[LEC] LESSON 2: RENAL MORPHOLOGY AND FUNCTION Flashcards
1
Q
-organ responsible for urine formation
A
Kidneys
2
Q
-bean-shaped paired organs that represent 0.5% of the total body weight
A
Kidneys
3
Q
-carries urine from the kidneys to the urinary bladder
A
Ureters
4
Q
-Approximately 25cm in length
A
Ureters
5
Q
-stores urine
A
Urinary Bladder
6
Q
-shaped like a 3-sided pyramid
A
Urinary Bladder
7
Q
-delivers urine for excretion
A
Urethra
8
Q
—area of attachment through which the blood vessels and nerves pass into and out of the kidneys
A
*Hilus
9
Q
—blood vessel through which blood enters the kidney
A
*Renal artery
10
Q
—blood vessel through which blood leaves the kidney
A
*Renal vein
11
Q
—outer layer of the kidney about 1.4cm thick which serves as the exclusive site for plasma filtration
A
*Renal cortex
12
Q
—portions of the cortex that extend between renal pyramids
A
*Renal columns
13
Q
—inner region that has a stringy macroscopic appearance-Contains the collecting ducts
A
Renal medulla
14
Q
—any of the conical masses that project as renal papillae into the renal pelvis
A
•Renal pyramids/Malphigian pyramid
15
Q
—overlying the cortex area
A
•Renal lobe
16
Q
—cup-like divisions of the renal pelvis surrounding one or more renal papillae
A
•Calyces (major and minor)
17
Q
—funnel-shaped structure that is formed at one end by the expanded upper portion of the ureter
A
•Pelvis
18
Q
—functional unit of the kidney located mostly in the cortex Each kidney contains 1 to 1.5 million nephrons
A
•Nephron
19
Q
TWO TYPES OF NEPHRON
A
- Cortical Nephrons
- Juxtamedullary Nephrons
20
Q
-Comprise approximately 85% of the total number of nephrons
-Function for urine concentration
A
Cortical Nephrons
Juxtamedullary Nephrons
21
Q
-Primarily located in the cortex and function for tubular reabsorption and secretion
-Have loops of Henle that extend into the medullary region
A
Juxtamedullary Nephrons
22
Q
COMPONENTS OF A NEPHRON
A
I. Renal Corpuscle
II. Renal Tubules
III. Collecting Duct
23
Q
-Tuft of capillaries within the Bowman’s capsule
A
Glomerulus
24
Q
-Structure that surround the glomerulus
A
•Bowman’s capsule
25
-Has a bigger lumen and carries blood to the glomerulus
•Afferent arteriole
26
-Has a smaller lumen and carries blood from the glomerulus
•Efferent arteriole
27
-Has a convoluted portion and a straight portion which becomes the Loop of Henle once it reaches the medulla
•Proximal Convoluted Tubule (PCT)
28
-Thin Descending Segment-U-Shaped Segment
-Thin and Thick Ascending Segment
•Loop of Henle
29
-Composed of 2 to 3 loops and begins at the juxtaglomerular paratus with the macula densa
•Distal Convoluted Tubule (DCT)
30
-Serves as the site of final urine concentration
III. Collecting Duct
31
Renal Physiology
I. RENAL BLOOD FLOW
II. Glomerular Filtration
III. TUBULAR REABSORPTION
32
-Directly affects the kidney’s functional ability
-1,200 ml/minute
RENAL BLOOD FLOW
33
Renal Plasma Flow:
600-700 ml/min
34
-process that involves the filtration of blood which leads to the formation of the ultrafiltrate
Glomerular Filtration
35
-Coil of ~8 capillary lobes (capillary tuft)
-Non-selective filter of plasma substances with MW of <70,000 Da
Glomerulus
36
Factors affecting filtration
a.Filtration Barrier
b.Net Filtration Pressure
c.Feedback mechanism of RAAS
37
: increases permeability
Fenestrated endothelium
38
: provides further restriction of main size discriminant barrier to protein passage
Basement membrane
39
: afforded by negatively charged components provides additional restriction by repelling positively-charged molecules
Shield of Negativity
40
: with intertwining foot processes (podocytes) forms filtration slitss
Visceral epithelium
41
-Pressure that forces substances from the glomerular capillaries into the Bowman’s capsule
Net Filtration Pressure
42
-pressure in the glomerular capillaries forcing water and solutes through filtration slits
Glomerular Blood Hydrostatic Pressure (GBHP)
43
-Pressure exerted against the filtration membrane by fluid already in the capsular space
Capsular Hydrostatic Pressure (CHP)
44
Blood Colloid Osmotic Pressure (BCHP)-Pressure exerted by the proteins in blood plasma
45
-Regulates the blood flow to and within the glomerulus
-Responds to changes in blood pressure and plasma sodium concentration
-Juxtaglomerular apparatus: (?)
