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Urinary System
Bio 12, Urinary System
Question | Answer |
---|---|
Urinary system | Involved in excretion, removal of metabolic waste from the body |
Urine | Product of urinary system, conducted outside the body, created in kidneys |
Urea | By-product of amino acid metabolism. Ammonia and carbon dioxide combined in the liver |
Creatinine | Creatine phosphate, excreted |
Uric acid | Product of the breakdown of nucleotides, |
Gout | Painful ailment, caused by excess of uric acid in the blood |
Osmoregulation | Maintenance of the balance of water and salt in the blood. Salts can cause osmosis. |
Renin | Enzyme that leads to the secretion of the hormone aldosterone, which promotes the reabsorption of sodium ions by the kidneys |
Erythropoittin | Hormone released when the oxygen carrying capacity of the blood is reduced, stimulates red blood cell production (kidneys) |
Kidneys | Pair of bean shaped organs the size of a fist. Covered in a fibrous tissue called the renal capsule |
Hilum | Concave side of the kidney the the renal artery enters and the renal vein and ureter exit. |
Ureters | Conduct urine from the kidneys to the bladder. 25 cm long. Peristaltic contractions cause urine to enter the bladder one to five times a minute |
How many Liters of urine produced a day | 1 to 2 |
Urinary bladder | Stores urine until it is expelled from the body. Located in the pelvic cavity. Has two openings for the ureters and one for the urethra. Expandable due to rugae |
Internal and external sphincters | Controls the entrance and exit of the bladder. Exit is voluntarily controlled |
Incontinence | Involuntary loss of urine, can be caused by pregnancy, enlarged prostate, or nervous system disorders |
Urethra | Small tube that extends from the urinary bladder to the external opening. 4 cm in females, 20 cm in males. For males, urethra carry both urine and semen |
Urination | When bladder fills to 250 mL, stretch receptors send impulses to the spinal cord. Nerve impulses cause the bladder to contract and the sphincters to relax. Brain controls this reflex |
Three regions of the kidney | Renal cortex (outer layer), renal medulla (contains renal pyramids), renal pelvis (cavity continuous with the ureter) |
Nephrons | Over 1 million form the kidney. Each has its own blood supply |
Glomerulus | know of capillaries in the glomerular capsule. Receives blood from the afferent arteriole and blood leaves through the efferent arteriole |
Peritubular network | surrounds the nephron, eventually joins a venule which joins with the renal vein |
Glomerular capsule | (bowman's capsule) closed end of the nephron, contain podocytes |
Podocytes | cling to capillary walls and leave pores that allow easy passage of small molecules from the glomerulus to the inside of the glomerular capsule |
Proximal convoluted tubule | Contains microvilli to increase surface area for reabsorption. Cuboidal epithelial cells |
Loop of Henle | Area where the Proximal convoluted tubule thins and makes a U-turn. Squamous cells. |
Distal convoluted tubule | Cuboidal epithelial cells with many mitochondria and no microvilli. Helps move molecules from the blood into the tubule (tubular secretion) |
Collecting ducts | Carry urine from many nephrons to the renal pelvis |
Pressure filtration | Whole blood enters the afferent arteriole and the glomerulus, water and small molecules move from the glomerulus to the glomular capsule. Large molecules are unable to pass. |
Filterable blood contents | Water, nitrogenous wastes, nutrients, salt ions |
Non filterable blood contents | Formed elements (blood cells and platelets), plasma proteins |
Glomerular filtrate | small dissolved molecules in the same concentration as plasma |
Selective reabsorption | Molecules and ions are passively and actively reabsorbed from the nephron into the blood of the peritubular network. Nutrients such as amino acids and glucose are also returned to the blood |
Reabsorbed filtrate components | Most water, nutrients, required salt ions |
Non reabsorbed filtrate components | Some water, most nitrogenous waste, excess salt ions |
Tubular fluid | Substances that are not reabsorbed and enter the loop of Henle |
Tubular excretion | Second way substances are removed from blood in the peritubular network and added to tubular fluid. Hydrogen ions, potassium ions, creatinine and drugs are removed. |
Urine contains... | substances that have undergone glomerular filtration but have not been reabsorbed, and substances that have undergone tubular excretion. |
Reabsorption of water requirements | Reabsorption of saltm establishment of a solute gradient dependent on salt and urea before water is absorbed. |
Aquaporins | Proteins embedded in the plasma membrane, water channels that act during reabsorption |
Aldosterone | secreted by adrenal cortex, promotes excretion of potassium and the reabsorption of sodium ions |
Juxtaglomrular apparatus | Region of contact between the afferent arteriole and distal convoluted tubule, secretes renin |
Renin | When blood volume is not sufficient, this enzyme is released that changes angiotensinogen to angiotensin I, which is later converted to angiotensin II which stimulates the adrenal cortex to release aldosterone |
Atrial natriuretic hormone | Hormone secreted due to increased blood volume. Inhibits renin and aldosterone leading to an excretion of sodium and therefore excretion of water, lowering blood volume |
Antidiutetic hormone | Released when the body is dehydrated, from the posterior pituitary glands, increases amount of aquaporins |
Neurosecretory cells | Sensitive to salt-water balance in blood, and release ADH |
Diuresis | Increased amount of urine |
Antidiuresis | decreased amount of urine |
Diuretics | Chemicals that influence the flow of urine. Alcohol and caffeine |
Pyelonephritis | Kidney infections resulting from infections of the bladder. Cured with antibiotics |
Kidney stones | Hard granules that form in the renal pelvis. Can be composed of calcium, phosphate, uric acid and protein. Can be caused by too much animal protein, imbalance of pH or UTI. Painful if passed. Might use lithotripsy to break up stones |
Albumin | White blood cells found in the urine that can be a sign of kidney damage |
Uremia | Waste products accumulate in the blood because of two-thirds of nephrons being destroyed |
Edema | Accumulation of fluid in body tissues, can be caused by diseased kidneys |
Hemodialysis | Patient's blood is passed through an artificial kidney machine |
Cystitis | Inflammation of the bladder |
Urethritis | infection of the urethra |
Bladder stones | Most commonly a results of another condition. Pain, difficulty urinating, or increased frequency of urination, blood in the urine. May be removed surgically or by lithotripsy |
Bladder cancer | Caused by contact with harmful toxins that are secreted in the urine. |