1. biological role of respiration Flashcards
what are the three compartments of the respiratory system?
conduction zone: conditioning of inhaled air
respiratory zone: gas exchange
musculo-elastic ventilation: drives ventilation
what is responsible for temperature and moisturising in the nasal cavity
large venous plexus in submucosa
what are vibrissae and what is their function?
hairs at entry to nasal cavity
prevent large particles entering
smaller particles trapped by mucus
what does mucus cover
lining all the way to terminal bronchioles
what is the type of epithelium in lungs
what does the submucosa look like in histology
is this type of epithelium present throughout nasal cavity?
respiratory- ciliated psuedostratified columnar
spongy due to venus plexus
no, olfactory epithelium at the top
sense of smell, sensory neurones. support cells
how is the trachea kept open
horse shoe shaped cartilage
seromucous glands in the submucosa.
Smooth muscle completes the rings which are partially formed by the cartilage.
the wall of bronchus
has cartilage, submucosal glands and sometimes incomplete ring of smooth muscle
what is this?
bronchioli
no cartilage in its wall
some characteristics of epithelium fewer goblet cells
complete ring of smooth muscle
no submucosal glands
terminal bronchioles give rise to respiratory bronchioles R
respiratory bronchioles epithelium and wall
no cartilage or glands
cuibodal
what do the connective tissue in alveoli and lower airways contain
elastin fibres
what is the blood air barrier in alveoli built of
thin walls of capillary endothelium and type I cells, which cover most of the alveolar surface.
where do alveoli get their circulation from
pulmonary
elastic arteries
where do bronchi get their circulation from
bronchial arteries from aorta
muscular
Problem: In a space of such a small diameter as an alveolus, any water on the alveolar surface would exert strong capillary forces, inhibiting the expansion of the lung.
solution?
surfactant to reduce surface tension
Type I pneumocyte: only nuclei discernible. Flat, at air interface. Often hard to distinguish from flat endothelial cells
Type II pneumocytes: In corners of alveoli. Roundish cells with light content and light granular nuclei
Macrophages: Within alveoli. Larger than type II pneumocytes
Cytoplasm often dirty, sometimes with inclusions. Nuclei larger than type II pneumocytes, also with heterochromatin spots
what can be seen in macrophages?
carbon deposits
Waldeyer’s Ring
what type of immunoglobulin and mainly found in alveoli
ring of tonsils at anterior pharynx- aggregates of lymph nodes
mainly IgA. In the alveoli, the alveolar macrophages are the primary line of defence.
