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The Skeletal System The skeletal system is essentially our bones. When held together with muscles and ligaments, the bones help to give structure to our physical bodies. They keep the physical body in shape so that the organs of the body may be held in the correct place. Some bones are joined by flexible parts, called moving joints, which give the physical body some flexibility and the ability to move as well as supporting the body structure. The smallest bones are in the ear whilst the largest bone, the femur, is found in the thigh. Some of the larger bones are hollow and contain bone marrow, a substance which manufactures blood cells. Bones store useful minerals such as calcium and iron. The skull protects the very delicate tissue of the brain in a case of bone. The spine helps to give central physical support to the body and protects the nerves running through it. The rib cage protects the delicate tissue of the lungs and the heart. The layout of the bones in what is called the pelvic girdle (the pelvis area) gives support to a woman when she is carrying a baby. The medical names for various bones are shown on the following pages. The first page shows the skeleton from the front followed by a picture of a skeleton from the rear www.healingenergies-at-londonwest.com www.healingenergies-at-londonwest.com www.healingenergies-at-londonwest.com The Muscular System As noted in the previous section, muscles hold the bone structure of the human body together as shown in the following diagrams from Gray’s Anatomy. They connect themselves to bones through the tendons which are a kind of stretchy tissue material. Muscles also enable the human body to move. They are made up of bundles of cells and fibres that can shorten (tighten up) or lengthen (relax), this resulting in movement. Many bones in the human body have two sets of muscles attached to them. When the muscles shorten, they pull on the tendons which pull on the bones and cause our limbs to move. Muscles only have a pulling effect. They never have a pushing effect. Muscles are connected to the brain through the nervous system. The brain sends messages to the muscles through the nerves to initiate tightening and relaxation of the muscles. There are 630 active muscles in the human body acting in groups to facilitate big bone movements such as walking or moving into a sitting opposition. Muscles are defined as being voluntary or involuntary. Voluntary muscles are those that are controlled by intention, such as the arms and legs. Involuntary muscles are those which are controlled automatically by the brain, such as the action of the heart, which is a muscle, and the movement of the muscles associated with the breathing mechanism. www.healingenergies-at-londonwest.com The three following diagrams show different cross sections of muscle formation in the abdomen. If you look carefully, you can see how the muscles shown in brown weave around the ribs in the rib cage structure to hold the ribs in place. This enables the rib cage to protect the lungs and also to flex as the lungs breathe in and out. www.healingenergies-at-londonwest.com Sometimes ruptures occur in the muscular system and the body parts that would normally lie behind the rupture such as a body organ start to protrude through the rupture in what are known as hernias. Usually, simple surgical procedures can treat hernias quickly by pushing the protrusion back into place and by mending the rupture, sometimes including the insertion of materials such as meshing to strengthen the weakened muscle tissue. If there is risk of something serious like restricted blood flow, blocks in digestive passages, etc., resulting from hernias, they should be treated as quickly as possible. www.healingenergies-at-londonwest.com The term ligament is given to a type of tissue that connects bones to other bones at bone joints. Ligament tissue is not the same material as muscle tissue. Torn and damaged ligaments impact upon the ability of bone joints to function correctly. www.healingenergies-at-londonwest.com This diagram tries to depict the extent to which the muscle system extends throughout the body under the skin, holding everything together and in place. At the open end of the rib cage where there is an absence of bone structure, the muscle system of the rectus abdominus holds all the vital organs in this area in place. www.healingenergies-at-londonwest.com The Nervous System www.healingenergies-at-londonwest.com The human body has an extensive network of nerves which enables the brain to communicate with every other part of the body. Some nerves carry information from the brain to the muscles to control the movement of our bodies. Nerves also transmit information from one area of the body to another and to the brain. This network of nerves enables us to experience our main senses of seeing with our eyes, hearing with our ears, smelling with our noses, tasting with our tongues, and the sense of touch all over the surface of our bodies. The brain is at the centre of the nervous system and is connected with the spinal cord. The spinal cord is a thick bundle of nerves which runs down the centre of the spine. From the spinal cord, smaller bunches of nerves branch out. These smaller bunches of nerves keep branching out into