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CH23 urinary Flashcards

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1
Q

What are the primary functions of the kidney ?

A
  • Regulating total water volume and total solute concentration in water
  • Regulating ECF ion concentrations
  • Ensuring long-term acid-base balance
  • Removal of metabolic wastes, toxins, drugs
  • Endocrine functions
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2
Q

What are the endocrine functions of the kidney?

A

–Renin - regulation of blood pressure

–Erythropoietin - regulation of RBC production

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3
Q

What is the structure marked A?

A

Adrenal Gland

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4
Q

What is the structure marked B?

A

Iliac Crest

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5
Q

What is the structure marked C?

A

Renal Artey

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6
Q

What is the structure marked D?

A

Renal Hilum

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7
Q

What is the structure marked E?

A

Renal Vein

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8
Q

What is the structure marked F?

A

Kidney

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9
Q

What is the structure marked G?

A

Ureter

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10
Q

What is the structure marked H?

A

Urinary Bladder

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11
Q

What is the structure marked I?

A

Urethra

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12
Q

What are the Kidneys?

A

major excretory organs

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13
Q

What is the function of the ureters?

A

transport urine from kidneys to urinary bladder

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14
Q

What is the urinary bladder?

A

temporary storage reservoir for urine

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15
Q

What is the function of the Urethra?

A

transports urine out of body

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16
Q

Which Kidney sits lower in the body?

A

The right

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17
Q

Why is the right kidney lower than the left?

A

Because it is crowded by the liver

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18
Q

Which gland sits atop each kidney?

A

Suprarenal adrenal gland

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19
Q

Ureters, renal blood vessels, lymphatics, and nerves enter and exit the kidney where?

A

Renal hilum

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20
Q

How many lobes do you ususally have per kidney?

A

7-8

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21
Q

Name the Layers of surrounding supportive tissue of the kidney

A
  • Renal fascia
  • Perirenal fat capsule
  • Fibrous capsule
  • Renal cortex
  • Renal medulla
  • Pyramids
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22
Q

Describe the renal fascia of the kidneys

A

•Anchoring outer layer of dense fibrous connective tissue

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23
Q

What is the function of the kidney’s perirenal fat capsule

A

fatty cushion

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24
Q

What is the function of the Fibrous capsule of the kidney?

A

•Prevents spread of infection to kidney

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25
Q

What is the Renal cortex?

A

Granular-appearing superficial region

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26
Q

What is the renal medulla made up of?

A

cone-shaped medullary (renal) pyramids separated by renal columns

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27
Q

What are the structures of the internaal anatomy of the kidney?

A
  • Papilla
  • Lobe
  • Renal pelvis
  • Minor calyces
  • Major calyces
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28
Q

What are renal papilla?

A

Tip of pyramid; releases urine into minor calyx

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29
Q

What is a renal lobe made up of?

A

Medullary pyramid and its surrounding cortical tissue

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30
Q

What is the renal pelvis?

A

–Funnel-shaped tube continuous with ureter

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31
Q

What is the function of the Minor calyces

A

Drain pyramids at papillae

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32
Q

What is the function of the Major calyces

A

–Collect urine from minor calyces

–Empty urine into renal pelvis

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33
Q

What is the pathway of urine?

A
  • Renal pyramid
  • minor calyx
  • major calyx
  • renal pelvis
  • ureter
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34
Q

What is Pyelitis?

A

–Infection of renal pelvis and calyces

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35
Q

What is Pyelonephritis ?

A

–Infection/inflammation of entire kidney

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36
Q

What is the structure Labelled A?

A

Renal Cortex

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37
Q

What is the structure Labelled B?

A

Renal medulla

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38
Q

What is the structure Labelled C?

A

Major Calyx

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39
Q

What is the structure Labelled D?

A

Papilla of Pyramid

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40
Q

What is the structure Labelled E?

A

Renal Pelvis

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41
Q

What is the structure Labelled F?

A

Minor Calyx

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42
Q

What is the structure Labelled G?

A

Ureter

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43
Q

What is the structure Labelled H?

A

Renal Pyramid in renal medulla

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44
Q

What is the structure Labelled I?

A

Renal Column

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45
Q

What is the structure Labelled J?

