1. The source of the electrical currents that you measured on the skin throughout a normal electrocardiogram is: a. regional differences in depolarization state between parts of the myocardium b. The SA node cells c. the opening and closing of the tricuspid and bicuspid valves d. depolarizations of the muscle and nerve cells close to the electrode site e. The AV node cells
Anatomy and Physiology of Special Sensory Organs
Sensory organs can be labeled as special sensory structures that permit sight, hearing, odor, and flavor. Sensory structures permitting proprioception, touch, thermal, and pain perception can be classified as more advanced sensory organs. The sensory neurons are trained to find out modifications in the external and internal conditions so that a person's body can react to that change. A stimulus is the first signal that is recognized by any sensory receptor of the body. Stimulus is an impulse generated when there is a change in the surroundings of a person. For example, a heated environment will alert the brain through the thermal sensory organs and generate a reflex accordingly.
Sensory Receptors
The human sensory system is one of the most complex and highly evolved structures, which processes a myriad of incoming messages. This well-coordinated system helps an organism or individual to respond to external stimuli, appropriately. The sensory receptors are an important part of the sensory system. These receptors are specialized epidermal cells that respond to external environmental stimuli. These receptors consist of structural and support cells that form the peripheral unit of the receptor and the neural dendrites which receive and detect the external stimuli.
1. The source of the
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a. |
regional differences in depolarization state between parts of the myocardium
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b. |
The SA node cells |
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c. |
the opening and closing of the tricuspid and bicuspid valves |
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d. |
depolarizations of the muscle and nerve cells close to the electrode site |
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e. |
The AV node cells |
2. Release or discharge from which of the following is likely to produce a slowing in the rate at which the AV node transmits a depolarization?
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a. |
Your coffee cup (caffeine) |
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b. |
the posterior lobe of the pituitary gland (Oxytocin)
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c. |
the sympathetic nervous system |
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d. |
the parasympathetic nervous system (vagus nerve) |
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e. |
the medulla of the adrenal gland (epinephrine) |
3.Which of the following is unlikely to affect the force of contraction of an individual ventricular myocyte (muscle cell)?
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a. |
the amount of intracellular calcium ion |
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b. |
the medulla of the adrenal gland (adrenaline) |
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c. |
the parasympathetic nervous system (vagus nerve or acetylcholine) |
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d. |
How much it is stretched |
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e. |
the sympathetic nervous system (noradrenaline) |
4.
In which of the following vertebrate groups did the spontaneous depolarization of cardiac muscle first evolve?
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a. |
Reptiles. The evolution of the cleiodotic egg required spontaneous myocyte depolarization
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b. |
Fish. The basal and most successful vertebrate group has spontaneous myocyte depolarization |
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c. |
Amphibians. Breathing air required hearts with spontaneous myocyte depolarization
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d. |
Humans. We are the only ones to do this, just watch Indiana Jones and the Temple of Doom for proof |
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e. |
Mammals & birds. The evolution of fur and feathers required spontaneous myocyte depolarization |
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