Practice Exam 2
Two opposing mechanisms determine alveolar expansion: _______ leads to alveolar expansion while ______ opposes alveolar expansion.
negative intrapleural pressure; lung recoil
The function of the tonsils is to
protect the body against inhaled and ingested pathogens
All of the following are components of lymph, except
red blood cells.
A decrease in tidal volume will decrease the PO2 in the alveoli. The decrease in PO2 will
reduce the percentage saturation of hemoglobin
As temperatures increase, hemoglobin
releases more oxygen to tissues.
The respiratory rhythm is generated by
reverberating neural circuits in the ventral respiratory group
Which of the following organs would be most likely to contain sinusoid capillaries?
spleen
Which of the following is NOT a function of the respiratory system?
taste
Resistance in the cardiovascular system
tends to increase if blood viscosity increases
The membrane attack complex is
complement proteins forming an aqueous pore in bacterial cells membranes
In capillary exchange, which of the following statements is true?
Most fluid that leaves the arterial end of a capillary reenters the venous end of a capillary
In cases of severe pneumonia, the skin of the extremities may have a bluish coloration. Why?
Severe pneumonia decreases oxyhemoglobin levels, causing cyanosis.
How does carbon monoxide affect red blood cells (RBCs)?
The hemoglobin within the RBC bind to carbon monoxide.
Which of the following is true of adaptive immunity?
The second response is faster and stronger than the first response.
Which of the following statements concerning blood vessel walls is FALSE?
The tunica media is smaller in arteries than in veins.
For air to flow into or out of the lungs, there must be
a pressure gradient established between the atmosphere and the alveoli.
In which of the following would the resistance be highest?
a vessel 0.5 cm in diameter and 10 meters long
The structure of a capillary wall differs from that of a vein or artery because
capillary walls have only endothelium and a basement membrane.
Which of the following does NOT contribute to the return of blood from the veins to the heart?
cardiac suction generated by atrial contraction
Relaxation of the diaphragm will
cause expiration
A loss of negative intrapleural pressure in the pleural space will
cause the lung to collapse
Sympathetic stimulation of the bronchi increases the diameter of these conducting tubes. This will
decrease resistance to flow
A decrease in hydrostatic pressure at the arterial end of a systemic capillary bed will
decrease the amount of lymph entering the lymphatic capillaries
Surfactant facilitates alveolar ventilation by
decreasing the surface tension between water molecules on the lining of the alveoli.
During exercise, arterioles to the skeletal muscles __________.
dilate in response to increased CO2 and decreased O2
In ventilation perfusion coupling, increased blood flow to one region of the lung will cause
dilation of the bronchioles in that region
Which direction does oxygen move when blood from the right ventricle enters the pulmonary capillaries?
from the alveoli into the blood
Interstitial fluid enters the lymphatic capillaries through
gaps between overlapping endothelial cells
After hyperventilating for several minutes, a person may develop short periods of apnea (temporary disruptions in breathing characterized by multiple extended pauses in breathing) because
the level of CO2 decreases below the level necessary to stimulate the inspiratory center.
As viscosity of the blood decreases,
the pressure required to force it to flow decreases.
In emphysema, there is a destruction of alveolar walls. This reduces the efficiency of gas exchange because
the surface area for gas exchange is decreased.
Mr. Huff and Puff is getting ready to blow up a pool float because he can't find the air pump. He takes a big breath in after exhaling normally. The air he takes in is the
inspiratory capacity.
A fever acts as a non-specific defense mechanism against pathogens because
it inhibits the reproduction of bacteria and viruses
Air entering the trachea from the mouth is not as warm and humid as air entering from the nasal cavity because
less air comes into contact with the mucus membranes during mouth breathing
The volume of air inspired or expired with each breath during eupnea (normal breathing) is the
tidal volume.
Where is the greatest volume of blood found in the body?
veins
As the result of an asthmatic attack
ventilation is inadequate to oxygenate blood
Which of the following would be classified as an innate physical barrier?
washing action of tears and saliva
Which of the following is NOT a function of the lymphatic system?
Aiding in erythropoiesis of red blood cells.
Which of the following is NOT a factor that influences the rate of gas diffusion through the respiratory membrane?
All of the above contribute to the rate of gas diffusion through the respiratory membrane
Which of the following hormones does NOT influence blood pressure?
All of the above influence blood pressure
Lymph movement is assisted by
All of these choices are correct.
What is the purpose of lacteals?
Absorb lipids from the digestive tract.
What is the most important force driving reabsorption at the venous end of a capillary?
Blood colloid osmotic pressure
Hypocapnia will lead to which of the following conditions?
Hypoventilation due to alkalosis
Binding of H+ to hemoglobin reduces its affinity for oxygen. Thus an increase in pH will cause
an increase in the volume of dissolved oxygen in the blood plasma
In what vessel is blood pressure the highest?
aorta
The walls of the alveoli
are composed of simple squamous epithelium
Most oxygen is carried in the blood ______; but most carbon dioxide is ________.
bound to hemoglobin; associated with bicarbonate ions in the plasma
Increased venous tone will
help return blood to the heart.