A

Fibrous capsule

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46
Q

Which element of blood do the kidneys filter?

A

Blood Plasma

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47
Q

What is the structure labelled A?

A

Corticol radiate vein

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48
Q

What is the structure labelled B?

A

Corticol Radiate Artery

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49
Q

What is the structure labelled C?

A

Arcurate Vein

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50
Q

What is the structure labelled D?

A

Arcurate Artery

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51
Q

What is the structure labelled E?

A

Interlobar Vein

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52
Q

What is the structure labelled F?

A

Interlobar Artery

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53
Q

What is the structure labelled G?

A

Segmental arteries

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54
Q

Name the Nephron-Associated blood vessels?

A

Afferent Arteriole

Glomerulus (Capillaries )

Efferent arteriole

Peritubular capillaries/Vasa recta

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55
Q

what is the path of blood in to the nephron?

A
  1. Aorta
  2. Renal artery
  3. segmental artery
  4. interlobar artery
  5. arcurate artery
  6. cortical radiate artery
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56
Q

What is the path of blood out of the nephron ?

A
  1. cortical radiate vein
  2. Arcurate Vein
  3. Interlobar Vein
  4. Renal Vein
  5. Inferior Vena Cava
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57
Q

What are Nephrons?

A

Structural and functional units of the kidney that form urine

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58
Q

What ae the two main parts of the nephron?

A

–Renal corpuscle

–Renal tubule

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59
Q

what are the two parts of the renal corpuscle?

A

Glomerulus

Glomerular capsule (Bowmans capsule)

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60
Q

What is the Glomerular capsule (Bowman’s capsule)

A

•Cup-shaped, hollow structure surrounding glomerulus

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61
Q

What is the glomerulus?

A

Tuft of capillaries; highly porous fenestrated endothelium allows filtrate formation

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62
Q

What is the section marked A?

A

Proximal Convoluted tube

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63
Q

What is the section marked B?

A

Thin section

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64
Q

What is the section marked C?

A

Descending Limb

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65
Q

What is the section marked D?

A

Ascending Limb

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66
Q

What is the section marked E?

A

Thick Segment

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67
Q

What is the section marked F?

A

Distal convoluted Tubule

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68
Q

What is the section marked G?

A

Collecting Duct

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69
Q

Describe the anatomy of the Glomerular capsule

A

–Parietal layer - simple squamous epithelium

–Visceral layer - branching epithelial podocytes

  • Extensions terminate in foot processes that cling to basement membrane
  • Filtration slits between foot processes allow filtrate to pass into capsular space
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70
Q

What are the three main sections of the Renal Tubule?

A

–Proximal convoluted tubule (PCT)

–Nephron loop

–Distal convoluted tubule (DCT)

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71
Q

Describe the anatomy of the Proximal convoluted tubule (PCT)

A

–Cuboidal cells with dense microvilli (brush border) large mitochondria

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72
Q

Describe the anatomy of the Nephron Loop

A

–Distal descending limb, descending thin limb; simple squamous epithelium

–Thick ascending limb; Cuboidal to columnar cells;

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73
Q

Name the two cell types found in the collecting duct

A

–Principal cells

  • Sparse, short microvilli
  • Maintain water and Na+ balance

–Intercalated cells

•Cuboidal cells; abundant microvilli; 2 types:

–A and B; both help maintain acid-base balance of blood

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74
Q

What is the primary function of collecting ducts?

A
  • Receive filtrate from many nephrons
  • Run through medullary pyramids
  • Fuse together to deliver urine through papillae into minor calyces
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75
Q

Name the two types of nephrons and where they are found.

A

Cortical Nephrons - Found almost entirely in renal cortex

Juxtamedullary nephrons - Long loops that deeply invade the medulla

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76
Q

What are Cortical nephrons

A
  • Short nephron loop
  • Glomerulus further from the cortex-medulla junction
  • Efferent arteriole supplies the peritubular capillaries
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77
Q

What are Juxtamedullary nephrons?

A

Long nephron loop

Glomerulus closer from the cortex-medulla junction

Efferent arteriole supplies the vasa recta

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78
Q

What type of nephron is pictured?

A

Cortical nephron

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79
Q

What is the most important function of a juxtamedullary nephron?

