Presentation on theme: "Chapter 17 - Urinary System. Cells produce waste that can become toxic if they accumulate Functions -the urinary system removes salts and nitrogenous."— Presentation transcript:
Cells produce waste that can become toxic if they accumulate Functions -the urinary system removes salts and nitrogenous wastes -maintains normal concentration of water and electrolytes -maintains pH, controls red blood cell production and blood pressure
Composition -consists of a pair of kidneys which remove substances from the blood -ureters which transport urine from the kidneys to the bladder -urinary bladder stores urine -urethra conveys urine to the outside of the body
17.2 Kidneys -lie on either side of the verebral column deep in the abdominal cavity -positioned behind the parietal peritoneum -lateral side is convex, medial is concave, kidneys sit in a depression called the renal sinus
superior end of the kidney forms a funnel shaped sac - renal pelvis -renal medulla = center of the kidney -renal cortex = outer shell around the medulla; the cortex appears granulated due to the presence of nephrons -renal arteries and veins supply blood to the kidneys
Nephrons -each kidney contains about 1 million nephrons -renal corpuscle: composed of a tangled cluster called a glomerulus which filters fluid
glomerular filtration - urine formation begins, plasma is filtered tubular reabsorption - returns most of the fluid to the body tubular secretion - removes what is not needed; produces urine
After urine forms in the nephrons,the ureters (starting with the renal pelvis) carry the urine away to the bladder Bladder is an expandable structure that stores urine before it is eliminated from the body. Transitional epithelial cells change shape to allow for expansion and contraction.
Micturation = urination; as the bladder fills this reflex occurs though it is also under voluntary control Urethra = tube carries urine to the outside of the body
Kidney Stones Extracorporeal shock wave lithotripsy (ESWL) is a procedure used to shatter simple stones in the kidney or upper urinary tract. Ultrasonic waves are passed through the body until they strike the dense stones. Pulses of sonic waves pulverize the stones, which are then more easily passed through the ureter and out of the body in the urine.
Cystitis = bacteria enters the bladder or kidneys (kidney infection); more common in women because the urethra is shorter Overactive Bladder = sudden contractions of the bladder produce sensation of urgency, also more common in women
Excretion The removal of waste from the body. Urea is a chemical waste product that comes from the break down of proteins.
Filtering Process First, both wastes and needed material, such as glucose, removed from the blood. Then, much of the needed material is returned to the blood.
Analyzing Urine Urine can be tested to detect number of diseases. High levels of glucose may indicate diabetes. High levels of protein (blood) is a sign that the kidneys are not functioning properly.
3. Muscular layer – smooth muscle tissue with circular and longitudinal fibers 4. Serosa – outer covering of the tube, moistens and lubricates structures
Movements Mixing – rhythmic contractions that mix food with digestive juices Propelling – ring of muscles contract and relax to push food through a canal
Mouth Mouth begins the digestion by mechanically breaking the food into smaller pieces using the teeth. Then the palate and tongue move the food.
Teeth Crown – projects from the gum. Root – extends below the gum and anchors the tooth. Enamel – outer covering of the tooth, made of calcium salts
Dentin – surrounds the tooth’s central cavity Blood vessels and nerves extend through the tooth through the root canal.
Salivary Glands Serous cells produce amylase that splits starch and glycogen into dissaccharides. The food material is then moved to the pharynx and then the esophagus.
Stomach J-shaped organ, that contains four parts and is located below the diaphragm. Produces chyme – a paste of food molecules after it has been broken down by digestive juices.
Pancreas Secretes juices that digest fat and break down nucleic acids into nucleotides
Liver Hepatic portal vein – delivers blood to the liver
Functions Functions: maintains normal concentration of blood glucose, breakdown of lipids and fats, protein metabolism, stores iron and vitamins, destroys damaged red blood cells, removes toxic substances from the blood, secretes bile
Bile Bile – yellowish-green liquid secreted from hepatic cells. The cystic duct delivers bile to the gall bladder.
Bile is stored in the gallbladder and then secreted into the duodenum via the common bile duct Cholesterol in bile may form crystals called gallstones Bile aids in digestion, bile salts break down fat globules into smaller droplets – emulsification
Small Intestine *tubular organ that extends from the pyloric sphincter, many loops and coils, fills much of the abdominal cavity *receives secretions from the pancreas and liver, completes digestion of nutrients and chyme, absorbs
1. Duodenum - first part of the small intestine 2. Jejunum – second part, ~2.2 m 3. Ilium – third part, longest ~3.3 m *jejunum and ilium are continuous *the main function of the small intestine is to secrete chemicals to break down food and carry away these nutrients in the blood (absorption)
Large Intestines 1. Cecum – beginning of the large intestine, pouchlike, closed end called the vermiform appendix (ileocecal valve) 2. Colon – ascending / transverse / descending / sigmoid 3. Rectum 4. Anal canal - ends in the anus
Functions – secretes mucus to protect the wall against abrasion; re-absorbs water and passes along material that was not digested; contains intestinal flora (bacteria to break down cellulose, also produce intestinal gas) Mass movements – large portions of the colon contract to move material through it, 2-3 times a day usually after eating