Your Body Systems Chapter 5

Body Organization Your Body is made of trillions of cells. Cells are the simplest and most basic units of all living organisms. A group of cells that are similar and work together to perform a specific function is called a tissue. Two or more tissues that work together to perform a specific function are called an organ.

Body Organization Cont. A group of organs that work together for one purpose is called a body system. Body Systems: Nervous system, Endocrine System, Skeletal System, Muscular System, Digestive System, Urinary System, Circulatory System, & Respiratory System.

The Nervous System The Nervous System is the body system that gathers and interprets information about the body's internal and external environments and responds to that information. Your nervous system is composed of your brain, spinal cord, nerves, and sensory organs, such as your eyes, ears and taste buds on your tongue.

The Nervous System Cont. The nervous system controls your body by conducting electrical messages to and from various parts of your body. These electrical messages are called nerve impulses.

The Nervous System Cont.

Your Brain Your brain is the mass of nervous tissue that is located inside your skull. The brain consists of three parts– The cerebrum, the cerebellum, and the brainstem.

The Central Nervous System The central nervous system, or CNS, includes your brain and Spinal Cord. The major function of the spinal cord is to relay impulses between the brain and different parts of the body. These impulses control most of the voluntary activities of the body.

The Peripheral Nervous System The peripheral nervous system, or PNS, is composed of nerves that connect all parts of your body to the CNS. A Nerve is a bundle of cells that conducts electrical signals through the body. Nerves are found only in the PNS. Nerves serve as a means of communication between the CNS and the rest of the body.

Common Problems of the Nervous System Description Treatment or Prevention Concussion An Injury to the brain caused by a blow to the head; may cause a brief loss of consciousness. Usually no hospitalization is required; may be prevented by wearing protective headgear Stroke The death of brain tissue due to lack of blood to the brain Requires immediate medical attention and hospitalization Rabies A viral infection of the brain that causes irritation of the brain and spinal cord; passed by the saliva or bite of an infected animal Can be prevented by avoiding wild or unfamiliar animals; requires medical attention

The Endocrine System Your Endocrine System is a network of tissues and organs that release chemicals that control certain body functions. Hormones are chemicals that travel in the blood and cause changes in different parts of the body. * Epinephrine is the hormone that is released to help fight off stress.

The Endocrine System Cont. Your glands: A gland is a tissue or group of tissues that makes and releases chemicals. Endocrine glands make hormones. The glands of your endocrine system are located at Various places in your body, but the hormones each gland releases can reach the entire body.

The Endocrine Glands See Attached example

Your Hormones Your body makes and releases different amounts of hormones at different times of the day, month, and different times of your life. For example, when you reach puberty, you begin to grow rapidly because your body releases more sex hormones, such as estrogen and testosterone. (pg.114)

Common Problems of the endocrine System Description Treatment Type II Diabetes A disease that is characterized by high levels of sugar in the blood. May be controlled by diet and exercise; may require insulin injections. Gigantism Individual has a very large body caused by excess production of HGH May be treated with medications that reduce the production of HGH Hyperthyroidism The thyroid gland produces too much of the thyroid hormone. Treated with medication, surgery, or radiation.

The Digestive and Urinary Systems Digestion is the process by which your body breaks down the food you eat. Digestion takes place in the mouth, stomach and small intestine. After the digestion, the food products are absorbed into the blood and the nutrients are used by the cells. Nutrients are the substances in the foods that your body needs to function properly.

The Journey of food Mouth Saliva moistens food to make it easier to swallow Throat (pharynx) Esophagus Stomach Small Intestine (gall bladder, liver, and pancreas release digestive aiding chemicals). Large Intestine (no digestion happens) The entire process of digestion takes about 24 hours.

The Journey of food

How the Body Absorbs Nutrients In the stomach, alcohol, simple sugars, and simple salts are absorbed. Most nutrient absorption happens in the small intestine. Digested carbohydrates, proteins, and fats are absorbed in the small intestine. Villi: fingerlike projections that cover the walls of the small intestine, increase the surface area and help with nutrient absorption.

Villi

Common Digestive Problems Description Treatment Ulcers A round, open sore in the lining of the stomach or small intestine caused by bacteria. Avoid certain foods and take antibiotics. Appendicitis Inflammation of the appendix in the large intestine, which can release harmful bacteria. surgery Heartburn Burning feeling in the esophagus caused by a back flow of acid from the stomach. Treated by antacids or medication.

