakdown elastic fibres in the small airways
- Serum Alpha 1 antitrypsin (AAT) counteracts the elastase activity.
how does smoking make emphysema worse?
- Persistent smoking elevates the neutrophils and elastase levels → increased destruction of elastic fibres → leads to permanent dilation of airways
what is cystic fibrosis?
CF is inherited in autosomal recessive disease. It is caused by the mutation of both copies of the cystic fibrosis transmembrane conductance regulator (CFTR) protein and chloride channel.
