Case 3 Flashcards
1
Q
What is the peritoneum
A
A thin, serous membrane that covers all the organs and lines the abdominal cavity
2
Q
What are the two layers of the peritoneum and where are they
A
The visceral peritoneum covers the abdominal viscera and organs
The parietal peritoneum lines the abdominal cavity
3
Q
How would you describe and organ if it is completely surrounded in peritoneum
A
intraperitoneal
4
Q
What are retorperitoneal organs
A
they only have peritoneum on their anterior surface
5
Q
What organs and viscera are intraperitoneal (6)
A
Liver Gall Bladder Spleen Stomach Small intestine (most of) Large intestine (some of)
6
Q
What organs and viscera are retroperitoneal
A
S uprarenal glands A orta & IVC D uodenum (most of) P ancreas (most of) U reters C olon K idneys O esophagus R ectum
7
Q
What is the mesentery
A
It’s an organ that attaches the intestines to the abdominal wall and it allows nerves to communicate between the viscera and the abdominal wall
It is double layered
8
Q
What is an omentum
A
The connections between viscera and other viscera
9
Q
What are ligaments with regards to the peritoneum
A
These are between viscera and other viscera or viscera and the abdominal wall
10
Q
Where is the lesser omentum between
A
The liver and stomach/duodenum
11
Q
What ligaments are in the lesser omentum
A
Hepatogastric ligament and heptatoduodenal ligament
12
Q
What structures are found within the hepatoduodenal ligament
A
The bile duct, hepatic vein and hepatic artery
13
Q
Where is the greater omentum between
A
The stomach down to the transverse colon
14
Q
How many layers does the greater omentum contain?
A
4
15
Q
Where is the phrenicolic ligament between
A
The colon and diaphragm
16
Q
Where is the lienorenal ligament between
A
The spleen and kidney
17
Q
What are mesentery reflections
A
Reflections of two layers of visceral peritoneal lying on top of each other and connect to the abdominal wall
18
Q
What do the lesser and greater sac communicate and pass fluid through
A
The omental foramen
19
Q
Where can the omental foramen be found (what ligament is it behind)
A
The hepatogastric ligament
20
Q
What three layers can be found within the greater sac
A
The supracolic, infracolic and pelvic areas
21
Q
What are recesses in the abdomen
A
Small places that fluid can congregate
22
Q
What recesses can be found in the infracolic region of the greater sac and what is their function
A
The paracolic gutters (either side of the left intestine)
Any fluid that accumulates in the infracolic region can settle in these gutters
23
Q
What recess can be found in the pelvis in males
A
The vesicorectal pouch
24
Q
What recesses can be found in the pelvis in female
A
Vesicouterine and rectouterine pouches
25
What is a problem if infectious fluid builds up within one peritoneal reflection
It may spread across the whole peritoneum as the spaces are consistent with one another
26
What can cause a build up of infectious fluid in peritoneal reflections and cavities?
Bacterial contamination during abdominal surgery
Rupture of the gut as a result fo infection/inflammation
When an ulcer in the stomach or duodenum perforates through the wall of an organ
27
What is the disadvantage of the paracolic gutters being linked with other recesses
They are able to spread infectious fluid or cancerous cells throughout the peritoneal organs
28
What is the role of the transversus abdominis muscle
It contains transverse fibres that support the viscera and rotates and flexes the trunk
29
What does the quadratus lumborum muscle do
Stavilises the 12th rib
30
What do the muscles psoas major/minor/iliacus do
They work with the hip flexor
31
Where is the lumbar plexus
This is from the anterior rami of spinal nerves T12-L4
32
What is the crossover of lumbar and sacral nerves known as and what is its function
the lumbosacral trunk
| it allows the passage of information between the two sections
33
What is the word for something related to the ureter
ureteric
34
What is the word for something related to the urethra
urethral
35
What is the word for something related to the uterus
uterine
36
Are the kidneys intra or retro peritoneal
retroperitoneal
37
What level of vertebrae are the kidneys found at
T12-L3
38
Which kidney is lower than the other
The right is lower than the left
39
What is the renal hilum
Found on the medial surface fo the kidney and it is where the main blood vessels and transport systems in and out of the kidney are found
40
What structures are anterior to the right kidney
The liver and parts of the small intestine
41
What retroperitoneal structures are attached to the right kidney
The right colic flexure (large intestine)
Descending part of the duodenum
the suprarenal gland
42
What intraperitoneal structures lie on the left kidney
The spleen
Stomach
Small intestine
43
What retroperitoneal structures lie on the left kidney
Pancreas
Left colic flexure (large intestine)
Descending colon
44
what is the renal capsule
A tough fibrous layer that protects the kidneys
45
What is the perirenal fat
Its a fatty capsule that surrounds the kidney to keep it protected, a layer within the renal capsule
46
What is between the two fat layers within the kidney
renal fascia
47
What is the layer of fat closest to the kidney called
pararenal fat
48
What five vessels are in the renal hilum
```
From anterior to posterior
Renal vein
Renal artery
Ureter
Renal pelvis
Lymphatics and sympathetics
```
49
