Renal Flashcards
1 - Describe the structure of the kidney and define its main roles in the body 2 - Describe the structure and function of the nephron 3- Explain the roles and mechanisms of the kidney in maintaining fluid, electrolyte and acid/base homeostasis 4- Discuss the role of the kidney as an endocrine organ (53 cards)
What are the three layers of kidney tissue?
Renal capsule – deep layer, maintains kidney shape
Adipose capsule – a mass of fatty tissue that protects the kidney from trauma and holds it in place
Renal fascia – superficial layer – the thin layer of connective tissue that anchors kidney to surrounding structures and abdominal wall
What are the three sections of the internal kidney anatomy?
Renal cortex – superficial
Renal medulla – inner region
Renal lobe – renal pyramid
Functions of the kidneys
Regulation of water and electrolytes
Regulate pH of blood
Regulate blood volume
Contribute to regulating blood pressure
Control osmolarity of blood
Act as an endocrine organ (produces hormones)
Contribute to regulating blood glucose level (once the renal threshold is exceeded glucose is excreted in the urine)
Excretes waste and foreign substances (ammonia, urea, creatinine, bilirubin, drugs and toxins)
What artery does the kidneys receive blood from?
Renal artery
How does blood leave the kidneys?
Renal vein
What % of blood goes to the cortex?
99%
What % of blood goes to the medulla?
1%
How many nephrons in each kidney?
Approx 1 million
What are the 2 parts of a nephron? And functions?
Renal corpuscle - Filters blood plasma
Renal tubule - Receives filtered plasma
What does the renal corpuscle consist of?
Glomerulus - capillary network
Glomerular (Bowmans) capsule - double walled cup surrounding glomerulus
What does the renal tubule consist of?
Proximal convoluted tubule
Descending and ascending loop of Henle (nephron loop)
Distal convoluted tubule
What are the 2 types of nephrons?
Cortical nephron
Juxtamedullary nephron
What nephrons do we have more of?
Cortical nephron - 80-85%
Compare and contrast cortical nephrons and juxtamedullary nephrons
Cortical - 80-85% of nephrons in the kidney
Juxtamedullary - 15-20% of nephrons in the kidney
Cortical - short loop of Henle
Juxtamedullary - long loop of Henle
Cortical - loop of Henle penetrate only outer renal medulla
Juxtamedullary - Loop of Henle penetrate deep into the renal medulla
Cortical - Small glomeruli
Juxtamedullary - Large glomeruli
Cortical - Low glomerular filtration rate
Juxtamedullary - High glomerular filtration rate
Cortical - Perform excretory and regulatory function of the kidney
Juxtamedullary - Involved in concentrating or diluting urea
Cortical - no vasa recta network, only peritubular to receive blood
Juxtamedullary - Large network of vasa recta, and peritubular
Cortical - Ascending limb of loop of Henle straight
Juxtamedullary - Ascending limb had thick and thin regions
What does the renal corpuscle consist of?
Bowman capsule and a glomerulus (cluster of capillaries)
What % of filtered fluid goes back into the bloodstream?
99%
Name the 2 types of capillary beds, under high or low pressure?
Glomerular capillaries - Under high pressure for filtering
Peritubular capillaries - Around tubule at low pressure
What does GFR stand for?
Glomerular filtration rate
3 Steps of urine formation
Simple filtration
Selective and passive reabsorption
Excretion
Describe the glomerular filtration rate
It is the amount of filtration formed in all the renal corpuscle of both kidneys each minute
Watch the video about nephrons
https://www.youtube.com/watch?v=8UVlXX-9x7Q
What are the 3 mechanisms that regulate GFR?
Renal autoregulation
Neural regulation
Hormonal regulation
what is renal autoregulation? And the 2 mechanisms?
Kidney maintain blood flow and GFR by using:
Myogenic mechanism - Stretching triggers contraction of smooth muscle cells in afferent arterioles - which reduces GFR
Tubuloglomerular mechanism - macula densa provides feedback to glomerulus, inhibits release of NO causing afferent arterioles to constrict and decrease GFR
What is neural regulation? And the 2 types of stimulation?
Kidney blood vessels supplied by sympathetic ANS fibers that release norepinephrine causing vasoconstriction
Moderate stimulation – both afferent and efferent arterioles constrict to same degree and GFR decreases
Greater stimulation - constricts afferent arterioles more and GFR drops