Histology of the Respiratory System: Heinbockel Flashcards
What is the primary function of the respiratory system?
- gas exchange which involves the lungs
- humidifies, cleans, and warms the air
Incoming air goes through which structures? List them in order.
- nasal cavities
- nasopharynx
- larynx
- trachea
- smaller bronchi
- bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
What is the conducting portion of the respiratory system responsible for?
supplying the lungs with air
What is the respiratory portion of the respiratory system responsible for?
site of gas exchange
Alveoli and alveolar ducts and sacs are part of what division of the respiratory system?
respiratory portion
Bronchi, bronchioles, terminal bronchioles are part of what division of the respiratory system?
conducting portion
As air travels from the nose to the alveoli, what happens to the number of glands, cilia, and goblet cells?
- gland number decreases to none
- cilia and goblet cells disappear
As air travels from the nasal cavity to the alveoli, what happens to the number of air passageways, their size, thickness, and rigidity?
- number of air passages increase
- luminal diameter (size) of the air passageways decrease
- decrease in the thickness and rigidity of the wall due to less bone and cartilage
What is the epithelium of the external surface of the nostrils or nares?
keratinized stratified squamous epithelium
Why do individuals often get nosebleeds when impacted on their nose?
the vestibule is highly vascularized (lots of blood vessels)
What is the epithelium of the anterior surface of the nasal cavity?
non-keratinized stratified squamous epithelium
What is the vestibule?
the most anterior part of the nasal cavity
What is the epithelium of the further posterior surface of the nasal cavity?
respiratory epithelium AKA pseudostratified ciliated columnar epithelium with goblet cells AKA PCC
What is the function of the sweat, mucous glands in the vestibule?
goblet cells produce mucus droplets comprised of glycoprotein and is secreted out on the surface of the epithelium to help trap dust particles that get into the nose??
What is responsible for the distinct line on the apical portion of the pseudostratified ciliated columnar epithelium?
basal bodies of the cilia
Describe the composition of cells of the pseudostratified columnar epithelium.
30% ciliated columnar cells
30% goblet cells
30% basal cells
10% endocrine cells (members of the diffuse endocrine system AKA DES AKA bronchial cell of kulchitsky
Which cells undergo mitosis and differentiation in the respiratory epithelium?
basal (short) cells which are generative stem cells
What type of connective tissue is found in the lamina propria?
loose connective tissue
What is the purpose of the superficial venous plexus in the lamina propria?
allows for countercurrent flow to help warm up the air during the cold for example
What type of arrangement does the cilia have in respiratory epithelium?
9 plus 2
What is the function of the cilia in the respiratory epithelium?
to move mucus around the epithelium to get it out of the respiratory system
Cilia have to move the mucous which requires lots of energy (ATP). What organelle will be predominant in the ciliated columnar cells?
mitochondria
What is Kartagener’s syndrome?
AKA immotile cilia syndrome
- the dynein or microtubules are missing; the cilia are not beating properly or moving around anymore: this means the goblet cells will continue to produce mucous which covers the cilia
- this can lead to recurrent chest infection (bacterial) or prolonged stagnation of mucal secretion and bacterial infections leading to a widening or dilation of airways leading to premature death
Describe the the key differences of the olfactory epithelium in comparison to the respiratory epithelium.
- no goblets cells but Bowman’s gland that secrete fluid
- have microvilli at apical portion
- olfactory receptors (bipolar) on the olfactory epithelium to bind to odorant molecules and turn them into electrical signals
- supporting or sustentacular cells, olfactory cells, basal cells
What is the upward flap-like extension of the anterior wall of the larynx?
epiglottis
The anterior surface and upper part of the posterior surface of the epiglottis is covered with what type of epithelium?
stratified squamous nonkeratinized epithelium (lingual surface)
-remember surfaces that are constantly impacted (receiving chemical stress) are most likely stratified squamous
The lower, more protected part of the epiglottis is covered with what type of epithelium?
pseudostratified ciliated columnar epithelium with goblet cells (pharyngeal surface)