Skeletal, Respiratory, Digestive, and Nervous Systems - Assignment Example

Information Sheets 1. Skeletal System The Skeletal System is generally defined as the biological system that provides support in all living organisms (Skeletalsystem.net, Online). The skeletal system is responsible for keeping the human body in shape and form and protecting the vital organs of the body such as the heart, brain, lungs etc., and enables movement. The skeletal system has five major functions. Firstly it provides rigidity and shape. The human skeletal system consists of 206 bones which provide a rigid framework for the softer tissues and other vital organs of the body. Since they are the most rigid and strong structures in the body, they control and determine the size and shape of each of the body parts. The second most important function of the skeletal system is protection. The bones of the skeletal system act as a security system for the most principal organs of the body. For example the skull protects the brain and the lungs are enclosed and shielded by the sternum and the ribcage. Thirdly, the skeletal system is responsible for movement. Bones of the skeletal system work alongside the muscles to enable movement. Bones are connected to each other through ligaments and muscles are connected to bones through tendons. When two bones meet each other it is typically known as the joint. Muscles which bring about movement of a joint are connected to two different bones that make up the joint. Muscles contract to pull the two bones together thereby causing movement. The fourth major function of the skeletal system is blood cell manufacture. Bone Marrow which is present deep inside some of the bones in the body produce red blood cells which assist the blood in delivering oxygen to all parts of the body. The bone marrow produces an average of 2.6 million red blood cells per second to replace those red blood cells lost by the liver due to damage. The fifth and final function of the skeletal system is Mineral storage. Bones are made up of calcium and phosphorous and serve as a storage are for these minerals. When an excess of these minerals is found in the blood it is stored in the bones and when the supply of these minerals are less, it is drawn from the bones for replenishment (Minnesota State University, Online and Gilbert, L, 2001). The human skeletal system is divided into two distinctive parts, namely the axial skeleton and the appendicular skeleton. The axial skeleton comprises of bones that form the axis of the body and support the organs of the head, neck and trunk. It consists of the skull, the sternum, the ribs and the vertebral column. The skull forms the framework for the head and the cranial bones are responsible for protecting the brain. The sternum is a flat, dagger shaped bone located in the middle of the chest. The sternum along with the ribcage protects the heart, lungs and major blood vessels. The rib cage is composed of thin, flat, curved bones that create a protective cage for the organs of the upper body. The rib cage consists of 24 bones arranged in 12 pairs. The vertebral column commonly known as the spine consists of 33 irregular shaped bones. It allows humans to stand upright and maintain balance. It also supports the head and the arms and allows freedom of movement. The appendicular skeleton consists of bones that affix the appendages to the axial skeleton. It includes the upper and lower extremities, the shoulder girdle and the pelvic girdle. The upper extremities include the arm, forearm and the hand. The lower extremities include the thigh, leg, foot and the kneecap. The shoulder girdle is composed of two bones, namely the collarbone and the shoulder blade. The pelvic girdle usually called the hip girdle comprises of two hip bones. (Minnesota State University, Online). Homeostasis is the ability of the body to physiologically control and regulate the inner environment to ensure stability when it responds to the changes in the outside environment. The skeletal system contributes towards homeostasis by maintaining correct calcium and phosphorous levels in the body. Some of the common diseases affecting the skeletal system include Arthritis, Rheumatism, and Osteoporosis. Arthritis is the inflammation of one or more joints and usually results in swelling, warmth, redness of the skin, pain, restriction of motion etc. Rheumatism is a painful disease affecting primarily the larger joints. The joints are painful, swollen and stiff. Osteoporosis is the loss of bone tissue. The bones become brittle and become liable to fracture (Ehrlich, A and Schroeder, C L, 2004). 2. Respiratory System All living beings need oxygen in order to live. Respiration is a process by which oxygen in the air is brought into the lungs to in order to be absorbed by the blood which carries it to all parts of the body. The blood also gives up the used air known as carbon dioxide which is carried out of the lungs with the air that is breathed out. The main function of the respiratory system is to take in oxygen from the air in the environment for the use of the cells in the body and the elimination of carbon dioxide which is produced by the cells. The lungs, airways, diaphragm, windpipe, throat, mouth, and nasal passages are all different components of the respiratory system each having its own function. The respiratory system is broadly divided into three parts. The first part is the Nose and Throat. Air is inhaled through the nose and it passes through the tiny hairs in the nose which is responsible for filtering and purifying the air that is inhaled. Following this is the nasal cavity which plays a very important role in breathing. The nasal cavity is a passage behind the nose and is divided into a left and right passageway. There