Where does urine drain into after exiting a nephron
minor calyces
50
What do minor calyces join together and where do these subsequently go
These join to form a major calyx which join to the renal pelvis and then ureter
51
Where does the ureter join the bladder
The ureteropelvic junction
52
How does the urine move down the ureters
Peristalsis
53
Where are the main constrictions in the ureters (3)
renal pelvis, pelvic brim and ureteric orifice
54
In what cavity is the bladder found
The pelvic cavity
55
What are the muscles in the bladder walls called
The detrusor muscle
56
What is the function of the internal urethral sphincter in males
To prevent ejaculatory reflux of semen into the bladder
57
Why are females more at risk of UTIs
They have a much shorter urethra
58
What are the four parts of the male urethra from bladder to penis end
Preprostatic
Prostatic
Membranous
Spongy
59
Where does urethral obstruction result in a calculus forming in males
The external meatus
60
What do you locate first on females in order to catheterise them
the external urethral meatus
61
Why is catheterisation more difficult with males
The penis has two angles and it is longer
62
If catheterisation doesn't work with regards to through the urethra what can be done
You can catheterise a patient through the anterior abdominal wall, just above the pubic symphis
63
What are the first two stages of kidney development, what is the functionality of each stage and when do they develop
Pronephros- no functionality
Mesonephros- limited functionality
3-4 weeks
64
What is the final stage of kidney development and when does it become functional
Metanephros- develops at 5 weeks but becomes functional at 12
65
When does urine production first occur and how does it work
It begins at the 12th week as the foetus takes on amniotic fluid, filters it through the kidney and then excretes it back into the amniotic cavity
66
What are the two definitive structures the kidney is formed from
The metanephric mesoderm and ureteric bud
67
When does the ureteric bud begin to branch and what does it branch into
6 weeks- it branches within the metanephric mass to form the major calyx, minor calyx and renal pelvis
68
What is the role of the mesonephric duct in males
It forms the male genital tract- it degenerates in females
69
By what stage do the kidneys need a blood supply and what is this supplied through
6 weeks- the transient renal vessels that are connected to the abdominal aorta
70
When do the kidneys move cranially, whilst the ureters are still attached
7 weeks
71
What replaces the transient renal vessels after complete kidney translocation
The renal vessels
72
What is renal agenesis and hypoplasia
When the kidneys fail to develop and grow
| this can be unilateral or bilateral (fatal)
73
What is supernumerary renal vessels and what complications may arise
This is when the transient renal vessels don't regress and stay attached
These may trap the ureter with the vessels which leads to hydronephrosis (a build-up of urine)
74
What is renal ectopia
When the kidneys fail to migrate so a kidney may remain in the pelvis or migrate to the wrong side
There also may be abnormal rotation where the hilum faces ventrally
75
What is a horseshoe kidney
This is when the caudal ends of the kidney migrate close together to eventually fuse
76
What is the order of structures the fluid flows through in a single nephron
Bowmans capsule> proximal convoluted tubule> descending limb> loop of Henle> ascending limb>distal convoluted tubule> collecting duct> minor calyx
77
How does the renal artery branch into a nephron
Reanl artery> interlobar arteries> interlobular arteries> afferent arteriole>glomerulus
78
How do the blood vessels link after the glomerulus
Glomerulus> efferent arteriole> peritubular plexus> arcuate veins
79
What are vasa recta
Small arteries associated with the Loop of Henle
80
What percentage of nephrons cross the cortex and medulla and what are these nephrons called
20%, most are cortical nephrons- juxtamedullary nephrons
81
What is the name of the tissue between glomerular capillaries and how is it adapted to its function
It's called the mesangium and contains fenestrated endothelium that contains small spaces within it
82
What are podocytes
Cells that wrap around the mesangium and capillaries through an interlocking process
83
What layer is between the podocytes and mesangium in glomerular capillaries
A three layered basement membrane
84
What cells in the kidney secrete renin
Juxtaglomerular cells
85
What cells line the inside of the ureters and bladder and how is it adapted to it's function
Urothelium- it is impenetrable to urine, even when it is stretched as it is made of stratified endothelium and contains umbrella cells on the surface
86
How is the body fluid split between intra and extracellular fluid (plasma and interstitial)
Intracellular fluid is about 25L~40% of body weight
| Interstitial fluid is about 80% of ECF- 12L
87
What is sensible fluid loss and what are examples of it
Sensible is easy to meausure fluid loss such as
sweat (100ml/day)
Faeces (100ml/day)
Urine (1.5L/day)
88
What is insensible fluid loss and what are some examples
Hard to measure fluid loss
Evaporation from skin (300-400ml/day)
Humidification during respiration (300-400ml/day)
89
If a cells volume increases and starts to swell what regulatory response will it take to decrease volume
It will lose solutes such as taurine
90
