control of repsiration Flashcards
(17 cards)
Breathing is a — , — event which can be altered — and can be influenced by — and — stimuli.
Ultimate goal of respiration is
to maintain and regulate — ( — ) and — ( — )
Other goals
To maintain — balance
—- maintenance
- —
- —
rhythmic spontanous
voluntairly
external and internal
artiel blood 02 ( Pa02) and C02 ( Pac02)
acid base
temp
excretion
immunity
Spontaneous respiration is an outcome of — discharge of — from–
These brain impulses are regulated by — and —
Respiratory activity can be — modified to accomplish speaking, singing, whistling, playing a wind instrument, or holding one’s breath while swimming.
rhythmic
neuronal impulses
brain
mechanical and chemical receptors
voluntailry
4 major sites of ventilatory control:
1-Respiratory control center in the —
2-chemo-recpetorsin the —
3-Chemoreceptors in the —
4-Pulmonary —
info:
— or—- control
Regulation by — stimuli, by — stimuli
brainstem
brain stem
peripheray
mechanorecpetors
central or neural
chemical or neural
Components Of Neural Control Of Respiration:
1- — systems: Factors that generate the alternating inspiration/expiration —
2- — and — influences: Factors that regulate the — of ventilation (that is, the – and — of breathing) to match body needs,
medullary
rhythm
pontine and vagal
magnitude
rate and depth
- neural control:
The — respiratory control center,
The Medullary Respiratory Center
consists of several — of — cell bodies within the — that provide — to the respiratory muscles. - meduarlly systems:
Rhythmic respiration generated by
— cells in —- complex (pre-BÖTC) in— - Dorsal & Ventral respiratory groups
-Located between —- and — - — receptors, — receptors and
— receptors are present
primary
aggregation
neuronal
medulla
output
pacemakers
pre Bötzinger
pre-BÖTC
medulla
nucleus ambiigus and
lateral reticular nucleus
NK1
µ-opioid
5-HT
dorsal groups of neurons ( medullary systems ) :
It contains “I”neurons which are — neurons.
It’s located in – portion of medulla oblongata.
It also includes the — which is the sensory termination of afferent fibers in 9th ( — NERVE) and 10th ( — NERVE) cranial nerves.
They receive impulses from peripheral — , carotid and aortic — and also other receptors in the lungs
inspiratory
dorsal
nucleus of tractus solitarius
GLOSSOPHARYNGEAL
VAGUS
chemorecepotrs
barorecpetors
dorsal group of neurons :
In this group inspiratory ramp signals are produced —
If we cut the medulla oblongata from other parts of brain and also the afferent nerves which enter the medulla, still inspiratory ramp signals are produced which indicate it’s the — property of medulla.
Significance of the signal in the form of ramp is that it causes progressive — of the lungs. After production, these ramp signals are transmitted to the contra — — neurons supplying the inspiratory muscles.
Rate and duration of inspiratory ramp signals is controlled by impulses from the — centre and impulses from the lungs via – .
spontanoisly
inherent
expansion
contra lateral motor
pneumotaxic centre
vagi
ventral group of neurons ( meduallry systems ) :
Include — and –
It contains both —- neurons.
This group is not involved during —
This group is stimulated when there is need for – pulmonary ventilation.
nucleus ambigus and retro ambiguous
I and E
quiet breathing
increased
so basicallu :
1- dorsal group is always active and is for isnpiratory neurons at the nuclease of tractus solitaius
2- ventral group is found in nucleus ambigus and retro ambiguous for inpsiratory and expiratory neurons and is inactive during quiet breathing and active during forced breathing
neural control:
Two other respiratory centers lie higher in the brain stem in the –
-The — and — cnetres
These pontine centers influence output from the medullary respiratory center
pons
Pneumotaxic Center and Apneustic Center
1- pneumotaxic centres:
The pneumotaxic center sends impulses to the DRG that help “— ” the – neurons, limiting the — of – .
Signals from this centre are transmitted to the — group of neurons to control – and — of — ramp signals.
When signals from this centre are strong, inspiratory ramp signals are terminated – and there is — in respiratory rate
When signals from this centre are weak, inspiratory ramp signals are not terminated — leading to – Respiratory rate.
2- apenustic centre:
Impulses from these neurones – the – area of medulla
it — the —
Receives inhibitory impulse from — centre
Inhibitory impulses to – centre
switch off
inspiratory
duration of inspiration
dorsal
rate and duration
inspiratory ramps
early , increase
not early , decreased
excite the inspiratory
prolongs inspiration
penomtacic centres
expiratory
Influence of Chemical Factors on Respiration:
-The magnitude of ventilation is adjusted in response to three chemical stimuli:
1—- (via – , brain — fluid H+ Conc)
2—- (Carotid and Aortic bodies)
3- — (Carotid and Aortic bodies)
-Arterial blood gases are maintained within the normal range by varying the — of ventilation ( — and – of breathing) to match the body’s needs for – uptake and — removal.
