october Flashcards
prox tubule
The proximal tubule
reabsorbs water, sodium, chloride, potassium,
bicarbonate, calcium, glucose, urea, phosphate
and any filtered proteins
The thick ascending limb reabsorbs sodium,
potassium, chloride and bicarbonate and secretes
hydrogen ions.
Reabsorption of sodium chloride, bicarbonate and
calcium takes place in the distal tube, and potassium and hydrogen ions are secreted into the
lumen
Aldosterone
stimulates sodium reabsorption and potassium
secretion by the principal cells of the cortical
collecting ducts. ADH increases the permeability
of cortical and medullary collecting ducts
to water.
principle
Principal aSALTed a student
potassium handling
https://teachmephysiology.com/urinary-system/ion-balance/external-balance-potassium/#:~:text=within%20the%20body.-,Renal%20Handling%20of%20Potassium,potassium%20secretion%20and%20potassium%20reabsorption.&text=Potassium%20is%20freely%20filtered%20at,most%20of%20it%20is%20reabsorbed.
sodium handlign
https://en.wikipedia.org/wiki/Renal_
sodium_reabsorption#:~:text=Renal%20reabsorption%20
of%20sodium%20(Na,inhibited%20by%20atrial%20natriuretic%20peptide.
calcium handling
More than 95% of filtered calcium is reabsorbed along the renal tubules. In the proximal tubules, 60% of filtered calcium is reabsorbed by passive mechanisms. In the thick ascending limb, 15% of calcium is reabsorbed by paracellular diffusion through paracellin-1 (claudin-16)
midaz dose
IV 0.1mg/kg
PO 0.5mg/kg
midaz effect
decrease HR and SVR 10%
decreased TV increased RR
lamina
- Adelta–>laminae 2,5, C fibers—>2 (P+H) 2 at 2 fast at 5
*
ANS structure
ANS
- SNS-efferent cell bodies in lateral grey column and in peripheral ganglion of T1-L2
- PSNS-efferent Brainstem CNs 3,7,9,10 and sacral primary rami—>pelvic splanchnic nerves
Exit as myelinated the ganglia then unmyelinated
Ganglia 2.5cm from midline for SNS and very close to organ for PSNS
SNS-mass effect
- exit lat grey column—>white rami communicans 3 options in the Sympathetic trunk
1. Synapse at that ganglion in white rami communicans
2. Travel upon down trunk to ganglions above # cervical ganglion
3. Pass through and synapse with a more distal ganglion
nerve AP
-70
ciral
quart nitrogen
dextro levo
the optical rotation of plane-polarized light.
QTc
QTc=Qt/squareroot of RR
The QT interval is longer when the heart rate is slower and shorter when the heart rate is faster. So it’s necessary to calculate the corrected QT interval (QTc) using the Bazett formula: QT interval divided by the square root of the R-R interval.
prolonged QT
Slow conduction due to
Hypokalaemia Hypomagnesaemia Hypocalcaemia Hypothermia Myocardial ischemia ROSC Post-cardiac arrest Raised intracranial pressure Congenital long QT syndrome Medications/Drugs
aldosterone
reab Na at expense of K and H
-trigger is high K, acisosis, ATII
upreg NaK basolat in principle
upreg Epithelial NaCh in CD
Acting on the nuclear mineralocorticoid receptors (MR) within the principal cells of the distal tubule and the collecting duct of the kidney nephron, it upregulates and activates the basolateral Na+/K+ pumps, which pumps three sodium ions out of the cell, into the interstitial fluid and two potassium ions into the cell from the interstitial fluid. This creates a concentration gradient which results in reabsorption of sodium (Na+) ions and water (which follows sodium) into the blood, and secreting potassium (K+) ions into the urine (lumen of collecting duct).
Aldosterone upregulates epithelial sodium channels (ENaCs) in the collecting duct and the colon, increasing apical membrane permeability for Na+ and thus absorption.
Cl− is reabsorbed in conjunction with sodium cations to maintain the system’s electrochemical balance.
Aldosterone stimulates the secretion of K+ into the tubular lumen.[11]
Aldosterone stimulates Na+ and water reabsorption from the gut, salivary and sweat glands in exchange for K+.
