Kidneys Flashcards
what are the main blood vessels connected to the kidneys?
Renl artery
Renal vein
What does the urine pass into out of the kidney?
ureter then urethra
What is the kidney primarily made up of?
nephrons
What are he 3 main structures of the kidney?
cortex- outer layer
medulla
pelvis
What happens in the cortex?
filtering of blood takes place because there is dense capillary network
What happens at the medulla?
it contains the tubules of the nephrons and the collecting ducts
What happens in the pelvis?
central chamber where urine collects
What is the strcuture of a nephron?
-Bowman’s capsule
-Proximal convoluted tubule
-Loop of Henle
-Distal convoluted tubule
-Collecting duct
What does the large capillary network around the nephrons join to?
venule then the renal vein
What is the Bowman’s capsule?
cup-shaped structure containing the glomerulus, tangle of capillaries, podocytes, and a basement membrane
What is the proximal convoluted tubule?
coiled region of tubules with microvilli in the cortex of the kidney, they have many mitrochondria for reabsorption
What is the loop of Henle?
a long loop of tubule with a very high solute concentration, found in medulla. It has a descending and ascending limb
What is distal convoluted tubule?
walls with variable permeability to water depending on the levels of ADH
What is the collecting duct?
situated in medulla into the pelvis, the walls are sensitive to ADH
What is ADH?
antidiuretic hormone
What is the process of ultrafiltration?
Glomerulus is supplied with blood from wide afferent arteriole and blood leaves via efferent narrower arteriole
This means there is a high hydrostatic pressure in the capillaries forcing blood out through the capillary wall. Hydrostatic pressure > oncotic pressure
The blood is then filtered by the basement membrane which is made of collagen fibres - acts as sieve.
Contains podocytes which have extensions called pedicels which makes sure no plasma proteins, or cells mange to get into the filtrate.
What is reabsorbed at PCT?
all glucose, amino acids, vitamins and hormones
What does the medulla have high concentrations of?
sodium and chloride ions
What part of the loop of Henle is not permeable to water?
ascending limb
What part of the loop of Henle is not permeable to ions?
descending limb
How does reabsorption occur in PCT?
Active transport of Na+ into blood out of microvilli, therefore conc Na+ decreases
Na+ diffuses from filtrate into blood and acts as a cotransporter for glucose and amino acids into microvilli cells
Glucose and aa can move into the blood via facilitated diffusion
What is the fluid in the hair pin bend compared to the blood of the capillaries?
hypertonic
Where does diffusion of Na+ and Cl- out of loop of Henle take place?
beginning of ascending limb
Where does active transport of Na+ and Cl- take place out of the loop of Henle?
upper section of loop of Henle
At the end of the loop of Henle what is the filtrate to the blood?
hypotonic
Where can more reabsorption take place if the body is lacking ions?
distal convoluted tubule
What does ADH do?
Increases DCT permeability to water
Binds to receptors on cell membranes producing cAMP, causing vesicles in the cells of the collecting duct to fuse with cell surface membrane which contain water channels making the cells permeable to water therefore more conc urine
What controls the levels of ADH?
osmoreceptors
What is ADH an example of?
negative feedback
What happens when water is in short supply?
Water potential decreases, detected by osmoreceptors in the hypothalamus , they send nerve impulses to the posterior pituitary then releases more ADH and increases permeability to water
What does a pregnancy test test for?
human chorionic gonadotropin
How do you make monoclonal antibodies?
a mouse is injected with hCG so it makes the antibody, these B cells are removed from the spleen of the mouse and fused with a myeloma, which forms a hybridoma. Therefore produces loads of the desired antibody
What are the main stages of a pregnancy test?
- soak the wick in urine in morning
-the wick contains monoclonal antibodies with attatched dye which will bind if hCG is present - first window there is a line of immobilised monoclonal antibodies which the hCG complex if present will bind to and a line will show
-second window immobilised antibodies which will bind to the mobile antibodies regardless to whether they are bound to hCG or not and show a line
How do you test for anabolic steroids?
Test urine using gas chromatography or mass spectrometry
What can cause kidney failure?
infections, high blood pressure
What can kidney failure cause?
blood in urine
weight loss
urea in the blood
high blood pressure
anaemia
brittle bones
death
What in the blood can give an estimate of glomerulus filtration rate?
creatinine
What are the two types of renal dialysis?
haemodialysis - attached to a machine
peritoneal dialysis- inside the body
What are the concerns over kidney transplants?
rejection ( have to be same tissue and blood type but still risk of rejection)
immunosuppressants
What are the advantages of kidney transplant over dialysis?
cheaper, more convenient, can last 10+ years, no restrictions
