Lex_Jordan

Humans vs. Polar Bears

HUMAN DIGESTIVE SYSTEM: the system that makes food absorbable into the body Digestion beings in the mouth with the breakdown of food. It then travels down the esophagus which is The part of the alimentary canal that connects the throat to the stomach. In the stomach gastric juices begin breakdown of proteins. As chemicals change the stomach starts to create mucus, this will act like a sheild aganist harmful chemicals. After 1-2 hours the stomach has made a thick solution called chyme this mixes with digestive juices from the pancreas which is a large gland behind the stomach that secretes digestive enzymes into the duodenum. After this it passes through the small intestine which is the part of the intestine that runs between the stomach and the large intestine. After the chyme is fully digested it is absorbed into the blood. 95% of nutrients are absored in the small intetsine. Water and minerals which are usually left get re-absorbed in the large intestine which job is to transport waste out of the body and to absorb water from the waste before it leaves. The liver is a large lobed glandular organ in the abdomen of vertebrates. The gallbladder is the small sac-shaped organ beneath the liver, in which bile is stored. Salivary glands produce saliva which help breakdown food.



EXCRETORY SYSTEM: a passive biological system that removes excess, unnecessary or dangerous materials from an organism. The kidneys are a pair of organs that are found on either side of the spine, just below the rib cage in the back. The kidneys job is removing waste products from the blood and regulating the water fluid levels. Uterus is a hollow muscular organ in the pelvic cavity of females; contains the developing fetus. The uniaray bladdder is a organ that collects urine excreted by the kidneys before disposal by urination. Lastly the Uretha is the duct by which urine is conveyed out of the body from the bladder, and which in male vertebrates also conveys semen.

RESPIRATORY SYSTEM: Main function is taking in oxygen and giving off carbon dioxide The nose or nasal cavity is the part projecting above the mouth on the face of a person or animal, containing the nostrils and used for breathing and smelling. The pharynx is the membrane-lined cavity behind the nose and mouth, connecting them to the esophagus and the Larynx is a hollow muscular organ forming an air passage to the lungs and holding the vocal cords in humans. The trachea is very important, it is 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. The Bronchi are major air passages of the lungs that diverge from the windpipe these are also are very important. The Aveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place. The Diaphragm is a dome-shaped, muscular partition separating the thorax from the abdomen, it play a major role in breathing. Lastly respiration is the action of breathing, taking a single breath.

CIRCULATORY SYSTEM: System that circulates blood and lymph through the body, consisting of the heart, blood vessels, blood, lymph, and the lymphatic vessels and glands. The flow of blood goes as follows: All blood enters the right side of the heart through two veins the superior vena cava (SVC) and the inferior vena cava (IVC) The SVC collects blood from the upper half of the body. The IVC collects blood from the lower half of the body. Blood leaves the SVC and the IVC and enters the right atrium(RA). When the RA contracts, the blood goes through the tricuspid valve and into the right ventricle (RV). When the RV contracts, blood is pumped through the pulmonary valve, into the pulmonary artery (PA)and into the lungs where it picks up oxygen. The heartbeat is the pulsation of the heart. Which is a complete cardiac cycle, during which the electrical impulse is conducted and mechanical contraction occurs. Blood Vessels are tubular structures that carry blood through the tissues and organs; a vein, artery, or capillary. A artery is any of the muscular-walled tubes forming part of the circulation system by which blood (mainly that which has been oxygenated) is conveyed from the heart to all parts of the body. Capilliaries arebranching blood vessels that form a network between the arterioles and venules. Blood is the red liquid when oxygenated that circulates in the arteries and veins of humans. Plasma is the colorless fluid part of blood, lymph, or milk, in which corpuscles or fat globules are suspended. Hemoglobin is a red protein responsible for transporting oxygen in the blood of vertebrates. Platelets are small colorless disk-shaped cell fragment without a nucleus, found in large numbers in blood and involved in clotting.



