Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Renal > Physiology > Flashcards

Physiology Flashcards

1
Q

What is osmolarity?

A

Concentration of osmotically active particles in a solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the units of osmolarity?

A

mosmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is osmolarity calculated?

A

Molar concentration of a solution (e.g. 150mM)
and
number of osmotically active particles present (Na+, Cl- = 2 particles)
150 *2= 300

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the osmolarity of plasma?

A

300mosmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is tonicity?

A

The effect on the cell that a solution has on it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is an isotonic solution?

A

Causes no change to cell volume. Water balance is the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a hypotonic solution?

A

Water moves from solution to cell since less water in cell.

Causes lysis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a hypertonic solution?

A

Water concentration is higher inside cell than outside so cell loses water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What makes up Total Body Water?

A 
Intracellular fluid (66%)
Extracellular fluid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What separates ICF and ECF?

A

Plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is included in ECF?

A

Lymph
Plasma
Interstitial fluid (80%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What tracer is used to measure total body water?

A

3H20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What tracer is used to measure ECF ?

A

Inulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What tracer is used to measure plasma?

A

Labelled albumin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is included in insensible losses?

A

Loss of water from skin by passive diffusion and lungs by expiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In relation to Na+ and Cl- where is most of it found?

A

Extracellular fluid, bathing the cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where is most K+ found?

A

Intracellular fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is fluid shift?

A

The movement of water between ICF and ECF in response to an osmotic gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What three factors affect fluid homeostasis?

A

Change in [water]
Change in [NaCl]
Gain or loss of isotonic fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why can small K+ changes cause such big differences?

A

It is ICF so has bigger impact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is glomerular filtration?

A

Bloods enters in afferent arteriole and is filtered through the glomerulus to the Bowman’s capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is tubular reabsorption?

A

While filtrate is in proximal convoluted tubule it has the opportunity to be reabsorbed back into the efferent arteriole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is tubular secretion?

A

While in the efferent arteriole, material may be transferred to PCT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is rate of filtration?

A

Mass of a substance filtered into the Bowman’s capsule per unit time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the equation for rate of filtration?

A

Concentration of substance in plasma X GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is GFR?

A

Glomerular filtration rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the equation of rate of excretion?

A

Concentration of X in urine X urine flow rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

If the total amount filtered is significantly more than the amount excreted what has happened?

A

Significant reabsorption has occurred.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the 3 barriers to filtration in the glomerulus?

A

Glomerular capillary endothelium
Basement membrane
Podocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the basement membrane made of?

A

Glycoproteins and collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does the basement membrane act as a barrier to filtration?

A

Has a net negative charge so repels negatively charged plasma proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the forces called that balance hydrostatic and oncotic pressures?

A

Starling Forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

In the kidney, what are the 4 forces which contribute to the net filtration pressure?

A

Glomerular BP
Bowman’s capsule hydrostatic pressure
Capillary oncotic pressure
Bowman’s capsule oncotic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is oncotic pressure?

A

Pressure exerted by plasma proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Which forces favour filtration?

A

Glomerular BP

Bowman’s capsule oncotic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Which forces disfavour filtration?

A

Bowman’s capsule hydrostatic pressure

Capillary oncotic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the equation for net filtration?

A

Forces favouring - forces against

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Why is the glomerular capillary blood pressure constant throughout the glomerulus?

A

Efferent is smaller than afferent so creates pressure in itself

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the normal GFR?

A

125

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the major determinant for GFR?

A

Glomerular BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

How is GFR regulated? (2)

A

Extrinsically by sympathetic control by baroreceptors

Intrinsic autoregulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What effect does vasoconstriction of the afferent arteriole have on the GFR?

A

Decreased GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the consequence of a decreased GFR?

A

Lower urine volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the equation for MAP?

A

1/3 (systolic-diastolic) +diastolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are the two mechanisms of autoregulation of glomerular BP?

A

Myogenic

Tubuloglomerular feedback - more NaCl leads to constriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Which cells in the juxtaglomerular apparatus sense NaCl?

A

Macula densa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is plasma clearance?

A

Measures how effectively the kidneys can clean the blood of a particular substance per minute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the equation for plasma clearance?

A

Clearance = rate of excretion / plasma concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

How does inulin excretion give an exact measurement of GFR?

A

It is freely filtered at the glomerulus and is neither reabsorbed nor secreted at PCT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Give an example of a substance which is completely reabsorbed

A

Glucose

Its clearance is 0.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

When would clearance be 0?

A

If a substance is not filtered and not secreted e.g. RBC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Give an example of a substance which is partly reabsorbed and not secreted

A

Urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Give an example of a substance which is filtered, secreted and not re-absorbed

A

H+ ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is renal plasma flow?

A

The amount of plasma that runs through the glomerulus in 1 minute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the value for RPF?

A

650

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Which substance is used to measure RPF?

A

Para-amino hippuric acid (PAH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Why is PAH used to measure RPF?

A

Freely filtered at the glomerulus, secreted into tubule and not reabsorbed. It is completely cleared.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Why is inulin not commonly used to measure GFR?