Aldosterone stimulates secretion of H+ via the H+/ATPase in the intercalated cells of the cortical collecting tubules
Aldosterone upregulates expression of NCC in the distal convoluted tubule chronically and its activity acutely.[12]
ADDISONS
Low blood sugar (worse in children due to loss of glucocorticoid’s glucogenic effects)
Low blood sodium, due to loss of production of the hormone aldosterone, to the kidney’s inability to excrete free water in the absence of sufficient cortisol, and also the effect of corticotropin-releasing hormone to stimulate secretion of ADH.
High blood potassium, due to loss of production of the hormone aldosterone.
Eosinophilia and lymphocytosis (increased number of eosinophils or lymphocytes, two types of white blood cells)
Metabolic acidosis (increased blood acidity), also is due to loss of the hormone aldosterone because sodium reabsorption in the distal tubule is linked with acid/hydrogen ion (H+) secretion. Absent or insufficient levels of aldosterone stimulation of the renal distal tubule leads to sodium wasting in the urine and H+ retention in the serum.
temp control
bulb of krause–.Post poles (polar bear)
bulb of raffiki is warm. ant pot senses local warming of blood->sweat
skin shunt
between arteries and veins, shunting blood directly into the venous plexuses
When body temperature equals
or exceeds 30°C, sympathetic activity to the skin
decreases under the control of anterior hypothalamus. is results in vasodilatation, especially of
arteriovenous anastomoses, and is enhanced by bradykinin released by sweat glands activated by cholinergic sympathetic bres. e fall in total vascular
resistance triggers an increase in cardiac output,
and a massive increase in skin blood ow accommodated in the dilated arteriovenous shunts and
venous plexus. is provides a large area for heat
transfer between the skin and the environment. e
cutaneous blood ow can increase 30-fold in heat
stress and decrease 10-fold in cold stress
ketamine
Ketamine rec Ach, Nicotinic, Na at high dose
gauge pressure
Gauge P: = P above or below atmospheric pressure
CSF alter with drugs
CAi acetazolamide
Spironloactone
hyponatraemia hyperkalaemia, acidosis
VWF desmopressin
increased release
measure ICP
EVD, codmann catheter easy but shit
protein C
These proteins that APC inactivates, Factor Va and Factor VIIIa,
VWF prod in endo
in endo
stored in endothelium and in PL
suports factor 8
dense granules
The dense granules of human platelets contain adenosine diphosphate (ADP), adenosine triphosphate (ATP), ionized calcium (which is necessary for several steps of the coagulation cascade), and serotonin.[6]
alpha granules
Contents include insulin-like growth factor 1, platelet-derived growth factors, TGFβ, platelet factor 4 (which is a heparin-binding chemokine) and other clotting proteins (such as thrombospondin, fibronectin, factor V,[3] and von Willebrand factor).[4]
pulmoanary art
The pulmonary artery catheter is frequently referred to as a Swan-Ganz catheter,
25/10
echo PAP
RAP+4V^2
CVP trace level
5cm below sternal notch at 30 degrees
sens
proportion of diseased that get postive test.
inductor
Used in defibrillators to prolong the discharging rate so that the current is
delivered over several milliseconds, allowing a critical mass of the
myocardium to depolarize.
collegiate
Boiling point increases in proportion to the molar concentration of the solutes
due point
Dew point temperature is defined simply as the
temperature at which water vapor, when cooled, will
begin to condense to the liquid phase, so it is the
most useful humidity parameter when dealing with
condensation problems.
low prevalence and PPV
high FP–>low PPV yes
Sagm
Saline Adenine Substrate for ATP synthesis Glucose Substrate for RBC glycolysis Mannitol
Cai
Some diuretics[9] inhibit the activity of carbonic anhydrase in proximal convoluted tubules and prevent reabsorption of bicarbonates from renal tubules. Lowered reabsorption of bicarbonates results in decreased activity of the apical sodium hydrogen exchanger, causing diuresis due to retention of sodium in the renal tubules. Acetazolamide is a carbonic anhydrase inhibitor. Other examples are;
assumptions of PCWP
- PAOP = LAP
- West zone 3
- End expiratory
- Normal PVR
- Normal MV function
- Normal intrathoracic pressures
- Operator consistent
- Normal ventricular compliance
transducer resistance
How does a transducer work?
• As the substance absorbs atmospheric water there is a change in electrical resistance or
capacitance
• This depends on the ambient humidity
SVP
The partial pressure that a vapour will exert if the liquid and the vapour of the liquid are
in equilibrium
HME
A hygroscopic substance is one that readily attracts water from its surroundings, through either absorption or adsorption.
HME
What are the disadvantages of the HME?
• Inefficiency with prolonged use
• Increased dead space
• Infection risk e.g. pseudomonas
warm bath
What is a hot water bath humidifier?
• Is an active system, in that dry gases bubble through water which is heated to 60°C (to
inhibit microbial contaminiation)
o Can deliver fully saturated gases
How do substances cross a capillary?
How do substances cross a capillary?
• Diffusion through intercellular clefts and fenestrations, determined by Fick’s law
• Bulk flow/ultrafiltration, determined by Starling forces
• Pinocytosis
• Brain has carrier-mediated transport (no intercellular clefts)
IVF cooling
An administration of fluids 1 L at room temperature may reduce a mean temperature by approximately 0.25℃.
dilute and conc urine
decrease in peritubular capillary oncotic pressure post IVF
–During water excess, the fluid leaving the loop of Henle, osmolality 100 mOsmol/kg H2O-without ADH—>dee out dilute urine.
-IVF to urine output (increased Hp and decreased oncotic)
-Glomerulotubular balance ensures a return to homeostasis by increasing free water excretion (the mechanism is triggered by a decrease in peritubular capillary oncotic pressure; it decreases the rate of water resorption from the proximal tubule).
PRODUCTION OF CONCENTRATED URINE During water deprivation, the distal convoluted tubule reabsorbs sodium and chloride but remains impermeable to water, and the fluid leaving the tubule still has an osmolality of less than 100 mOsmol/kg H2O. ADH changes the permeability of the collecting duct wall so that it becomes permeable to water. In the presence of ADH, tubular fluid leaving the cortical collecting duct has an osmolality of 300 mOsmol/kg H2O (the same as cortical interstitial fluid osmolality). With ADH, the medullary collecting duct reabsorbs much water because of the high medullary interstitial fluid osmolality produced by the loop of Henle, and a small volume of concentrated urine of osmolality 1400 mOsmol/kg H2O is excreted (the obligatory urine loss). Urea accounts for half of the osmolality of this concentrated urine and sodium, chloride, potassium, creatinine and other solutes account for the remainder (Figure 7.16).
shunt admix
Normal shunt fraction in healthy adults breathing room air is said to be close to 0% (probably 0.4-1%)
Normal venous admixture is usually about 3% of the cardiac output
USS
20kHz
20mHz in medical
gel
decreases reflection at interface of two dramatically diff densities. density stepdown
clopidog
P2Y12
propofol ph
Its pH is 7 and pKa in water is 11;
All phenols irritate skin and mucous membrane. Thus, propofol being an alkylphenol is expected to cause pain in spite of the fact that it is almost isotonic
luso
relax
dromo
peledrome
stages of anaesthesia
S1 onset-->loc S2 Loc-->eyelash lost S3 eyelash lost-->apnoe -P1 eyes move -P2 larynx -P3 IC -P4 -apneo S4 apnoea-->death
MAC95
1.3MAC
levo
ATP dep K ch open–>VD
Iga
tears
IGE
parasites
GABA
pres and post synapitic in brain alone
ANS
pregang myelinated
Artline elderly
• In elderly radial trace will look less different to aortic: = due to lower vascular compliance
which causes the pressure wave to travel faster and be less distorted.
• Changes to Aortic contour with ageing:
‣ slower upstroke (decreased contractility)
‣ Higher peak due to lower aortic compliance
amsorb
CaOH caCl CaSO4
size Glom
7000kdalton
size hep
15kda
MTP definition
Massive transfusion is defined as
replacement of >1 blood volume in 24 hours, or
>50% of blood volume in 4 hours (adult blood volume is approximately 70 mL/kg), o
MTP trigger
4 in 4 and expecting more
packed cell lesion
strucutral, functional
FFP
deficient in labile products 5,8
normal LVEDP
normal PCWP=10 The median (interquartile range) LVEDP was 19 mm Hg
protamine
1mg:100IU
heparin assessment
The Activated Clotting Time (ACT) was first described by Hattersley in 1966 and is essentially a point of care test (POCT) of coagulation that is used to monitor the anticoagulant effect of unfractionated heparin (UFH) in patients on cardio-pulmonary bypass
clexane
antiXa
codncution
heat or electricity is directly transmitted through the material
Co2 analysis
Mainstream devices
— need time to heat up to avoid condensation on the heater
— add dead space and weight to the circuit
prediction of PaCO2 from ETCO2 is variable (the major limiting factors = pulmonary blood flow and V/Q mismatch) and ETCO2 may be misleadingly different in conditions with significant V/Q mismatch
Sidestream devices
— can result in a time delay
— prone to blocking as not in line with gas flow
— may be inaccurate if low tidal volumes as fresh gas may be entrained (e.g. paediatrics)
— analysed circuit gases can also leak to the environment
utility in neonates and children may be impaired because of small tidal volumes
Cardiac output measurement can be performed:
Invasively Pulmonary Artery Catheter Thermodilution Fick Principle TOE Arterial waveform analysis PiCCO Vigileo
NIBP
Device for Indirect Non-Invasive Automatic Mean Arterial Pressure (DINAMAP).
Tramadol talent
In fact, tramadol is pharmacologically a “partial agonist.”2 In contrast, tapentadol is a full mu agonist with a binding affinity 18 times less than that of morphine, but is only 2- to 3-times less potent than morphine
wet bulb
nil difference in 100% humidity
ach bind sites
Nicotinic acetylcholine receptors (AChRs) are activated by ACh binding to two sites located on different α subunits.
PTC
3 second tetanic stimuli ! 3 ~ 6 second delay ! supramaximal stimuli at 1 Hz !
count number of twitches
Post-tetanic facilitation of NMJ persists for ~ 6 minutes
free water clearance
In the physiology of the kidney, free water clearance (CH2O) is the volume of blood plasma that is cleared of solute-free water per unit time. An example of its use is in the determination of an individual’s state of hydration. Conceptually, free water clearance should be thought of relative to the production of isoosmotic urine, which would be equal to the osmolarity of the plasma. If an individual is producing urine more dilute than the plasma, there is a positive value for free water clearance, meaning pure water is lost in the urine in addition to a theoretical isoosmotic filtrate. If the urine is more concentrated than the plasma, then free water is being extracted from the urine, giving a negative value for free water clearance. A negative value is typical for free water clearance, as the kidney usually produces concentrated urine except in the cases of volume overload by the individual.
preload
Ventricular filling and therefore preload is increased by:
Increased central venous pressure that can result from decreased venous compliance (e.g., caused by sympathetic activation of venous smooth muscle) or increased thoracic blood volume. The latter can be increased by either increased total blood volume or by venous return augmented by increased respiratory activity, increased skeletal muscle pump activity, or by effects gravity (e.g., head-down tilt).
Increased ventricular compliance, which results in a greater expansion of the chamber during filling at a given filling pressure.
Increased atrial force of contraction resulting from sympathetic stimulation of the atria or from increased filling of the atria and therefore increased atrial contractile force through the Frank-Starling mechanism.
Reduced heart rate, which increases ventricular filling time.
Increased aortic pressure, which increases the afterload on the ventricle, reduces stroke volume by increasing end-systolic volume, and leads to a secondary increase in ventricular preload.
Pathological conditions such as ventricular systolic failure and valve defects such as aortic stenosis, and aortic regurgitation (pulmonary valve stenosis and regurgitation have similar effects on right ventricular preload).
transcription
The outer (cytosolic) face of the rough endoplasmic reticulum is studded with ribosomes that are the sites of protein synthesis.
Within all cells, the translation machinery resides within a specialized organelle called the ribosome.
Mg dose PET
4g 1g per hour
adeonsie met
RBC vasc endo deaminatedx
N20 haem
cobalt ion in B12 nil methionine synthetase nil folate
Nad inf
0.05-0.5mcg/kg.min
addisons
fludrocortison
labetalol
1:3 and 1:7 following oral and intravenous (IV) administration, respectively