If theres a decrease in water content of cells what does the cell do to counteract this
It tries to gain osmotically active particles such as KCl
91
How do the kidneys regulate plasma volume
| e.g. if there is a decrease in blood plasma volume how would the kidneys react
The kidneys use stretch receptors in the body to sense this and then will release renin
This initiates the RAA system that acts to maintain Na+ balance within the body
92
How is plasma osmolality maintained by the kidneys (e.g. a decrease)
If there is a decrease in plasma osmolality then this is detected by osmoreceptors in the hypothalamus
This leads to the release of ADH down to the kidney byt he posterior pituitary gland and more water is reabsorbed
there is also increased vasoconstriction
93
What is isotonic dehydration
this is when there is an equal amount of water and solutes lost so the extracellular volume decreases but the osmolality stays the same
94
What causes isotonic dehydration
vomiting, diarrhoea, haemmorhage and/or burns
| It may also be caused by an internal effusion
95
How do you treat isotonic dehydration
By replacements fluids such as an isotonic NCl solution
96
What is hypo-osmotic dehydration
this is when the fluid that is lost contains more NCl than water and therefore the fluid volume and osmolality decreases
because there is balancing out between intr and extracellular environments this can result in an increase in cell volume as fluid moves down its concentration gradient, into cells
97
What causes hypo-osmotic dehydration
Addisons disease or rare cases of vomiting
98
What is hyper-osmotic dehydration
This is when more water is lost than salt levels
99
What causes hyper-osmotic dehydration
Osmotic diuresis, increased ADH secretion, high fever, heat stroke and diarrhoea
100
How is hyperosmotic dehydration treated
Slow water replacement
101
How is the release of renin stimulated and when
It is stimulated by the sympathetic nervous system in response to a fall in plasma volume or increase in Na+ concentrations
102
Where is erythropoietin produced
In the kidney by the peritubular interstitium and cells of the inner cortex
103
What does erythropoietin do
It acts on erythrocyte cells in the bone marrow and stimulates erythrocyte production
104
What stimulates the release of erythropoietin
hypoxia, anaemia or renal ischaemia
105
Where is vitamin D synthesised from in the external environment and where is it hydrolysed in our body
It's synthesised from the sun and is hydrolysed in our liver and then kidney
106
What is the role of vitamin D in the body
It's for the mineralisation of bones and it maintains calcium and phosphate homeostasis by promoting absorption form the gut
107
What is anomalous about glomerular capillaries when compared with other capillaries (3)
They have a relatively constant pressure throughout them
a lot higher pressure than systemic capillaries
Also arranged in a two capillary network with peritubular capillaries
108
What does vasoconstriction of the afferent arteriole mean for glomerular blood flow and pressure
Reduced blood flow and pressure
109
What does vasoconstriction of the efferent arteriole mean for glomerular blood flow and pressure
Increased blood flow and pressure
110
What causes vasoconstriction or dilation of glomerular arterioles
A sympathetic response will initiate the release of renin
Hormones and autacoids such as adrenaline
Autoregulation
111
What are the macula densa cells and where are they found (3)
These are cells found in direct contact with the afferent and efferent arteriole
They, upon sensing a change in Na+ and Cl- concentration, release paracrines that decrease afferent arteriole diameter
112
How can you measure renal blood flow
Using a renal arteriography or angiography- uses injection dyes
A flow probe however can be invasive
Ultrasound- only produce 2D image so overlapping organs difficult to distinguish
113
What is the glycolax and why is it charged
The glycolax is the luminal surface of endothelial cells in the glomerular filtration barrier and is negatively charged in order to repel negatively charged proteins
114
What are fenestrae
The openings between endothelial cells that allow water and small molecules to pass through
115
Where is the glomerular basement membrane found and what is its function
It is in the glomerular filtration barrier and acts as a negatively charged barrier to filtration
116
What is between podocyte cells
filtration slits
117
What is clearance with regard to glomerular filtration
This is how quickly something in the blood plasma is filtered into the kidney and removed through urine
118
Why is it hard to estimate GFR
Very few substances meet all the criteria that are required in order to be useful at estimating GFR
119
What is the gold standard substance for GFR measurements but what is its limitation
Inulin is a plant polysaccharide however it needs to be injected
120
What natural body waste product is commonly used to estimate GFR and why is it not perfect
Creatinine- there is some tubular secretion of it so it tends to overestimate GFR
121
How can we calculate the GFR hen given the urinary and plasma concentration of our substance and the urine volume
GFR= (U x V)/P
122
What is the most important trait of a substance in order to measure renal blood flow
The substance must be completely cleared of the kidney on first pass
123
What substance is a good measure of renal blood flow but by how much does it underestimate it?
