A&P 1- Chapter 23 Review Questions PDF

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A&P 1: Chapter 23 Review Questions

1. Define general senses and compare them with special senses 2. Define receptor potential a. Local potential that develops in receptor’s membrane when an adequate stimulus acts on the receptor b. It is a graded response, graded to strength if the stimulus. 3. Define adaptation in reference to receptor response a. Adaptation:

i. Is the condition of many sensory receptors in which the magnitude of receptor potential decreases over a period of time in response to a continuous stimulus 4. Distinguish exteroceptors, visceroceptors, and proprioceptors a. Exteroceptors i. On or near body surface ii. Often called cutaneous receptors 1. Examples of exteroceptors include: a. Those that detect pressure, touch, pain, and temperature. b. Visceroceptors i. Located internally, often within body organs (viscera) ii. Provide body with information about internal environment 1. Examples of visceroceptors include: a. Those that detect pressure, stretch, chemical changes, hunger, and thirst. c. Proprioceptors i. Special type of visceroceptors ii. Location limited to skeletal muscle, joint capsules, and tendons iii. Provide information on body movement, orientation in space, and muscle stretch iv. Two types: Tonic and phasic 1. Provide positional information about the body a. The firing of the nonadapting tonic proprioceptors allows us to locate, for example, our arm, hand, or foot at rest without having to look. b. Phasic proprioceptors are rapidly adapting receptors, so they are triggered only when there is a change in position. c. Phasic proprioceptors therefore permit us to feel the changing position of our body parts during continuous movement. 5. Describe each of the following: mechanoreceptors, chemoreceptors, thermoreceptors, nociceptors, photoreceptors. Speculate where they may be located in the body. The location may not be listed in reading. However consider their function and formulate a location. a. Mechanoreceptors are activated when “deformed” to generate receptor potential. i. Most mechanoreceptors are found in the skin and are needed for the sense of touch. Mechanoreceptors are also found in the inner ear, where they are needed for the senses of hearing and balance.

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A&P 1: Chapter 23 Review Questions

b. Chemoreceptors are activated by the amount or changing concentration of certain chemicals, such as taste and smell. i. They are found mainly in taste buds on the tongue — where they are needed for the sense of taste — and in nasal passages, where they are needed for the sense of smell. c. Thermoreceptors are activated by changes in temperature. i. They are found mostly in the skin and detect temperatures that are above or below body temperature. d. Nociceptors are activated by intense stimuli that may damage tissue; the sensation produced is pain. i. They are found in internal organs, as well as on the surface of the body. e. Photoreceptors are found only in the eye; they respond to light stimuli if the intensity is great enough to generate a receptor potential. i. Most photoreceptors are found in the eyes and are needed for the sense of vision. f. Osmoreceptors are concentrated in the hypothalamus and are activated by changes in the concentration of electrolytes in extracellular fluids. i. They are found in the hypothalamus of most homeothermic organisms that detects changes in osmotic pressure. 6. Describe the phenomenon of referred pain a. Pain felt in an area of the body distant to where it might be expected. b. The confusion arises because sensory nerves from different parts of the body

share common pathways when they reach the spinal cord. c. Referred pain in a heart attack: i. You often have referred pain to the jaw, left arm and chest ii. The brain is used to receiving a lot of pain signals from the arm, but less so from the heart. iii. The brain receives the signal that there is damage but takes an educated guess and says it must be coming from the left arm. iv. Therefore, the pain is registered as coming from the arm. d. Myofascial referred pain: i. Pain arising in myotomes or dermatomes different to where the damage is. ii. Voluntary muscle tension and shortening. iii. You have trigger points. 1. Example of myofascial referred pain: a. Pain in supraspinatus. b. It is innervated by the nerve roots C5 and C6. c. These roots also receive signals from the dermatomes of C5/6. d. This leads to pain over the shoulder and down the arm. e. You have damage to supraspinatus which presents as pain in the regimental badge area.

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A&P 1: Chapter 23 Review Questions

7. List and describe the different types of touch a. Free nerve endings informs the brain about pain. i. They are located over the entire body. b. Pacinian corpuscles detects pressure, telling the brain when a limb has moved. i. After the brain has told a limb, such as an arm, to move, the pacinian corpuscles tells the brain that that limb has actually moved into the correct position. c. The Tactile Corpuscles of Meissner are grouped on the skin of the fingertips, lips, and orifices of the body and the nipples. i. Only stimulated when touched, meissner corpuscles tells the brain the shape and feel of an object in the hand, or the touch of a kiss. ii. They adjust constantly to the environment, which is why the brain eventually ignores clothing that you are wearing. d. Ruffini's end organs are found over the entire body in the skin. 8. Describe proprioception a. Proprioception is the medical term that describes the ability to sense the orientation of your body in your environment. b. It allows you to move quickly and freely without having to consciously think about where you are in space or in your environment. c. Proprioception is a constant feedback loop within your nervous system, telling your brain what position you are in and what forces are acting upon your body at any given point in time. i. Example: 1. The way that we can tell that an arm is raised above our head, even when our eyes are closed, is an example of proprioception. 2. Other examples may include your ability to sense the surface you are standing upon, even when you are not looking at the surface. a. If you are walking along the sidewalk, and then turn to walk upon a grassy surface, your body knows how to adjust to the change in surface because of proprioception.

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