export_respiratory system Flashcards
What innate defense to foreign particles or MOs is present in the trachea?
Mucociliary escalator
What is the manubrium?
The Cranial part of the sternum
Where is the xyphoid process?
Base of the sternum
Describe the diaphragm’s location
- between the thorax and abdomen
- T12;
- hypaxial muscle composed of skeletal muscle tissue
- crural, costal and sternal
Holes of Diaphragm
1) Aorta Hiatus
2) Oesophageal Hiatus
3) Caval foramen
What is ciliary dyskinesia
Cilia not coordinated, congen. Animals will be prone to ear and resp infections.
Lobar bronchus becomes many tertiary bronchi which supplies..
Bronchopulmonary segments
What divides the lungs into lobules?
Peribronchiole CT
Luncg tumors can only be removed if…
within the same bronchopulmonary segment
What is monopodial division?
Equal sized daughters, stemming from below the growing point.
After 6 monopodial divisions, what happens?
Parent stem divides to produse many much smaller daughter bronci. Inc Xsectional Area
What does the trachealis muscle do?
It sits behind trachea inbetween trachea and esophagus. It relaxes during swallowing and contracts during coughing to narrow lumen
Semicircular tracheal rings in dogs allows….
tracheal expansion, effect of gravity.
Define a bronchiole
*
Define the order of bronchiole divisions
Bronchioles –> terminal –> resp zone –> resp b –> alveola sacs –> alveoli
Respiratory bronchioles have
- clara cells
- cuboidal epi, no cilia
- no goblet cells
What are clara cells
Cells in resp bronchioles and alveoli
Secrete surfactant
non-ciliated
Describe alveoli
ALVEOLI
- Round to cup-shaped
- Simp Sq epi surrounded by Capill.
What are type 1 alveocytes
epi cells, thinly ‘spread’
What are type 2 alveocytes
Clara cells. surfactant producing, very few
What is a Bronchovascular bundle?
- bronchi
- artery
- vein
- lymphatic vessel
What property of the capillary network means that secondary neoplasia is common?
There are no arteriovenous anastomoses so all blood must run through lung cap bed.
Describe the blood supply to the lungs
- Brochial a from aorta –> bronchi
- Follow and divide with bronchioles
- At resp bronchioles –> drain away
- drain = CR VC, Azygous, Pulm v –> LA
Nervous supply of lungs…
- pulmonary plexus
- parasymp from vagus
- symp from trunk T2-T5
Trachea forms from….
F-gut outpouching
The oesophagous is sep from the trachea by bilateral tracheo-oesophageal grooves which meet to form..
laryngeotracheal tube
Laryngeotracheal tube becomes
lobar bronchi
What embryological tissue forms the visceral lining
endoderm
Foetal Hb has a _______ affinity for Oxygen
Higher
What is the value of the negative pressure of the lungs
60mmHg below atmospheric
horses inspiration / expiration is
both passive and active - biphastic breathers
define compliance
= change in lung volume/change in lung pressure
surface tension is..
when Hbonds cause water to behave as a film
Surfactant is needed to …
- reduce surface tension
- break h bonds
- allows alveoli to inflate
Alveolar pressure is defined as:
P(alv) = 2 x surface tension/radius
Would a small alveolus have a smaller or larger pressure
same as higher conc of surfatant
Resistance is calc by:
R = 8 x length x substance/ Pi x radius x 4
How do horses increase the radius of their upper airways
nostrils and conchi dilate
Smooth muscle can be manipulated to increase radius of airways, how?
B2 Adreno-R agonists –> dil
Para stim —> bronchspasm
function dead space =
not perfused so no gas exchange
atmos p at sea level =
760mmHg
pO2 =
21%
The higher the partial pressure, the _____ it will dissolve
easier
PH20 at alveolus =
50mmGh
Ferric iron (Fe3+) has a higher or lower affinity to Hb than Fe2+?
Higher
What is methaemoglobin?
Hb Fe+++, not 2+! Lower Oxy carrying ability, higher affinity though!
Increased body temp, ___ Hbs affinity for O2
Decreases. exercising m need O2 when hot
What is chlorid shift?
When Cl- move into a RBC as a Bicarbonate ion moves into plasma
On an Xray veins are where?
Ventral and central
Alveolar vessels are
capillaries which undergo gas exchange
What happens during lung inflation to the alv and extraalv vessels?
- Alveolar vessels collapse via stretch of the alv wall
- Extraalv expand via radial traction and perfuse lungs tissue
Sympathetic control of the bronchial vasculature results in…
constriction
Nitrous oxide is released by endothelial cells when..
Para symp stim
Bradykinin
inc blood flow and speed
causes vasodil
(also red PLT and WBC adhesion!)
Hypoxia in lung tissue leads to
vasocon, to redirect blood to more well perfused area
Cattle has lots of smooth m in bronchioles, poor ventilation will lead to..
Pulmonary hypertension
inc afterload
CHF
Describe the hering-Breuer reflex (hint: over inhalation)
- DORS resp centre stimulate inspiration
- Stretch R in pons signal to pons to stop stimulation
- this prevents over inhalation
What group of neurons is in charge of active exhalation?
Ventral resp group (usually passive)
What do the peripheral chemoreceptors monitor?
PaO2
PaCO2
pH
Where is the carotid body located?
Close the bifurcation of the Common to the internal and external.
carotid sinus nerve (IX)
Central chemoreceptors detect..
PaCO2. AND pH when H+ is taken across BB with CO2
What pH is considered to be an alkalosis?
7.45
What is the normal blood pH?
7.4
Define metabolic acidosis?
Build up of acids (H+) from dissociation of non-volatile/fixed/nutritionally derived acids