A

concentration of urine

80
Q

What type of nephron is pictured?

A

Juxtamedullary nephron

81
Q

Why is the Glomerulus (Capillary bed) different from other capillary beds in the body?

A
  • specialized for filtration
  • fed and drained by arteriole
82
Q

Why is the blood pressure in the glomerulus high?

A

–Afferent arterioles larger in diameter than efferent arterioles

–Arterioles are high-resistance vessels

83
Q

What type of capillary bed is the juxtamedullary nephron associated with?

A

Vasa Recta

84
Q

What type of capillary beds are cortical nephrons associated with?

A

Glomerulus

peritubular capillaries?

85
Q

Describe the anatomy and function of peritubular capillary beds?

A

–Low-pressure, porous capillaries adapted for absorption of water and solutes

–Arise from efferent arterioles

–Cling to adjacent renal tubules in cortex

–Empty into venules

86
Q

Describe the anatomy and function of the Vasa Recta

A

–Long, thin-walled vessels parallel to long nephron loops of juxtamedullary nephrons

–Arise from efferent arterioles serving juxtamedullary nephrons

–Function in formation of concentrated urine

87
Q

What is the primary function of the juxtaglomerular complex (JGC)

A

It is important in regulation of rate of filtrate formation and blood pressure

88
Q

What are the three cell populations found in the JGC?

A
  • Macula Densa
  • Granular cells
  • Extraglomerular mesangial cells
89
Q

Describe the anatomy and physiology of Macula Densa Cells in the JGC?

A

–Tall, closely packed cells of ascending limb

–Chemoreceptors; sense NaCl content of filtrate

90
Q

Describe the anatomy and physiology of Granular Cells in the JGC?

A

–Enlarged, smooth muscle cells of afferent arteriole

–Secretory granules contain enzyme renin

–Mechanoreceptors; sense blood pressure in afferent arteriole

91
Q

Describe the anatomy and physiology of Extraglomerular mesangial cells in the JGC?

A

–Between arteriole and tubule cells

–Interconnected with gap junctions

–May pass signals between macula densa & granular cells

92
Q

How many litres of fluid are procecessed through the kidney per day?

A

roughly 180L

93
Q

How many litres of urine are produced per day?

A

1.5L

94
Q

what are the three stages of urine production?

A

–Glomerular filtration

–Tubular reabsorption

–Tubular secretion

95
Q

What is the purpose of Glomerular filtration

A

– produces cell- and protein-free filtrate

96
Q

What is the purpose of Tubular reabsorption

A

–Selectively returns 99% of substances from filtrate to blood in renal tubules and collecting ducts

97
Q

What is the purpose of Tubular secretion

A

–Selectively moves substances from blood to filtrate in renal tubules and collecting ducts

98
Q

What is filtrate?

A

–Blood plasma minus proteins

99
Q

What is Urine?

A

–<1% of original filtrate

–Contains metabolic wastes and unneeded substances

100
Q

Describe the process of glomerular filtration?

A
  • Passive process
  • No metabolic energy required
  • Hydrostatic pressure forces fluids and solutes through filtration membrane
  • No reabsorption into capillaries of glomerulus
101
Q

What are the three layers of the filtration membrane in the glomerular capsule?

A

–Fenestrated endothelium of glomerular capillaries

–Basement membrane (fused basal laminae of 2 other layers)

–Foot processes of podocytes with filtration slits; slit diaphragms repel macromolecules

102
Q

What is the filtration membrane in the glomerulus?

A

•Porous membrane between blood and interior of glomerular capsule

–Water, solutes smaller than plasma proteins pass; normally no cells pass

103
Q
A
104
Q

What do proteins in filtrate indicate?

A

problems with the membrane

105
Q

What happens to macromolecules that get stuck in the filtration membrane

A

Engulfed by glomerular mesangial cells

106
Q

Which molecules can pass through the filtration membrane?

A

–Water, glucose, amino acids, nitrogenous wastes

107
Q

What happens to plasma proteins?

A

They remain in the blood

108
Q

Why do plasma proteins remain in the blood stream?

A
  • maintains colloid osmotic pressure
  • prevents loss of all water to capsular space
109
Q

what is the driving force behind filtrate formation?

