General Anatomy and Physiology

Chapter 6 General Anatomy and Physiology Key Terms: Planes: An imaginary line used to define areas of the body and parts within those areas. Body Cavity: A space or area in the body where various structures and organs are found. Cell: The basic unit of all systems and the smallest functioning unit of the body. Tissues: Groups of cells that have a similar structure and act together to perform a specific function. Organs: A group of tissues in a living organism that have been adapted to perform a specific function Systems: A collection of parts able to work together to serve a common purpose Homeostasis: The state of steady internal, physical, and chemical conditions maintained by living systems. Axial Skeleton: Includes bones of the cranium, face, spinal column, ribs and sternum. Appendicular Skeleton: Composed of the bones from the upper and lower extremities and includes the arms, legs, hands, feet, shoulders, and hips Osseous Tissue: Composed of connective tissues and rendered hard by the deposits of mineral salts. Cancellous Bone: Consists of meshwork of interconnecting bone called trabeculae. Trabeculae:a series or group of partitions formed by bands or columns of connective tissue, especially a plate of the calcareous tissue forming a cancellous bone. Compact Bone: the strong and hard section of the bone, dense and forms the main shaft of long bones and the outer layer of other bones Osteoclast: A type of bone cell that breaks down bone tissue Osteoblasts: Bone building cells Cartilage: Found where bones join and forms part of such structures as the nose and ears, tough non vascular resilient connective tissue Articulation: An area where two or more bones meet or form a junction. Striated Muscle: Made of long, thin cells that have stripes or bands across them. Cardiac Muscle: Found only in the heart, have the same striped appearance as skeletal muscle but is in involuntary in action Smooth Muscle: Nonstriated tissue and involuntary meaning they are controlled by the autonomic nervous system Fascia: A fibrous sheet of connective tissue that covers, supports, and separates the muscle fibers Excitability: The ability to respond to a stimulus, which may be delivered from a motor neuron or a hormone. Irritability: Muscles receive and expand to stimulation. Extensibility: The ability of the muscle to stretch or spread in order to perform tasks. Tendon: A flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone. Aponeurosis: A broad flattened extension. Ligaments: Composed of bands or sheets of fibrous tissue and act to connect or support two or more bones. Origin: Where the muscle attaches to the more stationary bone Insertion Point: Where the bone is moveable Antagonistic Pairs: When one set of muscles contracts another corresponding set relaxes. Central Nervous System: Consists of the brain and the spinal cord Peripheral Nervous System: Consists of all the nerves outside of the Central Nervous System Autonomic Nervous System: A specialized group of peripheral nerves that function mainly automatically. Neuron: The basic structural unit of the nervous system. Dendrites: Nerve fibers that conduct impulses toward the cell body. Axons: Nerve fibers that conduct impulses away from the cell body. Synapse: A junction where chemicals are released from the ends of axons to allow the stimuli to jump to the next dendrite. Myelin Sheath: Layers of Schwann cells that insulate and protect nerves. Reflex Arc: A neural pathway that controls a reflex Hormones: Control the internal environment of the body from the cellular to the organ level. Pulmonary Circulation: Pathway that circulates blood through the heart to the lungs and back to the heart Systemic Circulation: Pathway that carries the blood from the aorta to the smallest blood vessels and back to the heart. Heart: A pump that circulates the blood throughout the body. Pericardium: The outer layer that is composed of a double-walled sac. Myocardium: A tough, muscular wall Endocardium: A thin lining on the inside of the heart Heart Valves: Regulate the flow of blood in one direction Vena Cava: Blood enters the heart through large vessels Aorta: Receives blood directly from the heart and is the largest artery. Arteriole: A small branch of an artery leading to the capillary Vein: Carries blood that has drained from the capillaries back to the heart. Capillary: The connection between the arteries and the veins. Blood: Transports nutrients, gases, waste products and hormones; regulates the amount of bodily fluids, pH balance, and body temperature; and protects against pathogens and blood loss after injury through the clotting mechanism. Plasma: The clear, straw-colored liquid portion of blood that remains after red blood cells, white blood cells, platelets and other cellular components are removed Hemostasis: Process that the body does to control building Rh Factor: A type of protein found on the outside of red blood cells Digestion: Breaking down food into small nutrient