Para-aminohippuric acid (PAH) however it underestimates it by about 10%
124
What do you need to take into account when measuring renal blood flow from renal plasma flow and how is this done
Haematocrit- the proportion of blood that is composed of RBCs
RBF= RPF/(1-HTC)
125
What are the differences between Starling's forces across a glomerular capillary when compared with an extra-renal capillary (6)
The hydrostatic pressure is constant across a glomerular capillary
Glomerular capillaries are less permeable to proteins so the oncotic pressure in the Bowman's capsule is lower than the interstitium
Plasma oncotic pressure rises along a glomerular capillary whilst it is constant normally
Hydrostatic pressure in the Bowman's capsule is greater than the interstitium of other tissues
ultrafiltration pressure is greater in glomerular capillaries
There is a net movement out of the glomerular capillaries as the gradient is always down with regards to oncotic and hydrostatic pressure
126
What is ureas role in the body and what percentage is reabsorbed by the kidney and why
Urea has an important role in nitrogen excretion with 50% being reabsorbed in order to maintain a good concentration gradient to reabsorb water
127
What are the two size limits for GFR from uninhibited filtration to barely any
7kDa and under have uninhibited filtration whilst molecules over 70kDa barely filter
128
what percentage of glucose is reabsorbed by the early proximal convoluted tubule and by what transporters
98% by GLUT2 and SGLT2 transporters
129
Where is the final 2% of glucose reabsorbed
The late proximal convoluted tubule
130
How does the kidney assist in a compensatory mechanism to metabolic acidosis
It produces ammonium that is excreted in the urine in order to facilitate the excretion of acid and bicarbonate to counter the acidosis effect
131
hat percentage of glucose production does renal gluconeogensis account for
20-25%
132
What is Tm or transport maximum- in the kidney
This is the point at which an increased concentration of a substance does not result in increased movement of that substance- this is the point no more is absorbed or secreted in the kidney due to transport channels being saturated
133
Why does diabetes mellitus produce glucose in the urine
The Tm of glucose is reached as there is high plasma glucose concentration so no more is absorbed and it is excreted in the urine
134
What is the role of secretion in the kidney (3)
It acts to eliminate exogenous solutes such as drugs and toxins, metabolic byproducts and delivers autacoids and drugs to distal nephron
135
What is plasma threshold with regards to renal function
Plasma threshold is the concentration of a substance in the plasma required in order for that substance to not be reabsorbed anymore
136
hat can lead to the overriding of renal blood flow autoreglation and why
Shock, trauma, haemorrhage and extreme exercise
| This results in greater efferent arteriole constriction in order to preserve BP
137
What is nephritic syndrome
This is an inflammatory response in the kidney that increases the permeability of the filtration membrane which can lead to proteinuria, haematuria and hypertension
138
What is nephrotic syndrome and how is it different to nephritic syndrome
This also increases permeability of the filtration membrane however it doesnt lead to haematuria- nor does it affect renal function
139
What is a positive Na+ balance and when would this happen
when you are taking on more Na+ than is being excreted- this occurs when there is a sudden dietary or IV influx of Na+ and resultantly more Na+ will be excreted as the ECF volume signals this
140
What does aldosterone do in response to a decrease in ECF
It acts in the kidney to increase the activity of ENaC and the number of Na/K pumps in principal cells (the cells in the collecting duct and distal tubule epithelium)
This increases Na+ and thus water reabsorption but results in increased K+ and H+ secretion
141
How does an increase in AGII result in a decrease in BP
It acts as a vasoconstrictor but also stimulates ADH secretion to increase DCT permeability
142
Where is aldosterone produced in the adrenal gland and what receptors does it act on
The zona glomerulosa- mineralocorticoid receptors
143
How does AGII effect the afferent and efferent arterioles (3)
It constricts them both however the efferent slightly more in order to decrease Starling's forces by decreasing HP
It increases oncotic pressure so more Na+ is reabsorbed
144
What happens if you decrease vasa recta blood flow
This decreases solute washout and less urea is moved away from the Loop of Henle
Therefore there is a higher concentration gradient for NaCl reabsorption
145
What are the two different mechanisms of GFR control mechanisms and when are they utilised
Spontaneous GFR control prevents effects from postural changes in blood pressure
Compensatory GFR changes modulate GFRs to combat excess in dietary sodium intake
146
How does atrial natriuretic peptide affect the renal system
It suppresses the sympathetic nervous system
This dilates the afferent arteriole
This increases GFR