A

Hydrostatic pressure in glomerular capillaries

110
Q

What is the Chief force pushing water, solutes out of blood

A

55 nn HG

111
Q

What are the forces inhibiting filtrate formation in the glomerular?

A

–Hydrostatic pressure in capsular space (HPcs)

•Pressure of filtrate in capsule – 15 mm Hg

–Colloid osmotic pressure in capillaries (OPgc)

•”Pull” of proteins in blood – 30 mm Hg

112
Q

What is the Sum of forces/ Net filtration pressure (NFP) in the Glomerulae?

A

–55 mm Hg forcing out; 45 mm Hg opposing = net outward force of 10 mm Hg

113
Q

Constant GFR allows kidneys to do what?

A

make filtrate and maintain extracellular homeostasis

114
Q

If GFR goes up what happens to Urine out put and blood pressure?

A

Urine output goes up and blood pressure goes down

115
Q

If GFR goes down, what happens to urine output and blood pressure?

A

Urine output goes down and blood pressure goes up

116
Q

What is the goal of extrinsoc controls in the kidneys?

A

–maintain systemic blood pressure

117
Q

What do Intrinsic controls (renal autoregulation) do ?

A

–Act locally within kidney to maintain GFR

118
Q

What are the extrinsic controls for the kidneys?

A

–Nervous and endocrine mechanisms that maintain blood pressure; can negatively affect kidney function

119
Q

When do extrinsoc controls take precedence over intrinsic controls of the kidneys?

A

if systemic BP < 80 or > 180 mm Hg

120
Q

How is GFP regulated?

A

via glomerular hydrostatic pressure (GHP):

121
Q

What happens if Glomerular Hydrostatic pressure ( GHP) rises?

A

NFP and GFR rises

122
Q

What are the two types of renal autoregulation?

A

–Myogenic mechanism

–Tubuloglomerular feedback mechanism

123
Q

Explain the myogenic mechanism

A

If BP rises, muscle stretch causing constriction of afferent arterioles and restricts blood flow into glomerulus

If BP is low, afferent arterioles dilate

124
Q

How does the Tubuloglomerular Feedback Mechanism work?

A
  • Negative feedback loop
  • If GFR high, the afferent arteriole constricts
  • If GFR low, afferent arterion dilates
125
Q

how does the extrinsic/SNS function in the kidney?

A

•If extracellular fluid volume extremely low (blood pressure low):

–Norepinephrine released by SNS; epinephrine released by adrenal medulla à

  • Systemic vasoconstriction occurs, increasing blood pressure
  • GFR à increased blood volume and pressure
126
Q

what is the : Renin-Angiotensin- Aldosterone Mechanism?

A

Main mechanism for increasing blood pressure

127
Q

What are the 3 pathways to renin release by granular cells in the kidney?

A

–Direct stimulation of granular cells by SNS

–Stimulation by activated macula densa cells when filtrate NaCl concentration low

–Reduced stretch of granular cells

128
Q

Which chemicals do the kidneys release that act as paracrines that affect renal arterioles?

A

–Adenosine

–Prostaglandin E2

–Intrinsic angiotensin II – reinforces effects of hormonal angiotensin II

129
Q

What is the Selective transepithelial process?

A

–~ All organic nutrients reabsorbed

–Water and ion reabsorption hormonally regulated and adjusted

130
Q

What are the two active and passive routes of tubular reabsorption?

A

–Transcellular or paracellular

131
Q

Explain the transcellular route of reabsoprtion in the kidneys

A

–Apical membrane of tubule cells

–Cytosol of tubule cells

–Basolateral membranes of tubule cells

–Endothelium of peritubular capillaries

132
Q

Explain the paracelllular route of reabsorption in the kidneys

A

–Between tubule cells

•Limited by tight junctions, but leaky in proximal nephron

–Water, Ca2+, Mg2+, K+, and some Na+ in the PCT

133
Q

What is the Transport maximum (Tm)?

A

for ~ every reabsorbed substance; reflects number of carriers in renal tubules available

134
Q

What happens when transport carriers reach maximum?

A

The excess of the given substance is excreted in the urine

135
Q

Which is the site of most Absorption?

