Lecture 9: Urinary System Flashcards
(192 cards)
1
Q
The kidneys are the major…
A
expiratory organs of your body
2
Q
Why kidneys have the largest role?
A
To help maintaining homeostasis
3
Q
What’s the second largest role?
A
Liver
4
Q
Kidneys are important to…
A
- fluid balance
- electrolyte balance
- acid base balance
5
Q
What do kidneys help you get rid of?
A
Nitrogenous waste
6
Q
Kidneys are involved in
A
helping get rid of waste products that come from gluconeogenesis
7
Q
Kidneys are going to affect
A
the secretion rates of ADH and Aldosterone
8
Q
Under the control of parathyroid hormone, kidneys
A
the organs that make Vit. D3
9
Q
Kidneys convert what?
A
Erythropoeitinogen to Erythropoietin
10
Q
They also make some what?
A
Prostoglandins
11
Q
Organs of Urinary System
A
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)
12
Q
Kidneys are shaped like what?
A
beans
13
Q
What is so different about the Left Kidney to the Right Kidney?
A
Left kidney is a little bit more larger and higher than the right
14
Q
The 10th rib to L3 and from the 11th rib to bottom part of L3
A
15
Q
Each kidney is surrounded by white fibrous capsule. The fat surrounds it is called…
A
Paranephric fat
16
Q
The kidney has a notch area on medial side called…
A
Hilum
17
Q
We have things that enter and exit the kidney. What exits the kidney at the hilum?
A
- Renal pelvis narrows and becomes URETER
- Renal Vein
18
Q
What comes in?
A
- Renal Artery
19
Q
Lighter pink area is renal cortex. Under that is the renal medulla. What is the renal medulla made up of?
A
Renal Pyramids
20
Q
There are cortical tissue in between the renal pyramids. This is called…
A
Renal columns
21
Q
Renal pyramids are oriented because…
A
So that the base of the pyramid is facing the cortex. The top is sticking in to the beginning of the renal pelvis.
22
Q
Minor calyces come together to form…
A
major calces
23
Q
Major calyces come together to form…
A
Renal pelivs
24
Q
What comes out of the renal pelvis?
A
Ureter
25
How many renal pyramids make up renal medulla?
12
26
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
27
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%
28
We have the renal artery, what does it branch off of?
The abdominal aorta
29
Where does the abdominal aorta branch enter?
enter the kidney and branch into segmental arteries
30
What do we need to know?
Renal arteries, segmental arteries, afferent arterioles, 3 types of blood vessels associated with nephrons, and renal vein
31
What we have with the kidneys is...
Extensive vascular system associated with extensive tubular system
32
The tubular system is made up of?
Nephrons
33
What is a nephron?
A functional unit of a kidney
34
What is a functional unit?
The smallest part that does what the whole thing does
35
The nephron does what?
Filtering, modifications, and produce urine.
36
A healthy adult is going to have approximately __________ nephrons per kidney
1 million
37
The first part of nephron is where we see..
the vascular system connect to the tubular system
38
This is where a knot of capillaries iscalled...
glomerulus
39
The glomerulus is surrounded by...
Bowman's capsule/ Nephron capsule/ Glomerular capsule
40
Blood moves into glomerulus through what?
Afferent arteriole
41
Blood moves out of the glomerulus through what?
Efferent arteriole
42
what does Afferent arterioles do?
Carries blood toward the center (glomerulus)
43
What does Efferent arterioles do?
carries blood away from center
44
Bowman's capsule has how many layers
2
45
The pinkish lavender is the visceral layer of Bowman's capsule. It's made up of cells called?
Podocytes (foot cells)
46
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.
47
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.
48
If you look at podocytes, what we have these projections sticking off of them. What are they called?
Pedicels
49
There are spaces in between the pedicels. What is it called?
Filtration slits
50
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.
51
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.
52
In the filtration slits, we have carbohydrate frame works mesh that do what?
keep the size the filtration slit constant.
53
In between the capillaries, we have a group of cells called...
Mesangial cells
54
What is the function of Mesangial cells?
They regulate the diameter of capillaries in the glomerulus.
