Renal System Flashcards
1
Q
What is the renal system
A
Kidneys
2
Q
What do the ureter, bladder and urethra do?
A
Store and carry urine
3
Q
Primary function of kidneys
A
Make urine and filter waste
4
Q
Blood sources to/from kidneys
A
Renal artery and renal vein
5
Q
Where does renal artery branch from
A
Abdominal aorta
6
Q
Where do renal vein drain filtered blood to
A
Abdominal vena cava
7
Q
Outer region of the kidneys
A
Renal cortex
8
Q
Inner region of the kidneys
A
Renal medulla
9
Q
Area in kidneys where urine collects and is eventually drained via ureter
A
Renal pelvis
10
Q
Groups of tubules in medulla that drain into renal pelvis
A
Renal Pyramids
11
Q
True/false: kidneys are also endocrine producers (make hormones)
A
True
12
Q
Hormone made by kidneys that acts on bone marrow to stimulate RBC production
A
Erythropoietin (EPO)
13
Q
Are kidneys also metabolic organs?
A
Yes
14
Q
What metabolic function do kidneys carry out?
A
Gluconeogenesis
15
Q
What does the process of gluconeogenesis make glucose from?
A
Lactic acid and amino acids
16
Q
Smallest functional unit of kidneys
A
Nephron
17
Q
How many nephrons in each kidney
A
About 1 million
18
Q
2 components of nephrons
A
Vascular and Tubular
19
Q
Claw-shaped tubule that wraps around glomerulus
A
Bowman’s capsule
20
Q
Tuft of capillaries where urine production starts
A
Glomerulus
21
Q
Tubule that comes after Bowman’s capsule
A
Proximal
22
Q
What tubule comes after proximal
A
Loop of Henle (descending and ascending)
23
Q
What tubules comes after ascending
A
Distal
24
Q
Where distal tubule goes to
A
Collecting duct
25
How many nephrons are typically attached to collecting ducts
8-10
26
Where are collecting ducts found?
Medullary pyramids
27
Where do collecting ducts drain to?
Renal pelvis
28
Smallest branch of renal artery that delivers blood to glomerulus
Afferent arterioles
29
Fluid moving from glomerulus to bowman’s capsule
Glomerular filtration
30
Fluid that goes from glomerular capillaries to bowman’s capsule is the same as plasma minus what?
Cells, proteins
31
Blood not filtered by glomerulus moves to where?
Efferent arterioles
32
Blood from efferent arterioles go to this mesh-like network of capillaries that surround the nephron
Peritubular capillaries
33
Where do peritubular capillaries drain blood to?
Abdominal Vena cava
34
Structure that is very important regulator of filtration
Juxtaglomerular apparatus
35
Where is juxtaglomerular apparatus located?
In distal tubule where a V is formed by afferent and efferent arterioles
36
What does juxtaglomerular apparatus measure in distal tubule?
BP, O2, fluid rate
37
Type of nephrons located in outer cortex
Superficial cortical
38
What percent of all nephrons are superficial cortical
80%
39
Nephrons located in inner cortex near medulla
Juxtamedullary
40
Percent of nephrons that are typically juxtamedullary
20%
41
Where are glomeruli of superficial cortical and juxtamedullary nephrons only found?
In the cortex
42
Superficial cortical nephrons have short loops of henle that extend to where?
Upper medulla
43
Juxtamedullary nephrons have long loops of henle that extend to where?
Deep in medulla with tip of loop next to renal pelvis
44
What kind of vessels do superficial cortical nephrons have?
Mesh of peritubular capillaries
45
What kind of vessels do Juxtamedullary nephrons have?
Single efferent loop that runs parallel to loop of henle
46
What is single efferent loop in Juxtamedullary nephrons called?
Vasa recta
47
What shape does vasa recta form after it leaves medulla?
Mesh
48
What is function of cortical nephrons?
Make urine
49
What is function of Juxtamedullary nephrons?
Concentrate urine and conserve water
50
3 processes of urine formation?
Glomerular filtration (GF)
Tubular reabsorption (TR)
Tubular secretion (TS)
51
How much of plasma is filtered at glomerulus?
20%
52
Where does the other 80% of plasma go that isn’t filtered by glomerulus
Efferent arterioles
53
At peritubular capillaries, what gets reabsorbed from filtered fluid?
Water and solutes
54
Glomerulus and bowman’s capsules together is called what?
Renal corpuscle
55
True/false: GF is both passive and non-selective
True
56
Name 3 layers of glomerular membrane
1. Wall of glomerular capillaries
2. Basement membrane
3. Inner layer of bowman’s capsule
57
What are individual foot-like processes of bowman’s capsule inner layer called?
Podocytes
58
What is the main function of the 3 layers in glomerular membrane?
Prevent plasma proteins and cells from passing through
59
What is fluid that enters bowman’s capsule called?
Filtrate
60
Are forces of GF active or passive?
Passive
61
How much is glomerular capillary blood pressure?
55 mmHg
62
Is glomerular capillary blood pressure a push or pull force?
Push
63
How much is plasma colloid osmotic pressure?
30 mmHg
64
How much is bowman’s capsule hydrostatic pressure
15 mmHg
65
What force promotes GF and is most important?
Capillary blood pressure
66
How much is net filtration pressure?
10 mmHg
67
GF rate (GFR) is an indicator of what?
