regulation of respiration:-

regulation of respiration:-

the adjustment of respiratory rate depending on need of metabolic activity is called as regulation of respiration.

necessity:-to maintain partial pressure in blood.

-to maintain pco2

-methods;-


Nervous regulation

Chemical regulation

Higher center ,cerebral cortex ,hypothalamus

Central chemoreceptor

Pneumotaxic center

Peripheral chemoreceptor

Apneutic center


Dorsal respiratory group


Ventral respiratory center



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Schematic representation of respiratory center






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Significance:-

Destruction of alveoli is prevented and protected by this during inspiration

-preventing alveoli collapsing during expiration

-compression during respiration inspiration 


Respiratory center features:-

RC is placed bilaterally.

-they communicate with each other  on the same site and also with the center of the other half.

-respiratory center show rhythmicity

-shows reciprocal inhibition.

Both are situated in medulla oblongata

Going through apneustic center meant for prolonged inspiration but it is inhibited by pneumotaxic center

Pneumotaxic center is situated in pones meant for alignment of ventilation therefore always send inhibitory impulses to inspiratory  center and impulse to expiratory center


Factors influencing R.C:-

I)reflexes-hering breuer inflation reflex

-deglutition reflex

-sneezing reflex

-ii)drugs:-

-anesthesia

-nicotine

-caffein

iii)higher center 

-central cortex and hypothalamus

-breath holding,forceful inspiration

iv)receptors

-stretch receptor ,compression receptors

-in joint muscles-muscle spindles golgi tendon organ


Hering breurs’ inflation reflex:-

Prevents total collapse of alveoli and discontinuation alveoli during inspiration.

-whenever alveoli get over distended ie)tidal volume is greater than 1500 ml ,stretch receptors  within the alveoli send -ve impulses to apneustic  center inspiration is inhibited.


Herring brewers’s deflation reflex:-

-during expiration to prevent total collapse of the alveoli the compression receptors within alveoli send +ve impulse to apneustic center to start with inspiration.


Chemoreceptors:-

Which are present in medulla oblongata and systemic arteries

i)central chemoreceptor

ii)peripheral chemoreceptors:-


Central chemoreceptor:-

-send impulses because of change in components of CSF

-MORE sensitivity to hypercapnia than hypoxia


Peripheral chemoreceptor:-

Send impulse due to change in composition of blood 

More sensitive to hypoxia than hypercapnia


Abnormal pattern of breathing:-

1)hypoxia decreased content of 02 in tissues and blood

Types::-


1)hypoxia

Due to environmental condition

-due to respiratory paralysis

2)stagnant

Viscosity of blood is increased causing thrombosis and heart block

3)anemic

Hb concentration is decreased causing anemia

4)cytotoxic

Unable to useo2 due to due to cleavage of cytochrome oxidase enzyme system

Seen in cyanide poisoning


Symptoms:-nausea ,headache ,dizziness,blackout,cyanosis


Treatment :-

Find out underlying condition of hypoxia

Hypotonic o2 therapy

cyanosis:-HHb reduced more than 5gm/d

In anemia:-Hb concentration is less than 5gm/dl

Therefore no cyanosis


Conditions:-

Asphyxia:_

Condition:-drowning,hanging,strangulation.

3 stages:-

i)hyperventilation because of co2 is increased

ii)Convulsion:-pupillary dilation,reflexes exaggerated

iii)depression of respiratory center


Treatment :-cardiopulmonary artificial respiration


3)dyspnea :-

Condition:-pathological ,physiological,,psychological.

Dyspneic index=max volume ventilation(MVV)-respiratory maximum ventilation/MVV*100

NORMAL VALUE 85%

 Below 70%person is dyspneic


Acute mountain sickness:-

At higher altitude-po2 decreases causing hypoxia

At 1000ft 1 atm pressure decreases

Symptoms -nausea,dizziness ,giddiness ,loss of appetite,bloatedness,rashes on skin.


Acclimatization:-ability to body to adjust in altered environment condition like in higher altitudes

12000-13000ft body adjust

-increases erythropoiesis

-cytochrome oxidase  increases-for o2 utilisation

-2,3,diphosphoglycerate increases -o2 dissociation more release of o2

-more blood supply to vital organs and to non vital organs


Drivers palsy:-(decompression sickness):-

Condition characterised by increased barometric pressure

From Every 33ft 1 atm pressure is increased during descend gases in body get dissolved 

O2 Utilised by tissue while co2 easily soluble and gets concentrated into bicarbonate

-during ascend N2 bubble are formed in blood and cause emboli which block major arteries


Symptoms:-

Severe pain in muscle,

Transmission of nerve impulse is affected

-N2 act as anesthetic agent 

-temporary paralysis


Treatment:_

SCUBA apparatus

-rapid ascend should be avoided

-decompression



Periodic breathing:-cyclic pattern of breathing where normal ventilation is followed by apnea


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