Organisms with a circulating body fluid that is distinct from the
fluid that directly surrounds the body's cells are likely to have _____
Closed circuit
The only vertebrates in which blood flows directly from
respiratory organs to body tissues without first returning to the
heart are the _____.
Fishes
Circulatory systems compensate for _____.
the slow rate at which diffusion occurs over large distances
Damage to the sinoatrial node in humans would ________.
disrupt the rate and timing of cardiac muscle contractions
Atrial systole occurs ________.
during ventricular diastole
what develops the greatest pressure on the blood in
the mammalian aorta?
the systole of the left ventricular
wat is true about human blood vessels?
Pulmonary veins carry oxygen-rich blood to the heart.
Stroke occurs when _____.
blood clot enters the cerebral circulation, blocking
an artery and causing the death of brain tissue
A normal event in the process of blood clotting is the
_____.
activation of prothrombin to thrombin
The primary functions of the _____ are to warm, filter,
and humidify air.
nasal cavity
An advantage of gas exchange in fresh water, compared
with gas exchange in air, is that _____. And Why?
water loss through evaporation across the respiratory
surface can be minimized; Respiratory surfaces are always moist, and
exposure to air results in water loss via evaporation.
The smallest airway through which inspired air passes
before gas exchange occurs in the mammalian lungs is the
Bronchiole
During aerobic exercise, the partial pressure of oxygen
in muscle cells will ________, thus the rate of diffusion of oxygen
into the muscle tissue from the blood will ________.
decrease; increase
What would be the consequence if we were to reverse the direction of
water flow over the gills of a fish, moving water inward past the
operculum, past the gills, then out the mouth? This reversal of water
flow would ________
reduce efficiency of gas exchange
Most carbon dioxide released from body tissues combines with water to
form carbonic acid, which then breaks up into hydrogen and bicarbonate ions.
TRUE
By picking up hydrogen ions, hemoglobin prevents the blood from
becoming too
Acidic
A decrease of blood pH from 7.4 to 7.2 causes hemoglobin to
________.A) release all bound carbon dioxide moleculesB)
bind more oxygen moleculesC) decrease its binding of H+D)
give up more of its oxygen molecules
give up more its O2 molecules