Number of functional nephrons and kidney health
68
What is GFR?
Volume of fluid filtered per minute
69
What 3 things does GFR depend on?
1. Net filtration
2. Surface area
3. Permeability of membranes
70
What is Filtration Coefficient (Kf)
Surface area x permeability
71
True/false: Kf should be a constant value in a healthy person
True
72
What is equation for GFR
Kf x net filtration
73
Why is GFR so important?
It is 1st step in urine formation
74
2 mechanisms of GFR
1. Auto regulation
2. Extrinsic sympathetic control
75
What mechanism controls GFR most of the time?
Auto regulation
76
How does auto regulation control GFR?
By preventing GFR change with normal BP changes
77
What does auto regulation change when BP fluctuates to maintain a constant GFR?
Diameter of afferent arteriole
78
What does auto regulation constrict or dilate to change afferent arteriole diameter?
Smooth muscle lining of vessel
79
What does extrinsic sympathetic control do?
Alters GFR to control blood volume
80
In what structure does GFR happen?
Juxtaglomerular Apparatus (JXA)
81
What are 2 special cells in JXA?
Granular (afferent)
Macula densa cells (distal)
82
What do macula densa cells constantly sense?
Fluid rate through distal tubule
83
If macula densa senses fluid change, what cells get a message to release vaso dilators or constrictors?
Granular cells in afferent arterioles
84
Can extrinsic sympathetic control override auto regulation?
Yes
85
What is released by sympathetic nerves in extrinsic control?
Epi and norepinephrine
86
What does epinephrine and norepinephrine attach to in afferent and efferent vessels?
Alpha adrenergic receptors
87
Is tubular reabsorption always selective?
Yes
88
Can tubular reabsorption (TR) be active or passive?
Either
89
How much of H2O filtered at capsule is reabsorbed?
99%
90
How much of glucose is reabsorbed
100%
91
How much sodium is reabsorbed
99.5%
92
How much of energy requirements of the kidneys is spent on Na+ reabsorption?
80%
93
What is only area where sodium is NOT reabsorbed?
Descending loop
94
What does sodium help reabsorb in proximal tubule?
Glucose
Aminos
H2O
Urea
95
What does reabsorption of sodium in ascending loop help?
Concentrate urine
Conserve H2O
96
What does sodium reabsorption in distal tubule and collecting duct regulate?
ECF volume and BP
97
How does sodium cross lumenal membrane
Passive channel or cotransporter
98
How does sodium leave basal membrane
ATP pump
99
Does ATP pump at basal membrane require energy?
Yes
100
Where in tubule does a lot happen in terms of sodium reabsorption
Proximal tubule
101
How does sodium cross lumenal membrane in proximal tubule?
Co-transporters for glucose, aminos or vitamins (each has specific one)
102
How do glucose, aminos, water soluble vitamins leave basal membrane
Passive facilitated diffusion carriers
103
Where is glucose filtered?
Glomerulus
104
What is max rate of reabsorption based on # of available transporters called?
Tubular maximum
105
What is amount of any substance filtered by kidneys per minute called?
Filtered load
106
What is normal plasma glucose level?
100mg/100ml
107
What is amount of glucose filtered per minute?
125mg/min
108
What is tubular maximum for glucose
375mg/min
109
What is term for maximum plasma concentration reached for any organic nutrient before it will show in urine
Renal threshold
110
What is renal threshold for glucose
300mg/ml
111
How does sodium reabsorb in ascending loop at lumenal membrane?
K+ and Cl- cotransporters
112
How does K and Cl cross basal membrane in ascending loop
Passive channel
113
How does sodium cross basal membrane in ascending loop
ATP Pump
114
What is sodium always coupled with?
Passive H2O reabsorption
115
H20 reabsorption is always active or passive?
Passive
116
What does H2O need for reabsorption
Osmotic gradient
117
Where does 80% of water reabsorption take place
Proximal tubule
118
What are 2 mechanisms of water reabsorption
Paracellular and trans cellular
119
Where are tight junctions most leaky for water to reabsorb
Proximal tubule and descending loop
120
How does sodium aid paracellular water reabsorption
Sodium pushed out along lateral wall attracts water
121
T/F: Water always moves from low to high Osmolarity
True
122
When sodium moves through a cell to interstitial space, what happens to osmolarity of interstitial space?
Increases
123
What structures help move water through membranes
Aquaporins
124
Aquaporins are always along basal membranes but only on lumenal in these parts
Proximal
Descending loop
125
Only place where water is NOT reabsorbed
Ascending loop
126
What 2 things are needed for water to reabsorb?
1. Osmotic gradient
2. Permeability (Aquaporins or leaky junctions)
127
3 substances that are secreted
H ions
K ions
Organic cations and anions (drugs, etc)
128
Where are H ions mostly secreted
Collecting duct and proximal tubule
129
How do H ions cross basal lateral membrane
ATPase pump
130
How do H ions cross lumenal membrane in proximal tubule
Sodium antiporter
131
How do H ions cross lumenal membrane in collecting duct and ascending loop
Facilitated diffusion
132
How much of filtered K is reabsorbed through passive diffusion in proximal
50%
133
How is K secreted in distal and collecting basal membrane
ATP Pump
134
T/F K reabsorption is unregulated but secretion is regulated
True
135
Why is K only secreted in distal and collecting
Only places with passive K channels on lumenal membrane