Inhibits renin
Increases vasa recta blood flow to decrease Na reabsorption
147
What is the oncotic pressure like in the efferent arteriole and peritubular capillaries in comparison to the filtrate and intersitium
Much Higher
148
What cells are on the inner lumen of the PCT
Brush boarder cells
149
How are brush boarder cells adapted for their function
They have microvilli on their apical surface
150
What channels is water reabsorbed through
Aquaporin AQP1 channels
151
What is the process of a substance moving up it's concentration through the assistance of another substance acting as a power generator by moving down its concentration gradient
Secondary active transport
152
Where is secondary active transport seen in the PCT
Through the movement of Na and many other substances acting as the secondary molecule
153
How is a low Na concentration maintained in the brush boarder cells
There are many Na/K pumps that pump Na out of these cells , into the interstitium and thus capillaries
154
What is paracellular transport
The movement of molecules between the leaky junctions of cells
155
What results in paracellular backflow of Na into the early PCT
There is a net negative charge as Na moves out due to the high concentration of Cl- ions in the PCT- not many are absorbed at these times- and thus Na+ flows back into the lumen
156
Why is there no paracellular backflow in the late PCT
Chloride ions are also absorbed alongside Na+ ions at this stage so there is no charge imbalance pulling them back
157
What do free H+ ions form with after being exchanged with Na+ in the brush boarder cells
They form Carbonic acid, H2CO3 with HCO3-
158
What reaction does carbonic acid catalyse and where
It catalyses the breakdown of H2CO3 in the apical border to H2O and CO2 so these products can move freely across the apical surface into the brush boarder cells
159
What carbonic anhydrase substrate reforms H2O and CO2 into H2CO3 in the brush boarder cells
Carbonic anhydrase type 2
160
Through what route is the HCO3- absorbed into the peritubular capillaries
Through the Na=/HCO3- cotransporter
161
What is osmolarity
The concentration of solute particles
162
What is the coritco-papillary gradient
The increase in osmolarity as you go from the cortex to the papilla- down the Loop of Henle
163
What is water reabsorption dependent on in the DCT
ADH levels
164
What is the descending limbs permeability to water and ions respectively
It contains AQP1 channels and has a lo permeability to ions
165
What is the ascending limbs permeability to water and ions respectively
It is impermeable to water and has a high permeability to ions with an Na/K ATPase pump
166
At which point of the descending limb is the water movement out by osmosis at its highest and why
At the base of it as the interstitium gets increasingly salty and osmolar so more water moves out due to the increase in concentration gradient
167
How does Na+ move out of the thin ascending limb
Through passive diffusion
168
How does Na+ move out in the thick ascending limb and why does water not follow it
It is actively pumped out by the many Na/K ATPase pumps
| Water doesn't follow it as there are no aquaporins to channel through
169
What is the trend of osmolarity of the filtrate as you go up the ascending limb
It becomes increasingly dilute as ions are moving out and water cannot follow
170
How do chloride ions move out of the thin ascending limb
Passively through chloride channels
171
How do we transport K and Cl back into the thick ascending limb lumen in order to create concentrated urine
Through Na/K/2Cl transporter as Na+ moves down its concentration gradient into the lumen and transports the other two by secondary active transport
This concentration gradient is maintained by the Na/K ATPase pumps pumping Na out of the lumen
172
Is the vasa recta permeable to solutes and water?
Yes
173
How does the vasa recta maintain the hyperosmotic interstitial gradient set up
As it bypasses the ascending limb it releases water down its concentration gradient and into the interstitium whilst salt is reabsorbed down its concentration gradient into the vasa recta
When it bypasses the descending limb it reabsorbs water but gives out salt to maintain the gradient and continue with the Loop of Henle
174
What is the permeability of the DCT and collecting duct changed by
The activation of ADH
175
As the filtrate moves down the descending Loop of Henle, what direction does the net movement of urea go in
More goes into the Loop as you go down as there is a higher concentration of urea in the interstitium, the further you go down towards to papillary
176
Is the ascending Loop permeable to urea and how does this help
No- this means there is a high concentration of urea in the DCT to increase the osmolarity of the filtrate and this results in more water moving out
177
Ho does ADH assist the movement of urea
It implants a urea transporter in the late collecting duct so urea moves out into the interstitium so it can be recycled back and maintain a cortico-papillary gradient
178
How does Na move out of the early DCT