55
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.
56
What do Mesangial cells respond to?
- Angiotensin II
- ADH
- Histamine
57
Branching of the efferent arteriole, we have a group of blood vessels called...
Paritubular capillaries
58
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
59
Why is this important?
it is one of the the things that makes juxtamedullary nephron different than the other types.
60
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.
61
The cells that make up the wall of the glomerular capillary are
Simple Squamous epithelium
62
What we have here is endothelium of the capillary, epithelial cells, and a shared basement membrane sounds like...
respiratory membrane
63
Shared basement membrane means...
I don't have as large a distance to go
64
Filtration membrane is talks about what?
talking about fluid and small particles moving from the capillary out into the capsular space.
65
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
66
Why is it proximal?
Because it is close to glomerulus and Bowman's capsule
67
Why is it convoluted?
Bc it is windy
68
After the Proximal convoluted tubule, we have a structure called...
Loop of Henle OR the Nephron Loop
69
After the Loop of Henle, we have what?
Distal Convoluted Tubule
70
Technically, at the end of the Distal Convoluted Tubule, is what?
the end of our nephron
71
What comes after it?
A set of tubules that shared by multiple nephrons called the collecting duct.
72
Why is the collecting duct considered not part of the nephron?
Because it doesn't belong to just one system
73
Proximal convoluted tubule is a structure that has...
Microvilli
74
Most of what's gonna happen in the Proximal convoluted tubule is what?
Reabsorption
75
Why is it considered Reabsorption and not just Absorption?
Bc it was already in the blood.
76
_________ what gets filtered out at the glomerulus, is going to be reabsorbed at the __________ ____________.
70% ; proximal convoluted tubule
77
At the nephron loop, the longer the loop is...
the more concentrated we make urine.
78
It is not urine until..
we get it some place in the urinary system that can no longer change it chemically.
79
What does this mean?
So long as it's in tubules, that have the ability to reabsorb things or put stuff into the tubule lumen, it's still filtering.
80
Loop of Henle has 4 sections. What are they?
- Thick descending lim
- Thin descending lim
- Thin Ascending lim
- Thick Ascending lim
81
After the Loop of Henle, the Distal Convoluted tubule, is going to do a little bit of reabsorption. But mostly, how it's gonna affect what it's filtering is by what?
Secretion
82
What's important about the Distal Convoluted Tubule?
It is ONLY permeable to water in the presence of ADH.
83
What does this mean?
No ADH = no water can leave the Distal Convoluted Tubule
84
The Distal Convoluted Tubule is one of the places in the nephron...
that Aldosterone will act
85
The collecting doesn't belong to...
a single nephron.
86
Collecting duct does a little bit of secretion. Reabsorption is going to be variable bc like the Distal Convoluted Tubule, the Collecting Duct is not permeable to water unless...
there is ADH.
No ADH = no water reabsorption
87
Collecting duct is
the second place that Aldosterone will work in a nephron
88
What is the area where Distal Convoluted Tubule rubs up against the Afferent Arteriole called?
Juxtaglomerular apparatus
89
What does juxta- and -glomerular mean?
Next to glomerulus
90
Where the Distal Convoluted Tubule and Afferent Artiole are touching, you see changes in the cells in the wall of each structure. The modified cells that are associated with the wall of the afferent arteriole are called...
juxtaglomerular cells or JG cells
91
The JG cells are what?
Baroreceptors of the kidney
92
They also contain what?
Renin
93
If they don't stretch them enough, what happens?
They release more renin
94
If they don't stretch enough, what does this say about the blood pressure
It is too low. The more those cells get stretched, the less renin you release.
95
What are the triggers for RAAS?
Low blood pressure
96
Even if my BP is low bc my Blood volume is really low...
it's still the low bp that these cells are detecting
97
what is RAS?
Renin Angiotensin Aldosterone System
98
The JG cells have one job. What is it?
To regulate and defend BP.
99
If they get too stretched, and renin release drops, what happens to the RAAS system?
everything else that would happen in an activated RAAS system is also gonna drop.
100
The macula densa cells are what?
darker cells in the wall of the Distal Convoluted Tubule
101
The macula densa cells are also...
