1- Anatomy of breathing 1 Flashcards
(44 cards)
what are alveoli?
thin walled air sacs, that have thin walled capillaries along surface. this histological arrangement allows diffusion of oxygen from alveoli →blood and CO2 from blood →alveoli
what makes up the upper respiratory tract?
- nasal cavity
- oral cavity
- pharynx
- larynx (voicebox)
what makes up lower respiratory tract?
- trachea - bifurcates into right & left main bronchus (primary bronchus)
- then into lobar bronchi (3 in right and 2 in left = 1 lobar bronchi for each lobe)
- segmental bronchi: both right & left have 10 bronchopulmonary segments so 10 segmental bronchi for left & right
- then into bronchioles then alveoli where gas exchange takes place
where is the divide of upper & lower respiratory tract?
at level of C6 vertebra
what happens at level of C6 vertebra?
- larynx becomes trachea
- pharynx becomes oesophagus
*where upper becomes lower respiratory tract
what are the different parts of the pharynx?
top = nasal pharynx (sitting behind nasal cavity)
middle = oropharynx (sitting behind oral cavity)
bottom = laryngopharynx/hypopharynx (sitting behind larynx)
what level does trachea bifurcate?
at level of sternal angle (T4)
what are the lobes on each lung?
right lung = upper, middle & lower lobe
left lung = upper & lower lobe
what is lingula?
left lung has extension on upper lobe instead of middle lobe(tongue like)
what are fissures?
deep crevices/spaces between each lung lobe
what supply does each lung lobe and each bronchopulmonary segment have?
it’s own air supply, blood supply, lymphatic drainage, nerve supply
= this means surgeons can remove a segment of lung rather than a whole lung or lobe
what is mucociliary escalator?
epithelium has mucous glands that secrete mucous onto epithelial surface. the cilia on surface will beat to sweep mucous superiorly towards pharynx and once in pharynx swallowed down into stomach
what are problems with mucociliary escalator?
cooling/drying of mucosa or toxins in cigarette smoke both interfere with normal beating and can cause cough
what parts of respiratory tract contain epithelial cells?
epithelial cells line the inside of bronchial tree all the way from trachea to segmental bronchus (not on bronchioles & alveoli)
what is purpose of hyaline cartilage in walls? and where is it?
to assist with patency of airways (holding them open)
= from trachea to segmental bronchi - reduces as moves down the tree
where is smooth muscle found in respiratory tract?
from trachea to bronchioles - becomes more prominent as moves through respiratory tree
restriction of bronchioles occurs in some diseases - what does it sound like?
a wheeze = the sound of air trying to pass down restricted bronchioles
what are the 4 principles of respiratory system?
- enough O2 and CO2 can diffuse between alveolus and blood at the pulmonary capillary beds
- We must ensure that we can move air freely into and out of our lungs
- We must ensure that we move warm, moist, “clean” air into and out of our lungs
- We must protect the lungs
what are the main requirements to allow enough oxygen and carbon dioxide diffuse betwen alveoli & blood? (principle 1)
- sufficient functioning lung tissue
- sufficient oxygen in the air we breathe
- no carbon dioxide in the air we breathe
- minimal thickness of walls of alveoli to facilitate diffusion
- minimal tissue fluid in tissue spaces around alveoli capillaries to facilitate diffusion (if build up of tissue fluid (oedema) then excess fluid would prevent diffusion of gases)
what are the main dangers that would prevent air moving freely into and out of lungs?
- narrowing respiratory tract (bronchioles constriction, swelling of mucosa lining from overproduction of mucus, growing tumour that externally compresses tract)
- foreign bodies inhaled which may partially or completely stop breathing
how many nasal cavities are there in the skull?
2 - right next to each other, separated by internal wall (septum)
what makes up the nasal septum?
- bony (posterior) part of the nasal septum ethmoid bone (superiorly) & vomer (inferiorly)
- cartilaginous (anterior) part of the nasal septum
what forms the floor and the roof of nasal cavity?
floor = formed by palate
roof = midline part of the floor of the anterior cranial fossa
what are the cartilages of the larynx?
- epiglottis = lid that closes over top of larynx when we swallow making sure food goes into oesophagus not trachea
- thyroid cartilage (big one at front) = adams apple (big in males)
- cricoid cartilage (small one)
- arytenoid cartilages = 2 posterior ones
