1. Explain how adaptation relates to our thermoreceptors and touch receptors. What is referred pain and how could it be dangerous?
Thermoreceptors perceive the impact of heat on the part of human body and send signals through neurons to brain that causes the feeling of pain. If the signals fail to pass from thermoreceptors to brain, the risk of burning the part of the body arises (Curcio, et al., 1990). The pain is the indicator of the danger to human body and the ultimate manifestation of pain is a pain shock, which may be deadly for human body.
2. Explain why olfaction and gustastion are considered “chemical” special senses (think of how these two senses work). Explain the importance of hair cells with the sense of hearing and equilibrium. Lastly, compare and contrast rod and cone cells’ location, function, and overall amount.
Olfaction is responsible for smell sense. Gustation is responsible for taste. They involve chemical reactions to taste and to smell. Hair cells contribute to hearing and equilibrium. They evoke receptors and help to convey the information via neurons and nervous system to the brain (Marieb & Hoehn, 2007). The waves of sound, for instance are perceived by hair cells and convey the perceived information via neurons to the brain. Cone and rod cells are located in the retina of the eye. Cone cells are responsible for color vision they function in relatively bright light. In contrast, rod cells function in dim light.
3. Explain how the body maintains homeostasis of serum (blood calcium) levels through the use of the thyroid and parathyroid glands.
Thyroid glands control how human body uses energy. The thyroid produces calcitonin, which plays role in calcium homeostasis. In such a way, the thyroid contributes to the regulation of the level of calcium in human body (Marieb & Hoehn, 2007). Parathyroid glands are located behind thyroid and produce parathyroid hormone in response to the low calcium level stimulating the production of calcium and balancing the amount of calcium in human body. In such a way, thyroid generates calcitonin, whereas parathyroid glands regulate the level of calcium in human body through production of hormones.
4. Explain the role the hypothalamus and pituitary gland have in the regulation of the endocrine system. What would happen if there were no negative feedback control on growth hormone and thyroid hormone?
The hypothalamus’ function is to link the nervous system to the endocrine system via pituitary gland (hypophysis). The hypopthalamus is responsible for certain metabolic processes, including synthesizing secreting certain neurohormones, which are called hypothalamic-releasing hormones, which stimulate or inhibit secretion of pituitary hormones. The hypothalamus controls body temperature, hunger, thirst, fatigue, sleep and circadian cycles (Baron, et al., 1999). If there is no negative feedback control on growth hormone and thyroid hormone, the human body may suffer over-exhaustion as well as the human body will be unable to control the body temperature, hunger, thirst that may lead to the failure of the endocrine system and put under a threat the life of an individual.
5. Explain how the nervous system, general senses, and endocrine system work together to maintain homeostasis. Remember the 3 steps of the nervous system function: afferent (input/sensory) information, analysis, and efferent (output/motor) information. This will be helpful along with remembering what homeostasis is.
The maintenance of homeostasis is crucial for the regulation of vitally important functions and systems of human body. In this regard, the nervous system, general senses, and endocrine system work together to maintain homeostasis stable. To put it more precisely general senses collect the afferent information, they receive signals from the outside world and send them to the brain (Marieb & Hoehn, 2007). At this stage, the nervous system come into play and transmits signals from receptors to the brain. This is the information analysis stage. In response to the signals received and information being processed, the endocrine system produces hormones and regulates vitally important systems and organs of human body maintaining homeostasis at the efferent stage.
Baron J, Beach M, Mandel J, van Stolk R, Haile R, Sandler R, Rothstein R, Summers R, Snover D, Beck G, Bond J, Greenberg E (1999). “Calcium supplements for the prevention of colorectal adenomas. Calcium Polyp Prevention Study Group”. N Engl J Med 340 (2): 101–7
Curcio, C. A., K. R. Sloan, et al. (1990). “Human photoreceptor topography.” The Journal of Comparative Neurology 292(4): 497-523.
Marieb, Elaine N. & Hoehn, Katja (2007). Human Anatomy & Physiology (Seventh ed.). San Francisco, CA: Pearson Benjamin Cummings.