Semester 2 Week 5 Quiz Flashcards
What structure prevents food from entering the trachea?
The epiglottis
Structures in the trachea that prevent its collapse or overexpansion as pressures change in the respiratory system are ______ __________.
C-shaped tracheal cartilages
At rest, what is the approximate tidal volume?
500 ml
Vital capacity in males averages _____ litres.
4.8
Where do chemical and gaseous exchange take place?
Only across capillary walls.
What does the binding of a haeme unit’s iron ion to an oxygen ion form?
oxyhaemoglobin
The binding of oxygen to haemoglobin is _____.
reversible
When is the bond between oxygen and haemoglobin broken?
when oxygen reaches systemic tissues, so that oxygen can enter body cells.
Lower pH ________ the oxygen affinity of haemoglobin.
decreases.
What percentage of total oxygen is typically carried within red blood cells chemically bound to haemoglobin?
98%
Why is it important that free H+ resulting from dissociation of H2CO3 combine with haemoglobin?
To reduce the possibility of an acidic condition within the blood.
Respiratory acidosis results due to ___________.
accumulation of CO2 in the tissues.
During quiet breathing, the diaphragm and external intercostal muscles contract. What effect does this have on the thoracic cavity?
It increases the volume and decreases the pressure of the thoracic cavity.
Which muscle does not increase the volume of the thoracic cavity during forceful inspiration?
External Oblique
Exhalation is ______.
passive
