Urinary Flashcards
What is the main purpose of kidneys
To produce urine
What is the main purpose of the ureters
To transport urine from the renal pelvis to bladder
Around 25cm long, does 5 jets a minute
What is the main purpose of the bladder
Stores urine and has nerve endings that trigger when full
What is the main purpose of the urethra
The elimination of urine
It is surrounded by the prostate gland
20cm in males, 4 cm in females
Describe the renal cortex
Outer layer of kidney
Contains the glomerulus, proximal, and distal tubules
Pressure filtration, selective reabsorption, and tubular excretion
Responsible for most of the kidney work (with nephrons)
Describe the renal medulla
Middle layer of kidney (renal pyramids)
Contains loop of henle and most of the collecting duct
Responsible for H2O reabsorption and salt balance
Describe the Renal Pelvis
Inner layer of kidney
Collects urine from all tubules and directs it into the ureter
What are the three parts of the kidney
The renal cortex (outer)
The renal medulla (middle)
The renal pelvis (inner)
What is the kidney composed of
Millions of tiny microscopic tubules called nephrons
What is the blood flow through the kidney and nephron
Dorsal aorta -> renal artery -> afferent arteriole -> glomerulus -> efferent arteriole -> Peritubular capillary network -> venule -> renal vein -> inferior vena cava
What is the glomerulus
A knot of capillary network that is unique to the kidney
In this area a large portion of the blood plasma filters from the blood vessels I to the bowman’s capsule
What are the three steps to making urine
A) pressure or glomerular filtration
B) selective or tubular reabsorption
C) tubular excretion
What occurs in the nephron
The filtration of substances out of the blood, reabsorption of important substances into the blood, and excretion of waste in form of urine
Where do the collecting ducts if the millions of nephrons drain into
They drain urine into the renal pelvis, which drains into the ureters
Describe the flow of filtrate through the kidney and nephron
Glomerulus, bowman’s capsule, proximal convoluted tubule, loop of henle, distal convoluted tubule, collecting duct, renal pelvis, ureters, bladder, urethra.
Filtrate becomes urine once in collecting duct
What substances stay In the renal blood vessels throughout the nephron
The blood cells and proteins
What renters the blood at the proximal convoluted tubule
Sugars and amino acids
What are the two parts of the loop of henle
The descending loop (going down)
The ascending loop (going up)
What moves from the descending (specifically) loop of henle into the peritubular capillary network
Water
What moves form the loop of henle to the peritubular capillary network across both descending and ascending versions
Important Salts
What exits the blood vessels at the distal convoluted tubule
Any remaining waste
What can exit the collecting duct into the renal vein
Water, through aquaporins
What happens to glucose in the nephron
It is 100% reabsorbed from the filtrate into the blood. It does drop from 100mg/L to 98mg/L because 2mg/L is used to make ATP to fill the active transport that occurs at in the nephron
What happens to urea in the nephron
It drops from 30mg/L to 25mg/L across the blood vessels because it is excreted in the filtrate, though some is reabsorbed by the tubules
Do kidneys remove all waste from the blood
No, they remove enough to keep it at a constant level. One kidney is enough to keep a human alive
What is ADH
Anti Diuretic Hormone
A hormone that controls H2O balance
What is involved with making ADH
Made by the hypothalamus, transferred and stores in a series of nerve cells running from the hypothalamus to posterior pituitary gland
Secreted by the posterior pituitary gland
What does ADH do
Increases the permeability of the distal tubule and collecting duct so that more water can be reabsorbed back into the blood
What happens when ADH is secreted
Blood volume increases
Blood becomes more dilute
Urine becomes more concentrated
What controls ADH secretion
The water content of the blood monitored by the hypothalamus
As blood conc. Increases, more ADH is secreted, so more water is reabsorbed and blood conc. Then decreases
What can alcohol do to ADH secretion
It can inhibit ADH secretion, leading to dehydration and hangover headaches due to higher urine volume and water concentration
What secretes aldosterone
The adrenal cortex gland (outer layer of the adrenal gland on top of each kidney
What does aldosterone do
Controls the excretion of Na+ and K+ ions
Increase’s reabsorption of Na+ (more in blood) and increases excretion of K+ (less in blood)
What happens if Na+ levels are too low
Aldosterone is secreted, reabsorption of Na+ by the kidneys occurs, so blood Na+ begins to increase
What else does aldosterone do
Controls blood volume and pressure since an increases of the [Na+] in blood causes H2O to be absorbed, increasing blood volume and pressure