A

Exogenous so needs to be measured.

Creatinine is used instead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the filtration fraction?

A

Fraction of plasma in glomeruli which is filtered into the tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

How is filtration fraction worked out?

A

GFR / renal plasma flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is glomerular filtrate?

A

Blood without RBC and plasma proteins

It is therefore iso-osmotic with plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is reabsorbed in the PT to the capillaries?

A

Sugars
Amino acids
Phosphate
Lactate

63
Q

What is secreted to the PT from the capillaries?

A 
H+ 
PAH
Uric acid
Drugs
Toxins
64
Q

Name the 5 layers the filtrate must pass through from the PT to the capillaries

A 
Apical membrane 
Cytoplasm
Basolateral membrane
Interstital fluid
Endothelium of capillary
65
Q

What two ways can the filtrate leave the PT?

A

Transcellularly

Paracellularly

66
Q

Name 3 types of carrier-mediated membrane transport than occurs in the PT

A

Primary active transport
Secondary active transport
Facilitated diffusion

67
Q

How does primary active transport work?

A

Energy required to move substrate against concentration gradient

68
Q

How does secondary active transport work?

A

Carrier molecule is coupled with another ion movement

69
Q

What is facilitated diffusion?

A

Passive carrier-mediated transport down the concentration gradient

70
Q

Where is a secondary active transporter used at the PCT?

A

To transport Na out of the tubular cell and into the interstitium. Uses K. Uses ATP

71
Q

At a Na/K pump, what is the ratio used?

A

3 Na in

2 K out

72
Q

Describe Na reabsorption at the PCT

A

Uses Co-transporters

Uses anteporters

73
Q

When Na leaves the tubular cells, what is the consequence?

A

Water follows into the interstitium

74
Q

How much glucose is reabsorbed into the capillary?

A

Almost all

75
Q

How is glucose reabsorption faciltated?

A

Co-transporters

Facilitated diffusion

76
Q

At what point will glucose no longer be fully excreted?

A

10-12 mmol/L

77
Q

What is glucose in urine called?

A

Glucosuria

78
Q

What does the loop of Henle do?

A

Creates a solute concentration gradient and forms hypertonic urine
Countercurrent multiplier

79
Q

What does the descending limb of the loop of Henle do?

A

Absorbs water but no effect on salts

80
Q

What does the ascending limb do?

A

Reabsorption of Na and Cl

No water absorption

81
Q

What is the difference in the thick upper part of the ascending limb and the thinner lower part?

A

Thick upper part reabsorbs by active transport

Thin lower part is passive reabsorption

82
Q

Where is the loop of Henle?

A

In the medulla

83
Q

Why is there no water absorption in the upper limb?

A

Tight junctions so no water can be reabsorbed

84
Q

What transport system for sodium is facilitated in the upper part of the ascending limb?

A

Triple co-transporter

85
Q

What happens to the K+ in the co-transporter?

A

K is recycled and put back to the ascending limb

86
Q

How does the fluid leaving the ascending limb become concentrated?

A

Solute is removed from ascending limb and water cannot follow.
Water leaves in the descending limb though so the fluid is concentrated

87
Q

What happens to the osmolarity as the fluid leaves the DL?

A

Osmolarity increases

88
Q

Why does water move passively from the DL?

A

Because solute is pumped into the interstitial fluid, which increases the osmolality of the interstitial fluid

89
Q

What is the purpose of countercurrent multiplication?

A

To concentrate the medullary interstitial fluid

90
Q

Which hormone is responsible for producing urine of various concentrations and volumes?

A

Anti-diuretic hormone (ADH)

91
Q

What role does the vasa recta play?

A

Equilibrates with the interstitial fluid alongside the loop of Henle

92
Q

What are the vasa recta permeable to?

A

NaCl and water

93
Q

On leaving the loop of Henle and entering the distal tubule, how is the fluid described?

A

Hypo-osmotic at 100mosmol/L

94
Q

What does an increased amount of ADH cause?

A

Increased water reabsorption to blood

95
Q

If there is more water reabsorption to the blood by ADH what is then urine like?

A

Small amounts of concentrated urine.

ANTI- diuretic.

96
Q

What is the distal convoluted tubule divided into?

A

Early and late

97
Q

What does the early part of the distal convoluted tubule do?

A

Reabsorbs NaCl

98
Q

What does the late part of the distal convoluted tubule do?

A

Reabsorbs Ca++, Na+ and K+

99
Q

How is the collecting duct divided?

A

Early

Late

100
Q

What part of the collecting duct is particularly influenced by ADH?

A

Late

101
Q

Where does ADH come from?

A

Neurohormone produced by supraoptic and paraventricular nuclei in hypothalamus

102
Q

Where is ADH stored?

A

Posterior pituitary

103
Q

What receptor on the basolateral membrane of the collecting tube is sensitive to ADH?

A

Type 2 vasopressin receptor

104
Q

What kind of receptor is the type 2 vasopressin receptor?

