Renal Flashcards
What are the main functions of the Kidneys?
Homoeostasis - osmolarity, blood volume (therefore long-term blood pressure), excretion of waste - especially nitrogenous waste.
Hormone release - EPO and Activates Vit D
What is the normal amount of urine produced a daily?
1.5-2L
What is the anatomical name that the medullary pyramids drain into, and where does the glomerular filtrate go from there?
Renal Papilla > Minor Caylx > Major Caylx > Renal Pelvis > Pelviuretic Junction > Ureter > Bladder > Urthera
Anatomically in the abdomen where are the kidneys?
Retroperitoneal
Outline the BASIC blood supply to and through the kidneys.
Aorta > Renal Artery > Afferent Arterioles > Glomerulus > Efferent Arterioles > Vasa Recta > Renal Vein > Inferior Vena Cava
The Nephron consists of TWO main parts, what are they?
Renal Corpuscle and Renal Tubes
The Renal tubes are made up of what? and what are there order?
Proximal convoluted tube > descending loop of Henle > Ascending Loop > Distal convoluted tube
What are the types of Nephrons? and what are their percentages?
Cortical Nephrons - 80-85%
Juxtamedullary Nephrons - 15-20%
What are the cells found within the Glomerulus? and their layers?
podocytes - form the visceral layer
Filtration membrane
Mesangial cells - which constrict
What is the histology of the proximal convoluted tubules?
Simple cuboidal epithelial cells with microvilli and brush border. Large amount of mitochondria
Describe the histology of the loop of Henle
Descending is simple squamous
first part of ascending is simple squamous
distal ascending is Cuboidal epithelial
What are the three layers the filtered must pass through to enter the bowman’s space?
Endothelial cells, basal lamina, podocytes
What is special about the endothelial cells of the glomerulus vessels?
they contain fenestrations which are leaky pores, making them 50 times more permeable than regular epithelial cells.
What factors control the pressure of the arterioles within the glomerulus?
Mesangial cells - if they constrict, less blood = less filtrate and vice verse
Efferent arteriole is smaller in diameter, increasing the the back pressure
The epithelial cells have fenestrations
membrane is thin and porus
Where does the majority of filtration take place? what are some percentages?
Proximal convoluted tubule?
65%-70% of water and salt
100% of glucose
50% of Cl-
How does the PCT reabsorb water and salt?
The Na/K ATPase pumps on the basolateral aspect pump sodium out, this creates a low intracellular concentration>
This then creates a electric/chemical gradient drawing Na2+ to cell.
- which is then pumped into the tissue. This creates a electrically charge across the tubules and tissue, drawing the negative Cl- out, which joins with the Na to make NaCl - salt.
This then creates an osmotic gradient and draws water out.
What is the overall function of the Loop of Henle?
to concentrate the medulla to allow water to be reabsrobed by osmosis
In the descending loop what is absorbed and what is the percentage of the overall filtrate of this is reabsorped?
Only Water. 20%
What is reabsorped in the ascending loop? and what is not?
NaCl. water is not reabsrobed
What is controls the re-absorption out of the collecting ducts?
ADH/ Vasopressin.
Physically how does ADH/ Vasopressin increase absorption? and what receptor do they bind to?
Upregulation of Aquaporins
V2 receptors
What is the normal osmolarity of blood?
~300 miliesmoles
What is the condition where the kidneys during development fuse to form one large mass?
Horseshoe kidney
How does the uterer pass urine into the bladder?
Peristalsis contractions
What is the recommended intake of salt a day?
6g/per day
What tissue makes up the uterer?
Transitional
