Urinary System (Lec 20) Flashcards
1
Q
What system is responsible for water and electrolyte homeostasis, osmoregulation and acid-base balance
A
- urinary system
2
Q
What is the secretory function of the organ system?
A
- excretion of toxic and metabolic waste products especially urea and creatinine
3
Q
Urea and creatine are?
A
- N-containing compounds from metabolism of proteins
4
Q
what produces uric acid?
A
- birds and reptiles( more efficient way to excrete) contians 4 nitrogen molecules
5
Q
What is urea?
A
- 1 nitrogenous waste product in mammals that is soluble
6
Q
Is uric acid soluble?
A
- nope it is insoluble
7
Q
Can mammals secrete uric acid?
A
- yes, dalmations
- can be dangerous
8
Q
What is BUN?
A
- measurement of blood
- blood urea nitrogen - (includes urea, creatinine, uric acid, and ammonia)
9
Q
Does the the urinary system metabolize and excrete various drug?
A
- Yes
10
Q
What synthesizes renin and maintains normal blood pressure via renin-angiotensin- aldosterone system?
A
- Kidneys
11
Q
What produces erythorpoietin?
A
- kidney
12
Q
What does erythropoietin do?
A
- stimulates rbc production (erythropoiesis)
13
Q
What converts vitamin D to its active form?
A
- liver and kidney
14
Q
Are kidneys mesenteric organs?
A
- no they are retroperitoneal organs with fibrous connective tissue capsule
15
Q
where do blood vessels and ureters enter/exit?
A
- hilus
16
Q
What supplies the kidney?
A
- renal artery
17
Q
What does the renal artery branch into?
A
- renal artery –> interlobar artery –> arcuate artery –> then interlobular artery –> affarent arterioles to goleruli
18
Q
What gives off the affarent arterioles?
A
- interlobular artery
19
Q
what is the kindey divided into?
A
- outer cortex and inner medulla
20
Q
What does the cortex contain?
A
- mostly renal corpuscles and convoluted tubules
21
Q
What does the medulla contain?
A
- mostly loops of Henle
- collecting tubules
- collecting ducts
22
Q
What lines the renal pelvis/calycx?
A
- transitional epithelium unique to urinary tract
23
Q
What does the transitional epithelium tract have?
A
- varying # of layers- stratified, cuboidal to polygonal, with scalloped outline (= umbrella cells”)
24
Q
What allows for changing of urine volumes?
A
-the highly distensible transitional epithelium
25
What is the functional unit of the kidney?
- nephron
| 1 million in each human kidney
26
Where doe nephrons derive from?
- nephrogenic blastema
27
What is the neprhogenic blastema a part of?
- part of developing urogenital ridge
28
What are the three types of nephrons?
- cortical or subcapsular
- juxtamedullary
- intermediate
29
What are the different classifications of nephrons based on?
- location in cortex
30
______ or ______ are located in outer rim of cortex and have short loops of henle?
- cortical or sub capsular nephrons
31
_______ nephrons are adjacent to medulla and have long loops of henle
- juxtamedullary
32
What nephrons have short loops of henle?
- cortical or sub capsular nephrons
33
What nephrons are located in outer rim of cortex?
- cortical or sub capsular nephrons
34
What nephrons have long loops of henle?
- juxtamedullary nephrons
35
Where are juxtamedulary nephrons located?
- adjacent to medulla
36
______ nephrons are in the middle of the cortex and have intermediate length loops of Henle?
- intermediate nephrons
37
What are the two major components of the nephron?
- renal corpuscle
| - renal tubule
38
What part of the nephron filters the blood plasma?
- renal corpuscle
39
What part of the nephron collects filltrate?
- renal tubule
40
What are the two components of the renal corpuscle?
- bowman's capsule and glomerulus
41
_____ single layer of squamous epithelial cells resting on basement membrane (=parietal layer)
- capsule
42
What does the capsule form?
