Toxins are poisonous substances that can cause harm to human beings via one or more of its physiological systems. For example, DDT is a toxin used to kill insects but which also affects the human endocrine system. Tetrodotoxin is a toxin found in the venom of animals like frogs and pufferfish, but if it enters the human nervous system can cause paralysis or death. Mercury is a naturally-occurring element like tetrodotoxin, but exposure to the cardiovascular system in human beings can cause hypertension and even worse health effects. Although each of these toxins operates differently in the body, their consequences can be grave. Whereas DDT is a synthetic chemical compound first developed in the late 19th century, both tetrodotoxin and mercury are naturally-occurring substances. Tetrodotoxin is manufactured in the bodies of venomous animals like pufferfish and certain types of poisonous frogs and stored in their livers or sex organs. Mercury, on the other hand, is a chemical element that is usually found in metals like cinnabar. Whereas Mercury has a silvery liquid appearance, tetrodotoxin is a "colorless crystalline solid," (NIOSH, n.d.). Of these three substances, only DDT has used as a pesticide. Until relatively recently, DDT was used...
Because of its toxicity in human beings, DDT has been banned in the United States and some other countries. Mercury's toxic effects themselves are not used in the way that DDT is, but the element is used widely in the manufacture of thermometers, barometers, and other instruments, as well as compact fluorescent bulbs and some types of clocks (Blaszczak-Boxe, 2014). However, mercury has been used for thousands of years in various medical systems and was even used until the 20th century to treat syphilis (Blaszczak-Boxe, 2014). Unlike either DDT or tetrodotoxin, mercury is actually a metal, and is the only liquid metal in the periodic table. Mercury is also the only actual element (its symbol is Hg) of these three.
Endocrine control of BP Hormonal Control of Osmotic pressure: Stimulation Arterial blood pressure (BP) is under tight control by the mammalian nervous system, cardiovascular system, kidneys, and endocrine system (Vivas et al., 2014). The VII, IX, and X cranial nerves conduct peripheral taste, osmo-sodium, volume, and baroreceptor information to the solitary tract, while the distinct bundles of neurons in the lamina terminalis respond to changes in plasma and cerebral spinal fluid sodium
These indications then proceed to the neuromuscular connections of skeletal muscles. From there, acetylcholine is released from the axon terminal knobs of alpha motor neurons and received by postsynaptic receptors of muscles, thereby communicating the stimulus to contract muscle fibers (Ihlen & Vereijken, 2010). Psychological Influences Research on patient's brains scanned by Positron Emmision Tomography have designated that the kind of thoughts people have influence the balance of brain chemicals, so
E. hypertrophy). In the elderly, this process is reverse. Hence, the functional reserve capacities of the skeletal muscles decline with age, largely due to diminished levels of physical activity. As a result daily tasks once taken for granted become progressively more difficult, and eventually impossible, to perform. In illustration, a great deal of muscle force is required to simply stand up or to climb stairs. Therefore, skeletal system is relying
The circulatory or cardiovascular system is responsible for moving nutrients, wastes and gases between body cells, transporting blood across the whole body and battling disease (Circulatory System). Its principal elements are the heart, numerous blood vessels, and blood. The heart forms the circulatory system's core. This 2-sided, 4-chambered pump which distributes blood to various arteries comprises of the right and left ventricles, and right and left atria. The ventricles, situated within
anatomy and physiology of the Nervous System The nervous system is a "network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment." ("Nervous System 2000) There are two segments of the nervous system which include the peripheral and central systems. ("Nervous System 2000) The peripheral nervous system consists of spinal, cranial, and autonomic nerves, and their branches. ("Nervous System" 2000) The central nervous system
Space Physiology Love Of Extremes: Space Physiology About the effect of gravity on the human being in space Early milestones in space exploration and space physiology Gravity The effects of microgravity on human physiology Physiological changes during a space flight The effects of microgravity on the human body The Vestibular System Orientation in space Space Adaptation Syndrome (SAS) and Space Motion Sickness (SMS) The effects of radiations on astronauts in space DNA damage mechanisms by radiations The biological effects of radiations Acute effects
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