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Physiology exam 2

Terms in this set (26)

1. Which of the bands/lines in the figure below shorten during muscle contraction.
Both 1 and 3
2. Which of the following statements is/are true regarding regulatory proteins in skeletal muscle?
A conformational change takes place when the skeletal muscle cells are activated or excited.
3. How can one explain the reason for the shift from point 1 to point 2 in the figure below?
An increase in ventricular end diastolic volume increased the degree of blood that is pushed out or ejected from the ventricle as part of the systole. This causes stroke volume to increase, as this is the amount of blood that is directly pushed out of the ventricle.
4. Which of the following is correct regarding the cross-Bridge cycle?
The cross-Bridge cycle leads to the muscle fibers shortening as a result of contractile proteins acting upon them. This cycle allows actin and myosin to move against one another to generate a shortening action of the muscle.
5. In contrast to a twitch, tetanic contraction
allow twitches to overlap (they normally occur one at a time without any overlap).
6. You successfully earned an A in BIO 131 and are very happy with all you learned. The following semester, you are taking a new course that focused on mechanisms that regulate neurotransmitter activity. Which of the following statements can you expect to see on your instructor slides?
The activity of neurotransmitters is affected by the neuronal circuits and their synapses. Specifically, the neuronal axons allow action potentials to propagate due to the action of neurotransmitter activity.
7. You discuss what you learned in the cardiovascular physiology portion of BIO 131 with your super-smart niece. She is interested in learning about cardiac valves. You can explain that:
cardiac valves prevent blood flowing back into the blood vessel from which it was pushed out of. These valves act in a one-way manner, as they allow blood to flow in only one direction.
8. In cardiac contractile cells, the plateau of the cardiac action potential results from the opening of voltage-gated channels in the plasma membrane of the cardiac cell and contribute to
Calcium, contractions of the heart
SA node
cardiac output is increased due to the SA node experienced an increase rate of firing, which allows for greater oxygenation and perfusion___
End Diastolic Volume (EDV)
end systolic volume would increase if cardiac output also increases
Capillary radius:
when capillary radius increases, stroke volume decreases due to resistance being lowered
Purkinje fibers:
stimulation at the Purkinje fibers would increase stroke volume
10. When/during the time that the heart is stimulated by the sympathetic system
the sympathetic neurons release norepinephrine and the membrane of ventricular cells becomes more permeable, allowing for greater movement of positive calcium ions (Ca+).
11. During the T-wave of the electrocardiogram (ECG):
there is a repolarization of the ventricles in the electrical sense and a relaxation of the ventricles in the functional sense.
12. During the isovolumetric phase of ventricular diastole
The semilunar and atrioventricular valves close and there is relaxation of the ventricles.
13. Which of the following will NOT increase stroke volume?
Increased end-systolic volume
14. Resistance to flow of liquid down a tube or vessel increases when:
the radius of affected tubes or vessels is reduced.
15. Which of the following would result in a decrease in the filtration of fluids from capillaries to the interstitial fluid (tissue edema):
This would cause a greater degree of permeability of the cell membrane, leading to large molecules moving from the cytoplasm into the interstitial fluid. This would reduce the filtration rate in the capillaries, leading to a smaller degree of water molecule absorption. This last aspect is what would lead to tissue edema.
16. Jim, Mike and Bob are identical triplets with the same volume of anatomical dead space (145 mL) in their respiratory system. Jim is at the spa doing yoga and practicing deep, slow breaths. His tidal volume is 1100 mL and his respiratory rate is five breaths/min. Mike is sitting down, reading a book and breathing quietly. His tidal volume is 500 mL, and his respiratory rate is 12 breaths/minute. Bob is anxious about an upcoming oral presentation and is beginning to hyperventilate. His tidal volume is 200 mL and his respiratory rate is 35 breaths/minute.
Tidal volume refers to the amount of air that is inspired and expired during each respiration. Normal tidal volume are 400 mL in women and 500 mL in men. As such, tidal volume is affected by gender, age, geographic altitude, the weight and height of the affected person, the degree of physical activity that the person engages in, and the person's ethnicity. If tidal volume increases, this has an inverse effect on the respiratory rate, and vice versa. The only difference between the triplets is their level of physical activity. Jim, due to doing yoga, would be breathing slowly and deeply, leading to his tidal volume being high and the resulting respiratory rate being low. The same, or similar, would be true for Mike, as his respirations would not be rushed, which would also mean that his tidal volume would be considered to be within the normal range. Finally, Bob is experiencing anxiety, which means that his respirations would be fast, leading to a low corresponding tidal volume. Respirations, in terms of how fast they occur and how deep the breaths, is something that is regulated by the medulla oblongata.
17. Control of respiration during normal ventilation is predominantly controlled by:
pCO2 being elevated, which causes carbonic anhydrase within the brain to convert these higher levels into positive H ions (H+).
18. Which statement about partial pressures is correct
The partial pressure within the alveoli would be highest to lower in this order: pN2, pO2, pH2O, and pCO2.
19. You sit in the library and read an article that describes a molecular technique that allows for continuous induction of large amounts of Ach release from a somatic efferent function. The article states that "upon induction, the release of Ach exceeds the breakdown of Ach by acetylcholinesterase and Ach spills out of the neuromuscular junction to the area that surrounds it." Which of the following could you predict?
I would predict that the this would adversely affect voluntary movements due to the motor neurons not being able to fire properly.
20. You recently started working in a lab that studies muscles, and today represents your one-month anniversary of working in the lab. Your mentor surprises you and gives you a dish in which they co-cultured all three types of muscle cells. They say you can run whatever experiment with these cells. You decide to electrically stimulate all three muscles simultaneously. Which of the following can safely hypothesize?
This would be expected to prevent the cells from communicating with one another, along with the polarization of the cells being affected, as calcium is needed to slow down the inward current and increase the plateau during the action potential. A lack of calcium would increase the action potential, affected the length of the release of neurotransmitters.
21. A large pharmaceutical company recently hired you as a research and development researcher. You join a team that explores new ways to increase mean arterial pressure. Your team leader brings to the first meeting you attend notes from a previous session with a list of potential targets. Which of the following directions are you likely to find on the list?
The critical closing pressure within the arterioles, along with the output of the heart and systemic vascular resistance.
22. Untreated diabetes mellitus can lead to ketoacidosis, during which blood pH is decreased below the normal physiological range. This is expected to
increase the amount of ketones in the bloodstream, which interfere with the normal function of the body, such as the brain experiencing swelling.
23. The pressure within the alveoli is greater than atmospheric pressure when:
the thoracic cavity experiences an expansion
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