A

PCT

136
Q

What is absorbed at the PCT?

A
  • All nutrients, e.g., glucose and amino acids
  • 65% of Na+ and water
  • Many ions
  • All uric acid; ½ urea
137
Q

What filters out at the descending limb of the nephron loop?

A

Water, solutes cannot

138
Q

What filters out at the ascending limb of the nephron loop?

A

Solutes, H20 cannot

139
Q

What is the mechanism in the thin segment of the nephron loop?

A

passive Na+ movement

140
Q

What mechanisms are in use in the thick segment of the nephron loop?

A

Na+-K+-2Cl- symporter and Na+-H+ antiporter; some passes by paracellular route

141
Q

How is reabsorption regulated at the DCT and Collecting duct

A

Hormonal

  • Antidiuretic hormone (ADH) – Water
  • Aldosterone – Na+ (therefore water)
  • Atrial natriuretic peptide (ANP) – Na+
  • PTH – Ca2+
142
Q

What is the effect of Antidiuretic hormone (ADH) on DCT and collecting ducts?

A

–Causes principal cells of collecting ducts to insert aquaporins in apical membranes increasing water reabsorption

143
Q

What happens as levels of ADH increase in renal tubules and collecting ducts?

A

Water absorption increases

144
Q

What is the function of aldosterone in renal tubules and collecting ducts

A

increase blood pressure; decrease K+ levels

145
Q

What is the function of Atrial natriuretic peptide in renal tubules and collecting ducts?

A

Parathyroid hormone acts on DCT to increase Ca2+ reabsorption

146
Q

Where does the majority of tubular secretion occur?

A

PCT

147
Q

What substances are secreted at the PCT?

A
  • drugs
  • urea and uric acid
  • excess K+
148
Q

what is the function of tubular secretion in the PCT?

A

•Controls blood pH by altering amounts of H+ or HCO3– in urine

149
Q

What is the mechanism by which the kidneys regulate urine volume and regulation?

A

Countercurrent mechanism

150
Q

What is the most important factor in the regulation of urine volume and concentration?

A

Osmolarity

151
Q

What is the countercurrent mechanism?

A

•Occurs when fluid flows in opposite directions in 2 adjacent segments of same tube with hair pin turn

152
Q

What is the countercurrent multiplier?

A

interaction of filtrate flow in ascending/descending limbs of nephron loops of juxtamedullary nephrons

153
Q

What is the countercurrent exchanger

A

Blood flow in ascending/descending limbs of vasa recta

154
Q

What is the role of the countercurrent mechanisms?

A

–Establish and maintain osmotic gradient (300 mOsm to 1200 mOsm) from renal cortex through medulla

–Allow kidneys to vary urine concentration

155
Q

What occurs in the descending limb as part of the countercurrent mechanism?

A

–Freely permeable to H2O

–H2O passes out of filtrate into hyperosmotic medullary interstitial fluid

–Filtrate osmolality increases to ~1200 mOsm

156
Q

What occurs in the ascending limb during the countercurrent mechanism?

A

–Impermeable to H2O

–Selectively permeable to solutes

•Na+ and Cl– actively reabsorbed in thick segment; some passively reabsorbed in thin segment

–Filtrate osmolality decreases to 100 mOsm

157
Q

How is the Constant 200 mOsm difference between 2 limbs of nephron loop and between ascending limb and interstitial fluid maintained?

A

•Difference “multiplied” along length of loop to ~ 900 mOsm

158
Q

What is the role of the Vasa Recta in the countercurrent mechanism?

A
  • Vasa recta
  • Preserve medullary gradient

–Prevent rapid removal of salt from interstitial space

–Remove reabsorbed water

Water entering ascending vasa recta either from descending vasa recta or reabsorbed from nephron loop and collecting duct

159
Q

Which Nephrons create an osmotic gradient within the renal medulla that allows the kidney to produce urine of varying concentration

A

Juxtamedullary nephrons

160
Q

What type of feedback loop is the countercurrent mechanism?

A

Positive feedback loop

161
Q

Which three properties of the nephron establish the osmotic gradient?

A
  • Countercurent movement
  • Descending limb is permeable to water and not salt
  • Ascending limb is impermeable to water and pumps out salt
162
Q

filtrate entering the nephron loop is….