There are Na/Cl cotransporters that allow Na to move down its concentration gradient and transport Cl- via secondary active transport
179
How is Na+ reabsorbed in the late DCT and collecting duct
Through ENaC channels
180
What are osmoreceptors and what do they do
These are specialised cells found in the anterior hypothalamus that sense the osmolarity of extracellular fluid through AQP4 channels in their apical surface
181
How do the osmoreceptors respond to an increased osmolarity in the bloodstream
If there is an increased osmolarity water will move out of the osmoreceptors, through the APQ4 channels
this will cause them to shrink and in turn release action potentials that trigger the 'thirst response'
182
What does the thirst response do
It activates the posterior pituitary gland to release ADH and retain water from the kidney
183
How do the juxtaglomerular cells initiate a thirst response
They detect a low blood volume and secrete renin to initiate the RAAS
AGII converges on the hypothalamus to trigger a thirst response
184
What channels does ADH indirectly promote the binding of after a signaling cascade
AQP2 channels after ADH binds to V2 receptors on the basolateral membrane of principal cells
185
What is hyponatremia and at what value is it considered
This is a deficiency of sodium and is at <135mM
186
What is hypernatremia and at what value is it considered
An excess of sodium >145mM
187
What are the major causes of hyponatremia (3)
A net loss of Na (hypoaldostrenism, thiazides, bodily functions)
Disturbances of water input (voluntary or mental illness water intoxication)
Disturbances of water output (increased ADH secretion)
188
What are the causes of hypernatremia
A net gain of Na (dietary, Iv, hyperaldostrenism)
Disturbances of H2O input (unconscious patient, lack of water access, voimiting)
Disturbances of H2O output (increased insensible losses, vomiting, diarrhoea)
Diabetes insipidus results in non functional ADH that means excessive water loss
189
What is neurogenic diabetes insipidus
The failure of ADH secretion as a result of a lesion in the hypothalamus or posterior pituitary gland and is treated with synthetic ADH
190
What is nephrogenic diabetes insipidus
the failure of the principal cells to respond to ADH caused by a V2 receptor mutation
191
What do thiazides inhibit
The Na/Cl cotransporter in the DCT
192
How do Loop diuretics work
They work on th eLoop of Henle by inhibiting the Na/K/2Cl cotransporter in the thick ascending loop
193
How do aldosterone antagonists work
They don't allow aldosterone to bind with its mineralocorticoid receptors so it cannot translocate to the nucleus and transcribe the ENaC channels
It also inhibits the generation of K channels so less K is excreted out and the Na/K channels work less effectively
194
What is specific about potassium sparing diuretics
They antagonise the ENaC channels in the principal cells of the late collecting duct as well
This spares K from being transported into the urine because the function of Na/K pumps is greatly reduced
195
How does inhibiting the RAAS help to retain sodium
Decrease in ADH to release dilute urine
Reduced Na reabsorption in the PCT and Loop of Henle (increased vasa recta washout so decreased gradient)
There's decreased sympathetic activity so more arteriole dilation and more Na in filtrate
Decreased binding of Na/H exchanger in PCT
196
What is the normal body pH
7.4
197
Why is a constant pH important
To maintain enzymes, receptors and transporters
198
What is the main reaction in the bicarbonate buffer system to neutralise protons
HCO3- + H+ ---> H2CO3
199
What does H2CO3 dissociate into and what catalyses this reaction
It dissociates into H2O and CO2 by the enzyme carbonic anhydrase
200
How do protons react with phosphate
2H+ + PO4(2-) --> H2PO4
201
What do protons and proteins form as part of our internal buffer system
Protonated proteins
202
How does haemoglobin combine with protons as part of our internal buffer system
It forms haemoglobinic acid
203
What is the biggest contributor to a potentially acidic pH in our blood and how is this combated
The partial pressure of CO2
| It is combated by the bicarbonate system
204
How can we calculate the pH of the blood using CO2 partial pressure and HCO3- concentration
Pk' (6.1) +log( {HCO3-}/{dissolved CO2}
205
Why re endogenous acids dangerous
They are not contributed by CO2 and thus cannot be lost through the lungs
206
Ho do we normally lose alkali substances
Through stools from the GI tract
207
What is the rapid response due to a decrease in pH and what takes longer out of the respiratory and renal methods
The respiratory is a rapid response whilst the renal response is a lot slower
208
What is the main outcome of the renal response to acidosis with regards to the movements of molecules
The kidney removes protons and increases the reabsorption of HCO3-
209
What main pump releases protons into the tubular lumen
The Na/H pump
210
What stimulates an increase in HCO3- reabsorption and by what channels are they reabsorbed
A decrease in cell Ph
| HCO3- reabsorbed by Na/3HCO3 or Cl/HCO3 pump
211