Osmoreceptors
102
What does this mean?
They are looking at the particle concentration in the filtrate in the Distal Convoluted Tubule.
103
The filtrate that is moving through Distal Convoluted Tubule at the point where you have macula densa cells...
should have an osmotic concentration lower than blood. It should be slightly dilute.
104
If it's isotonic with blood, if it's slightly warm concentrated than blood, what does this mean?
We don't have enough water
105
We don't exactly know how this works. But this happens, macula densa cells have some indirect affect on...
ADH release
106
What does this mean?
It's not the macula densa cells being connected to the posterior pituitary and causing it, but they AFFECT things that directly affect ADH release.
107
If the fluid is more dilute than it should be...
we have too much water
108
Whatever that signal from the macula densa, is going to cause ADH to drop. What does this cause?
To lose more water
109
The JG cells are about...
regulating and defending blood pressure
110
The macula densa cells are about...
helping to regulate blood volume
111
What the Osmotic concentration is...
is a reflection on what the water concentration is
112
If it's too concentrated, what does it mean?
I have too much particles than water
113
If it's too dilute, what does it mean?
I have too much water for the particles I have
114
If you look at the Juxtaglomerular apparatus, it's job is to...
help regulate pressure and blood volume
115
That thing in the kidneys that converts erythropoietinogen to erythropoietin is...
JG cells
116
True or False?
Anything that affects what goes in the urine is urine forming.
FALSE
117
There are 3 urine forming functions. What are they?
1. Filtration
2. Tubular Reabsorption
3. Tubular Secretion
118
What is Filtration?
moving fluid and small solute from glomerulus into capsular space
119
What is the only basis for Filtration?
size
120
If it's small enough to get through a fenestration or intercellular cleft, then...
filtration slit it will go into the filtering. If it's too big, it won't.
121
What is Tubular Reabsorption?
Take stuff now in the filtrate and cells from the particular part of the tubule are gonna bring it in and move it towards the paratibular capillaries or vasae rectae and it wind up into the blood.
122
Stuff that's getting reabsorbed is...
not gonna leave the body in the urine. This is how we're going to fix stuff that's small enough to get filtered, but that we don't want to leave the body like glucose.
123
What is Tubular Secretion?
From paritubular capillaries or from vasae rectae, stuff can move from the blood into the filtrate.
124
It's possible that there is so much of something in our blood that we want to get rid of and small enough to filter, that we can't it all out of the blood and into the filtering at the glomerulus. What can happen?
That stuff can be moved from the blood after the glomerulus.
125
When we're talking about secretion in the kidney, we're talking about what?
Moving material from the blood into the tubule after the glomerulus.
126
Urine formation is dependent on what two important things?
1. Surface Area
2. Pressure Gradient
127
There's a reason you have 2 million nephrons instead of 2. Why?
It gives you a lot more surface area to do all this processing of plasma.
128
Instead of channels, we're going to have...
carriers.
Whether they're active transport or passive transport carriers like we use for facilitated diffusion, will depend on where we are.
129
What are the Types of Carrier Mediated Transport?
1. Facilitated Diffusion
2. Active Transport
3. Cotransport
4. Countertransport
130
We've got facilitated diffusion carrier bind...
something moves it in the direction down its concentration gradient. No energy is required.
131
Active transport talks about pumps because we're talking about...
carriers
132
Now, whatever this carrier binds, it's gonna move from...
low concentration to higher concentration against the gradient and use ATP to do that.
133
Variation on facilitated diffusion, we have co-transport. This means...
Two things are binding to the same carrier and they're bing moved in the same direction.
134
Another variation on facilitated diffusion, we're still moving two things but they're moving in the opposite direction. This is called...
Countertransport or Exchange
135
What are the characteristics of Carrier Mediated Transport?
- Specific
- Works in One Direction
- Carrier distribution varies over cell
- Many types of carriers in one cell
- Carrier proteins can be saturated
136
The filtrate keeps moving. If even i keep putting stuff into the filtrate, because it's moving, that region where i was adding "m&m's"...
the m&m's keep moving with the filtrate, so I can't accumulate m&m's in that area to reverse the carriage? (58:39)
137
Second thing, these carriers are specific.
