MECHANICAL AND CHEMICAL CONTROL OF BREATH HOLDING

Breath-holding and the sensations due to chemical and mechanical stimuli to breathing.

EVERY medical student and, indeed, every schoolboy knows that it is possible to hold the breath for a longer time with lungs fully inflated than at a smaller lung volume, and that the breath-holding time can also be prolonged by hyperventilation beforehand. This prolongation is possible because the onset of the unpleasant sensations which arise during breath-holding is delayed. Thus both mechan...

Breath-holding and its breakpoint.

This article reviews the basic properties of breath-holding in humans and the possible causes of the breath at breakpoint. The simplest objective measure of breath-holding is its duration, but even this is highly variable. Breath-holding is a voluntary act, but normal subjects appear unable to breath-hold to unconsciousness. A powerful involuntary mechanism normally overrides voluntary breath-h...

The limits of breath holding.

Breath-holding spells in infants.

QUESTION I have children in my clinic who experience seizurelike episodes in which they cry and hold their breath to the point of cyanosis and loss of consciousness. Their examination or investigation findings are normal and referral to a pediatric specialist results in no further investigation. Are breath-holding spells common, and what type of investigation is needed? ANSWER A breath-holdin...

determination of some physical and mechanical properties red bean

چکیده: در این تحقیق، برخی خواص فیزیکی و مکانیکی لوبیا قرمز به-صورت تابعی از محتوی رطوبت بررسی شد. نتایج نشان داد که رطوبت بر خواص فیزیکی لوبیا قرمز شامل طول، عرض، ضخامت، قطر متوسط هندسی، قطر متوسط حسابی، سطح تصویر شده، حجم، چگالی توده، تخلخل، وزن هزار دانه و زاویه ی استقرار استاتیکی در سطح احتمال 1 درصد اثر معنی داری دارد. به طوری که با افزایش رطوبت از 54/7 به 12 درصد بر پایه خشک طول، عرض، ضخام...