Where do the kidneys generate bicarbonate ions and how does this occur (3)
The kidneys generate bicarbonate ions in the PCT
This can occur through gluconeogensis, triggered by the excretion of ammonium salts as bicarbonates are a biproduct of this process
it may also occur through activation of the phosphate buffer system as bicarbonates are generated as acid is removed
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Where are alpha intercalated cells found and what is their function
These are found in the collecting duct and they generate a small amount of HCO3- in response to a low pH
213
Where are alpha intercalated cells found and what is their function
These are in the collecting duct and they respond to a high pH by secreting bicarbonate into the lumen to extrude H+ into the ECF
214
What is respiratory acidosis and what causes it
This is when the retention of CO2 occurs and is usually down to respiratory problems such as hyperventilating or lung disease
It results in a decrease of Ph and increase of p.p of CO2
215
How does the body compensate respiratory acidosis
it signals the kidney to retain HCO3- and shift the equilibrium of the bicarbonate dissociation equation back to the middle, increasing pH
216
What is respiratory alkalosis and what causes it
This is an excessive loss of CO2 generally caused by hyperventilation
This decreases the p.p. of CO2 and the carbonic acid equation shifts to the left to accommodate this, increasing pH
217
What is the compensatory response to respiratory alkalosis
there is a net loss of bicarbonate by the kidney in order to return to a normal pH and shift equilibrium of the carbonic acid equation back to the right
218
What is the carbonic acid equilibrium
CO2 +H2O H2CO3 H+ + HCO3-
219
What is metabolic acidosis and how is it caused
It increases the H+ concentration in the body and is caused by diabetes, heart failure, renal failure and diarrhoea
It shifts the equilibrium of the carbonic acid equation to the left
220
What is the compensatory response to metabolic acidosis
The lungs blow off more CO2 to decrease p.p. of CO2 and shift the carbonic acid equilibrium to the left to decrease {H+}
221
What is metabolic alkalosis and what causes it
It's a net loss of H+ caused by things such as vomiting
| This raises pH as the equilibrium is shifted to the right
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What compensatory response occurs in reaction to metabolic alkalosis
The lungs blow off less CO2 by hypoventilation
223
What is the role of potassium in the body (6)
Regulating cell volume
Regulating intracellular pH
Synthesising DNA and proteins for growth
Cellular enzyme function
Maintaining a resting membrane potential
Cardiac and neuromuscular activities and BP
224
What body function problems can arise during hypokalaemia (<4mM)
Cells become more negative and less sensitive to depolarisation
muscle weakness can lead to paralysis
Abnormal neural conduction leads to confusion and eventually comas
Increased cardiac excitability
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What problems can arise due to hyperkalaemia (>5mM)
Cardiac arrhythmia and risk of cardiac arrest
| Abnormal neural conduct
226
What are major sources of K+ in the diet
Meat, fruit and fruit juice
227
What occurs to potassium as soon as it is ingested
It is distributed around cells in the body and then sloly let out into the ECF until the next meal
228
What is the uptake of potassium stimulated by
Insulin and adrenaline and aldosterone
229
How does a build up of plasma protons result in hyperkalaemia
When there is an excess of protons in the plasma they are absorbed into cell through a K/H pump so a build up of K+ can occur in the bloodstream as these are exchanged
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How is K+ reabsorption controlled by the kidney
If a person has a high K+ diet less K+ is reabsorbed in the DCT and collecting duct and some may even be secreted into the DCT and collecting duct
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How is K+ reabsorbed into the late proximal tubule
The K+ is reabsorbed paracellularly as the lumen is positive so it is driven by a potential difference
232
How is K+ reabsorbed in the thick ascending Loop of Henle
The Na/K/2CL cotransporter
233
How do the principal cells drive increased K+ secretion due to an excess in the blood plasma
They contain many Na/K ATPase pumps and as a result reabsorb more Na in exchange for K
This is stimulated aldosterone that is released independently of the RAAS
234
What bodily state increases K+ secretion- alkalosis or acidosis and why
Alkalosis as it increases Na/K pump activity and increases the number of K+ channels
235
What are the main symptoms of UTIs (7)
```
Change in urinary frequency
Dysuria (painful urination)
Passing of only small amounts of urine
Haematuria
Pyuria (foul smelling or cloudy urine)
Urgency
Urinary incontinence
```
236
What symptoms of UTIs are specific to upper UTIs (kidneys) (3)
Upper back and flank pain
Shaking and chills
High fever
237
What are severe symptoms of UTIs
Rigors (feeling weak dizzy and uneasy)
Pyrexia (high temp.)
