Histology of Resp. System Flashcards
what are the three regions of the nasal cavity?
nasal vesitbule (dilated space inside nostrils)
resp. region (2/3, lined with resp. mucosa)
olfactory region (apex of each cavity - olfactory mucosa)
what type of cells line the nasal cavity respiratory system - respiratory mucosa?
what are the 3 different types?^
what is role? (2)
respiratory mucosa:
- ciliated, pseudostratified columnar epithelium
a) goblet cells - tall columnar cells producing mucous
b) brush cells - bear short microvilli
c) basal cells - stem cells
role:
warms, moistens and filters the inspired air
where do you find the ciliated pseudostratified columnar resp. epithelium?
covers most ofthe parts of the conducting system!
what lies below the ciliated pseudostratified columnar resp. epithelium of nasal cavity in resp system?
below pseudostratified columnar resp. epithelium = lamina propria (thin layer of connective tissue that forms part of the moist linings known as mucous membranes or mucosa)
in the lamina propria:
seromucous glands - drain to surface.
CT
and blood vessels
explain structure of olfactory epithelium
- still ciliated pseudostratified columnar resp. epithelium - but thicker.
- *- NO GOBLET CELLs !!
- olfactory cells:have sense receptor cilia on surface. connect toolfactory nerve
- olfactory (Bowmans) glands**: secrete serous secretion that serves as a trap and solvent for odiferous substances
how does respiratory and olfactory epithelium differ? / how can you tell the difference? (2)
olfactory epithelium is thicker (but still not stratified)!!
AND
nerve fibres in olfactory lamina propria
describe the histology of the pharynx (nasopharnx (2) and the oropharnynx and hypopharnxy (1))
what is found in lamina propria? (2)
- nasopharynx: ciliated resp epithilium & stratified squamous epithelium
- oropharynx & hypopharynx: non-keritinised stratified squamous epithelium
- laminia propria: connective tissue with mucous gland & elastic layer
what are the true vocal fold / cords histology like? what is the underlying skeltal muscles called?
vocal cords:
- lined with both
a) non-keratinised stratified squamous epithelium
b) ciliated columnar epithlium cells - underlying layer: vocalis muscles
describe the histology of the ventricular folds / false vocal cords
- *- what are they covered with?**
- function?
- underyling CT has what?
- covered with: respiratory mucosa
- function: sound resonance
- underyling CT has: mucous glands
what are the blue and black arrows pointing to here in larynx ?
1 = vocalis muscle
2 = mucous glands
3 = ventricular folds
label 1-5 of larynx
1 = vocalis muscle
2 = vocal fold
3 = ventricles
4 = ventricular fold
5 = mucous glands
what are the 4 layers of the trachea?
- mucosa: ciliated pseudo. columnar epithelium and elastic rich lamina propria
- submucosa: serous and mucous glands, BV and nerve fibres
- cartilaginous layer: c shaped hyaline cartilage (!). joined posteriorly by bands of SM called trachealis muscle
- adventitia- CT that binds trachea
label 1-5 of trachea
- Endothelium of trachea
- Seromucous glands
- Lamina propria and submucosa
- Hyaline cartilage
5 adventita
label 1-3
C- Hyaline cartilage. This can be seen as a C-shaped ring (stained blue) which support the tracheal mucosa and prevent its collapse during inspiration
T- Trachealis muscle / Smooth muscle. These bands of smooth muscle join the free ends of the C-shaped hyaline cartilage ring posteriorly. Contraction of the trachealis muscle reduces tracheal diameter and thereby assists in raising intrathoracic pressure during coughing.
LM – Longitudinal muscle. A few strands of longitudinal muscle can be seen behind the trachealis muscle
tracheal epithelium:
consists of which cells? (5)
- *- ciliated cels
- mucous (goblet cells)**
- brush cells (have blunt, squat microvill)
- small granule cells (secrete various hormones)
- *- basal cells**
how do you tell the histological difference between trachea and bronchi?
- *bronchi =** cartilage chips
- *trachea =** cartialge c ring (picture shows this - c)
explain structure of bronchi - 5 layers ?
- mucosa (resp. epithelium)
- muscularis - SMC
- submucosa - glands, CT
- cartilage layer (chips)
- advenitia
diffference between bronchi and bronchioles?
bronchi = **cartilage present** bronchiole = **no cartilage**
what are alveolar ducts ?
what are alveolar sacs?
what are alvelolar cells aka?
- *alveolar ducts:** elongated airways with almost no walls of alveoli
- *alveolar sacs:** spaces surrounded by clusters of alveoli
alveolar cells aka: pneumocytes
how do you tell between type I and II avlevolar cells?
what else do you see around alveolar?
pneumocytes is that type 1 pneumocytes are thin and flattened alveolar cells responsible for the gas exchange between alveoli and capillaries,
type 2 pneumocytes are cuboidal alveolar cells that are responsible for the secretion of pulmonary surfactants that reduce surface tension in the alveoli.
also get pulmonary macrophages in the alveoli BUT not within the walls
what are the 4 layers that exist between the bllod and inspired air in the blood-air barrier?
capillary endothelium
fused basal lamina
alveolar epithelium (type 1 pnemocyte_
surfactant
to which layers in resp. aiways do we get:
- goblet cells
- ciliated cells,
- glands
- hyaline cart
- smooth muscle
- elastic fibres
which part of resp system is this?
bronchiole (no cart, thick smooth muscle and folded of the mucosa)
fill in the table xox
what is pleura histology like?
label the alveoli :)
P1- Type 1 pneumocyte, P2- Type 2 pneumocyte, RBC – Red blood cells, C – capaillary, E – endothelial cell
label this bronchus slide
1 : Smooth muscle. The lamina propria of the segmental bronchi are completely encircled by smooth muscle, which is disposed in a spiral manner. This arrangement permits contraction of the bronchi in both length and diameter during expiration.
2= Small aggregates of lymphocytes (2) which are part of the MALT (mucosa-associated lymphoid tissue) are seen in the adventitia.
3- Seromucous glands. These are sparser in segmental bronchi submucosa. These glands are rarely found in the smaller airways, as you descend down the airway the number decrease gradually.
4- Cartilage framework. The cartilage here is reduced to a few irregular plates. Cartilage does not usually extend beyond segmental bronchi.
5- Submucosa. Note that the submucosa merges with the surrounding adventitia.
