Questão 1
Questão
How much waste are we obliged to eliminate in urine per day?
Responda
-
600mosmol
-
600osmol
-
800mosmol
-
1osmol
Questão 2
Questão
What is the maximum urinary osmolarity possible?
Responda
-
1400mosm/l
-
140mosm/l
-
14osm/l
-
1.4mosm/l
Questão 3
Questão
How much urine are we obliged to produce per day if we need to eliminate 600mosmol but can only produce urine concentrated up to 1400mosm/l?
Responda
-
600/1400 = 0.428l
-
600/1400 = 0.428ml
-
600 x 1400 = 840,000ml
-
1400/600 = 2.3l
Questão 4
Questão
What is oliguria?
Responda
-
Daily urine output of less than 0.428l
-
Daily urine output of more than 0.428l
-
Hourly urine output of less than 0.428l
-
The presence of starch in the urine
Questão 5
Questão
What is polyuria?
Responda
-
Urinary output above 3l per day
-
Urinary output below 3l per day
-
Urinary concentration of over 300mosmol/litre
-
Urinary concentration of less than 300/mosmol/litre
Questão 6
Questão
Why do we consider urine dilute when it has a concentration of less than 300mosmol/litre?
Responda
-
The osmolality of plasma is 300mosmol/l
-
The osmolality of the filtrate is 300mosmol/l
-
The osmolality of interstitial fluid is 300mosmol/l
-
The osmolality of intracellular fluid is 300mosmol/l
Questão 7
Questão
What is the name given to the volume of plasma cleared of osmotically active particles per unit time?
Responda
-
Osmolar clearance
-
Free water clearance
-
Renal clearance
-
Reabsorption
Questão 8
Questão
What is the correct equation for osmolar clearance if...
V = urine flow rate
Uosm = urine osmolarity
Posm = plasma osmolarity
Responda
-
(Uosm x V) / Posm
-
(Uosm x Posm) / V
-
(Uosm + Posm) / V
-
Uosm x Posm x V
Questão 9
Questão
What is the correct equation for free water clerance if...
V = urine flow rate
Uosm = urine osmolarity
Posm = plasma osmolarity
Responda
-
V - (Uosm x V)/Posm
-
V + (Uosm x V)/Posm
-
V + (Uosm x Posm)/V
-
V - V/(Uosm x Posm)
Questão 10
Questão
If free water clearance is greater than 0, the urine will be hypo-osmotic or [blank_start]dilute[blank_end].
If free water clearance is 0, the urine will be [blank_start]iso[blank_end]-osmotic with respect to [blank_start]plasma[blank_end].
If free water clearance is less than 0, the urine will be [blank_start]hyper[blank_end]-osmotic or concentrated.
Questão 11
Questão
Where are the osmoreceptors found in the brain?
Questão 12
Questão
Fill in the blanks below to describe the release of ADH.
1. When plasma osmolality is [blank_start]high[blank_end], receptors in the o[blank_start]rganum vasculosum lamina[blank_end], m[blank_start]edian preoptic nucleus[blank_end] and s[blank_start]ubfomical organ[blank_end] signal to neurosecretory cells in the [blank_start]paraventricular[blank_end] and [blank_start]supraoptic[blank_end] nuclei in the [blank_start]hypothalamus[blank_end].
2. The nuclei synthesise a [blank_start]precursor[blank_end] of ADH
3. The [blank_start]precursor[blank_end] is passed into axons of neurons where it is cleaved into a [blank_start]9[blank_end] amino acid ADH molecule in the [blank_start]posterior pituitary[blank_end]
4. ADH is released into the blood of the [blank_start]internal carotid[blank_end] artery to be targeted to the [blank_start]collecting duct[blank_end]
Responda
-
high
-
rganum vasculosum lamina
-
edian preoptic nucleus
-
ubfomical organ
-
paraventricular
-
supraoptic
-
hypothalamus
-
precursor
-
precursor
-
9
-
posterior pituitary
-
internal carotid
-
collecting duct
Questão 13
Questão
ADH has a long half life in the blood.