An example of a — feedback control system
The controlled variables are — tensions, especially –
c02
csf , brain interstial
02
h+
magnitude
depth and rate
02
c02
-ve
blood gas
c02
central chemoreceptors:
Situated near the surface of the — of the —
Respond to the [—] of the — fluid (—)
CSF is separated from the blood by the — barrier
Relatively impermeable to – and –
— diffuses readily
CSF contains — protein than blood and hence is – buffered than blood
CO2 + H2O –> <— H2CO3 —> <– H+ + HCO3-
peripheral chemoreceptors:
Sense – of – and — ; and [—] in the blood
medulla
brainstem
h+
cerebrospinal
csf
blood brain barrier
H+ and HCO3-
c02
less
less
tension
oxygen carbon dixoide and h+
info:
CO₂ crosses the blood-brain barrier → forms H⁺ → stimulates chemoreceptors → increases breathing rate.
Therefore, CO₂ is the main driver of ventilation under normal conditions, via its effect on H⁺.
regulations from neural stimuli:
1- Impulses from Higher centers: During —- states, respiration is modified by impulses from higher centers i.e. — cortex, — system, and— .
2-For voluntary hypo and hyperventilation: Impulses arise from the — and go directly to the. — neurons supplying the — muscles.
3-Impulses from Proprioceptors: Proprioceptors are the receptors presents around – , in— , ligaments, tendons and — parts of skin. These receptors respond to changes in — and — . Impulses from these proprioceptors go to the — to stimulate it. These are the major stimulatory factors to stimulate respiration during –
emotional
cerebral , limbic , hypothalamus
cerebral cortex
motor neurons
inspiratory
joins muscles ligaments , deeper
position and movement
respiratory centres
excersie
regulation of neural stimuli:
1- Impulses from Irritant receptors: These are — present in the — of airways; these are stimulated by — irritants like mucus, sputum or foreign body or may be stimulated by — stimuli like histamine and bradykinin. These receptors are involved in — and — .
2-Impulses from stretch receptors in the lungs: when lungs are inflated, impulses from — receptors in the lungs are stimulated and transmitted along the — to the respiratory centre to terminate — ramp signal. These receptors are stimulated when lungs are — and in human beings, — inflation reflex is activated, when the tidal volume is — liters. This reflex prevents — of lungs. Similarly Herring Breuer deflation reflex is also present.
nerve endings
epithelium
mechincal
chemical
cough and sneezinf reflex
stretch receptors
vagi
inspiratory ramp
over inflated
Herring Breuer
1-1.5 liters
over infaltion
regulation from neural stimuli:
1- Impulses from J receptors: J means – position to— , These are stimulated when some irritant — is present in the pulmonary blood or when there is — of pulmonary capillaries or there is —. This leads to — breathing.
2-Visceral reflexes: There is physiological – during — .
-There is short apnea during — , — .
-During inspiration heart rate — and during expiration it — .
-Application of cold water over the body leads to —.
-When cold water is applied only to the face, there is —- .
3-Effect of temperature on Respiratory centre: Increased temperature stimulates respiratory centre by two mechanisms
-> — stimulatory effect
-> — by increased — rate, Increased — , decreased —, H ions concentration — which leads to — .
juxta
pulmonary capillaries
irritant chemical
engorgement
pulmonary edema
rapid
apnea
swallowing
defecation , vomitting
increases
decreases
hyperventialtion
hypoventialtion
direct
indirect
metabolic rate
PC02
P02
increases
hyperventialtion
Hypoxic Drive of Respiration:
-The effect is all via the —
-Stimulated only when arterial — falls to low levels
-Is not important in — respiration
- May become important in patients with chronic — (e.g. patients with — )
It is important at —
peripheral chemoreceptors
p02
normal respiration
chronic c02 retention
COPD
high altitudes
the h+ drive of respiration:
The effect is via the—
H+ doesn’t — cross the blood brain barrier ( — does!)
The peripheral chemoreceptors play a major role in adjusting for — caused by the addition of H+ to the blood (e.g. lactic acid during exercise; and diabetic ketoacidosis)
Their stimulation by H+ causes — and increases elimination of – from the body (remember CO2 can generate —, so its increased elimination help reduce the load of – in the body)
This is important in — balance
peripheral chemoreceptors
readily
c02
acidosis
hyperventialtion
c02
h+
h+
acid base
