1.4 PHYSIOLOGY - Renal Flashcards
(108 cards)
1
Q
Waste product from proteins
A
Urea
2
Q
Waste product from purines
A
Uric Acid
3
Q
Waste product from muscles
A
Creatinine
4
Q
Waste product from RBCs
A
Bilirubin
5
Q
3 functions of the kidney
A
- Excretion
- Homeostasis
- Secretion
6
Q
Renal Circulation
A
Renal Artery –> Segmental Artery –> Interlobar Art. –> Arcuate Art –> Interlobular (Cortical radiate/Radial Art) –> Afferent Arteriole –> Glomerular Capillaries –> Efferent Arteriole –> Peritubular capillaries/Vasa recta –> Interlobular Vein –> Arcuate Vein –> Interlobar –> Segmental –> Renal Vein
7
Q
Organs that produce glucose during starvation state
A
Liver and Kidney
8
Q
Define Urine
A
an ultrafiltrate of blood
9
Q
Location of the kidney
A
T12-L3
10
Q
Weight of the kidney
A
150g
11
Q
Basic parts of the kidney from lateral to medial
A
Capsule Cortex Medulla Renal Papilla Renal Calyces (Major and Minor) Renal Pelvis
12
Q
Only capillaries in the human body that leads to arterioles and not venules
A
Glomerular capillaries
13
Q
2 types of nephrons
A
Cortical and JM nephrons
14
Q
Capillaries of cortical nephrons
A
Peritubular capillaries
15
Q
Capillaries of JM nephrons
A
Vasa recta (Peritubular capillary)
16
Q
Capacity of the bladder
A
600ml
17
Q
Volume when urge to urinate is felt
A
150ml (25% filled)
18
Q
Reflex contraction of bladder
A
300ml
19
Q
Stretch sensitive muscle of the bladder
A
Detrussor
20
Q
Voluntary sphincter of the urethra
A
External urethral sphincter
21
Q
Involuntary sphincter of the urethra
A
Internal urethral sphincter
22
Q
Number of nephrons per kidney
A
1 Million
23
Q
Nephrons cannot be regenerated. True or false?
A
True
24
Q
2 Major parts of the nephron
A
- Renal Corpuscle
2. Renal Tubular System
25
How many percent damage until compensatory hypertrophy of the kidneys?
75%
26
Differentiate cortical nephrons and JM nephrons based on:
Percentage
Location
Loops of Henle
Capillary Network
Percentage 75% Cortical - 25%JM
Location - Cortical, JM
Loops of Henle - Short LH - Long LH
Capillary Network - Peritubular capillaries - Vasa recta
27
3 barriers to filtration in the glomerulus
1. Endothelial Cell
2. Basement Membrane
3. Podocytes
28
Cells that secrete renin
JG Cells
29
Podocytes contain
1. Foot processes
| 2. Filtration Slits
30
Components of the basement membrane
Type IV Collagen
| Lainin, Agrin, Perlecan, Fibronectin
31
Function of the Macula Densa
Monitor Na concentration and consequently blood pressure
32
Where are JG Cells and Macula Densa found?
Mnemonic: "JGA, MD"
JG - Afferent Arteriole
MD - Macula Densa Distal tubule
33
Workhorse of the nephron
PCT
34
Parts of the loop of henle
Descending limb
Thin ascending limb
Thick ascending limb
35
Parts of the distal tubule
Early and Late
36
Substances that are filtered only
Inulin and Creatinine
37
Substances that are filtered and partially reabsorbed
Many electrolytes
38
Substances that are filtered and completely reabsorbed
Glucose, Amino acids
39
Substances that are filtered and secreted
PAH, Organic acids and bases
40
Define filtration fraction
Fraction of renal plasma flow that is filtered
GFR/RPF
41
Normal filtration fraction
20%
42
Filterability of substances accdg to size
Water>Na, Glucose, Inulin>Myoglobin>Albumin
43
Filterability of substances accdg to charge
Positive Substances>Neutral>Negative Substances
44
Formula for GFR
GFR = Kf [(Pgc -Pbs) - (Ogc - Obs)]
45
Net filtration pressure
10 mmHg
46
Glomerular hydrostatic pressure
60mmhg
47
Bowman's capsule pressure
18 mmHg
48
glomerular oncotic pressure
32 mmHg
49
Describe the effect on GFR:
Afferent arteriole dilate
Increase
50
Describe the effect on GFR:
Aferrent arteriole constrict
Decrease
51
Describe the effect on GFR:
Eferrent arteriole dilate
Decrease
52
Describe the effect on GFR:
Eferrent arteriole constrict moderately
Increase
53
Describe the effect on GFR:
Eferrent arteriole constrict severely
Decrease
(Albumin collects in the glomerulus)
Gibbs-Donnan Effect
54
Describe the effect on GFR:
GC hydrostatic pressure increased
Increase
55
Describe the effect on GFR:
GC oncotic pressure increased
Decrease
56
Describe the effect on GFR:
BS hydrostatic pressure increased
Decrease
57
Describe the effect on GFR:
Kf increased
Increase
58
What are the causes of decreased Kf?
Renal diseases
DM
HTN
59
What is the cause of increased BS hydrostatic pressure?
Urinary tract obstruction
60
What are the causes of decreased GC hydrostatic pressure?
```
Hypotension (dec arterial pressure)
ACE-I (decreased eferrent arteriole constriction)
Sympathetic activity (inc aferrent arteriole constriction)
```
61
What are the hormones that will increase GFR?