molecules the cells can use Pharynx: Connects the oral cavity to the esophagus Oral Cavity: Receives food and begins breaking the food down Epiglottis: A small leaf shaped cartilage that covers the Larynx Deglutition: Provides movement for the food to proceed from the mouth to the stomach Esophagus: Extends from the pharynx to the stomach and muscles help move food toward the stomach Stomach: An organ that extends from the esophagus to the small intestine and can expand to hold half a gallon food Peristalsis: the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward. Chyme: the pulpy acidic fluid which passes from the stomach to the small intestine, consisting of gastric juices and partly digested food. Small Intestine: the pulpy acidic fluid which passes from the stomach to the small intestine, consisting of gastric juices and partly digested food. Large Intestine: absorbs water from wastes, creating stool. Liver: essential for digesting food and ridding your body of toxic substances Gallbladder: stores bile produced by the liver and sits just under the liver. Pancreas: An organ located in the abdomen. It plays an essential role in converting the food we eat into fuel for the body's cells, and has two main functions: an exocrine function that helps in digestion and an endocrine function that regulates blood sugar. Nasopharynx: the upper part of the pharynx, connecting with the nasal cavity above the soft palate. Oropharynx: the part of the pharynx that lies between the soft palate and the hyoid bone. Laryngopharynx: where both food and air pass. It can be found between the hyoid bone and the larynx and esophagus, which helps guide food and air where to go. Larynx: the hollow muscular organ forming an air passage to the lungs and holding the vocal cords in humans and other mammals; the voice box. Vocal Cords: 2 bands of smooth muscle tissue found in the voice box, vibrate and air passes through the cords from the lungs to make the sound of your voice. Trachea: a large membranous tube reinforced by rings of cartilage, extending from the larynx to the bronchial tubes and conveying air to and from the lungs Bronchi: airways that lead from the trachea into the lungs and then branch off into progressively smaller structures until they reach the alveoli Bronchioles: any of the minute branches into which a bronchus divides. Alveolar Sacs: Resemble clusters of grapes at the end of the Bronchioles Alveoli: tiny air sacs in your lungs that take up the oxygen you breathe in and keep your body going. Lungs: Two cone shaped organs inside the rib cage, Respiration: The process of breathing and exchanging gases (oxygen and carbon dioxide) between the body and its environment Inhalation: Muscles contract, the chest enlarges, and air flows into the lungs Exhalation: Muscles relax and air is moved out of the lungs. Lymph: A clear liquid formed in tissue spaces Lymph Nodes: Found in groups along the lymphatic vessels, filters the lymph as it journeys back to the bloodstream and to manufacture antibodies and other active materials of the immunity process Spleen: Located behind the stomachs and is protected by the rib cages, as blood moves through the spleen it removes bacteria and other foreign materials. Thymus: a specialized primary lymphoid organ of the immune system, cell lymphocytes or T cells mature Tonsils: a pair of soft tissue masses located at the rear of the throat Nonspecific Immunity: The body's defense against any harmful agents Specific Immunity: Body's defense against selected agents Skin: Composed of several layers including the epidermis, dermis, and subcutaneous layers Cuticle: a layer of clear skin located along the bottom edge of your finger or toe Specific Instructional Objectives: 1. The body systems include the Skeletal, Muscular, Nervous, Endocrine, Reproductive, Circulatory, Digestive, Respiratory, Lymphatic, Immune, and Integumentary systems. Body planes and directions include anterior (in front of), ventral (on the front), posterior (in back or behind), dorsal (on the back), medial (toward the middle of the body), mesial (toward the midline of the body, primarily used in dentistry), lateral (toward the outside or away from the midline that divides the body), distal (away from the midline of the body), proximal (part of the body closest to the point of attachment), inferior (below or under), superior (above or higher). The body cavities include the dorsal cavity, ventral cavity, thoracic cavity, abdominal cavity, pelvic cavity, and cranial cavity. The cell is the basic unit of all systems and the smallest functioning unit of the body. The basic components of a cell include the cell membrane, nucleus, cytoplasm, and chromosomes. 