Excretion: Removing Liquid Wastes The removal of liquid wastes from the body is called excretion. Three of your body systems are involved in excretion: your skin, lungs, and the urinary system. The urinary system removes waste products from your body.

The Urinary System Cont. Your blood carries wastes from your cells to the kidneys. Your kidneys clean the blood of liquid waste. Clean blood leaves the kidneys and travels through the body. The wastes pass from the kidneys to the bladder by way of tube like structures called ureters.

The Urinary System Cont. The bladder is a muscular, baglike organ that stores this liquid waste until it can be released from the body. When the bladder is full, the waste leaves the body through a single tube like structure called the urethra. The release of this waste from the body is called urination.

The Urinary System

Filtering Blood When blood enters a kidney, the blood contains nutrients, gases, water, and waste products. Inside your kidneys are microscopic filters called nephrons that remove harmful products from your blood. The nephrons remove the wastes from the blood through a process called filtration.

How the Kidneys Filter Blood

Common Problems of the Urinary System Description Treatment or Prevention Urinary Tract Infection (UTI) An infection of one or more of the organs of the urinary tract caused by bacteria, viruses, fungi, or parasites. Treated with antibiotics or antiviral drugs; may be prevented by drinking plenty of water and urinating frequently. Stones Crystallized mineral chunks that frequently form in the kidneys and the bladder; small, stones will leave the body with the urine; larger stones may become trapped and cause pain. Treated with medications that dissolve the stones or with surgery to remove the stones. Overactive bladder Inability to control urination Treated with medications, surgery or inserting a catheter.

The Circulatory and Respiratory Systems

Circulation: All Aboard Your Circulation system is a system made up of three parts– your heart, your blood vessels, and your blood. The major function of this system is to transport nutrients and gasses to different parts of the body where they can be used by the cells. The heart is the pump that pushes blood through your body.

What Is Blood? Blood is a tissue that is made of liquid, cell parts, and two types of cells. Your body has about 5 liters of blood. Approximately 55 percent of blood is a liquid called plasma. 90 percent of plasma is water. Plasma contains proteins that are important for blood clotting and fighting disease.

What Is Blood Cont. The other 45 percent of blood consists of solids that include blood cells and cell parts called platelets. Platelets are cell fragments that help repair blood vessels and form blood clots. Red blood cells transport oxygen and carbon dioxide through the body White blood cells are large cells that help fight off infection.

The Components of Blood

Supply Lines When the heart contracts, it pumps blood into the arteries. Arteries are blood vessels that carry blood away from the heart. The vessels that return blood to the heart are called veins. The microscopic blood vessels of the body that link the arteries and veins are called capillaries.

Problems of the Circulatory System Description Treatment or Prevention Hypertension Abnormally high blood pressure in the arteries of the body Lose weight, eat healthy, don’t smoke, and some medications Heart Attack The blood supply to the heart is reduced or stopped, which injures the heart muscle Must be treated by a medical professional immediately Anemia A condition in which the number of red blood cells is below normal Treated with vitamin B-12, iron supplements, and medications to increase red blood cells. Hemophilia A genetic disease in which the blood does not clot or clots very slowly. Treated by blood transfusions and by avoiding situations that might cause bleeding.

The Respiratory System The respiratory system is the body system that brings oxygen into the body and removes carbon dioxide from the body. When you breathe, air enters the body through the nose and mouth. Air then passes into the throat, or pharynx. Then, air passes into the voice box, or the larynx. Air then enters the windpipe, or trachea.

The Respiratory System Cont. The trachea divides into two tubes called bronchi, which allow the air to enter into the lungs. The lungs are large, sponge like organs in which oxygen and carbon dioxide are passed between the blood and the environment.

How You Breathe The movement of air into and out of the lungs is caused by movement of the diaphragm. The diaphragm is a dome-shaped muscle beneath the lungs. When the diaphragm and the muscles between the ribs contract, air enters the lungs. In the lungs, gases move between the blood and tiny air sacs called aveoli.

The Respiratory System

Problems of the Respiratory System. Description Treatment or Prevention Tuberculosis A contagious infection that affects the lungs and causes chest pain and difficulty breathing; caused by bacteria in the air Antibiotics Pneumonia An inflammation of the lungs in which the alveoli become filled with a thick fluid Treated with rest, fluids, and antibiotics, may be prevented by avoiding contact with infected people Asthma An allergic response in which the airways constrict and fill with mucous; caused by pollen, dust, smoke, cold air, stress, or strenuous exercise. Treated with drugs that widen the airway and reduce mucous production; may be prevented by avoiding triggers