EDRF, PGE2, PGI2, Bradykinin, Glucocorticoids, ANP, BNP
62
Which hormone will preserve GFR?
Angiotensin II
Preferentially constricts eferrent arteriole
Net effect is a decrease in GFR but only slightly hence preserves GFR
63
Blood flow is greater where?
Cortex or medulla?
Cortex
64
Local autoregulation of renal blood flow is exhibited at a BP range of?
75-160 mmHg
65
What do you call massive sympathetic stimulation that results in massive vasoconstriction of the kidneys?
CNS Ischemic Response
66
Other name for tubuloglomerular feedback
Macula densa feedback
67
Feedback mechanism that is responsible for autoregulation of GFR at a BP of 75-160 mmHg
Tubuloglomerular feedback
68
Action of adenosine in tubuloglomerular feedback
Vasoconstricts afferent arteriole
69
Action of nitric oxide in tubuloglomerular feedback
Vasodilates aferrent arteriole
70
Illustrate regulation of GFR in scenarios of High and low BP.
Pathways at Page 19 of handouts
71
Define glomerulotubular balance
Percentage of solute reabsorbed is held constant; Buffers effect of drastic GFR changes in urine output.
72
Define Renal threshold
Substances start to appear in the urine.
| SOME nephrons exhibit saturation.
73
Define renal transport maximum.
ALL excess substances appear in the urine.
| ALL nephrons exhibit saturation.
74
Some solutes do not have a transport maximum or threshold. What is this principle and how does this happen?
Gradient-Time transport
Rate of transport is dependent upon electrochemical gradient, membrane permeability and time.
Occurs for active and passive transport. The greater the concentration, the greater the flow rate and vice versa.
75
Tubule with the highest number of mitochondria
PCT
76
Lining of the PCT
Low columnar with extensive brush border (microvilli)
77
Percent of glucose and amino acids reabsorbed in the PCT.
| Percent of NaCl and H20 rebasorbed in the PCT.
100%
| 66%
78
Which substances are rapidly filtered and almost none are reabsorbed in the PCT?
H+, Organic acids, bases, (bile salts, oxalate, urate and catecholamines) and drugs
79
Which is more hyperonic relative than the other? The fluid entering the PCT or the fluid leaving the PCT?
None. Isoosmotic.
80
Permeability of the loop of henle
"ASIN DING LIMB"
Descending limb
IMPERMEABLE to solutes
Permeable to water
Ascending limb
PERMEABLE to solutes
IMPERMEABLE to water
81
Histology of the thin and thick segments of the loop of henle
Thin segment - simple squamous with no brush border and few mitochondria
Thick segment - simple cuboidal
82
Percent of water reabsorbed in the loop of henle.
20%
83
Percent of Na, K, Cl reabsorbed in the loop of Henle
25%
84
Where is Mg2+ mainly reabsorbed?
Loop of henle
85
Hydrogen is secreted in the LH via the
Na-H countertransport
86
The distal tubule is divided into the
First part and second part
87
Histology of the distal tubule
Simple cuboidal without brush border
88
What is contained in the first part of the distal tubule?
JGA - macula densa, JG cells, lacis cells
89
Permeability of water in the first part of the distal tubule?
Relatively impermeable to water (similar to thick segment of the LH)
90
Structures contained in the second part of the distal tubule.
Principal cells
| Intercalated cells
91
The second part of the distal tubule is responsive to which hormone?
Aldosterone
92
Absorption and secretion of principal and intercalated cells?
"PRINCIPE K"
Principal cells- secrete K, Absorb Na+ and H2O
Intercalate cells - secrete H+ , absorb K
93
Channels for absorption of Sodium in principal cells
ENaC channels
94
Secretion of H+ in intercalated cells is possible through the
H-ATPase pump
| Na-H countertransport
95
Histology of collecting ducts
Cuboidal with well defined boundaries between cells
96
Site for regulation of final urine volume and concentration
COllecting ducts
97
Main hormone acting on the collecting ducts
Vasopressin
98
Collecting duct is permeable to ____ and secrets ____
Urea, H+ ions
99
What happens to tubular reabsorption and tubular secretion when peritubular capillary hydrostatic pressure increases?
Reabsorption decrease
| Secretion increase
100
What happens to tubular reabsorption and tubular secretion when peritubular capillary oncotic pressure increases?
Reabsorption increase
| Secretion decrease
101
Determine the site of action and effect of the hormone.
Aldosterone
DT and CD
Inc Na reabsorption
Inc H20 reabsorptiom
Inc K secretion
Inc H secretion
102
Determine the site of action and effect of the hormone.
ANP and BNP
DT and CD
Dec Na reabsorption
103
Determine the site of action and effect of the hormone.
Dopamine
PCT
Dec Na and water reabsorption
104
Determine the site of action and effect of the hormone.
Uroguanylin, Guanylin
PCT CD
Dec water and Na reabsorption
105
Determine the site of action and effect of the hormone.
PTH
PCT TAL LH
Dec phosphate reabsorption (phosphate trashing hormone)
Inc Ca reabsorption
Stimulates 1 alpha hydroxylase
106
What are the triggers of ADH secretion?
Inc plasma osmolarity
Dec blood pressure
Dec blood volume
107
What is the effect of alcohol on ADH secretion?
Dec ADH
108
Which hormone secreted by DT and CD acts similar to ANP?
urodilatin