2. The function of the skeletal system includes support for the body's framework and overall body shape. It provides a surface for muscles to attach to and protects the fragile organs of the body. Finally it also manufactures blood cells and stores minerals for use when they are needed. The bone is constructed of connective tissue, this connective tissue is rendered hard by the deposits of mineral salts. Bone tissue is 20% water and the remaining 80% consists of two thirds minerals and inorganic matter and one third is composed of organic matter such as blood cells, lymphatic vessels, and nerves. The types of joints include the fibrous joint, cartilaginous joint, and synovial joint. 3. The muscular system makes up 30-40% of total body weight. Muscles contract and release to provide for all movements of the body, internally and externally. Internal muscles move food along the digestive track and keep the heat beating and external muscles allow the body to walk, run, jump, stand straight and communicate. There are 3 types of muscles, the striated muscle, cardiac muscle, and smooth muscle. 4. The nervous system transmits stimuli from outside and inside the body and is the body's communication system. It also has the ability to respond and transmit stimuli to maintain the body's unity and harmony. The nervous system consists of 3 sections, the brain, spinal cord, and nerve cells. The brain and the spinal cord make up the central nervous system and all other nerves make up the peripheral nervous system. There is a specialized group of peripheral nerves that function mainly automatically called the autonomic nervous system. 5. The endocrine system is a control and communication system similar to the nervous system. The endocrine system generally controls body growth, protects the body in stressful situations, controls development of sex characteristics, regulates utilization of calcium, aids in reulating the bodys water balance, and produces insulin which aids in the transport of glucose into cells. Made up of glands that are spread throughout the body, they are grouped according to structure and interrelated functions. 6. Pregnancy can cause the need for dental procedures to be altered and changed, Primary and accessory organs must be protected in certain procedures used in dentistry such as providing adequate ventilation during nitrous oxide sedation and wearing a lead apron when exposing radiographs. 7. The circulatory system is the body's means of transporting a continuous supply of oxygen, nutrients, hormones, and antibodies throughout the body while carbon dioxide and other cellular waste are being removed from the body. It maintains a balance between intracellular and extracellular fluids. The circulatory system is divided into two pathways. The first pathway circulated blood through the heart to the lungs and back to the heart (pulmonary circulation). The second pathway carries the blood from the aorta to the smallest blood vessels and back to the heart (systemic circulation). 8. The digestive system provides a means for consumed foods to be prepared for use by the body, circulated to all the cells, and eliminating wastes. It breaks down foods into small nutrients molecules the cells can use, after digestion it is then transferred into the bloodstream, this is called the absorption process. It is here that the small nutrient molecules are circulated by the bloodstream to all cells of the body. The digestive system is divided into two groups: the alimentary canal and the accessory organs. The alimentary canal forms a canal or tube from the mouth to the anus. Accessory organs aid in the process of digestion. 9. The respiratory system’s main function is breathing. Air is inhaled through the nose into the lungs, where it is then absorbed into the bloodstream and carried to all body cells. Once oxygen reaches all the cells it is exchanged for the waste product, carbon dioxide. Carbon dioxide is then transported by the blood back to the lungs and exhaled. The respiratory system consists of the nose, pharynx, larynx, trachea, bronchi, and lungs. 10. The lymphatic system is a network of vessels that drains and filters the tissue fluid surrounding cells. The parts of this system are the lymph, lymph nodes, lymph vessels, spleen, and thymus gland. The immune system is part of the body’s defense against harmful organisms. It protects the body from pathogens, foreign materials, debris, and damaged cells by removing these elements. It is composed of specialized cells (phagocytes and lymphocytes) and molecules (antigens and antibodies), it is also organized into nonspecific and specific defenses. The immune system involves organs or vessels from several other systems. 11. The integumentary system is composed of the largest organ of the body, the skin, the hair, and nails. It makes up 16% of the body’s weight and is composed of many types of cells and tissues. It acts as a sensory receptor and informs the brain of external stimuli. Messages are sent to the brain to inform that the body is experiencing something that is hot or cold and also when the body is in contact with something hard or smooth. Some other important functions include, protection, temperature regulation, metabolic regulation, prevention of water loss, and synthesis of vitamin D.