A sodium glucose carrier is not gonna transport sodium and fructose or sodium and galactose.
138
Third thing, the carrier proteins aren't uniformly distributed on any of the cells.
Different jobs, different directions. Things that were passive at one end of the cell may require active transport in the other.
139
Each tubular cell has a lot of different carrier proteins. The proximal convoluted tubule that's gonna reabsorb 70% of what we filtered is gonna have a huge number of different types carriers. This would mean that...
We're gonna have a different sodium acid carrier a different one for each of the 20 amino acids that we use in the human body. We're gonna have a different sodium carb carrier for each of the different simple sugars that we use in the human body.
140
Finally, the carriers can be saturated. Meaning...
It's possible to have too much stuff for all of it to get carried.
141
What is the transport maximum
So that maximum amount of concentration of something that the tubular cells can handle.
142
For example, if the concentration of glucose is higher in filtrate than the concentration that is the transport maximum, what happens?
You won't reabsorb it all and you'll start to see it in the urine.
143
Transport maximum refers to what?
The concentration of that stuff at which you start to see that, you've saturated the carriers.
144
There's a term that goes with it, called...
Renal threshold
145
What is renal threshold gonna tell you?
If you've hit renal threshold, that's substance that shouldn't be in the urine, is now starting to show up bc the carriers are saturated.
146
We have two different varieties of nephrons. They are...
85% -> Cortical nephrons
15% -> Juxtamedullary nephron
147
What is a Cortical Nephron?
Has a much shorter Loop of Henle than a Juxtamedullary nephron.
148
Most of the nephron is in the cortex. And bc it's in the cortex, it's gonna hav e slightly different functions than the kidney in the longer loop called the Juxtamedullary nephron.
The cortical nephron are the ones mostly get rid of stuff that we want to leave the body. This is where most of the filtration for disposal is gonna happen.
149
In the Juxtamedullary nephron, the whole Loop of Henle is in the...
renal medulla
150
Bc of that, the main role of the Juxtamedullary nephrons is...
to be in adjusting your fluid balance
151
This means...
Do I make concentrated urine?
Do I make dilute urine?
Do I make isotonic urine?
What would I need to do to keep my fluid balance right?
152
The other difference between both nephrons anatomically are...
Cortical nephron is gonna have peritubular capillaries associated with it.
153
What you have her is peritubular capillaries weaving in and out of the proximal and distal convoluted tubule so it's wrapped around. The closer you get those, the easier it is to move stuff from the tubular to the blood. This is what?
Reabsorption
154
Or from the blood into the tubule. This is?
Tubular Secretion.
155
When you look at the loop, we have blood capillaries all around the loop. There's a big difference here. These are just paritubular capillaries because they're all around the loop. If you look at the Juxtamedullary nephron...
the loops of capillary follow the Loop of Henle. In fact, this is the descending limb of this particular nephron and the blood is flowing in the same direction as the filtrate is flowing. So it's flowing down in this side of the vasae rectae and we go around the loop and we go up and the filtrate is going up and the blood is moving up.
156
When revisiting Starling, the same 4 pressures that we talked about in systemic capillaries, are going to occur in and around the capillaries of the glomerulus. Now two things...
It's fairly common to change the names of those pressures when talking about kidneys. (no problem using the same pressure names we used for systemic capillaries)
157
There is pressure inside the capillary. The fluid is...
CHP, COP, IFHP, IFOP
158
The angle that the ureters connect to the urinary bladder is such that as urine accumulates in the...
urinary bladder and the wall stretches, it acts as a valve and closes the entrance to the ureter.
159
If ureters connect that the top, it would be much easier for urine in the urinary bladder to...
work its way back up the ureters and get to the kidneys which can cause kidney damage.
160
The ureters have an epithelial lining called
Transitional epithelium
161
What does transitional epithelium do to the ureter?
We can stretch the ureter having higher urine production.
162
Why is there smooth muscle in the ureters?