Renin-Angiotensin-Aldosterone System (RAAS)
juxtataglomerular cells + macula densa
46
Effects of Angiotensin II
-Release of (?) to increase Na reabsorption (DCT)
-Release of (?) to increase water reabsorption (CD)
-constriction of (?) to increase blood pressure
ALDOSTERONE
Antidiuretic Hormone (ADH)
efferent arterioles
47
-Essential substances are returned to the circulation
-Substances are transported from the filtrate back to the blood
TUBULAR REABSORPTION
48
Reabsorption Mechanisms:
a. Active transport
b. Passive transport
49
-Substance must combine with a carrier protein
-Transfer of substance is brought about by the electrochemical energy
Active transport
50
-Movement of molecules across a membrane by diffusion because of a physical gradient
Passive transport
51
ACTIVE TRANSPORT
PCT:
ALH:
PCT and DCT:
glucose, amino acids, salts
Cl ions
Na and Cl ions
52
PASSIVE TRANSPORT
All areas except ALH:
PCT and ALH:
ALH:
water
urea
Na and Cl ions
53
: major site (65%) of reabsorption
Proximal Convoluted Tubule
54
Urine Concentration
-Begins in the (?)
-Final urine concentration begins in the (?) and continues up to the
-Affected by the two hormones
Loop of Henle
late DCT
CD
55
-responds to the body’s need for Na
-promotes Na reabsorption in the DCT
-responds to the body’s need for water
-promotes water reabsorption in the DCT and CD
Countercurrent Mechanism
-DLH: (?) is reabsorbed
-ALH: (?) are reabsorbed
1. Aldosterone
2. Antidiuretic Hormone
water
Na and Cl ions
56
-Movement of substances from the blood in renal capillary beds to the filtrate in the tubular lumen
TUBULAR SECRETION
57
2 major functions:
1.Elimination of waste products not filtered by the glomerulus
2.Regulation of acid-base balance through H+ ion secretion
58
GLOMERULAR FILTRATION TESTS
ENDOGENOUS: 1.CREATININE CLEARANCE 2.UREA CLEARANCE 3.BETA2MICROGLOBULIN 4.CYSTATIN-C B.EXOGENOUS: 1.INULIN CLEARANCE 2.RADIOISOTOPES
59
TUBULAR REABSORPTION TESTS
FISHBERG B.MOSENTHAL C.OSMOLARIITY D.FREE WATER CLEARANCE 1.FREEZING POINT 2.VAPOR PRESSURE
60
TUBULAR SECRETION TESTS:
A.PHENOLSULFONA PHTHALEIN (PSP)
B.PAMINOHIPPURIC ACID (PAH)
C.TITRATABLE ACIDITY
D.URINARY AMMONIA
61
Procedures performed to determine the ability of the kidneys to carry out its metabolic functions
RENAL FUNCTION TESTS
62
–Standard test used to determine the filtering capacity of the glomeruli
Clearance Test
63
1. Some creatinine is secreted by the tubules, and secretion increases as (?)
blood level rise
64
2. (?) is secreted by the tubules, and secretion increases as blood present in human plasma react in the chemical analysis.
Chromogens
65
3. Medications, including (?) inhibit tubular secretion of creatinine
gentamicin, cephalosporins, and cimetidine (Tagamet)
66
4. (?) will break down urinary creatinine if specimens are kept at room temperature for extended periods.
Bacteria
67
5. An increased intake of (?) can raise the urine and plasma levels of creatinine during the Measurement of hour collection period.
meat
68
7. Accurate results depend on the accurate completeness of a (?)
24 hour collection.
