Flashcards
excretion flashcards
Flashcards do conjunto (36)
- 1Excretion at the kidneys what are the 3 main structures of the kidney?cortex
medulla
renal artery
renal vein - 2Excretion at the kidneys what is the kidney surrounded by and what's it functionkidney surrounded by capsule to protect the fragile structures underneath
- 3Excretion at the kidneys what extends Cortex into the medulla and what's their functionthe nephrons extend from the cortex into the medulla and are the sites of ultrification selective reabsorption and urine formation
- 4Excretion of the kidneys what is the renal tubule of each nephron lined withlined with microvilli to increase the SA for respiration
- 5Nephron structure what are the 7 main structures of the nephronproximal convulated tubule
bowmans capsule
glomerulus
loop of henle
distal consulated tubule
vasa recta
collecting duct - 6ultrification what is ultrificationcarried out in glamerular capsule
everything expect larger proteins red blood cells and most white blood cells is forced out of the blood and into glamerular capsule due to high pressure caused by the difference in diameter between afferent and efferent arteriole
efferent arteriole much wider - 7What is selective reabsorptionwater amino acids glucose and ions are selectively reabsorbed first into proximal convoluted tubule
the final composition of urine is dependent on:
selective reabsorption out of nephron
secretion of nitrogenous waste in nephron by surrounding capillaries - 8nephron structure what is a nephron and how does it form the glomerulustheir is one million nephrons in each kidney.
each nephron originates in the cortex.
within the cortex capillaires form a knot this is the glomerulus - 9what is the glomerulus surrounded by and what does it dosurrounded by a cup shaped structure the bowmans capsule
fluid from the blood pushed into bowmans capsule via ultrification - 10where does the bowmans capsule lead into to and what does It split intoleads into the nephron then divides into four parts
1) proemial convoluted tubule
2) loop of henle
3) distal convoluted tubule
4) collecting duct - 11what happens as fluid moves along the nephronas fluid moves along the nephron its composition is altered this occurs due to selective reabsorption. The final product in the collecting duct is urine this passes into the pelvis and down the utter and out
- 12compositional changes what happens at proximal convoluted tubeall sugars reabsorbed most salt and some water 85% of fluid reabsorbed.
- 13compositional changes what happens at loop of henlewater potential decreased by addition of salt and the removal of water
- 14compositional changes what happens at the ascending limbwater potential increased as salts are Removed by active transport
- 15compositional changes what happens at the collecting ductwater potential is decreased by removal of water ensuring that the urine has a higher concentration of solute than is found in blood and tissue
- 16osmoregulation what is osmoregulationthere is osmoreceptors in the hypothalamus detect water composition in the blood
if water level drops hypothalamus secretes antidiuretic hormone (ADH) and signals for pituitary gland to release it into blood stream - 17ADH how does ADH helpwhen ADH reaches cells in collecting ducts, they become more permeable to water and so reabsorb more water
this increases concentration of urine and appears darker - 18how do we avoid dehydration1) osmoreceptors in hypothalamus detect water level in blood has dropped
2) hypothalamus secretes ADH
3) pituitary gland releases antiduirecric hormone into bloodstream
4) ADH hormone reaches cells in collecting ducts and they become more permeable
5) more water reabsorbed into blood and urine becomes darker - 19kidney failure and treatment causes of kidney failurekidney disease, heart disease, hypotension, diabetes can all cause kidney failure.
- 20what is glomomerular filtration rateindicates how well kidneys are functioning and estimates amount of blood passing through kidneys per minute
normal gfr: 90-100 mL/min
kidney failure: >15 mL/min (>15% kidney function) - 21electrolyte balance what is electrolyte balance and how does kidney failure effect itkidney faliure affects the balance of electrolytes in body most commonly causing
hypervolemia
hyperkalemia
hyperphosphatatemia
bicarbonate deficiency - 22peritoneal dialysis (treatment) what is peritoneal dialysis treatment and how does it workits a type of renal dialysis.
a catheter inserted Into abdomen, dialysate fluid pumped into peritoneal cavity.
waste substances are removed from blood by exchange into dialystate across membrane of peritoneam.
carried out overnight using automated machine or around four times a day using manual exchange. - 23Haeamodialysis (Treatment) what Is haemodialysis and how does it worksessions in a clinic 3-4 hours
catheter placed in large vein in groin or neck or a more permanent fistula is created in wrist or elbow
200mL of blood per minute passes through dialyser and over membrane to exchange substances - 24kidney transplant (treatment) pro and cons of kidney transplantsometimes only option
long waiting list and possibility of organ rejection following transplant
means patients do not always survive long enough for treatment to work. - 25urinalysis what is urinalysisthe presence of specific excretory products in urine can be used in diagnostic tests for pregnancy and the use of performance enhancing and recreational drugs
- 26urinalysis how is urinalysis used in pregnancy testing part 1Human chorionic gonadotrophin is a hormone only produced in urine during pregnancy
in pregnancy tests mobile antibodies specific the hCG hormone are attached to enzymes which can change colour of a dye
more monoclonal antibodies specific to hCG hormone are fixed in a line on the test if hCG antibody enzyme complexes are formed enzyme changes colour of the dye and Shows positive test. - 27urinalysis how is urinalysis used in pregnancy testing part 2more monoclonal antibodies specific to hCG hormone are fixed in a line on the test if hCG antibody enzyme complexes are formed enzyme changes colour of the dye and Shows positive test.
- 28urinalysis how is urinalysis used for anabolic steroids testingratio of testosterone to epitestosterone in urine is measured
increased testosterone levels relative to epitestosterone indicates anabolic steroids have been used
imbalance can remain in body and be tested between 14 and 28 days after anabolic steroids have been taken - 29The liver what is the function of the liverincreased levels of waste can become toxic so must carefully monitored and removed. Liver is major part of excretory system
- 30The liver structure of the liverhas a highly vascularised lobular structure = increased surface area
liver cells called hepatocytes have microvilli to further increase surface area
hepatic portal vein carries blood directly from digestive system into the liver, so fun of products of digestion - 31The liver what's its role in detoxificationhepatocytes are specialised to contain many enzymes to detoxify chemicals
substances first oxidised and then made more water soluble to be excreted in urine - 32The liver what's its role in glycogen storageheptocyets respond to the binding of Insulin to receptors in cell membrane by converting glucose into glycogen for storage
glycogen can be realised when blood glucose levels are low - 33The liver what's its role in urea formationammonia = nitrogenous waste formed when amino acids are dominated to form ketones and ammonia.
the orthine cycle describes the process of combining ammonia and C02 to form urea
urea much less toxic and soluble in water so can be excreted in urine. - 34formation of urea how is urea formedurea is formed by amino acids being broken down via deamination.
there is a second process called ornithine cycle.
Amino Acid -> ammonia + keta acids -> urea (deamination). (orthine cycle) - 35what is deaminationdeamination us the the production of ammonia which is highly toxic and shouldnt be accumulate. removal of amine group from amino acids which converted into ammonia and secreted in urine.
- 36what is the ornithine cycleAmmonia has to be converted because its very soluble and toxic so it is combined with carbon dioxide to produce urea
Informações
- Descrição
- A level Biology FlashCards sobre excretion flashcards , criado por Dylan Jones em 04-09-2021.
- Criado por
- Dylan Jones
- Visualizações
- 2
- Avaliação
Mais sobre Kidney Structure and Function