Function of the Kidney Flashcards
What does the kidney excrete?
Metabolic waste products and foreign chemicals
What production does the kidney regulate?
Red blood cell production
What does the kidney keep in balance?
Regulates acid-base balance
Water & electrolyte balance
What pressure does the kidney regulate?
Arterial pressure
What part of body fluids does kidney regulate?
Body fluid osmolality
Electrolyte concentration
What hormone does the kidney synthesise?
Calcitriol
What are the 5 symptoms of kidney impairment?
- Body weakness
- Blood pressure is high
- Swollen legs
- Loss of appetite
- Vomiting
What abnormal levels of ions can affect the heart in kidney impairment?
High K+
Low Ca2+
What is a xenotransplant?
A transplant from a donor of a different species from the recipient
What does the ureter lead from and to?
From kidney to urinary bladder
What is the role of the urethra?
Urine stored in the bladder is emptied through the urethra
How many lobes does a kidney have and what are they composed of?
18 lobes composed of nephrons
What is the outer layer of the kidney called?
Renal cortex = granular apprearing
What is the inner layer of the kidney called?
Renal medulla = striated-appearing
What is the role of the renal pelvis?
Collects the urine as it is produced
What does the renal pelvis lie outside of?
Peritoneal cavity
What is the flow of urine through the calyxes?
Renal pyramid > Renal Papillae > Minor renal calyx > Major renal calyx > Renal pelvis
What happens to nephrons when damaged?
Nephrons cannot be regenerated
Treatment can only try to preserve what is remaining
What two layers separate the blood from the glomerular filtrate?
Capillary endothelium
Specialized epithelium of Bowman’s capsule
Describe the capillary endothelium
Endothelium is fenestrated = has small pores
Completely surrounded by glomerular basement membrane and podocytes
Podocytes create filtration slits
What are podocytes?
Bowman’s capsule cells that have foot processes
They interact with each other to forma mesh-like structure
Where are mesangial cells located?
Between endothelium and glomerular basement membrane (basal lamina)
Commonly found between two neighbouring capillaries
What do mesangial cells do?
Regulate blood flow in glomerulus
By regulating the surface area available for filtration by contracting or relaxing in response to various signals
What does the juxtaglomerular complex consist of?
Macula densa
Juxtaglomerular cells
What and where are macula densa and their role?
Tubule cells in initial portion of the distal tubule
They act as chemoreceptors, sensing changes in NaCl concentration in the tubular fluid
What are juxtaglomerular cells and their function?
Special cells of the blood vessel walls
Blood vessels = afferent and efferent arterioles
Produce and release the enzyme renin = primary function
What is the function of the juxtaglomerular complex?
Regulate blood pressure, Na reabsorption and glomerular filtration
Synthesize renin
What are the two types of nephron?
Cortical nephron = 85%
Juxtamedullary nephron = 15%
Describe the cortical nephron
Short loop of Henle
Small network of vasa recta
Describe the juxtamedullary nephron
Long loop of Henle = reaches medulla
Large network of vasa recta
What role does the juxtamedullary nephron play?
Concentrating and diluting urine
What is the vasa recta and their role?
Network of blood vessels that run parallel to the loops of Henle in the kidney medulla = arise from the efferent arterioles
Supply oxygen and nutrients to the medullary tissue while also removing waste products
Crucial role in maintaining the osmotic gradient in the medulla, which is essential for the kidney’s ability to concentrate urine
What percentage is renal blood flow in relation to cardiac output?
22% of CO = 1,100 mL/min
What capillary beds does the renal circulation have?
Glomerular capillaries = starts and ends as arteriole
Peritubular capillaries = starts as artery ends as venule