Organ Systems

Organ Systems Overview Includes skin, hair and nails Creates waterproof barrier aro8und the body Works with bones to move parts of the body Supports, protects, and woks with muscles to move parts of the body Detects changes in the environment and signals to the body, which then responds Manufactures and releases hormones, keeping body systems in balance Transports blood, nutrients, gasses and wastes

Organ Systems Overview Part of the immune system Defends the body against infection Controls breathing Exchanges gasses Takes in food and breaks it down Absorbs nutrients Removes solid waste Removes liquid waste from body Produces and transports sex cells Development of new organisms

Digestive System

Mouth Starts the process of breaking down food; mechanically (teeth) and chemically (enzymes in saliva) Saliva is produced by salivary glands in epithelial tissue of the mouth Once food is broken up an softened with saliva it may be swallowed and begin its journey into the digestive tract

Esophagus and Stomach The esophagus is a muscular tube that connects your mouth to your stomach Movement of muscle tissue in the esophagus is controlled by the nervous system unconsciously to move food along The stomach is used to hold food and churn it to continue the process of digestion The stomach lining produces digestive enzymes and acids Muscles in the stomach aid in the mixing of food Nerves in the stomach signal when it is full and you have had enough to eat

The Small Intestine Once your food is fully mixed within the stomach a round muscle at the bottom of the stomach, called a sphincter opens an transfers stomach contents into the Small Intestine The first meter of the small intestine is called the duodenum which is where most digestion takes place Tubes in the duodenum are connected to the pancreas liver, and gall bladder. These organs release more digestive enzymes which completes the chemical breakdown of food. Food entering the reaming length of the small intestine is ready to be absorbed into the body

The Large Intestine The Large Intestine acts to absorb water, vitamins and salts from the remaining digested food and eliminate undigested food through the anus as feces The large intestine includes the Colon, rectum and anus Bacteria in the large intestine also assist in the completion of food digestion

Urinary System Liquid waste is eliminated from the body via the Urinary system Your Kidneys are the key organ used to filter and flush away waste substances from cellular processes and maintain a proper volume of water in the body and a balance of electrolytes (dissolved sodium, potassium and calcium) Liquid waste is sent for temporary storage via the ureter to the bladder. Once the bladder is full urine is released through the urethra

Nervous System The most critical organ in your body is the Brain The Brain is the information processing centre for your body The rest of your nervous system is the network of nerve tissue that connects the brain to all parts of the body and transmits signals to and from all types of body cells The core of the nervous system is called the Central Nervous System (CNS) and includes the Brain and Spinal Cord The nerves that carry signals between the CNS and the body are part of the peripheral nervous system

Nervous System Nerves are responsible for controlling; voluntary muscle carrying information from sensory organs (eyes, ears, taste buds, skin, nose) regulation of involuntary functions such as breathing, heart beat and digestion To protect it from damage the CNS is shielded by bones (skull and spinal column) and fluid (cerebrospinal fluid) that acts as a cushion

Nerve Tissue Nerve tissue is made up of Neurons There are approximately 100 billion neurons in your brain alone The structure of neurons allow them to conduct information in the form of electrical impulses Neurons only conduct electrical impulses in one direction Bundles of neurons are called Nerves Nerves allow for two way communication within the body Neurons in the CNS typically do not regenerate if damages Peripheral nerve tissue can repair small gaps (a few millimeters)

Circulatory System The circulatory system is made up of blood, heart and blood vessels (veins and arteries) The main role of the circulatory system is to move nutrients obtained by the intestines and oxygen from the lungs to all cells in the body. The circulatory system also transports solid and liquid waste materials to the kidneys to be filtered out and excreted. Waste gas (CO 2 ) is expelled by the lungs The circulatory system is also important in regulating body temperature and transporting white blood cells that fight unwanted disease vectors (viruses and bacteria)

Blood Red blood cells are the are the most plentiful cells in blood (45%). They transport Oxygen using a protein called Hemoglobin with is high in iron giving blood its red colour White Blood cells are the bodies defence mechanism. They are able to recognize and destroy invading bacteria and viruses. Only about 1% of blood volume are white blood cells Platelets are small cells that aid in clotting Plasma is the protein rich liquid that suspends all blood cells. It makes up about 55% of your blood’s volume

Heart The muscle that pumps all blood through the circulatory system Brings deoxygenated blood from upper and lower parts of the body, sends it to the lungs, returns oxygenated blood back to the heart and then out to the body.

Blood Vessels Arteries carry oxygenated blood away from the heart Blood being pumped away from the hear is under high pressure and therefore arteries must be thick walled Veins carry deoxygenated blood toward the heart Both Veins and Arteries are largest closest to the heart and become smaller in diameter farther away as the volume of blood they must gets smaller Capillaries are tiny blood vessels with very thin walls where gas and nutrient exchange takes place This exchange takes place through a process called diffusion All body tissues are connected to the circulatory system by a network of capillaries

Circulatory Issues Heart attack: If blood vessels (pulmonary arteries) become blocked (blood clot, plaque) as the heart is supplied with oxygenated blood the heart will stop pumping and tissue will start to die (Necrosis) Stroke: Where blood vessles supplying your brain with blood become blocked (usually a clot). Without oxygen and nutrients brain tissue begins to die Hypertension: “High Blood Pressure” is a sign that the heart and blood vessels are being overworked. May lead to atherosclerosis, a systematic build up of plaque in the arterial wall Atherosclerosis often leads to heart disease and/or stroke

Respiratory System The Lungs are where blood acquires oxygen and disposes of excess carbon dioxide Inside the lungs is a network of increasingly narrow branching airways all ending in tiny air sacs called alveoli

Respiratory System Alveoli are thin walled structures surrounded by capillaries Gasses are exchanged through the Alveoli via diffusion The remainder of the respiratory system simply connects the lungs to the outside air (trachea) or assists in the mechanics of breathing (diaphragm)