Questão 14
Questão
Alcohol inhibits ADH secretion.
Questão 15
Questão
Nicotine, nausea, pain and stress stimulate ADH secretion.
Questão 16
Questão
Which factor is ADH secretion most sensitive to?
Responda
-
Plasma osmolality
-
Blood pressure
-
Blood volume
-
Blood temperature
Questão 17
Questão
What symptoms characterise diabetes insipidus?
Responda
-
Polyuria, polydipsia and nocturia
-
Oliguria, hematuria
-
Polydipsia, oliguria, dehydration
-
Jaundice, hematuria
Questão 18
Questão
What is neurogenic diabetes insipidus?
Responda
-
Lack of ADH secretion due to a congenital brain defect or head injury
-
Mutated V2 receptors or aquaporins
-
Caused by side effect of drugs or infection
-
Increased urination due to small molecules in renal tubule lumen causing excess water reabsorption
Questão 19
Questão
What name is given to diabetes insipidus caused by mutated V2 receptors or aquaporin channels OR acquired by infection or drug use?
Responda
-
Nephrogenic diabetes insipidus
-
Inflammatory diabetes insipidus
-
Neurogenic diabetes insipidus
-
Mutagenic diabetes insipidus
Questão 20
Questão
What condition is typical of diabetes mellitus whereby the presence of small molecules in the renal tubule prevents water reabsorption causing production of large quantities of dilute urine?
Questão 21
Questão
Potassium has a concentration of [blank_start]5[blank_end]mM in the extracellular fluid and [blank_start]150[blank_end]mM in the intracellular fluid.
Questão 22
Questão
In the proximal tubule, the Na+/K+ [blank_start]pump[blank_end] moves potassium ions [blank_start]into[blank_end] the epithelial cell. This concentration gradient draws potassium into the epithelial cell from the [blank_start]lumen[blank_end] and out into the [blank_start]interstitial[blank_end] fluid via [blank_start]channel[blank_end] proteins. Potassium can also diffuse between cells via [blank_start]tight junctions[blank_end].
Responda
-
pump
-
into
-
lumen
-
interstitial
-
channel
-
tight junctions
Questão 23
Questão
How does potassium enter the epithelial cells of the thick ascending limb of the loop of Henle?
Questão 24
Questão
How does potassium enter the epithelial cells of the distal tubule?
Questão 25
Questão
In the collecting duct, potassium is reabsorbed by [blank_start]type A[blank_end] intercalated cells in exchange for [blank_start]H+[blank_end] ions. This is outweighed by [blank_start]secretion[blank_end] by the [blank_start]prinicipal[blank_end] cells. In the principal cells, potassium moves out of the epithelium via [blank_start]renal outer medullar K+ channels[blank_end] (ROMKs). It also moves out through [blank_start]calcium[blank_end]-activated big-[blank_start]conductance[blank_end] K+ channels when tubular flow rates are [blank_start]high[blank_end]. The K+/[blank_start]Cl-[blank_end] transporter also removes potassium from the cell.
Questão 26
Questão
If more sodium enters the principal cells in the collecting duct epithelium, what happens to the secretion of potassium?
Responda
-
Increases because the filtrate becomes less positively charged
-
Increases because the filtrate becomes more positively charged
-
Decreases because the filtrate becomes more positively charged
-
Decreases because the filtrate becomes less positively charged
Questão 27
Questão
What hormone stimulations the K+ channels, Na+ channels and Na+/K+ ATPases of the collecting duct to increase secretion?
Responda
-
Aldosterone
-
ADH
-
Adrenaline
-
Testosterone
Questão 28
Questão
Which favours secretion more?
Responda
-
High tubular flow rates
-
Low tubular flow rates
Questão 29
Questão
What is hypokalaemia?
