SAP - Body Senses Lesson

Learning Target:

  • Describe sensory processes, including the specific nature of energy transduction, relevant anatomical structures, and specialized pathways in the brain for each of the body senses.

AP psychology course and exam description, effective fall 2020. (n.d.). https://apcentral.collegeboard.org/media/pdf/ap-psychology-course-and-exam-description.pdf

Touch and Pain

Our skin is our largest sense organ. Each one of us has approximately twenty square feet of skin weighing about six pounds.

There are four distinct skin senses:

  1. pressure
  2. itch
  3. temperature (hot and cold)
  4. pain

Some parts of the body are especially sensitive to one of these senses.

Pressure is the only skin sense with identifiable receptors. The receptors are called the Pacinian corpuscle. They are stimulated by pressure; the stimulation is then converted, and neural messages are sent to the brain. Pressure is also affected by sensory adaptation. Researchers found that we also have specific neurons that are sensitive to itch. These neurons are unresponsive to pressure and temperature but react strongly to histamines producing an itchy feeling. Temperature receptors react to cold and warm. If both are stimulated simultaneously the sensation of hotness occurs.

Pain

Pain is an unpleasant sensory and emotional experience that is associated with actual or potential tissue damage. Pain helps you survive! Nociceptors are your body's pain receptors. They are small sensory fibers with free nerve endings. Our skin contains the most, our muscles and internal organs fewer. Your body has a fast and slow pain system. The fast system is activated by A-delta fibers. These are myelinated and provide sharp, short, and intense pain. For example, when you get a paper cut, that sharp initial pain is your A-delta fibers. C-fibers on the other hand are unmyelinated and provide throbbing pain that lasts long after the initial sharp pain subsides.

Gate Control Theory of Pain

Pain is an individual experience and is subject to variation. The sensory information received by the brain is integrated with information about psychological and situational factors. The Gate Control Theory of Pain explains that the combination of physical and psychological factors works together to cause spinal cord gates to open and relay intense stimulation to the brain which receives them as pain. If the gate is open, pain is intensified; if it is closed, pain is reduced.

Vestibular

The vestibular sense is the body's ability to sense and maintain balance and spatial orientation via signals from the inner ear. This sense detects changes in head position and movement, as well as changes in direction and speed. The vestibular system is also responsible for coordinating eye movements with head movements, which helps keep eyes clear while moving. Dizziness, vertigo, and balance and spatial orientation problems can be caused by dysfunctions in the vestibular system. We depend on the vestibular sense for activities such as walking, running, and driving, and for athletes, dancers, and pilots who require precise balance and coordination. Consequently, understanding the vestibular sense is essential to understanding how we navigate and interact with our surroundings as well as developing treatments for vestibular-related conditions.

Kinesthesis

Kinesthesis is the ability of the body to sense the position and movement of muscles, joints, and limbs. It is essential for performing coordinated movements and maintaining balance as it provides information about the body's location and orientation in space. A person's movements are controlled by kinesthetic receptors found in muscles and joints, which send information to the brain. Proprioception, the ability to determine the location of body parts without seeing them, is also enhanced by kinesthetic feedback. Motor control, coordination, and balance issues can be caused by disorders of the kinesthetic sense.

Complete the Senses Review activity below.

 

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