69
8. It must be corrected for (?), unless normal is assumed, and must always be corrected for children.
body surface area
70
Measurement of creatinine clearance not a reliable indicator in patients suffering from (?) or persons involved in heavy exercise or (?) supplementing with creatine
muscle wasting diseases
athletes
71
creatinine suffering from muscle clearance is not a reliable indicator in patients wasting diseases or persons involved in heavy exercise or athletes supplementing with creatine
72
Formulas developed to provide estimates of the GFR based on the (?) without the urine creatinine
serum creatinine
73
-most frequently used formula-used to evaluate patient placement on kidney transplant lists
1. Cockcroft and Gault
74
* Multiply results by (?) for female patients
0.85
75
2. Modification of Diet in Renal Disease (MDRD) System Formula
GFR = 170 x serum creatinine - 0.999 x age -0.176 x [0.822 (if patient is female)] x [1.1880(if patient is black)] x BUN-0.170 x serum albumin + 0.318
76
By far the greatest source of error in any clearance procedure utilizing urine is the use of
improperly timed urine specimens
77
Routinely performed for screening glomerular filtration
UREA CLEARANCE
78
First substance to be used for clearance test
UREA CLEARANCE
79
Readily-filtered but partially reabsorbed by the renal tubules
UREA CLEARANCE
80
Measures renal functions and is not specific for glomerular filtration
UREA CLEARANCE
81
No longer performed
UREA CLEARANCE
82
dissociates from HLA at a constant rate and is rapidly removed from the plasma by glomerular filtration
BETA2MICROGLOBULIN
83
not reliable on patients with a history of immunologic disorders or malignancy
BETA-2-MICROGLOBULIN
84
produced at a constant rate by all nucleated cells
CYSTATIN-C
85
readily filtered by the glomerulus and reabsorbed and broken down by the renal tubular cells
CYSTATIN-C
86
recommended for pediatric, diabetic, geriatric and critically-ill patients
CYSTATIN-C
87
test requires an infused substance
Exogenous Clearance Test
88
stable exogenous substance, neither reabsorbed nor secreted by the tubules
INULIN
89
provides filtration a method through for the determining plasma disappearance enables glomerular of the radioactive filtration
Injecting 125 radionucleotides Iiothalamate
90
This in material one or and both procedure kidneys can measure kidney .
Injecting 125 radionucleotides Iiothalamate
91
used to evaluate tubular reabsorption
Concentration Test
92
stable exogenous substance, neither reabsorbed nor secreted by the tubules
FISHBERG
93
volume and specific gravity comparison of day and night urine samples
MOSENTHAL
94
Influenced by the numberand densityof particles in a solution
SPECIFIC GRAVITY
95
Influenced by the numberof particles in a solution
OSMOLARITY
96
Based on the measurement of colligative properties
OSMOLARITY
97
Osmometers:
1. Freezing Point Osmometers
2. Vapor Pressure Osmometers
98
Normal Serum Osmolarity:
275 to 300 mOsm
99
Normal Urine Osmolarity:
50 to 1400 mOsm
100
Normal Urine to Serum Osmolarity Ratio is
1:1 to 3:1
101
evaluates the ability of the kidney to respond to the body’s state of hydration
FREE WATER CLEARANCE
102
FREE WATER CLEARANCE
Interpretation of Results:
(-):
less water is being excreted
103
FREE WATER CLEARANCE
Interpretation of Results:
0:
no renal concentration or dilution
104
FREE WATER CLEARANCE
Interpretation of Results:
(+):
excess water is being excreted
105
Determine solution measured the by freezing point supercooling amount of of sample approximately 27C
FREEZING POINT OSMOMETERS
106
1 Osm or 1000m Osm/kg of H2O will lower the freezing of point H2O by 1.86C
Clinical osmometers use solutions of known NaCl concentration as their reference standards because a solution of partially ionized substances is more representative of urine and plasma composition
107
The by depression solute of dew point temperature by solute parallels the decrease in vapor pressure, thereby providing a in vapor measure this colligative property
uses microsamples of less than 0.01 mL; therefore, care must be taken to prevent any evaporation of the sample prior to testing
Used primarily to analyze serum and sweat microsamples for disorders not related to renal function, such as cystic fibrosis
VAPOR PRESSURE OSMOMETERS
108
Non-toxic substance loosely bound to plasma proteins
p-Aminohippuric Acid Test
109
Completely removed as the blood passes through the peritubular capillaries
p-Aminohippuric Acid Test
110
Historically used to evaluate tubular secretion and renal blood flow
2. Phenolsulfonphthalein Test
111
Obsolete, hard to interpret
2. Phenolsulfonphthalein Test
112
Evaluates the ability of the kidneys to produce an acid urine
Titrable Acidity and Urinary Ammonia
113
Sample required: fresh or toluene-preserved urine collected at 2-hour intervals
Titrable Acidity and Urinary Ammonia
114
Patient is primed with an acid load of oral ammonium chloride
Titrable Acidity and Urinary Ammonia
115
Amount of free H+ and total acidity is determined
Titrable Acidity and Urinary Ammonia
116
Evaluates unilateral kidney disease-Involves the intravenous administration of 100 mg indigo carmine
Indigo Carmine Test
