Biomaterial Database

Comparison of human vocal cord movements during isocapnic hypoxia and hypercapnia. 1982

S J England, and D Bartlett, and S L Knuth

Respiratory vocal cord movements were analyzed in healthy human subjects during air breathing and in isocapnic hypoxia and hypercapnia. In the majority of experiments, expiratory glottic narrowing was substantially greater during hypoxia than during hypercapnia. Because ventilations were carefully matched under these two conditions, it is concluded that hypoxic stimulation of peripheral chemoreceptors favors expiratory glottic narrowing and leads to a relatively high laryngeal airflow resistance. In contrast, hypercapnia is accompanied by low expiratory laryngeal resistance. Similar rates of expiratory airflow with these two stimuli must be achieved by different balances of the factors that determine this flow.

UI	MeSH Term	Description	Entries
D009068	Movement	The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.	Movements
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D005931	Glottis	The vocal apparatus of the larynx, situated in the middle section of the larynx. Glottis consists of the VOCAL FOLDS and an opening (rima glottidis) between the folds.	Rima Glottidis,Glottidi, Rima,Glottidis, Rima,Rima Glottidi
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006935	Hypercapnia	A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000860	Hypoxia	Sub-optimal OXYGEN levels in the ambient air of living organisms.	Anoxia,Oxygen Deficiency,Anoxemia,Deficiency, Oxygen,Hypoxemia,Deficiencies, Oxygen,Oxygen Deficiencies
D013990	Tidal Volume	The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.	Tidal Volumes,Volume, Tidal,Volumes, Tidal
D014827	Vocal Cords	A pair of cone-shaped elastic mucous membrane projecting from the laryngeal wall and forming a narrow slit between them. Each contains a thickened free edge (vocal ligament) extending from the THYROID CARTILAGE to the ARYTENOID CARTILAGE, and a VOCAL MUSCLE that shortens or relaxes the vocal cord to control sound production.	Vocal Fold,Vocal Folds,Vocal Ligament,Cord, Vocal,Cords, Vocal,Fold, Vocal,Folds, Vocal,Ligament, Vocal,Ligaments, Vocal,Vocal Cord,Vocal Ligaments