Chapter 2 Flashcards
What is homeostasis?
Homeostasis, from the Greek words for “same” and “steady,” refers to any process that living things use to actively maintain fairly stable conditions necessary for survival.
structure of the kidneys
located at the back of the abdominal cavity on either side of the vertebral column. The concave side faces the column, and the kidney receives blood from the dorsal aorta via the renal arteris and the renal veins return the blood through the inferior vena cava. At the center of the concave surface is a depression called hilus, where the renal artery, renal vein and the nerves connect to the kidney.
What is a nephron?
The functional amd structural unit of the kidney, with each containing about one million nephrons. It consists of a long tubule, and is. composed of renal corpusle and renal tubule.
Renal tubule consists of bowman’s capsule and its glomerulus. The bowman’s capsule is a double walled hollow cup that surrounds a tuft of blood capilaries known as the glomerulus.
function of nephron
urea is a nitrogenous waste that material that needs to be removed in the form of urine, which is formed in the kidneys. This involves three processes: glomerulus filtration, tubulur or selective reabsorption and tubulur secretion
describe glomerulus filtration
First step of the kidney filtrstion.
movement of small moleculesacross the glomerular wall as a result of blood pressure. when blood enters the glomerulus, the pressure is sufficient enough to cause small molecules like water, nutrients, and wastes to move from the glomerulus into the bowman’s capsule.fluid that leaves the body is called glomerular fluid. Proteins and blood cells are too large to filter so they remain in bloodstream.
describe selective absorption
second step of kidney filtration.
during this step, 99% of water abd most solutes reenter the bloostream, as the filtrate flows through the nephron. Substances like glucose and amino acids are completely reabsorbed. Some water and solutes are reabsorbed from the proximal convoluted tubule. the descending loop of henle allows the reabsorption of water while the limb loop of henle allows the reabsorption of salts. the distal convoluted tube allows reabsorption of water into the blood.
Describe tubular secretion
third step in the removal of urea.
some substances are actively transported in from capillaries into the nephron tubule by tubular secretion. these include k+ and h+ ions, drugs, uric acid and creatinine.
after this final step, the filtrrate present in the renal tubes is urine. it moves into the collecting ducts then into the pelvis.
What is the (osmoregulatory) function of the kidneys?
It is an osmoregulatory organ which regulates water and salts in blood. if the blood has too much water, less water is absorbed, leading to more water entering the bladder. After drinking alot, large volume of dilute urine is produced and the body rids of extra water. If the blood is more concentrated more water is reabsorbed into the blood from the kidney tubule.
Rise in blood concentrations triggers thirst center ( hypothalamus) in the brain. the following drinking returns the blood to its stable concentration.
Kidneys also help balance pH, blood pressure, and blood plasma.
briefly go over disorders of human excretory systems
Many types of diseases lead to renal diseases and failures. Urinary track infections are particularly common in females, while the most common causes of overall kidney damage is high blood pressure, diabetes, stones, and glomerular blockage.
talk about kidney stones and treatment
can develop at any part of the u system, composed of uric acid crystals or calcium oxalate.
Causes are: Presence of high amounts of calcium in the blood.
Presence of higher oxalate content in the blood resulting in the formation of oxalate calcium stones.
A decrease in water intake.
Age and family history.
Can be passed through the system painfully or removed with surgery. Non surgical removal is call lithotripsy, which breaks apart the stones by shockwaves from outside the body. if a stone enters the ureter. it causes. extreme pain in the pelvis, adomen, kidneys, and legs accompanied by nausea and vomiting.
kidney failure and dialysis
A general term of declined kidney function is called kidney failure. this can cause a rise in urea which increases blood pressure and can cause anaemia. If failure is not treated, death will result in a couple of weeks.
To treat the rise in urea, patients are treated with dialysis. It is the process of removing waste and excess from blood. There are two types of dialysis, haemodialysis and peritoneal dialysis.
haemodialysis
Catheter is inserted into the vein, usually in the arm causing the blood to flow in and through a machine called the dialyzer> inside it is pumped over a dialysis membrane (semi-permeable). This seprates the patients blood from the dialysis fluid: urea diffuses out of the blood, across the dialysis membrane and into the dialysis fluid, which already ahs sugar and salts so the sugar and salts from the blood do not exit. The clean blood then passes back into the other vein of the other arm through the second catheter. Fresh dialysis fluid enters the machine from one end, while the used exits from another side.
Peritoneal dialysis
Dialysis fluid is pumped into the peritineal cavity, which is the space around the stomach. it is lined with a peritoneum which acts as a dialysis membrane, fluid that is pumped into the cavity exchanges with the tissue fluid in the abdomen. it can be performed t home, but needs to be done 4-5 times a day.
Kidney transplant
Kidney of a healthy person can be transplanted to s diseased one. It can be donated by a donor, altough the tissue and the blood chemistry must match that of the patient, otherwise it can be rejected by the immune system and destroyed by the patient’s body.
What were the contributions of Al farrrabi and abul qasim in removing kidney stones from the bladder
Who were Al farrabi and abul qasim
Abul qasim was a surgeon and invented many surgical procedures like removing kidney stones.
Al farrabi was the greatest scientist and philosophers of his time. he wrote many books with info on kidney diseases.