A

isosmotic to both blood pasma and cortical interstitial fluid

163
Q

In the descending limb filtrate is…

A

concentrated as water moves down the osmotic gradient into the interstitial medullar

164
Q

filtrate reaches it’s highest concentration at the

A

bend of the nephron loop

165
Q

What occurs in the ascending limb

A

na+ and Cl- are pumped out increasing interstitial fluid osmolarity

166
Q

filtrate is at it’s most dilute (hypo-osmotic)

A

as it leaves the nephron loop

167
Q

Which chemicals enhance urinary output

A
  • ADH inhibitors, e.g., alcohol
  • Na+ reabsorption inhibitors, e.g., caffeine, drugs for hypertension or edema
  • Loop diuretics
  • Osmotic diuretics
168
Q
  1. What factors must be assesed to examine renal function?
A

both blood and urine

169
Q

How do we calculate renal clearance rate?

A

•C = UV/P

Clearance= concentration of substance in urinexflow rate of urine/concentration of same substance in plasma

170
Q

Which substance is used as the standard when calsculating renal clearance rate?

A

Inulin(Plant polysaccharide)

171
Q

What does GFR < 60 ml/min for 3 months indicate?

A

Chronic renal disease

172
Q

What does a GFR < 15 ml/min indicate

A

Renal failure

173
Q

What are the normal characteristics of urine?

A

–Clear

–Pale to deep yellow from urochrome

–Slightly aromatic when fresh

  • PH 6 (slightly acidic)
  • Specific gravity should be 1.001 to 1.035
  • •95% water and 5% solutes
174
Q

•Abnormally high concentrations of any constituent, or abnormal components, e.g., blood proteins, WBCs, bile pigments in the urine could indicate what?

A

indicates pathology

175
Q

What is the function of ureters?

A

Convey urine from kidneys to bladder

176
Q

What are the three layers of the ureter

A
  1. Mucosa (inner)
  2. Muscularis (middle layers)
  3. Adventitia (external)
177
Q

what are renal calculi?

A

kidney stones in the renal pelvis

178
Q

What is the treatment for renal calculi?

A

shock wave lithotripsy

179
Q

What is the urinary bladder?

A

•Muscular sac for temporary storage of urine

180
Q

What is the trigone?

A
181
Q

Where do urine infections tend to be most prolific?

A

in the trigone

182
Q

Name the three layers of the urinary bladder

A

–Mucosa - transitional epithelial mucosa

–Thick detrusor - 3 layers of smooth muscle

–Fibrous adventitia (peritoneum on superior surface only)

183
Q

What is the normal size and volume of the full bladder?

A

12 cm long; holds ~ 500 ml

184
Q

What is the urethra

A
  • Muscular tube draining urinary bladder
  • Lining epithelium
  • Mostly pseudostratified columnar epithelium,
185
Q

Name the sphincters in the urethra

A

–Internal urethral sphincter

•Involuntary (smooth muscle)

–External urethral sphincter

•Voluntary (skeletal) muscle

186
Q

Name the three regions of the male urethra

A
  • prostatic
  • intermediate
  • spongy
187
Q

Which three mechanisms are required for urination/voiding to occur

A
  1. Contraction of detrusor by ANS
  2. Opening of internal urethral sphincter by ANS
  3. Opening of external urethral sphincter
188
Q

What is micturition?

A

•Reflexive urination (urination in infants)

189
Q

At what age to pontine control centers mature?

A

•between ages 2 and 3

190
Q

What is the usual reason for incontinence?

A

weakened pelvic muscles

191
Q

What is Stress incontinence?

A

•Increased intra-abdominal pressure forces urine through external sphincter

192
Q

What is Overflow incontinence?

A

Urine dribbles when bladder overfills

193
Q

What are the common reasons for urinary retention?

A

–Common after general anesthesia

–Hypertrophy of prostate

194
Q

what are the three most common congenital abnormalities in the kidneys

A

Horseshoe kidney

Hypospadias

Polycyctic kidney disease

195
Q

Which bacteria accounts for 80% of urinary tract infections?

A

E.coli

Bio 151 (12 decks)

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