Module 1 Pulmonary Flashcards
How many divisions/generations in lower respiratory tract?
23 1st 16 are conducting zone 17-19 have some alveoli (transional) 20-22 are lined with alveoli 23 is alveolar sac
Gross anatomy of pulmonary system (3)
- Upper respiratory tract with nasal cavity and pharynx
- Larynx -connects upper and lower respiratory tracts with epiglottis thyroid cricoid cartliages
- Lower respiratory tract with pulmonary tree
sternal angle is called..
carina
where is bifurcation of pulmonary tree?
sternal angle/carina
how many lobar bronchi are in R/L side?
3R 2L
Segmental bronchi are also called
surgical lobes - 10 of them
roots of lungs, bvs, lymph vessels and nerves is called
hilum
what is the acinus composed of?
respiratory bronchiole, alveolar ducts, alveolo
what is the region of gas exchange?
acinus
order of the pulmonary tree?
trachea-lobar bronchi-segmental bronchi-terminal bronchioles-respiratory bronchioles-alveolar duct-alveoli - alveolar sac
describe conducting zone vs respiratory zone
conducting- no gas exchange; trachea thru terminal bronchioles
respiratory- gas exchange thru ventilation;respiratory bronchioles thru alveoli sac
what are 2 functions of the pulmonary system? (general functions)
- primary gas exchange: - o2 co2
- non-respiratory functions:-phonation-acid base balance-air conditioning-olfaction- removal of metabolites-production of ACE-filtration and removal of particles/microorganisms thru mucociliary escalator and reflexes in airways
what happens to particles that enter airway?
they will be trapped in mucous sheath lining the tubules and removed by ciliary action and reflex mechanisms
define mucociliary escalator
mucous is propelled away from alveoli via cilia which traps particles
and coughing will transport it to pharynx where it can be swallowed or blown thru nose
irritant receptors in _ cause sneeze reflex
irritant receptors in _ cause cough reflex
nasopharynx
trachea
function of the conducting zone
provide passage for air into and out of gas exchange area of lung
why does air flow slow down as it travels down pulmonary tree?
increasing cross sectional area
define anatomical dead space
conducting zone- does not reach respiratory zone for gas exchange
what are the defense mechanisms of the conducting zone?
- mucociliary escalator
- sneeze
- cough
- airway clearance
if particle is greater then 10 micrometer in diameter:
nasal hair (50-80 microm) - sneeze
if particle is between 2-10 micrometer in diameter:
cilia in trachea and segmental bronchi- cough
ex. bacteria is between 1-10micrometers
if particle is less then 2 micrometer in diameter:
macrophages on alveoli surface will engulf them, transport them to terminal bronchiole to be removed by lymphatic system
- if this does not happen, lung disease will occur ex. pulmonary fibrosis due to inflammation and scar tissue
- no cough reflex here - too deep
portion that is surrounded by the grape-like cluster of the alveoli
alveolar ducts
clusters of individual alveoli
alveolar sacs
allow adjacent alveoli to exchange air btwn each other
pores of kohn
we have about __ alveoli
300 million
describe alveolar septa
two layers: 1. epithelial layer with two types of cells. 2. basement membrane (outer portion that is thin/elastic and allows gas exchange)
type 1 vs type 2 alveolar cells
type 1 provide physical structure of alveoli (outer layer)
type 2 produce surfactant (lipoprotein that coats surface of alveoli) (inner layer)
composition of trachea
smooth muscle, cartilage, pseudostratified ciliated columnar, goblet cells, mucous glands, lastic fibers, lymphatic vessels
composition of larger bronchi-smaller bronchi
smooth muscle, cartilage, pseudostratified ciliated columnar??, goblet cells, mucous glands, lastic fibers, lymphatic vessels
composition of bronchioles
less then 1mm diameter
smooth muscle, cartilage, cilia, simple columnar, goblet cells, mucous glands, elastic fibers, lymphatic vessels
composition of terminal bronchiole
smooth muscle, no cartilage, cilia, simple cuboidal, clara cells, mucous glands?, elastic fibers, lymphatic vessels
composition of respiratory bronchioles
smooth muscle, no cartilage, no cilia, simple cuboidal? elastic fibers
composition of alveolar ducts
elastic fibers, simple squamous
composition of alveoli
type 1 and type 2 cells in membrane, basement membrane, macrophages, pores of kohn
3 wall layers of tracheal tree
inner: epithelial lining
middle: smooth muscle
outer: connective tissue (aka adventitia?)
what is not lined by mucous producing cells and ciliated cells?
respiratory bronchioles - region of gas exchange
anterior 1/3 nose
portions of pharynx
cilia-how many beats per minute
600-900
goblet cells
proximal to bronchioles -mucus producing and secreting cells
clara cells
terminal bronchioles- mucous secreting and producing
describe chronic bronchitis
increase mucous production blocks airways
describe intubation
increased mucous production but no way to remove mucous (ex. no cough)
describe cystic fibrosis
increase mucous, sweat, and digestive juice of many organs
the mucous increase in lungs accumulate and cause infection
pulmonary circulation
non o2 air leaves L ventricle goes to lung and returns to L ventricle
Bronchial circulation
o2 blood leaves R ventricle goes to body and structures of lung and returns to R ventricle
3 functions of pulmonary system
- facilitate gas exchange
- acts as reservoir for left ventricle
- acts as filter system to remove particles or emboli (clots of air)
pressure of pulmonary circulation
low pressure (10-20mmHg) only 1/3 of pulmonary vessels are filled at any moment which increases stroke volume without increasing pressure
define alveolocapillary membrane
basement membrane and capillary wall merged with interstitial space
site of gas exchange
alveolocapillary membrane ratio of blood to surface area
100ml of blood in capillaries over 70-100m^2 of aveolocapillary membrane
-1/10 L spread out over 10mX10m
if alveolocapillary membrane is damaged..
plasma can leak into alveolar space or impair gas exchange
define hypoxic vasoconstriction
partial pressure of o2 drops and arterioles direct blood away from the site (in systemic circulation blood is directed to the site)
is bronchial circulation involved in gas exchange?
no, but it does supple structures of the lung (conducting system, pleura, etc)
describe Right to Left shunt of blood flow
bronchial veins leave nonO2 into o2 blood as they return - an example is an atrial defect
define lymphatic capullaries
drain structures of the lungs
located in tracheal tree thru the terminal bronchial
chest wall is made of
ribs and intercostal muscles
define pleura
double folded serous membrane
visceral (lines lungs)
parietal (lines chest wall)
define pleural space/cavity
space between visceral and parietal layers, secretes pleural fluid which is a lubricant low pressure (negative) to allow lungs to expand and suck in outside air
define pneumothorax
as air enters pleural cavity, pressure is increased which collapses/compresses the lung
