Resp 4- Flashcards
How is inspiration related to Diaphragm/ external intercostals/ accessory muscle
diaphragm
- C3-C5
- Flattens on contraction
- major insp muscle
External intercostals
- intercostal nerves at the rib level
Accessory muscle
- Sternocleidomastoid/ scalenes
- chest expands, intrapleural pressure falls.
expiration is
mainly pasisve during quiet breathing (elastic recoil)
forced experiation ( excerice/ coughs/ sneezing..)
what is the pons respirator center made up of
pnumotaxic center
Apneustic center
what are the medullary repiratory center
Dorsal respiratory group
ventral respiratory group
what are cranial motorneurons are important for
opening/ closing the glottis/ affecting upper airway diameter/
where is the central pattern generator (CPG) located
the brainstem (pons medulla)
what is the Pre botzinger Complex ?
The pre-Bötzinger complex (preBötC) is a cluster of interneurons in the ventral respiratory group of the medulla of the brainstem
what is a respiratory rhythm generator ?
a network of internierosn that produce a predictbale and repetiivte motor pattern. in breathing inspiratory neurons must be activated before expiratory neurons.
what are the 3 properties of Respiratory rhymthm generator?
always acitve even in unconsious input- endogenous cyclical oscillation
tramit in an orderly sequence to respiratory muscles
responds to inputs from other parts of the brian as well as sensory afferent nuerons
what are the 3 phaases of breathing cycle
Inspiration/ Post inspiration/ Late expiration
how many types of neuronal discharge are there ?
6:
- pre- I
- early-I
- 3 Inspiration
- Late- I
- early- E
- E
how are breathing patterns changed
central chemoreceptors- medulla surface
Peripheral Chemoreceptors- Carotid body/ aortic body/ neuroepithelial airways
how is total ventilation volume calculated ?
Tidal volume+ frequecy
what are the central chemoreceptors monitoring ?
CO2 presure in cerebral spinal fluid
what are the peripheral chemoreceptors monitoring
monitor the partial pressure of O2 and CO2 also pH of the blood and mixed lung gase
fill in the gaps in the diagram
central chemo receptors control what ?
control system for normal breathing and directly respond to CO2 driven pH changes in the Cerebral spinal fluid.
CO2 travels in the blood as …
HCO3- which cannot cross the blood brain barrier and therefore it is converted to H2CO3
the dissolved CO2 can now cross ther blood brain barrier
in the cerebral spinal fluid the CO2 is ….
no converted as carbonic anhydrase does not exists and there is no pH buffer in brain.
Therefore the small changes are detected.
what dio the central chemoreceptors on the medulla surface do ?
detect pH changes on the cerebral spinal fluid. these can be desenstitised by chronic hypoxia
Small change in the alverola CO2 can make a big change as hypoxia can..,.. response ….. chemoreceptors cells.
make the repsonse steeper (causing a left ward shift.
hypoxia can bring the central chemo receptors cells closer to firing threshold
chemreceptors are able to adapt to ….
sustained changes in the pACO2 over serveral days.
deep sea divers decrease their sensitivity.
what are the 2 peripehral chemoreceptors ?
carotid body- cardotid sinus
Aortic body- aortic arch.
what ido peripheral chemorepcetors offer as a primary repsonse.
hypoxia
hypercapnia (increased pCO2)/acidosis (decrease in pH) raise sensiitivity of chemoreceptors to pAO2
explain this diagram starting with pH/ O2/ CO2