A

G protein coupled

105
Q

What does the activation of the type 2 vasopressin receptor do?

A

Causes ATP to release cAMP which causes increased expression of aquaporins at the apical membrane

106
Q

What is the result of more aquaporins at the apical membrane?

A

Increased permeability for water to move from the collecting tube to the interstitial fluid and then to the capillary.

107
Q

If ADH is low then what is the urine like?

A

High volume of dilute urine

108
Q

True or False

More ADH causes more salt to be excreted

A

False.

Salt excretion is constant, regardless of ADH

109
Q

What hormone causes arterial vasoconstriction?

A

ADH

110
Q

If blood pressure is low, what happens to ADH secretion?

A

Increases to reduce water lost in urine to maintain blood volume

111
Q

Which substance inhibits ADH release?

A

Alcohol.

Low ADH –> more urine

112
Q

If ADH is low, how does this affect glomerular flow?

A

Increases flow to 20ml/min

113
Q

If ADH secretion is maximal, how does this affect glomerular flow rate?

A

Reduces flow to 0.2ml/min

114
Q

Why does osmolarity increase in the collecting duct if ADH secretion is high?

A

High ADH means less water in tubule so a higher proportion of salt, raising the osmolarity

115
Q

Where is aldosterone secreted from?

A

Adrenal cortex

116
Q

What does aldosterone do?

A

Activates RAAS to stimulate Na+ reabsorption and secrete K+

117
Q

If there was no aldosterone what effect would this have on sodium?

A

Sodium would be excreted

118
Q

What does an increase in plasma potassium cause?

A

Stimulation of adrenal cortex to make aldosterone

119
Q

Which organs makes angiotensinogen?

A

Liver

120
Q

Which organ makes renin?

A

Kidney

121
Q

Which organ makes angiotensin converting enzyme?

A

Lungs

122
Q

What does ACE do?

A

Converts angiotensin 1 to angiotensin 2

123
Q

What does angiotensin 2 do?

A

Stimulates adrenal gland to make more aldosterone
Increases thirst
Increase ADH

124
Q

Which cells in the juxtaglomerular apparatus sense a difference in Na?

A

Macula densa

125
Q

What is the relationship between renin and Na?

A

More renin means more sodium will be reabsorbed

126
Q

How does aldosterone cause Na reabsorption?

A

Acts on sodium channels to open them

127
Q

What is ANP?

A

Atrial natiuretic peptide

128
Q

What does ANP do?

A

Released from atrial muscle cells when they are stretched due to increased plasma volume.
Promotes Na excretion to reduce BP

129
Q

What is the micturition reflex?

A

Involuntary emptying of the bladder by simultaneous bladder contraction and opening of the internal and external urethral sphincter

130
Q

What is the equation for pH?

A

pH = log 1/ H+

131
Q

What is the pH of arterial blood?

A

7.45

132
Q

What is the pH of venous blood?

A

7.35

133
Q

What effect does an increase in H+ ions have on pH?

A

Reduces pH

134
Q

What effect does an acidic environment have on the body?

A

Denatures enzymes
Depresses CNS
Changes K+ levels

135
Q

What is the dissociation constant?

A

K = [H+] [A-} / [HA]

136
Q

What is the Henderson Hasselbach equation?

A

pH = pK + log [A-] / [HA]

137
Q

What systems controls bicarbonate levels?

A

Kidneys

Lungs

138
Q

What enzyme is needed to balance carbon dioxide and water?

A

Carbonic anhydrase

139
Q

Where is HCO3- reabsorbed?

A

Proximal tubule

140
Q

How does kidney make new HCO3-?

A

CO2 in interstitial fluid forms with water.

141
Q

What substance produced in the liver forms ammonia?

A

Glutamine

142
Q

What should HCO3 in plasma be?

A

25

143
Q

What is respiratory acidosis?

A

Retention of CO2, reduces pH

144
Q

How does kidney compensate for respiratory acidosis?

A

H+ secretion is stimulated, raising pH

145
Q

What is respiratory alkalosis?

A

Removal of CO2 from body

High pH

146
Q

What causes respiratory alkalosis?

A

Hyperventilation

Low pO2

147
Q

How does kidney compensate for respiratory alkalosis?

A

No new HCO3 is produced.

Maintains/lowers pH

148
Q

What is metabolic acidosis?

A

Excess H+ not from CO2

pH low

149
Q

What causes metabolic acidosis?

A

Loss of base e.g. diarrhoea
Ingestion of acids
Lactic acid production

150
Q

How is metabolic acidosis compensated?

A

Ventilation increased to blow off CO2 to reduce acid

151
Q

Why does metabolic acidosis compensated by kidney?

A

Acid load is excreted.

Takes a long time

152
Q

What is metabolic alkalosis?

A

Excessive loss of H+ from body

pH high

153
Q

What causes metabolic alkalosis?

A

Loss of HCl from vomiting
Ingestion of alkali
Aldosterone hypersecretion

154
Q

How does the respiratory system compensate for metabolic alkalosis?

A

CO2 retention

Renal (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions