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NUR111 > TOPIC 6 > Flashcards

TOPIC 6 Flashcards

1
Q

REVIEW URINARY SYSTEM DIAGRAM

A

REVIEW

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2
Q

Functions of the kidney

A
  • waste removal ( urea, uric acid, creatinine, drugs)
  • Preserve valuable substances our body’s cells need ( glucose, amino acids, electrolytes)
  • Maintenance of fluid balance, electrolyte concentrations and pH
    Regulate blood volume

-Regulation of blood pressure
( less volume = less pressure)

  • Production of erythropoietin - responsible for triggering production of red blood cells. Without erythropoietin ppl can become anemic
  • Activation of vitamin D by kidneys from the precursor we take up with our diet
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3
Q

Which kidney is lower

A

right kidney lower than left

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4
Q

Are adrenal glands near the kidney

A

adrenal glands above both kidneys

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5
Q

Which side is the vena cava and which side is the renal artery

A

Right Blue inferior vena cava and left red renal artery

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6
Q

Are kidneys retro or intraperitoneal

A

Kidneys are retro peritoneal

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7
Q

When looking at the kidney cut in halves what does the cortex look like

A

cortex around-> granular appearance as all the renal corpuscles ( do all filtration of blood, contain start and end points of tubules that reach down into our medulla area into pyramids ) located here

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8
Q

When looking at the kidney cut in halves what does the medulla look like

A

Middle is medulla-> made up of lobes, pyramids ( renal tubules and capillaries and end in the top called the papillar) plus the columns

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9
Q

When looking at the kidney cut in halves what does the renal pelvis look like

A

Renal Pelvis is where the urine starts collecting coming from the minor and major calyx’s

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10
Q

What is poiseuilles law

A

How much fluid flows accords a tube at a certain time ( fluid flow) depends on radius and length

Fluid flow higher with a wider tube.
Decreases drastically when the radius decreases

Blood vessels in the kidneys can actually adjust their diameter and therefore adjust the fluid flow

Fluid flow = Pi x pressure difference x radius^4 / length x viscosity

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11
Q

What is hydrostatic pressure

A

Hydrostatic pressure ( pressure that a fluid has on surrounding tubes- blood vessels. Also depending on gravity higher something is = more hydrostatic pressure. Hydrostatic pressure also increases with atmospheric pressure Eg, if under water= higher hydrostatic pressure)

The hydrostatic pressure we have in our vessels is partly due to the pumping of the heart.

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12
Q

What is osmotic pressure

A

Osmotic pressure ( pressure headed to push a solvent across a semi permeable membrane depending on the amount of solutes present)

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13
Q

T or F

Fluid is impaired by resistance

A

fluid is impaired by resistance ( the force you have to use to get fluid along a tube depends on tubing length and diameter)

-blood vessels have resistance as long tubes get smaller and smaller in diameter ( what our heart has to overcome)

  • Arteries eventually become arterioles, they then enter tissues giving nutrients and oxygen to the cells in exchange for wastes and carbon dioxide which then travel out the venules and then veins.
  • Also as travel from large vessels to small vessels pressure reduces reduces reduces in our Venus system pressure is much lower than in the arteries
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14
Q

how much blood in kidneys per day

A

Nearly 200 litres every day but only 1-2 litres per day

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15
Q

blood in liver vs blood in kidney

A

Liver Venus blood, kidney arterioles blood

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16
Q

apart from being filtered what else does the kidney use blood for

A

Apart from blood that comes in for filtration some of the blood is also used for the kidneys to function. 25% of the oxygen requires at rest goes to the kidneys, 2nd most oxygen hungry organ after our brain

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17
Q

what is a nephron

A

Functional unit of the kidney

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18
Q

what artery enters the afferent /efferent arterioles

A

cortical artery goes into affertent/ efferent arterioles

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19
Q

goal of the nephron

A

Goal is to filter blood and produce urine

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20
Q

what is the renal corpuscle like

A

Renal corpuscle has a bunch of bunched up arterioles ( glomerulus)

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21
Q

wat is the PCT like

A

Proximal convoluted tubule enters the loop of henle leading to distal convoluted tubule which then leads to collecting ducts. There is ascending and descending loop with thick and thin parts.

Proximal convoluted tubule has cells with a lot of microvilli as they are responsible for reabsorption from filtrate back into blood.

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22
Q

cells of the distal convolued tubule

A

the distal convoluted tubule cells have an apical side where micro villi are and a basolateral side.

Collecting ducts have some cells called principle cells responsible for maintaining water sodium balance and intercalated cells play a role in acid base balance.

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23
Q

REVIEW cells at different sites of the nephron

A

REVIEW cells at different sites of the nephron

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24
Q

where does re absorption happen

A

PCT

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25
Q

role of principle cells in the collecting duct of the nephron

A

Collecting ducts have some cells called principle cells responsible for maintaining water sodium balance and intercalated cells play a role in acid base balance.

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26
Q

2 types of nephons

A

Cortical nephrons

Juxtamedullary nephrons

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27
Q

what are cortical nephrons like

A

Cortical nephrons - short and stay within the cortex not reaching into the medulla of the kidney, bunched up allot more 85%.

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28
Q

what are juxtamedullary neprons like

A

Juxtamedullary nephrons- reach deep into the medulla, whole thing is elongated and blood vessels ( vasa recta) are parallel to defending and ascending look 15%

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29
Q

afferent vs efferent arterioles role

A

afferent arteriole leads into the glomerulus, efferent leads out

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30
Q

what type of membrane do tubule vessels in the nephron have

A

Vessels have filtration membrane

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31
Q

what types of cells can you find on the filtration membrane

A

Podocytes a part of filtration membrane

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32
Q

where is the ascending loop located in a real life nephron not looking at a spead out diagram

A

ascending loop as nephron is actually bunched up is actually close to the afferent and efferent arteriole as there are some cells that are important (macula densa, granular, extra glomerular mesangal)

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33
Q

what do mascula densa cells in the ascending limb of the nephron do

A

Macula desa cells in ascending limb -monitor the salt content of filtrate,

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34
Q

what do granular cells on the arteriole do

A

granular cells on arteriole monitor the blood pressure and release enzyme called renin

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35
Q

what do extra glomerular mesangal cells in Between the other two types of cells of the juxtaglomerular complex do?

A

pass on messages from the other two cell type locations. Keeping the opposition informed of salt levels and pressure

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36
Q

The arterioles and ascending tubule and cell’s is called …

A

the juxtaglomerular complex

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37
Q

what is filtration

A

kidneys receive blood and everything apart from cells and protein gets put into filtrate

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38
Q

what is re absorption

A

In tubular structures body starts reclaiming what it wants to keep

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39
Q

what is secretion

A

Body Can also throw out things it doesn’t want Eg. Drugs, unwanted electrolytes, ware products

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40
Q

Amount that is filtered by kidneys

A

Of the approx 1200 ml blood that passes through 650ml is plasma and 120-130 will be filtered across

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41
Q

What is the filtration membrane like

A

filtration membrane consists of three layers

( capillary endothelium, basement membrane, foot process of podocyte of glomerular capsule)

The filtration membrane is the wall of the capillary and the interior of the capsule.

Endothelial is fenostrated allowing allowing all the blood components to come through (even protiens - they get blocked by the basement membrane which only allow smaller solutes to get through).

Should anything manage to get through basement membrane as well, then the filtration skits between the extensions/ processes of the podocytes will prevent them from entering the capsular space and the filtarate

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42
Q

What is filtrate

A

The filtrate is basically the precursor of urine

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43
Q

Is filtration active or passive

A

The filtration process is a passive process. It travels passively due to the pressure gradients ( pressure from blood getting pumped, gravity/ standing up of the body causing hydrostatic pressures

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44
Q

What is the net filtration pressure

A

Outward pressure - inward pressure= 10mmhg

55mm Hg millimetres mercury In the afferent arteriole forcing the plasma out INTO the capsular space

Fluid in the glomerular capsule also exerts a hydrostatic pressure of about 15 mm Hg coming OUT

There is also an osmotic pressure. 30mmhg.
No protein can get through the glomerular capsule from the vessel so the concentration of those protiens is much higher in the blood ( water wants to go back butt if we add it all up 1 outward - 2 inward ones = pressure on the whole forces the fluid to go from the arteriole into the glomerular capsule

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45
Q

How does diameter impact flow rate

A

depending on how wide a tube is the flow rate increases. And that’s what the arterioles can do by changing their diameter

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46
Q

What happens to BP when exercising

A

Blood pressure changes when exercising, lying down, sitting up, are hydrated or dehydrated buttt our kidneys would like to maintain that filtration rate as constant as possible ( 125-135 ml per min)

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47
Q

How do we regulate filtration rate to keep it constant

A

It can regulate that by an auto regulation and there’s 2 main intrinsic mechanisms - myogenic and tubule glomerular

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48
Q

Explain the myogenic mechanism

A

If BP drops in arterioles = decreased filtration rate in the glomerular = stretch of muscles in walls of afferent arterioles= vasodilation = increased flow rate and gfr

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49
Q

Explain the tubular glomerular mechanism of

A

if BP drops= decreased filtrate flow and decreased NaCl in ascending limb of nephron loop = masculine dense cells of juxaglomerular complex of kidney = Vado dilation of afferent arterioles = increased gfr

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50
Q

What pressure changes can kidneys handle

A

Kidneys can handle pressure changes between 80-100 ml Mercury but don’t do well with a BP below 80, as means that don’t have enough pressure to get blood back up to brain = autoregulation turns off and autonomic nervous system triggers vasoconstriction and other hormones triggering an increase in blood volume.

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51
Q

What happens in the PCT

A

in PCT most reabsorption happens
Glucose, amino acids, water, electrolytes

2 processes-
trans cellular route - through quite easily through the cell
Para cellular route- in between the cell

52
Q

Tubular reabsorbtion of sodium process

A

Requires active transport mechanisms ( primary at the basolateral end, secondary at the apical end)

Pump throws out sodium and brings back 2 potassium in exchange decreasing sodium concentration in our tubule cells meaning that sodium will drawn in again via the concentration gradient dragging other things with it particularly glucose, water

Everything ends up in interstitial fluid first then the capillaries

53
Q

How much of filtrate is reabsorbed

A

tubular reabsorption can see 65% filtrate volume reabsorbed

54
Q

Where is water mainly reabsorbed

A

Water mainly reabsorbed in descending limb, a lot of aquaporins
In ascending limb usually no water reabsorption ( unless ADH acts );but there is transport of electrolytes, also in this limb urea is secreted
Distal convoluted tubule fine tuning happens,

55
Q

What are nitrogenous wastes

A
  • waste comes from protein metabolism ( degradation of amino acids)
  • From bacteria in large intestines
  • Ammonia is a product of metabolism and bacteria and it NH3 gets converted into urea in liver and is excreted via kidneys
  • Uric acid is the end product of metabolism, also excreted by the kidneys

…
Non toxic NH4 ammonium ion is also extended by the kidneys

56
Q

Aim of filtration, reabsorbtion and secretion

A

To form uribe

57
Q

Factors affecting using volume and concentration

A

…hydrogen status/ how much we drink
…elecrolyte concentration in the blood
…Blood volume and pressure

…regulated by hormones

…type of nephron involved

…counter mechanisms

58
Q

Role of anti diuretic hormone

A

antidiuretic hormone (ADH) = decreases urine output by increasing water reabsorption particularly in collecting duct in those principle cells that cause when acted on by ADH to insert more aqua porins into the apical membrane so more water gets reabsorption

59
Q

Role of aldosterone

A

also acts on principle cells of collecting ducts increasing Ana+ reabsorption and water follows so increases blood volume/ pressure. Can also be triggered by increased potassium in blood in order to increase sodium reabsorption to chuck out potassium in exchange

60
Q

Role of Atrial natriuretic peptide ( ANP)

A

Atrial natriuretic peptide ( ANP)= inhibits Na+ reabsorption so decreases blood volume pressure ( counterplayer of aldosterone). Released when heart measures too much blood volume

61
Q

Role of parathyroid gland

A

Parathyroid hormone (PTH) = increases reabsorption of calcium

62
Q

Triangle region above top of urethra is

A

Trigone

63
Q

T or F

Osmolarity/ concentration of solutes in the cortex and medulla increases as we move from the cortex to the medulla

A

True
Because the Jutamedullay nephrons reach far into the medulla exchange happens not just by pressure gradient of hydrostatic pressure but also by osmotic pressure.

64
Q

What does the fact that urine gets concentrated by counter current mechanisms

A

urine gets concentrated via counter current mechanisms. Less water and more solutes if dehydrated and contains more water and less solutes if over hydrated

65
Q

How do we test renal function

A
  • urinalysis ( check for protein and blood, uric acid, specific gravity )
  • Clearance and glomerular filtration rate (how much blood gets filtrate in the glomerulus)
  • Using Creatinine ( byproduct of muscular activity) which gets filtered in the glomerulus- none of it gets reabsorbed. Can use it to determine how much blood or plasma the glomerulus filters. normal 120-125 per min, if below 60 approx half of your kidney function has gone = no good
  • Blood urea nitrogen (BUN)- measuring waste product of blood. If increase in kidney failure, less waste products getting into the urine.
66
Q

Where do ureters join bladder

A
  • ureters loop around the back and come in from the bottom so that we don’t get any back flow
  • Ureters join the bottom of the bladder
67
Q

Prostate urethra issues

A

Prostate wraps around urethra which can cause problems in male with prostate enlargement

68
Q

Female urethra issues

A

Urethra in women is much shorter

Risk of UTIs

69
Q

What are the sphincters on the urethra like

A

2 sphincters, internal involuntary and external sphincter made up of voluntary skeletal muscle
External and internal sphincter have to relax when urinating

70
Q

Is bladdder a muscle

A

Whole bladder is a muscle called the detrusor muscle ( 3 layers of muscle 2 longtudinal and one circular that have to contract when urinating- while sphincters relax) regulated by spinal nerves and autonomous nervous systems
Can be problems urinary retention or inconstinence

71
Q

How much water do we consist of

A

-we consist of about 60% water

-Content depends on body mass, age, gender and content of body fat
Eg. Women have less body fluid about 50% body fluid, males 60%

-Highest water content we ever have is when we are babies, we have about 70% then and as we get older we lose the water content. In older age only about 45% water

72
Q

2 main fluid compartments

A
  • Two main fluid compartments are intracellular (40% of body weight) and extracellular fluid ( 20%)
  • Intracellular is fluid inside cells and is about 25 litres
  • Extracellular fluid is plasma and interstitial fluid, plasma is about 3 litres

and interstitial fluid between cells and blood vessels is 12 litres

73
Q

Do we have Mechanisms to preserve, conserve and recoup water and also certain triggers to make us drink and increase fluid intake

A

Yes

But the body can regulate these things using membranes, capillary walls and cell plasma membranes which can determine what gets in and what gets out

Hormones too

Both the osmotic pressure and hydrostatic pressures play a role but also the concentration of the electrolytes

74
Q

Body fluid is composed of

A

water, non electrolytes ( some protiens, some organic molecules, some waste products).. non electrolytes don’t carry electrical charge and are mainly responsible for osmotic pressure in the blood like the bigger parts proteins cause the oncotic pressure.

75
Q

What are non electrolytes

A

some protiens, some organic molecules, some waste products)..

non electrolytes don’t carry electrical charge

are mainly responsible for osmotic pressure in the blood like the bigger parts proteins cause the oncotic pressure.

76
Q

The more particles you have in a solution ….

A

the more water that will draw into it for a certain concentration to be maintained

77
Q

Concentration of ECF vs ICF

A

The concentration of extracellular and intracellular fluid would be the same because

otherwise we’d have constant fluid loss into one compartment.

But the body can regulate these things using membranes, capillary walls and cell plasma membranes which can determine what gets in and what gets out

78
Q

What are electrolytes

A
  • Electrolytes are everything that has very strong chemical bonds and therefore doesn’t dissociate in water and therefore carries electrical charge.
  • Positively charged electrons- cations
  • Negatively charged electrons- anions
    And mostly very small, often salts
    Eg. Sodium, potassium, calcium and magnesium but they can also be small proteins
  • Even though mass wise the electrolytes are not as many as the non electrolytes… because there’s more particles of them they have the greatest powers with regards to osmotic pressure.
  • as some of them are very small they can cross over the different membranes and draw water with them and are responsible for maintaining a balance between the fluid flow
79
Q

Increase in electrolytes or non electrolytes in the cells INtracellular fluid

A

Eg. Increase in electrolytes or non electrolytes in the cell that would encourage water to flow into the cells

or

increase of hydrostatic pressure in blood vessel that would encourage water to be pushed out into the interstitial fluid

80
Q

What pressure is more at play when it comes to blood vessels

A

Hydrostatic pressure perimeter is probably most important one when it comes to the blood vessels because we have a pressure that comes from the pumping of the heart so we do have a certain hydrostatic pressure, where as with the cells it’s often the content of the cells particularly the non electrolytes

81
Q

Is plasma membrane permeable for water

A

Plasma membranes usually quite permeable for water but other substances have to either get co transported or have facillitated diffusion or active transport mechanisms

82
Q

Output must equal input (water?]

A

the body keeps losing water all the time BUT water output must equal water input so we are forced to take water into us,

83
Q

Most water we take up is

A

Most of water we take up is through liquids and food but we also produce water with cellular respiration ( co2 and water are products)

84
Q

Insensible water loss

A

Water output through skin and lungs is insensible water loss

85
Q

Sensible water loss

A

Sweating faeces and urination is sensible water loss as that can be regulated by the body much better where as the insensible water loss is just something that happens

86
Q

Body’s reaction to dehydration

A
  • water loss causes leaves higher concentration in ECF so osmotic pressure rises due to more concentration of electrolytes and particles, the increase in osmotic pressure causes water to flow into ECF by osmosis causing cells to shrink
  • Thirst center in hypothalamus reacts to certain stimuli eg. Dry mouth or increase in osmotic pressure makes you want to drink
  • The moment you start drinking water the thirst reflex immediately stops in order to prevent over hydration so that we take fluid in family measured state.
87
Q

What is is osmolarity

A

extracellular fluid Concentration

88
Q

What is the body’s reaction too dehydration

A

Over hydration/ hypotonic hydration= osmotic pressure falls in ECF and water falls into the cells causing the cells to well
Not good for brain, brain swells caused cerebral oedema and leads to confusion, coma, death,…

89
Q

Odema

A

oedema can happen in interstitial space, often due to increase leakage of blood vessels. Water leaving capillaries and getting into interstitial space. Often impact of kidney or cardiac malfunction

90
Q

Kidneys cN be influenced by what to adjust whether water is absorbed more or less

A

kidneys are influenced by hormones which determine eater is reabsorbed more of less.

91
Q

Anti diuretic hormone targets

A
  • acts on the collecting ducts and distal convoluted tubules and it basically causes more aquaporins to be inserted into the apical membranes of out cells in the nephron tubules
  • Anti- no, diuretic-dieresis means exertion of urine
  • Increase in ECF osmolarity/ decrease in BP = osmoreceptors or baroreceptors = trigger posterior pituitary gland= release ADH= targets Collecing ducts = increased water reabsorption= decreased osmolarity / increase plasma volume
  • ADH really only acts on water reabsorption
92
Q

What does aldosterone triggered

A
  • acts on sodium content not the aquaporins, it finetunes sodium reabsorption into the blood plasma and triggered by drop in sodium or increase in potassium
  • decreased sodium content in juxtaglomerlar complex detected by macular densa cells trigger renin release from granular cells
    (part of arteriole walls of afferent/ efferent arterioles )
  • renin released goes through 2 steps
  • ( triggers angiotensin 1 which then gets triggered into angiotensin 2 which then will act on the adrenal cortext to release aldosterone which then acts on the DCT and CD to increase sodium reabsorption

… increased potassium concentration in ECF can also trigger adrenal cortex to release aldosterone

93
Q

For every sodium ion reabsorbed potassium ion

…

A

gets chucked out ( increased potassium secretion)

94
Q

How can estrogen cause odema

A

estrogen is very similar to aldosterone and can all have a similar effect on kidney tubules… that’s why before period when estrogen levels rise sometimes you get water retention ( increased sodium reabsorption for no reason= increase in sodium concentration and water follows= more water than needed in ends up in interstitial = odema and bloated)

95
Q

Aldosterone and antidiuretic hormone vs at risk natriuretic peptide

A

Aldosterone and Antidieuretic increase blood volume

pressure ANP - Atrial natriuretic peptide - acts when there is too much fluid and bp is too high to lower it

96
Q

What is ANP triggered by

A
  • triggered by too much stretch in the atria of the heart due to too much volume or increased blood pressure= releases ANP from atria which
    1) blocks release of renin in granular cells of juxtraglomerular complex
    2) blocks release of ADH from Posterior pituitary gland and
    3) blocks direct release of aldosterone that can be released by the sympathetic nervous system

= no aldosterone, no antidieuretic hormone, no inbetween step of renin to angiotensin to aldosterone

Angiotensin 2 is a very potent vasoconstrictor, no angiotensin 2 means blood vessels will dilate

97
Q

What is the most abundant cation in the extracellular fluid

A

Sodium

Important as 
Plasma concentration ( causes resting membrane potential) and body content important( plays a role in fluid balance- how much sodium determines how much water you have
98
Q

Regulation of sodium

A
  • Chemoreceptors (macula densa of JGC), baroreceptors (arteries), osmoreceptors (hypothalamus)
  • 90% already reabsorbed in PCT and loop (regardless of hormonal influences)
  • Aldosterone – ↑ Na+ absorption in DCT and collecting ducts (water follows!)
  • ANP – blocks Na+ absorption
  • Female sex hormones mimic aldosterone
99
Q

What is the most abundant cation in the intracellular fluid

A

K+ most abundant cation in ICF

100
Q

Importance of potassium

A

Vital for resting membrane potential 3 sodium’s out 2 potassium’s in and heart muscle function

101
Q

Body’s regulation of potassium

A
  • 90% reabsorbed in PCT and loop (regardless of need)
  • Aldosterone – ↑ K+ secretion in DCT and collecting ducts
  • ↑ K+ plasma levels causes principal cells in collecting ducts to secrete (and excrete) more K+, ↓ K+ plasma levels depress secretion
102
Q

What fruit has lots of potassium

A

Bananas

103
Q

Where is calcium stored

A

Ca2+ stored in muscle cells (SR) and part of bones

104
Q

Importance of calcium

A

Vital for neuromuscular function – hypercalcaemia (too much calcium) inhibits neurons and muscle cells, hyocalcaemia ( not enough calcium) causes increased excitability

105
Q

What is hypercalcaemia

A

too much calcium inhibits neurons and muscle cells,

106
Q

What is hyocalcaemia

A

( not enough calcium) causes increased excitability

107
Q

Calcium levels regulation in the body

A
  • 98% reabsorbed in PCT
  • PTH acts on bones – osteoclasts break down bone matrix, DCT – ↑
  • Ca2+ reabsorption in DCT, small intestines – enhanced Ca2+ absorption with help of Vit. D
108
Q

What is a buffer

A

combination of a weak base and a weak acid

109
Q

What is an acid

A

Acid- lots of free hydrogen ions

110
Q

What is a weak acid

A

weak acid- not as many don’t dissociate completely, dissociate depending on what the surrounding solvent is Eg if solution is more alkaline it will dissociate to relealease more hydrogen ions. If more acidic solvent will dissociate to release more alkaline

111
Q

strong acid + weak acid

A

Strong acid + weak acid= weak acid dissociates according to surroundings and will dissociate to release more basic bits and alkaline
= good for homeostasis and maintaining blood ph