- hollow, dilated end of proximal convolated tubule, surrounding glomerulus
43
What type of epithelium is the capsule?
- flattened squamous epithelial cells
44
Parietal layer continues onto glomerulus as ______
- visceral layer
45
What are the highly modified cells of the visceral layer?
- podocytes
46
Space between visceral and parietal layers is ________
- bowman's space
47
What is the function of bowman's space?
- it collects glomerular filtrate and empties into renal tubule
48
What do podocytes surround?
- glomuleral capillaries
49
what is the glomerulus?
- a network of densely packed, anastomosing, fenestrated capillaries
50
What supplies the golmerulus?
- afferent and efferent arterioles
( unique that there is not a efferent venule with afferent arterioles)
This prevents leakage
(venule too thin)
51
Blood plasma passes through several cell layers to become _____
- filtrate
52
Where are water and small molecular weight molecules filtered from blood into?
- bowman's space
53
First layer consists of ?
- capillary endothelial cells of glomerulus and glomerular basement membrane
54
______ surface of capillary endothelium is negatively charged due to surface layer of glycoprotein podocalyxin
- Luminal
55
what is the function of podocalyxin?
- sets up negatively charged barrier, prevents loss of anions, large protein molecules
56
What does glomerular basement membrane do?
- acts as physical barrier and ion- selective filter
57
What is the space between capillary basement membrane and second layer of cells?
- subpodocyte space
58
What are the second layer of cells?
- podocytes
59
What do podocytes do?
- surround glomerular capillaries and posses cytoplasmic extensions know as foot processes
60
Can 1' foot processes give off 2' foot process?
- Yes
61
what is the space between foot processes?
- filtration slits
62
What is the size of filtration slits?
~40 nm in diameter
63
What lines the filtration slits?
- protein called nephrin which makes up slit diaphragms
64
What is the function of slit diaphragms?
- act as additional barrier
| - function to restrict passage of large macromolecules, proteins, negatively charged molecules, and blood cells
65
Do podocytes have a phagocytic function?
- Yes and they can remove trapped macromolecules
66
What ultimately passes into renal tubule?
- ultrafiltrate
67
What are the four distinct zones of the renal tubule?
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting tubule/duct
68
Do the four zones of the renal tubule have the same function?
- No each has a different physiological function
69
Where does the renal tubule start?
- bowmans capsule
70
What lines the renal tubule?
- bowman's capsule
- filtrate produced at rate of ~ 120 ml/min in humans
(most filtrate later resorbed)
71
What is the primary function of renal tubule?
- selective resorption of water, inorganic ions (Na and bicarbonate) and large molecules like aa's proteins and glucose from glomerular filtrate
72
What is another function of renal tubule?
- concentration of waster products such as urea, creatinine, and excess H+ and K+
73
Where is the proximal convoluted tubule confined to?
- cortex
74
Where is the primary site of water resorption?
- resorbs ~75% of water and ions (Na, Cl) from filtrate
75
What facilitates water resorption?
- aquaporins
76
What are aquaporins?
- integral proteins forming specialized pores or channels for transport of H20 in brush border of epithelial cells
77
What resorbs all proteins, AA,s and sugars (glucose)
- proximal convoluted tubule
78
What epithelium lines the proximal convoluted tubule?
- simple cuboidal epithelium with apical microvilli (=brush border)
- characteristic of proximal convoluted tubule
79
Why are they called PROXIMAL convoluted tuble?
- close or proximal to golmerulus
80
What is characteristic of proximal convoluted tubule?
- brush border
81
What are the 4 parts of the loop of henle?
- pars recta (thick descending limb)
- thin descending limb
- thin ascending limb
- thick ascending limb
82
where does the bulk of the medulla extend into?
- medulla
83
Thin limbs are long in ____ nephrons and short in _______ nephrons
- jextamedullary, cortical
84
What epithelium does the thin limb have?
- simple squamous epithelium
85
What epithelium does the thick limb have?