Urine gets moved partly by gravity and partly by peristalsis
163
The higher the urine flows...
the faster and stronger the peristalsis we get in the ureters
164
What is the urinary bladder?
It is a muscular bag
165
Where is it?
anterior to the rectum and behind pubic symphisis
166
There are sex differences to what's around the bladder, in a male...
it sits on top of prostate gland
166
In a female,
urinary bladder sits a little bit inferior to the uterus
167
In a pregnant woman, the larger the uterus gets,
the more the uterus sits on the bladder
168
We have 3 layers of smooth muscle in the urinary bladder, what are they?
- Longitudinal Layer
- Circular Layer
- Oblique Layer
169
Why do we have those layers in the urinary bladder?
- stretch
- contract in all directions
- protection against having urine go somewhere besides out the urethra
170
The urinary bladder is lined w/transitional epithelium bc
it allows to stretch the bag w/o tearing the lining.
171
Why do we need rugae in urinary bladder?
Having folds and transitional epithelium would help you stretch even more w/o tearing the lining
172
There are 3 openings in the wall in the urinary bladder. They are
The opening of both the ureters and the opening of the urethra.
173
Those 3 things together are called
Trigone
174
What is the function of the urinary bladder?
- Stores urine
- Expelling urine
175
The final part of urinary system is the urethra. What does the urethra do?
Connects the urinary bladder to the outside world
176
In a male, the urethra is how long?
~ 20 cm long
177
In a female, the urethra is....
~ 3 cm long
178
When you look at the urinary bladder in a male, we have the urethra...
exiting thru the prostate gland, we have the internal urethral sphincter where urethra + urinary bladder meet, external urethral sphincter where urethra pass thru floor of pelvic cavity
179
While we're still in the prostate gland, the reproductive structure called the...
ejaculatory duct connects to the urethra. From that point on, reproductive and urinary structures are SHARED in the male.
180
In a female, we have a shorter urethra by far. The internal urethral sphincter (like in a male) is where...
the junction between the urinary bladder and the urethra is.
181
The external ureththral sphincter is not quite at the exit, but close to it. Instead of having a prostate gland, we have other things such as...
Posterior to the urethra in a female, we have the vagina. And posterior to that, we have the rectum.
182
Who gets more UTI? Males or Females?
Why?
Females
- they have a short urethra
- short proximity to the rectum and vagina
- Urethra is a 1/3rd of a length than how it is in a male so those bacteria doesn't have to move all that far to get into the bladder
183
The process of emptying the bladder is called?
Micturition
184
How does this work?
Urinary bladder starts to get stretched > trigger nerve impulse > waves of contraction of the bladder > internal urethral sphincter will relax involuntarily > urine moves further into urethra and put pressure on the external urethral sphincter (once innervation in pelvic floor is connected, its under voluntary control) > make decision to urinate > voluntarily relax external urethral sphincter and contract the muscle of bladder
185
That stretch to get the urge to urinate is from...
when there's ~ 250 mL of urine in the bladder
186
Why do pregnant women urinate more?
It happens at a lower volume bc the bladder can't expand as much bc baby is on top of the bladder
187
The more stretch the bladder gets, the more...
waves of contraction we get
188
How do you start that urine to move in the urinary bladder if you can't voluntarily contract that smooth muscle?
When you contract abdominal muscles, it puts pressure on the bladder and then as you start to move urine, we activate autonomic innervation to control smooth muscle and bladder contracts more fully.
189
What is secondary renal hypertension?
person has a blockage or narrowing of a renal artery. They're arterial bp might be norma, but there's a smaller pathway for blood to get into the kidney so it can't get in as fast and bp in the kidney is lower.
190
Every single afferent arteriole in that kidney says "there's low Bp, let's crank up RAAS". There's still blockage/ narrowing of renal artery so that kidney's afferent arterioles are still seeing low BP. What happens?
^RAAS, ^ systemic arterial BP . But it doesn't fix what's at the renal artery.
191
How do we fix this?
Take out the blockage, put a stent in that will hold it to it's normal diameter and then the afferent arteriole in that kidney will get a look at real BP, renin will drop, and RAAS will turn down.
