Clickers Flashcards
- Which of the following best describes homeostasis
a. Organisms maintain a constant, static internal environment
b. Most organisms have identical internal environments
c. Organisms do not change in response to an environmental change
d. Organisms maintain a narrow range of internal conditions
d. Organisms maintain a narrow range of internal conditions
- Which of the following best illustrates homeostasis?
a. Most adult humans are between 5 and 6 feet tall
b. All the cells of the body are about the same size
c. When the salt concentration of the blood goes up, the kidneys expel more salt
d. When oxygen in the blood decreases, you feel dizzy
c. When the salt concentration of the blood goes up, the kidneys expel more salt
- The process that produces the most ATP molecules per molecule of glucose is
a. Substrate-level phosphorylation
b. Oxidative phosphorylation
c. Anaerobic glycolysis
d. Negative feedback
b. Oxidative phosphorylation
- Which of the following descriptions of movement of molecules across the plasma membrane is correct?
a. If 2 similar molecules can both combine with the same carrier, the presence of one of these molecules decreases the rate of entry of the other
b. In simple diffusion, the rate of transport of a molecule into the cell is directly proportional to the molecule’s extracellular concentration
c. When a carrier becomes saturated, the maximum rate of transport across the membrane is reached
d. Two of the above are correct
e. All of the above are correct
e. All of the above are correct
- Which of the following is (are) NOT part of the peripheral nervous system?
a. Motor neurons
b. Sympathetic nervous system
c. Spinal cord
d. Afferent division
e. Autonomic nervous system
c. Spinal cord
- Graded potentials
a. Are local changes in membrane potentials that occur in varying degrees of magnitude
b. Are local changes in membrane potential that occur only when threshold potential has been exceeded
c. Can be depolarizations or hyperpolarizations
d. Answers a and c are correct
e. Answers b and c are correct
d. Answers a and c are correct
- Resting vm= -50mV
For K+: EK= -60mV
For Na+: ENa= +60mV
For which ion, Na or K, is the resting membrane potential further away from equilibrium?
a. Na+
b. K+
c. No difference
a. Na+
- Next, you experiment with higher concentrations of BTX and find cases when the cell began to repolarize, it immediately depolarized again. This tells you that the toxin:
a. Prevents voltage-gated K channels from opening
b. Increases the speed that Na ion channels open
c. Prevents Na ion channels from closing
d. Makes Na ion channels close too soon
e. Doesn’t affect the Na ion channels at all, it affects the sodium-potassium pump instead
c. Prevents Na ion channels from closing
- Poison dart frogs produce toxins (BTX) that act on voltage-gated Na channels in neurons and muscle cells. What is the effect on their predators?
a. Paralysis (no signaling)
b. Seizures (too much signaling)
c. Color change
d. Croaking
b. Seizures (too much signaling)
What mechanism prevents these frogs from killing themselves?
a. They have no excitable cells
b. They have special colored skin
c. They have Na channels insensitive to BTX
d. They substituted K channels for Na channels
c. They have Na channels insensitive to BTX
- Why can we not use X-rays for vision?
a. X-rays contain too little energy to affect rhodopsin
b. X-rays contain too much energy to affect rhodopsin
c. Our eyes block x-rays
d. The on and off center fields will flip-flop
b. X-rays contain too much energy to affect rhodopsin
- A drug blocks nicotinic receptors. Administration of this drug will
a. Block parasympathetic activity on the heart
b. Block sympathetic activity on the heart block the release od epinephrine from the adrenal gland
c. A and b are both true
d. A, b, and c are all true
d. A, b, and c are all true
- A sample of blood is withdrawn from the vessels or heart chambers listen below. Which sample best represents a mixture of venous blood from all systemic organs?
a. Vena cava
b. Right atrium
c. Left atrium
d. Pulmonary artery
e. Pulmonary vein
d. Pulmonary artery
Which of the following could contribute to an increase in heart rate during exercise
a. Stimulation of sympathetic nerves to the heart
b. Inhibition of parasympathetic nerves to the heart
c. Release of catecholamines from the adrenal medulla gland
d. Only a and b are true
e. A, b, and c are all true
e. A, b, and c are all true
- As a hospitalist is treating a patient with a pulmonary embolism, would the situation be most urgent if the clot was present in the pulmonary artery or the pulmonary vein?
a. The presence of a clot in the pulmonary artery would be more serious
b. The presence of a clot in the pulmonary vein would be more serious
c. The presence of a clot in the pulmonary artery or the pulmonary vein would be equally as serious
b. The presence of a clot in the pulmonary vein would be more serious
- Administration of heparin to a patient with a deep vein thrombus will
a. Dissolve the blood clot
b. Prevent the blood clot from enlarging
c. Have little or no effect on the pre-existing blood clot
b. Prevent the blood clot from enlarging
Resting heart rate (~70 beats per minute) is typically less than the inherent rhythm of the SA node (`80 to 100 events per minute). Which of the following could explain this phenomenon?
a. Sympathetic nerves stimulate the SA node under resting conditions
b. The vagus nerve stimulates the heart under resting conditions
c. Under resting conditions some impulses originating in the SA node are unable to move through the AV node
d. Beta receptors are stimulated by circulating epinephrine
b. The vagus nerve stimulates the heart under resting conditions
- Production of protein hormones uses a multi-step process. Why not a single-step process? What is the most likely reason?
a. A multi-step process is faster
b. A multi step process allows an increased redundancy in case of a possible defect in pathway
c. A multi step process allows more control of the amount of end product (including amplification)
d. A multi-step process can be reversed if needed
e. Answers b and c
e. Answers b and c