We are continuously inhaling the gas known as oxygen-without it, we would die. Oxygen plays a vital role in breaking down nutrients such as glucose that need to be transported to various locations to provide the body with energy. This process is known as cell respiration.
The energy produced through cell respiration is contained in a molecule that is called ATP, which stands for adenosine triphosphate. ATP can be thought of as the fuel required for various cellular processes to occur throughout the body.
In addition to producing ATP, cell respiration also produces carbon dioxide. So while oxygen is inhaled, carbon dioxide is exhaled, and is con sidered a waste product. It is exhaled because it is a waste product of cell respiration. Like other waste products that are covered throughout this book, carbon dioxide must leave the body. If carbon dioxide builds up in the body, it can disrupt the chemical balance in the body. This can cause acidosis, when fluid becomes too acidic, which can result in calcium deposits in the body’s soft tissue. Carbon dioxide buildup in the body is toxic to the heart.
Water, which scientists estimate comprises approximately 60 to 75 percent of the human body, is important for three primary reasons: it acts as a solvent, it acts as a lubricant, and because it changes temperature slowly, it is vital in regulating the body’s temperature. The first reason because it is a solvent-means that many substances can dissolve in it, which allows nutrients and other vital components to be transported throughout the body. This is because the body’s main transportation systems, blood, are largely composed of water.
Therefore, substances like glucose (which comes from food) that are needed for energy in the body can be dissolved in the blood and then delivered to the heart and cells. Another important function is the elimination of waste. Materials that the body does not need, called waste products, are dissolved in the water component of urine and then flushed out of the body through the urinary system.
In addition to acting as a solvent, water is a lubricant, which means it prevents friction between the various surfaces inside the body, such as bones and blood vessels. One example of water acting as a lubricant is in the diges tive system. One of the fluids present in this system is the fluid mucus, which, like blood, is primarily made up of water. Mucus enables food to move through the intestines and be digested, providing the body with fuel.
The third function of water in the body is that of a temperature regulator. The temperature of water does not change quickly-it has to absorb a lot of heat or lose a lot of heat before the temperature increases or drops. This property enables the body to stay at a fairly constant temperature. In addition, water does an important cooling job for the body in the form of perspiration. When the body is absorbing an excess amount of heat, sweat forms on the skin, which allows the heat to escape the body without damaging any cells.
The Reproductive System: The role of this system is to carry out the process of sexual reproduction, which is necessary to continue the human species that contains genetic information that determines a person’s physical characteristics, but also their resistance to certain mutations also ensures the future of the species.
This system is unique because there are distinct sets of organs for females and males. In addition, there are internal and external organs in the male and female, with the internal organs located inside the body and external organs located outside the body. Some examples of the internal female reproductive system include the cervix, vagina, and fallopian tubes; external organs include the mammary glands or breasts. For males, internal organs include the ejaculatory ducts and urethra; external organs include the penis and testicles.
The Respiratory System: The primary organs are located in two areas: the upper and lower respiratory tracts. The upper tract contains the nose and nasal cavity (also known as the nasal passage), the pharynx (or throat), and the larynx (or voice box).
The lower respiratory tract contains the trachea (windpipe), the bronchi, the alveoli, and the lungs. This system’s major responsibility is to control and regulate the breathing process, which involves moving air into and out of the lungs.
The Nervous System: The primary organs of the nervous system are the brain and spinal cord. Through the nervous system’s two divisions, the central nervous system (CNS) and the peripheral nervous system (PNS), stimuli and other information is processed into the form of reaction and activity.
In addition to the endocrine system, the nervous system is known as one of the body’s key communication centers. This communication is done through nerve impulses that travel through the body’s nerve fiber system.
The Muscular System: Three types of muscles make up this system: the skeletal muscle, which helps the body to move; the smooth muscle, which is associated with the internal muscles; and cardiac, which works to help the heart to function.
The movement of each of these muscles is determined by direction they receive from different areas of the body. Specifically, the autonomic nervous system controls the smooth and cardiac muscles and the central nervous system controls the central nervous system.
The Lymphatic System: The primary organs of this system are the bone marrow and thymus, while the secondary organs are the spleen, tonsils, adenoid, Peyer’s patches, and appendix.
The lymphatic system’s job is to protect the body against toxins and other potentially harmful substances that can cause illness and disease. While not an organ, one of this system’s most important components are lymphocytes. These specialized cells detect organisms that might be harmful to the body and then prompt an immune response to drive them out of the body.
The Endocrine System: The primary organs of this system (more commonly called glands in the case of the endocrine system) are the hypothalamus, pituitary, thyroid, parathyroids, adrenal, pancreas, and sex glands.
The endocrine system is one of the body’s two communication hubs, the other being the nervous system. In this system, the communication is carried out through hormones, which are chemicals that travel through the bloodstream that prompt stimulation and inhibition of nerve impulses.
Psychotherapy is a formal process of interaction between two parties, each party usually con sisting of one person but with the possibility that there may be two or more people in each party, for the purpose of amelioration of distress in one of the two parties relative to any or all of the following disability or malfunction: cognitive functioning (disorders of thinking), affective functions (suffering or emotional discomforts), or behavioral functions (inadequacy of behavior), with the therapist having some theory of personality’s origins, development, maintenance and change along with some method of treatment logically related to the theory and professional and legal approval to act as a therapist.
Some instructors are good lecturers, others not so much. But whatever your circumstance, you can do a lot on your end to get the maximum benefit out of attending lecture:
Write notes in your own words. Listen to what your instructor is saying and write your own notes. Writing your own notes is very different from just sitting there and writing down whatever the instructor says or writes on a board. If you’re listening and writing things in your own words, you’re processing the information as you go.
Take notes on interesting stories and anecdotes. Instructors often tell stories and give examples to show the relevance of the information they’re presenting. They don’t usually write down these stories, how ever, so many students don’t write them down either. If the instructor tells a good one that helps you grasp the concept they’re talking about, jot down a few notes about it in the margin of your notes. When you’re studying later, these side notes may help you recall the topic.
Sit in the best place for you in lecture. Usually, the front is best. It’s too easy to get distracted and tune out in the back. However, if you’re some one who gets sleepy and might need to move around a little to wake up, then try an aisle seat. If you get sleepy, you can get up and take a short walk to the rest room. It’s better to get up and move than to miss half of lecture because you took a nap.
Ask questions when you don’t understand. If you’re prepared for class and following the lecture but something doesn’t make sense to you, then ask about it. Chances are if you don’t get it, someone else doesn’t either.
Be in good physical shape for class. Get enough sleep, exercise, and healthy food so that you’re ready to participate.