are many tissues that cover the wall of the nasal cavity and these tissues have blood vessels. Heat from these blood vessels keep the air inhaled warm. Furthermore moisture is also added to the air that is inhaled with the help of special cells that are present along the walls of the nasal cavity. Thus the nasal cavity aids in warming and moistening the air that is inhaled before it reaches the lungs. The throat passes the air inhaled from the nose into the windpipe. The second part is the Windpipe and Bronchial Tree. The windpipe, also called the trachea links the upper respiratory tract to the lungs. The bottom of the trachea also splits into two branches known as the bronchi, one of which enters the left lung and the other enters the right lung. The windpipe is responsible for transporting the air that is inhaled. The Bronchial tree’s primary responsibility is to spread the air from the windpipe into a wide are as quickly as possible. The bronchi are subdivided into two bronchioles. The bronchioles open into air sacks called alveoli. There are about 300 alveoli in each lung. The alveoli are responsible for giving the lungs a large surface to absorb oxygen in the air. The third part of the respiratory system is the lungs. Lungs are responsible for providing the breath of life. The lungs fill the chest from the neck to the ribs. The lungs are the pick up and drop off place for oxygen and carbon dioxide respectively. Blood is pumped into the lungs, from the heart via the pulmonary arteries. Here the blood absorbs the oxygen in the lungs and taken to the heart through the pulmonary veins (ThinkQuest Library, Online). The respiratory system contributes to homeostasis in two ways, namely gas exchange and maintaining of pH levels. Gas exchange happens in the lungs by the elimination of carbon dioxide from the body and absorption of oxygen. The respiratory system also maintains the pH levels in our blood which is essentially the acid balance in our blood. It contributes towards the body’s ability to cope with changes in pH levels. There are some common diseases affecting the respiratory system, namely Pneumonia, Asthma and Lung Cancer. Pneumonia is an infection of the alveoli and is caused by many types of bacteria and viruses. These viruses cause tissue fluids to accumulate in the alveoli thereby reducing its surface area exposed to oxygen. This further causes breathing difficulty. Asthma is the recurring constriction of the bronchi and bronchioles making it more difficult to breathe. Lung cancer is the most common form of cancer and like other cancers is caused by the uncontrolled increase of cells. Normally the airways have two layers of cells. Cancer causes these layers to increase and eventually kills the patient if not treated early (Kimball’s Biology pages, Online, 2007). Source: www.cartage.org 3. Digestive System The human Digestive System is a complex array of organs and glands that are involved in the processing of food that is taken in. In order to absorb the energy from the food we consume, the body has to break down the food into smaller molecules and parts. This is the process of digestion. The different organs that combine to form the digestive system include the mouth, esophagus, stomach, small intestine, large intestine also called the colon, rectum, and anus. The process of digestion begins in the mouth. Food is partly broken down when it is chewed and by a chemical reaction in the mouth with the help of certain enzymes from the salivary glands. These enzymes break down starch in the food into smaller molecules. After the food is chewed and swallowed it enters the esophagus. This esophagus is a long tube like structure that runs from the mouth to the stomach and is responsible in carrying the food that has been chewed and swallowed. The esophagus uses rhythmic wave-like movements by the muscle to push the food down into the stomach. Once the food reaches the stomach, it is churned and bathed in strong acid called the gastric acid. The stomach is a large sack like organ where the food is partly digested and broken down and mixed with the acids called chyme. After the food is broken in the stomach it enters the small intestine. It first enters the duodenum which is the first part of the small intestine. It then passes through the jejunum and the ileum, which is the final part of the small intestine. In the small intestine bile which is produced by the liver and stored in the gall bladder, pancreatic enzymes and other digestive enzymes which are manufactured by the wall of the small intestine break down the food further. Once this is done the broken down food passes to the large intestine. In the large intestine some water and chemicals like sodium are removed from the food. The microbes in the large intestine help in the completion of the digestion process. The first part pf the large intestine is called the cecum. The digested food travels upward into the colon, travels across the abdomen, in the transverse colon goes into the descending colon and then through the sigmoid colon. The digested nutrients are absorbed by the walls of the large intestine and transported to different parts of the body. Solid waste from the digestion process is transferred and stored in the rectum till it exits the body through the anus (Enchanted Learning, Online and NDDIC, Online). The bacteria in the digestive system contribute towards homeostasis. These bacteria are mostly present in the large intestine help with digestion, help produce vitamins, help formulate excrement and guard against harmful bacteria. They are also responsible for maintaining the pH balance. Some of the common diseases affecting the digestive system include Appendicitis, Gastritis and Indigestion. Appendicitis is the irritation, infection and inflammation of the appendix which is a narrow hollow tube that branches off the large intestine. It plays a major role as the immune system in the first few years of life. Infection of the appendix may occur after a viral infection of the digestive system. Gastritis is the inflammation or swelling of the stomach lining. It may be caused due to drinking, spicy food, smoking, major surgery etc. Indigestion is one of the most common ailments of the digestive system. Indigestion usually induces a painful, burning feeling in the upper abdomen and causes nausea, bloating of stomach, gas, vomiting etc. It is usually a result of a disease or ulcer in the digestive tract. Avoiding certain foods that cause indigestion is the best way of treating the problem (Rush University Medical Centre, Online). 