Chapter 18
increase the rate of breathing
An increase in the level of carbon dioxide in the blood will
Over 90
At a PO2 of 70 mm Hg and normal temperature and pH, hemoglobin is ________% saturated with oxygen.
Emphysema
Decreased surface area for gas exchange
emphysema
Destruction of alveoli
surface area and concentration gradient.
Diffusion rate is directly proportional to
membrane thickness
Diffusion rate is indirectly proportional to
surface area
Emphysema causes a loss of septa between individual alveoli, resulting in fewer, but larger, alveoli. What component of gas diffusion would be most affected by emphysema?
pulmonary edema
Fluid accumulation in interstitial spaces
Hypercapnia
High carbon dioxide concentration in body fluids is called
decreased barrier permeability
If alveolar PO2 is normal but arterial PO2 is low, what is the most likely cause?
pulmonary edema
In ________, fluid accumulates in the interstitial spaces of the lungs, slowing gas exchange.
dorsal respiratory group
In the medulla oblongata, the nucleus tractus solitarius contains the ________ of neurons.
as bicarbonate ion
In what form is most carbon dioxide transported in the blood?
pharynx and larynx, obstructive sleep apnea
Inappropriate relaxation of the ________ muscle(s) during sleep contributes to ________, a sleep disorder associated with snoring.
Decrease
Increased Pco2
Asthma
Increased airway resistance
pulmonary edema
Increased diffusion distance
bound to hemoglobin
Most of the oxygen transported by the blood is
concentration gradient
Of the factors that influence diffusion of respiratory gases, the most variable and, therefore, important factor to consider is the
dissolved in the plasma
Oxygen is carried in the blood in two ways. Most of it is bound to hemoglobin while the remainder is carried in what form?
higer
PCO2 tends to be ________ in tissues than in systemic capillaries.
dorsal respiratory, ventral respiratory
The ________ group of neurons contains mostly inspiratory neurons. The ________ group of neurons controls muscles used for active expiration and some inspiratory muscles.
abdominal and internal intercostal, diaphragm and external intercostal
The expiratory neurons control the ________ muscles, whereas the inspiratory neurons control the ________ muscles.
pulmonary edema
The lung pathology most likely to result from certain kinds of heart disease is
carbon dioxide
The most important chemical regulator of respiration is
dorsal respiratory, diaphragm, vagus
The output of the ________ group of inspiratory neurons controls the ________ muscle(s) by way of the ________ nerve.
diffusion
The process by which dissolved gases are exchanged between the blood and interstitial fluids is
fibrotic lung disease
Thickened alveolar membrane and decreased lung compliance
Hypoxia
Too little oxygen in cells is called
carbon dioxide, hypercapnia
Too little oxygen in cells is often accompanied by too much ________, which is called ________.
decreased O2 bound to hemoglobin
What is the definition of "anemic hypoxia"?
simple diffusion
What is the primary mechanism by which gases move from the alveoli into the blood and cells and back?
dorsal respiratory group
Which area of the brain stimulates the diaphragm to contract to initiate inspiration?
arterial P CO2 increasing to 46 mmHg
Which change would cause the greatest stimulus for an increase in ventilation?
Plasma CO2
Which chemical can stimulate ventilation by binding both peripheral and central chemoreceptors?
pulmonary edema
Which disorder would usually result in a normal alveolar PO2 but a decreased arterial PO2?
increased H+ concentration
Which of the following would make the oxygen-hemoglobin curve shift right?
Emphysema
________ is characterized by a decreased surface area for gas exchange in the lungs.
Fibrotic lung disease
________ is characterized by a thickened alveolar membrane, slowing respiratory gas exchange.
Asthma
________ is characterized by an increased airway resistance and decreased ventilation.
