Lecture 9: Urinary System Flashcards
The kidneys are the major…
expiratory organs of your body
Why kidneys have the largest role?
To help maintaining homeostasis
What’s the second largest role?
Liver
Kidneys are important to…
- fluid balance
- electrolyte balance
- acid base balance
What do kidneys help you get rid of?
Nitrogenous waste
Kidneys are involved in
helping get rid of waste products that come from gluconeogenesis
Kidneys are going to affect
the secretion rates of ADH and Aldosterone
Under the control of parathyroid hormone, kidneys
the organs that make Vit. D3
Kidneys convert what?
Erythropoeitinogen to Erythropoietin
They also make some what?
Prostoglandins
Organs of Urinary System
2 kidneys
2 Ureters ( one connecting each kidney at one end and urinary bladder at the other)
1 Urethra (connects urinary bladder to the outside world)
Kidneys are shaped like what?
beans
What is so different about the Left Kidney to the Right Kidney?
Left kidney is a little bit more larger and higher than the right
The 10th rib to L3 and from the 11th rib to bottom part of L3
Each kidney is surrounded by white fibrous capsule. The fat surrounds it is called…
Paranephric fat
The kidney has a notch area on medial side called…
Hilum
We have things that enter and exit the kidney. What exits the kidney at the hilum?
- Renal pelvis narrows and becomes URETER
- Renal Vein
What comes in?
- Renal Artery
Lighter pink area is renal cortex. Under that is the renal medulla. What is the renal medulla made up of?
Renal Pyramids
There are cortical tissue in between the renal pyramids. This is called…
Renal columns
Renal pyramids are oriented because…
So that the base of the pyramid is facing the cortex. The top is sticking in to the beginning of the renal pelvis.
Minor calyces come together to form…
major calces
Major calyces come together to form…
Renal pelivs
What comes out of the renal pelvis?
Ureter
How many renal pyramids make up renal medulla?
12
A lot of the jobs that are performed by the kidneys, are going to involve what?
Examining blood and taking things out of the blood
If we use filter to filter the blood. We need to make sure they have a substantial blood supply. If we look at the blood supply of two kidneys combined, they get about __________ of cardiac output.
20%
We have the renal artery, what does it branch off of?
The abdominal aorta
Where does the abdominal aorta branch enter?
enter the kidney and branch into segmental arteries
What do we need to know?
Renal arteries, segmental arteries, afferent arterioles, 3 types of blood vessels associated with nephrons, and renal vein
What we have with the kidneys is…
Extensive vascular system associated with extensive tubular system
The tubular system is made up of?
Nephrons
What is a nephron?
A functional unit of a kidney
What is a functional unit?
The smallest part that does what the whole thing does
The nephron does what?
Filtering, modifications, and produce urine.
A healthy adult is going to have approximately __________ nephrons per kidney
1 million
The first part of nephron is where we see..
the vascular system connect to the tubular system
This is where a knot of capillaries iscalled…
glomerulus
The glomerulus is surrounded by…
Bowman’s capsule/ Nephron capsule/ Glomerular capsule
Blood moves into glomerulus through what?
Afferent arteriole
Blood moves out of the glomerulus through what?
Efferent arteriole
what does Afferent arterioles do?
Carries blood toward the center (glomerulus)
What does Efferent arterioles do?
carries blood away from center
Bowman’s capsule has how many layers
2
The pinkish lavender is the visceral layer of Bowman’s capsule. It’s made up of cells called?
Podocytes (foot cells)
The outer layer is away from the layer of podocytes. We have a space in between. What gonna happen here is…
filtering fluid and small particles are going move and to be pushed out of capillary and go into capsular space and then move into the beginning of tubular system proper.
Capillaries in the kidney are…
fenestrated (has holes). stuff that is smaller than the holes move through. Stuff that is larger than holes or same size is gonna stay in the blood and NOT go in capsular space.
If you look at podocytes, what we have these projections sticking off of them. What are they called?
Pedicels
There are spaces in between the pedicels. What is it called?
Filtration slits
What happens if blood pressure goes up in that glomerulus? What’s going to happen to the size of the filtration slits?
If you stretch the capillary, the filtration slit will stretch and get bigger.
How this filtration system works is based on size. Why?
If we’re constantly changing the size of the filtration slits, we’re changing the size of stuff that can leave the blood and go into filtration.
In the filtration slits, we have carbohydrate frame works mesh that do what?
keep the size the filtration slit constant.
In between the capillaries, we have a group of cells called…
Mesangial cells
What is the function of Mesangial cells?
They regulate the diameter of capillaries in the glomerulus.
Capillaries don’t have muscle in wall, only endothelium. They can’t vasoconstrict or vasodilate. What does the Mesangial cells do?
They change size which would adjust the diameter of the capillaries a little bit.
What do Mesangial cells respond to?
- Angiotensin II
- ADH
- Histamine
Branching of the efferent arteriole, we have a group of blood vessels called…
Paritubular capillaries
Paritubular capillaries are going to be associated with different parts of the nephron. If I have something called the juxtamedullary nephron, and it has a real long loop, I’m going to have another type of blood vessels associated with my nephron. This is called…
Vasae rectae
Why is this important?
it is one of the the things that makes juxtamedullary nephron different than the other types.
Cortical Nephron’s loop isn’t as long as juxtamedullary nephron. All the parts of a cortical nephron are surrounded by what?
by peritubular capillaries. They don’t have vasa recta.
The cells that make up the wall of the glomerular capillary are
Simple Squamous epithelium
What we have here is endothelium of the capillary, epithelial cells, and a shared basement membrane sounds like…
respiratory membrane
Shared basement membrane means…
I don’t have as large a distance to go
Filtration membrane is talks about what?
talking about fluid and small particles moving from the capillary out into the capsular space.
Once we get fluid into the capsular space, we have specific regions of the tubular system that filtrate is gonna through. The part that’s closest to the glomerulus and Bowman’s capsule is called…
Proximal convoluted tubule
Why is it proximal?
Because it is close to glomerulus and Bowman’s capsule
Why is it convoluted?
Bc it is windy
After the Proximal convoluted tubule, we have a structure called…
Loop of Henle OR the Nephron Loop
After the Loop of Henle, we have what?
Distal Convoluted Tubule
Technically, at the end of the Distal Convoluted Tubule, is what?
the end of our nephron
What comes after it?
A set of tubules that shared by multiple nephrons called the collecting duct.
Why is the collecting duct considered not part of the nephron?
Because it doesn’t belong to just one system
Proximal convoluted tubule is a structure that has…
Microvilli
Most of what’s gonna happen in the Proximal convoluted tubule is what?
Reabsorption
Why is it considered Reabsorption and not just Absorption?
Bc it was already in the blood.
_________ what gets filtered out at the glomerulus, is going to be reabsorbed at the __________ ____________.
70% ; proximal convoluted tubule