- simple cuboidal epithelium
86
______ has brush border of apical microvilli
- Pars recta (thick descending limb)
| - continuation of proximal convoluted tubule
87
What surrounds the loop of henle?
- peritubular capillary network, called the vasa recta
88
What is the function of the loop of henle?
- to generate high osmotic pressure in ECF of renal medulla
89
How does the loop of henle generate high osmotic pressure?
- via Na-K pumps in thick ascending limb of loop of henle
90
Where are the Na-K pumps in the loop of henle?
- the thick ascending limb
91
Sodium accumulates in medulla due to these pump? T/F
- true
92
The high Na concentration in medulla and low salt/high water resorption in proximal convoluted tubule in cortex produces what?
- cortico-medullary interstitial gradient
93
What does the cortico-medullary intersitital gradient do?
- produces counter current (exhange) multipier system of urine concentration
94
What does the counter current result in?
- production of hypertonic urine
95
What is a continuation of the thick ascending limb of Loop of henle?
- distal convoluted tuble
96
Where is the distal convoluted tubule located?
- present within the cortex
97
What is the epithelium of the distal convoluted tubule?
- simple cuboidal epithelium
| with short apical microvilli
98
Does the distal convoluted tubule have a brush border?
- NOPE
99
What does the distal convoluted tubule do?
- responsible for active resorption of Na and Cl, coupled with secretion of H and K ions
100
_________ is responsible for active resorption of Na and Cl, coupled with secretion of H and K ions
- Distal convoluted tubule
101
What two types of cells control the distal convoluted tubule?
- principal cells
| - intercalated cells
102
What do principal cells do?
- resorb Na and water, secrete K
103
What do intercalated cells do?
- resorb K, and secrete H
104
_____ resorb Na and water and secrete K
- principal cells
105
______ resorb K and secrete H
- intercalated cells
106
What hormone controls the distal convoluted tubule?
- aldosterone (adrenal mineralocorticoid)
107
Why is the two step (two cell type) process important in the distal convoluted tubule?
- it allows finer titration
| - important in acid base balance
108
Why do we have aldosterone to help us conserve sodium?
- the reason is bc sodium is scarce in the environment
- salt is hard to find other than ocean
- why it was expensive commodity
- roman soldiers got paid in salt
109
What is the terminal portion of the nephron?
- collecting tubule
110
several tubules converge to form large _______
- collecting duct
111
Are collecting ducts visible?
- yes as medullary rays
112
What is the epithelium of the collecting tubule?
- simple cuboidal to columnar epithelium
113
The straight terminal portion of the nephron is the____
- collecting tubule
114
where do the collecting ducts coverge?
- renal papilla and empty into minor calyces
115
How do the collecting tubules/ducts function?
- function in Na resportion and maintenance of acid-base balance, K secretion and resorption
116
What type of cells do the collecting tubules have?
- principal and intercalated cells
117
T/F epithelial cells of collecting duct are normally impermeable to water
- True
118
What happens to collecting tubules in the presence of ADH?
- collecting tubules become permeable and will resorb water (via aquaporins)
119
What is ADH
- vasopressin
120
What secretes ADH?
- posterior pituitary
121
T/F the collecting tubule does not work in conjunction with Loop of Henle and vasa recta to form counter-current exchange mechanism to concentrate urine
- False it does help with this
122
Collecting tubule are a second major site of urine concentration
- true
123
Proximal convoluted tubules are 2X as long as distal convoluted tubule (and much more convoluted) so most tubules in cortex are proximal
- True
124
____ convoluted tubules more oval to elongate with thinner flatter (but still cuboidal) epithelium
- distal
125
What do we mostly see in medulla?
- Loop of henle
(smallest tubules, with squamous to cuboidal epithelium)
- fewer collecting tubules (medium sized) and occasional collecting ducts (largest with simple cuboidal epithelium) and surrounding blood vessels (vasa recta)
126
When talking about specialized structure in kidney typically talking about?
- juxtaglomerular apparatus