smaller branches of nerves the nervous system has branched out into all areas of the body. The central nervous system controls a gland called the hypothalamus, which in turn controls another gland called the pituitary. The cells of the pituitary gland secrete growth hormone which triggers the liver to produce a material which stimulates growth in a range of body tissues (body material) including muscle, cartilage, bone, liver, kidney and skin. There are around 30,000 million nerve cells in the human body. Each individual nerve cell can transmit 1,000 nerve impulses each second. Information transmission within the nervous system is usually very fast and can exceed 100 metres per second. This means that each of us is carrying a very highly engineered internal information system. www.healingenergies-at-londonwest.com The front view of the head in the last diagram can be used to understand the concept of how the nervous system works. Different nerves in the head connect to the brain so that it can receive information and control different body functions as follows: The Offactory Nerve carries the sense of smell to the brain. The Optic Nerve carries visual information to the brain. The Oculomotor Nerve enables the brain to direct the movement of the eyes. The Trochlear Nerve is also related to the movement of the eyes. The Facial Nerve is related to movements of the face muscles, to the secretion of saliva in the mouth and to the sense of taste from the front part of the tongue. The Auditory Nerve carries the sense of sound, movement and gravity to the brain which is related to keeping one’s physical balance. The Glosspharyngeal Nerve carries the sense of taste from the back part of the tongue to the brain. The Vagus Nerve travels down into the upper abdomen and connects the brain to key parts of the body like the heart and the lungs. The Hypoglossal Nerve enables the brain to direct the movement of the tongue muscles. The Accessory Nerve enables the brain to direct the movement of the muscles of the neck. The diagram on the next page shows the nerves (in yellow) in the arm. Nerves can be damaged due to accidents such as cuts or involvement in car crashes. Medical experience has been that nerve cells do not usually have the same repair ability as do most other cells in the body. Consequently, substantive damage to part of the nervous system such as fracture of the spinal column can often leave part of the nervous system broken permanently with a loss of body function such as movement. Nerve malfunction can also be of a more temporary nature. For example, swelling due to bruising might put physical pressure on a nerve and result in feelings of pain or numbness. As long as the cause of the pressure on the nerve is temporary, there is usually no long term effect on the nerve. We have a brief look later in this chapter at the chemistry behind information transmission through the nervous system. www.healingenergies-at-londonwest.com www.healingenergies-at-londonwest.com The Respiratory System The respiratory system is what we use to breathe in fresh air and to expel used air. We breathe in by contracting our rib muscles to pull the ribs up and out and by contracting the diaphragm muscle to pull down the lungs in our chest. We breathe out by relaxing the rib muscles and diaphragm muscle and releasing the air from our lungs. This muscle movement causes air to be sucked in through the nose or mouth and down through the windpipe (trachea). The windpipe is a pipe shaped by rings of cartilage which divides into two tubes called bronchi, (singular form – bronchus) one of which goes into the left lung and the other of which goes into the right lung. Inside each lung, the bronchi split into smaller and smaller tubes called bronchioles. At the end of the bronchioles are small air balloons or air sacs called alveoli. The alveoli are surrounded by a very high density of very fine blood vessels (capillaries) with very thin walls. The alveoli are able to absorb into the blood cells in the bloodstream the oxygen from the air around that is needed to oxidise the food that we eat, thereby releasing the energy of the food. Oxygen is also needed by the cells in the body. Carbon dioxide is created as a by-product from the oxidisation of our food, and is carried in the blood stream to the alveoli where it is processed out into the lungs and expelled with our out breaths. On the next page is a diagram showing the bronchioles in what is often referred to as the bronchiole tree. This is followed by a diagram of the horizontal cross section of the abdomen through the lungs and heart. This shows the flow of the blood being pumped through the heart and around the lungs. The red indicates blood rich in oxygen that has been received through the alveoli and the blue indicates blood rich in carbon dioxide to be expelled through the alveoli. The final diagram is a representation of the process of receiving oxygen and releasing carbon dioxide through the alveoli. Damage to the very fine blood vessels occurs through the breathing in of poisonous gases such as those released by cigarettes. This affects the effectiveness of receiving oxygen into the blood stream and the release of carbon dioxide. www.healingenergies-at-londonwest.com www.healingenergies-at-londonwest.com www.healingenergies-at-londonwest.com