4. Nervous System The nervous system is a network of cells that communicate information about the surroundings and other happenings in the environment to the brain. The brain processes the information that has been transmitted and induces the different body parts to function accordingly. The nervous system comprises of neurons and specialized cells known as the glial cells that help in the functioning of the neuron. Neurons are electrically impulsive cells in the nervous system that are responsible for transmitting the information to the brain. Neurons are the primary components of the brain, spinal cord, ventral nerve and peripheral nerves. Different types of neurons exist each with a different function namely, touch, smell, sight, sound, and other sensory stimuli. The glial cells are not neurons. They aid the neurons in transmitting the information, provide nutrition and maintain homeostasis. The basic function of the nervous system is to receive sensory input from the external as well as internal environment, assimilate the input and respond to stimuli.(Columbia Encyclopedia). The nervous system is broadly classified into two parts, namely the central nervous system and the peripheral nervous system. The central nervous system (CNS) is the largest part of the nervous system and includes the brain and spinal cord. The spinal cavity protects and holds the spinal cord and the head or skull contains and protects the brain. The brain is further composed of three parts namely the cerebrum, cerebellum and medulla oblongata. The cerebrum is the base of consciousness. The cerebellum is the largest part of the brain next to the cerebrum and is responsible for muscle coordination, muscle posture and maintains balance. The medulla oblongata is closest to the spinal cord at the base of the brain and is responsible for the regulation of heartbeat, breathing, blood pressure and reflex. The spinal cord connects the brain to the rest of the body. The gray matter in the spinal cord mostly comprises of cell bodies and dendrites. It is responsible to carry messages to and from the brain and certain reflex actions. The peripheral nervous system (PNS) primarily contains nerves and connects the brain and the spinal cord to the rest of the body. The two important components of the PNS include sensory pathways and motor pathways. Sensory pathways transmit input from the body to the CNS while the motor pathways carry signals to muscles and glands (Estrella Mountain Community College, Online). The brain, spinal cord and nerve bundles that are present all over the body help in contributing towards homeostasis. Sensory nerves identify the external and internal conditions to transmit it to the brain which in turn interprets the information and induces the necessary action. Some of the common ailments affecting the nervous system include headache, meningitis and paralysis. Headaches can be caused by stress, ear, nose and throat, nerve problems etc. It can affect an array of nerves on the head, scalp, face and mouth. Meningitis causes the membranes that surround the brain and spinal cord to be infected by bacteria and viruses. The symptoms of meningitis include Symptoms of meningitis in adults and older children include headache, fever, vomiting, neck stiffness and joint pains, drowsiness and confusion etc. It can cause death if not treated on time. Paralysis is the total loss of muscle function of one or more muscle groups. It can cause loss of mobility and is usually the result of damage to the nervous system or brain. (Health Insite, Online). References Minnesota State University. The Skeletal System. Minnesota State University Website. Retrieved 20 May, 2009. http://www.mnsu.edu/emuseum/index.shtml Gilbert, L (2001). The Skeletal System. The Rosen Publishing Group, 2001. Ehrlich, A and Schroeder, C L (2004). Medical Terminology for Health Professions. Cengage Learning, 2004. ThinkQuest Library. Respiratory System. Think Quest Website. Retrieved 20 May 2009. http://library.thinkquest.org/5777/resp1.htm Kimball’s Biology Pages (2007). The Human Respiratory System. Retrieved 20 May 2009. http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pulmonary.html Enchanted Learning, Online. Human Digestive System. Retrieved 20 May 2009. http://www.enchantedlearning.com/subjects/anatomy/digestive/ Rush University Medical Centre. Digestive Disorders. Retrieved 20 May 2009. http://www.rush.edu/rumc/page-1098987318800.html National Digestive Diseases Information Clearinghouse. Digestive System and How it Works. Retrieved 20 May 2009. http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/ Columbia Encyclopedia. Nervous System. Columbis University Press. Estrella Mountain Community College. The Nervous System. Retrieved 20 May 2009. http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookNERV.html#Table%20of%20Contents Health Insite. Nervous System Diseases. Retrieved 20 May 2009. http://www.healthinsite.gov.au/topics/Nervous_System_Diseases Read More