NERVOUS SYSTEM: The network of nerve cells and fibers that transmits nerve impulses between parts of the body. Cerebrum is theanterior part of the brain in vertebrates, located in the front area of the skull and consisting of two hemisphers. The cerebellum is part of the brain at the back of the skull in vertebrates. Its function is to coordinate and regulate muscular activity. Olfactory bulb is one of two enlargements at the terminus of the olfactory nerve at the base of the brain just above the nasal cavities. Optic lobe Either of two lobes of the dorsal mesencephalonl ontaining primary visual centers. Medulla Oblongata is the continuation of the spinal cord within the skull, containing control centers for the heart and lungs. Lastly the Spinal Cord is the cylindrical bundle of nerve fibers and associated tissue that is enclosed in the spine and connects nearly all parts of the body to the brain, with which it forms the central nervous system.

LOCOMOTION: Movement or the ability to move from one place to another. Axial Skelton is the part of the skeleton that includes the skull and spinal column and sternum and ribs. Appendicular Skelton is the part of the skeleton that includes the pectoral girdle and the pelvic girdle and the upper and lower limbs. Cartliage is firm, whitish, flexible connective tissue found in various forms in the larynx and respiratory tract, in structures such as the external ear, and in the articulating surfaces of joints. It is more widespread in the infant skeleton, being replaced by bone during growth. Joints are the place at which two things, or separate parts of one thing, are joined or united. Skeletal Muscle is A muscle that is connected to the skeleton to form part of the mechanical system that moves the limbs and other parts of the body. Smooth muscle is Muscle tissue in which the contractile fibrils are not highly ordered, occurring in the gut and other internal organs. Cardiac muscle is the muscle tissue of the heart; adapted to continued rhythmic contraction. Tendons are flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.



POLAR BEAR

DIGESTIVE SYSTEM It is the same in that there is a 4-chambered heart, and the right side receives blood coming back from the body through the vena cava, which leads to the right atrium. This leads to the right ventricle, which pumps deoxygenated blood to the lungs via pulmonary arteries to dump off CO2 and pick up O2. Then the blood is returned, via the pulmonary veins, to the left atrium, then to the left ventricle and out through the aorta. The difference is the body structure is different so the route of the blood around the body differs a bit, but the mechanism of blood vessels and exchange of gases, metabolic wastes and nutrients are the same.

EXCRETORY STSTEM The excretory system is about the same as in a human. There are slight differences because of the different layout of the body in the polar bear.

RESPIARATORY SYSTEM The polar bear uses respiration to gain biochemical energy. The respiratory body organs allows the polar bear to stay beneath water longer. The polar bears system has the same features as a humans. CIRCULATORY SYSTEM Closed circulatory system meaning the oxygen goes in the nose into the lungs from lungs moved around body without any breaks in it. They have the same parts as in humans because both are mammals. NERVOUS SYSTEM contains a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral.

LOCOMOTION Polar bears muscular and skeletal system have the same parts as humams but they are arranged in a very diferent way. Their front paws are used for swimming and hunting. TAXONOMY Kingdom:Animalia Phylum:Chordata Class:Mammalia Order:Carnivora Family:Ursidae Genus:Ursus Species:maritimus

ECOLOGICAL HABITAT Encompass the entire circumpolar Arctic region. Polar bears have adapted to be able to live in the water and on land. Unlike other bear species, the polar bear are excellent swimmers. The polar bears main habitat is on offshore pack ice, and along costs and island of the Arctic region.

FOOD CHAIN The Polar Bear is at the top of the "food chain" in the Arctic. They maintain the balance of nature, by preventing an overpopulation of seals. Seals are the Polar Bear's primary food. The only thing that can beat a polar bear is a hunter, and another polar bear.They are at the top of the food chain in their natural environment. Humans are also at the top of our food chain in our natural enviroment.

MATING BEHAVIOR As with most animals, polar bears mate in the spring. Scientists aren't sure how sexually mature males find females who are ready to mate. Humans know when and who wants to mate with them.

RESOURCES
 * []
 * []
 * anatomy notes and book