112
Q

Normal blood ph

A

Normal ph 7.35-7.45

113
Q

What are the bodies 3 buffers

A

Bicarbonate Buffer System

Phosphate Buffer System

Protein Buffer System

114
Q

What is bicarbonate buffer system

A
  • Mixture of H2CO3(weak acid) and salts of HCO3 (weak base)

* Main ECF buffer; also operates in ICF

115
Q

What is the phosphate buffer system

A
  • Salts of H2PO4 (weak acid) and HPO42  22 (weak base)

* Important buffer in urine and ICF

116
Q

What is the protien buffer system

A
  • Some amino acid side chains can act as weak acids (-COOH) or weak bases (e.g.,-NH2)
  • Most important buffer in ICF; also in blood plasma
117
Q

Why does the body have to buffer

A

we have a lot of acidic substances in our blood come form food and metabolic processes Eg. Ketone bodies, lactic acid and carbon dioxide

The 3 buffers act in the ECF particularly in the plasma to react straight away in a fracture of a second to buffer those ph changes when those acidic substances enter the body.

118
Q

Why doesn’t co2 have a massive impact on acidity in day to day life

A

Co2 is produced all the time and it gets expelled from the lungs so it doesn’t have a big effect on the blood ph because we can get rid of it straight away but it can be used to compensate/ adjust the blood ph quickly by either providing hydrogen ions making blood more acidic or get blown off and therefore remove some acidic substances

Happens within a few minutes and is regulated by the brain stem which measures the blood ph and can help with that

119
Q

Can buffers compensate

A

The buffers can compensate within the extracellular fluid and within the cells but we still have to get rid of those acidic substances and that is done by the kidneys which produce new bicarbonate and reabsorbing bicarbonate

Cells responsible for doing this are the intercalated cells in the collecting duct
Principle cells- electrolyte eater balance
Intercalated cell- acid base balance

120
Q

What are the cells of the collecting ducts and how do they help regulate acidity

A

have to get rid of those acidic substances and that is done by the kidneys which produce new bicarbonate and reabsorbing bicarbonate
Cells responsible for doing this are the intercalated cells in the collecting duct
Principle cells- electrolyte eater balance
Intercalated cell- acid base balance

121
Q

What happens if bicarbonate is not reabsorbed

A

Blood becomes too acidic

122
Q

How is bicarbonate removed

A
  • bicarbonate gets reabsorbed by the type a intercalated cells in the collecting ducts and in exchange for one bicarbonate we chuck out one hydrogen ion
  • Hydrogen ion actually end up in the filterate where it comes across bicarbonate as well, gets combined to carbonic acid and then gets split up with the help of an enzyme into water and CO2 which the body can deal with very easily
  • Depending on how much co2 travels in or out will determine how much bicarbonate we have in the cell as the reaction can work backwards too
  • The more co2 that’s coming in/ the more acidic the blood is = the more we have the reaction happening= we get more bicarbonate which can be reabsorbed whichmeans we get more hydrogen ions that get chucked into the filtrate and produce more co2
  • A cycle where the bicarbonate always gets recycled and the hydrogen ion gets kind of neutralised by being tuned into co2 and water

(reabsorbingbicarbonate but we are not making any new bicarbonate… that’s just bicarbonate that’s floating around in the urine.. so it’s not anything new)

123
Q

2 ways to make new bicarbonate

A

Via phosphate buffer

Or True production of bicarbonate happens via ammonium ion

124
Q

How does phosphate buffer create new bicarbonate

A
  • Water and carbon dioxide in the cell gets tuned into carbonic acid which gets split into hydrogen which gets secreted and bicarbonate which gets reabsorbed
  • The hydrogen in the urine combines with phosphate buffer and gets excreted
  • Bicarbonate is produced that’s not part of that previous cycle going round p, this time as were losing the hydrogen completely we basically have made sort of a new bicarbonate
125
Q

True production of bicarbonate happens via ammonium ion

A

substance in cells called glutamine ( an amino acid) goes through catabolic reactions and gets broken into 2 bicarbonate ions and some ammonium ions which get excreted via urine

NUR111 (6 decks)

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