Responda
-
Plasma potassium concentration of less than 3.5mM
-
Plasma potassium concentration of more than 3.5mM
-
Intracellular potassium concentration of more than 3.5mM
-
Urinary potassium concentration of less than 3.5mM
Questão 30
Questão
Hypokalaemia can occur due to increased internal losses.
For example, in the kidney, [blank_start]high[blank_end] tubular flow rates favour [blank_start]high[blank_end] rates of potassium [blank_start]secretion[blank_end]. Hyperaldosteronism [blank_start]increases[blank_end] the activity of the potassium channels, favouring potassium [blank_start]secretion[blank_end]. Alkalosis is also associated with hypokalaemia because potassium is secreted due to changed in [blank_start]electrochemical gradients[blank_end].
In the GI tract, vomiting and [blank_start]diarrhea[blank_end] can cause excess potassium loss.
Potassium can be lost from the skin due to burns or intense [blank_start]sweating[blank_end].
Questão 31
Questão
How does insulin affect potassium uptake in cells?
Questão 32
Questão
Why does potassium intake into cells increase due to metabolic alkalosis?
Responda
-
H+ ions bound to buffers leave cells, K+ enter to maintain charge
-
H+ ions bound to buffers enter cells, K+ leave to maintain charge
-
K+ ions act as buffers to reduce plasma pH
-
K+ ions are exchanged for H+ on the K+/H+ exchanger
Questão 33
Questão
What is severe hypokalaemia?
Responda
-
< 2.5mM
-
> 2.5mM
-
< 3.5 mM
-
< 5 mM
Questão 34
Questão
In hypokalaemia, membrane potentials become more [blank_start]negative[blank_end]. Therefore, a larger intake of [blank_start]sodium[blank_end] is required to exceed the [blank_start]threshold[blank_end] and fire an [blank_start]action potential[blank_end]. Therefore, action potentials are less likely to fire and the [blank_start]refractory[blank_end] period is [blank_start]longer[blank_end] so muscles become weak and paralysed.
Responda
-
negative
-
sodium
-
threshold
-
action potential
-
longer
-
refractory
Questão 35
Questão
What is hyperkalaemia?
Responda
-
> 5.5mM
-
< 5.5mM
-
< 3.5 mM
-
> 3.5 mM
Questão 36
Questão
Reduced release of what hormone can cause hyperkalaemia?
Responda
-
Aldosterone
-
Adrenaline
-
ADH
-
Oestrogen
Questão 37
Questão
Hyperkalaemia can be caused by redistribution of potassium out of cells. Check the two specific examples of this.
Questão 38
Questão
In hyperkalaemia, the resting membrane potential becomes more [blank_start]positive[blank_end]. This means less [blank_start]sodium[blank_end] is required to exceed the [blank_start]threshold[blank_end] and fire an [blank_start]action potential[blank_end]. Action potentials are [blank_start]more[blank_end] likely to fire, causing hyperreflexia and [blank_start]cramping[blank_end] of the muscles.
Responda
-
positive
-
sodium
-
threshold
-
action potential
-
cramping
-
more
Questão 39
Questão
What can we administer intravenously to treat hyperkalaemia to decrease the action potential threshold in the heart?
Responda
-
Na+
-
K+
-
Ca2+
-
Acetylcholine
Questão 40
Questão
Which drug could we administer during hyperkalaemia to shift K+ into cells?
Responda
-
Insulin
-
Glucagon
-
Adrenaline
-
Diuretics
Questão 41
Questão
Of the treatments listed below, which are appropriate for treating hypokalaemia?
Responda
-
Eating potassium-rich foods
-
Oral or IV administration of KCl
-
Correction of alkalosis
-
Use of K+-sparing diuretics
-
Administration of insulin
-
IV Ca2+
-
IV Na+
Questão 42
Questão
What is severe hyperkalaemia?
Responda
-
> 7.5mM
-
< 7.5mM
-
> 5.5mM
-
< 5.5mM