Nausea and vomiting
Acute confusional state
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What is bacteriuria
Bacteria being present in the urine
239
What is a relapse with regards to bacteriuria
This is when a patient becomes reinfected with the same bacterium they were infected with before
240
What is urethritis
Infection of the urethra
241
What is cystitis
Infection of the bladder
242
What is pyelonephritis
Infection of the kidney
243
What is the trend of UTI frequency with increasing age
As age increases so does the frequency of UTIs
244
What are the main risk factors to contracting a UTI
```
Female gender
Increasing age
Recent antibiotic use
Recent sexual activity
New sexual partner
Diabetes
Presence of catheter
Pregnancy
```
245
What are uncomplicated UTIs
These are infections in a structurally and neurologically normal urinary tract and persistent infection can lead to kidney problems
246
What are complicated UTIs
```
infections of the urinary tract with abnormalities such as
Diabetes
Kidney stones
Blockages
Developmental abnormalities
```
247
What are the three conditions for a bacteria to cause a UTI
Get into the urinary tract
Adhere to the epithelial surface
Multiply and elicit an inflammatory response
248
What are the two routes for a bacteria to enter the urinary tract
The ascending route as the bacteria ascend the UT by bowel flora
The haematogenous route is by blood borne bacteria and is mainly due to infection of the renal parenchyma
249
What is the main causative organism in UTIs
UPEC- uro-pathogen E.coli
250
Why can catheters lead to increased risk of UTIs
in catheters the urine is not washed away properly by the flow of excreting urine and this gives a chance for bacteria to colonise and develop
251
What lab tests can be run to clinically diagnose UTIs
Urine microscopy can show leukocytes which indicate the presence of infection
Dipstick analysis of urine
Urine culture
252
What drugs can be used to treat a lower UTI
Trimethoprim or Nitrofurantoin
253
with which drugs can you treat pyelonephritis
Cefalexin
254
What is microscopic haematuria
When blood is present in the urine but not enough to be visible to the naked eye
255
What is proteinuria
When there is protein in the urine
256
What is glycosuria
When there is glucose in the urine
257
What enzyme tests for the presence of leukocytes
leukocyte esterase
258
What does increased leukocytes in the urine suggest
infection in the kidneys or urinary tracts
259
What does a positive nitrites result in the urine suggest
it may indicate a UTI as gram negative bacteria converts to nitrites in the bladder
260
What does increased urobilinogen suggest
Liver cell damage or increased bilirubin excretion to intestines
261
What does protein in the urine suggest
Kidney disease
262
What does acidic urine suggest
kidney disease or diet
263
What does blood in the urine suggest
Infection or disease in the kidney or bladder
264
What does increased ketones suggest
Diabetes, low carb diet or starvation
265
What does increased bilirubin concentration suggest
liver damage
266
What does glucose in the urine suggest
Diabetes mellitus
267
What factors increase the likelihood of an individual having a kidney stone
```
Structural abnormalities affecting urine flow (e.g. horseshoe kidney)
Loop Diuretics
Relative dehydration
Diet high in purines
Hypercalcaemia
Metabolic disorders
increasing oxalate levels
consequence of necrosis following AKI
History of renal calculi or recurrence
```
268
How can hyperparathyroidism lead to hypercalcaemia
hyperparathyroidism results in an increase in parathyroid gland and this increases bone reabsorption which releases calcium
269
What does cystinuria cause an excess of to be released into the urine
Amino acids
270
What is the most common type of kidney stone
Calcium oxalate stones- approximately 60% of stones
271
What are the main symptoms of kidney stones
```
loin to groin pain
sweating
nausea
vomiting
dysuria
haematuria
```
272
Where will stones high up in the kidney cause pain
In the flank
273
What is the character of the loin to groin pain caused by lower down kidney stones
It has spasms of sharp pain due to dilation of the ureter and small periods of relief but a persistent dull ache
274
What investigations should take place upon the potential for a kidney stone
An x-ray as 90% of kidney stones are opaque however the gold standard is CT-KUB (kidney ureter bladder)
Ultrasound is used when radiation should be avoided
275
When should you consider hospital admissions upon the presence of kidney stones
```
Fever
Solitary kidney function
Inadequate pain or persistent pain
Inability to take adequate fluids
Anuria
Pregnancy
```
276
What drugs can be used to reduce ureteric spasm and help stones pass
Alpha blockers and calcium channel blockers
277
What technique can be used to break down stones into smaller crystals so they can pass
Extracorporeal shockwave therapy
278
What is ureteroscopy
This is the insertion of a ureterscope into the ureter via the external meatus to the stone under general anesthesia
279
What is percutaneous nephrolithotomy
This is the use of keyhole access through the skin in the flank directly into the kidney under anaesthesia
280
What is a case control study
This is when exposure and outcome have already occurred
It proceeds backwards form effect to cause
It uses a control group to compare
281
What is a cohort study
two or more groups are selected on the basis of their differences of exposure to a particular agent
these groups are then followed
this can be used to study incidence, causation and prognosis
282
What is a cross-sectional study
Looks at data on a population at a specific point in time to provide a snapshot
it's observational so you can't draw cause and effect conclusions from it
these are inexpensive and fast studies that provide a basis for further research
283
What are randomised control trials
Aim to compare doses or treatments on two or more groups
| The participants are randomly assigned to groups and then these groups are followed up and analysed over time
284
What are systematic reviews
Overviews of primary literature that focus on a research question
285
What is meta analysis
This is presenting a balanced summary of all existing research
this is to be done on a quantitative basis
286
What is fabrication
The making up or manipulation of data
287
What is improper analysis
using the wrong statistical test
288
What is selective reporting
This is only including the data that supports the hypothesis the author is after
289
What is epidemiology
The study of how often diseases occur in different groups of people and why
290
What is absolute risk
The risk of a patient developing a condition over a given period of time
291
What is relative risk
This is the comparison of two groups of people and how likely they are to develop a disease
292
What is the odds ratio
The association between an exposure and an outcome
293
What is attributable risk
A measure of the proportion of the disease occurrence that can be attributed to a certain exposure
