Lecture 16 Flashcards
What 3 things have to happen for micturition
Detrusor muscle must contract
Internal urethral sphincter must open
External urethral sphincter must open
Where is the detrusor muscle
The wall of the bladder
What is the role of the pontine storage center
Inhibits micturition
What is the role of the pontine micturition center
Promotes micturition
What is stress incontinence
Incontinence as a result from increased abdominal pressure - sneezing, laughing
What is incontinence
The inability to control micturition voluntarily
What is urinary retention
bladder unable to expel urine
What is renal failure
Running out of nephrons that work properly
How can prolonged pressure on skeletal muscle cause renal failure
As muscle cells get broken, they release a lot of substances that go into the blood, and can damage the kidney
When is dialysis needed
once renal functioning is below 25%
What is hemodialysis
artificially filtering blood through a machine
What is peritoneal dialysis
filtering blood through BV of the peritoneal membrane
What is the liquid infused with peritoneal dialysis
Dialysate
What is dialysate composed of
Mostly salts and sugars
Why is dialysate composed of mostly salts and sugars
to encourage filtration - very high solute concentration
What is Dialysate
the liquid infused with peritoneal dialysis
How is dialysate infused into the peritoneal cavity
through a catheter
What are the two types of peritoneal dialysis
Continuous ambulatory
Continuous cycling
What is continuous ambulatory peritoneal dialysis
Where you put a 2L of dialysate into peritoneal cavity, wait 4-5 hours and drain it back into the bag
How many times a day do you do CAPD
about 4-5
What machine does CCPD use
a cycler
How long does each CCPD cycle last
1-1.5 hours
When is CCPD done
At night while patient sleeps
What is done during CCPD
The cycler does multiple exchanges, so it’ll fill the cavity, filter, drain, and repeat every once in a while
What is 60% of your total body fluid
Intracellular fluid
What is 40% of your total body fluid
extracellular fluid
What are the two parts of extracellular fluid
Interstitial fluid
Plasma
What percent of ECF is interstitial fluid
80%
What percent of ECF is plasma
20%
What volume is ICF
25L
What volume is ECF
15L
What has greater osmotic power: electrolytes or non-electrolytes
Electrolytes: because they break down into 2 solutes
ie/ NaCl - Na + Cl
In ECF the chief cation is ____
sodium
In ECF the chief anion is ____
chloride
In ICF the chief cation is ____
potassium
In ICF the chief anion is ____
phosphate
Changes in solute concentrations in blood plasma will affect ______ fluid volumes
Intracellular
What is your typical plasma osmolairty
280-300mOsm
What two things happen when you have increased plasma osmolairty
You get thirsty
ADH stimulates renal water reabsorption
What two things happen when you have decreased plasma osmolality
Thirst not stimulated
ADH not secreted
What are the 3 obiligatory water losses
Insensible via skin/lungs
Via feces
Urinary loss
What happens with dry mouth
Osmoreceptors of hypothalamic thirst center lose water to hypertonic ECF: become irritable and depolarize
When does dry mouth occur
increase of plasma osmolality of 1-2%
What occurs with an increase of plasma osmolality of 1-2%
Dry mouth
When do baroreceptors trigger thirst mechanims
When plasma volume is down 5-10%
A decrease in what percent of plasma volume triggers baroreceptors
5-10%
What is hypotonic hydration
Too much water intake, water enters cells, cells swell
What is edema
Accumulation of fluid (and salts) in IF but not inside cells
Accumulation of fluid (and salts) in IF but not inside cells
Edema
Too much water intake, water enters cells, cells swell
Hypotonic hydration
What percent of the ECF solutes is sodium
90-95%
What two things does sodium determine
Plasma osmolality
Blood volume
What does aldosterone do
Signals reabsorption of sodium
What percent of sodium is reabsorbed even without aldosterone
85%
What is the most influential sodium agent at the level of the kidney
Aldosteron
Does aldosterone act quickly or slowly
Slowly
What two things stimulate aldosterone secretion
Renin-angiotensin system
High K+ or low Na+
What 3 things are renin secreted in response to
Sympathetic NS
decreased filtrate osmolarity
Decreased stretch of afferent arteriole
What is addison’s disease
Hyposecretion of aldosterone: loss of Na+ and water in urine
What disease is signified by hyposecretion of aldosterone
Addison’s disease
What is the main function of ADH
increase water reabsorption in the collecting ducts
What receptors (and where) are the first signals for ADH
Osmoreceptors in hypothalamus
If there is a high plasma osmolality, name the pathway of signals for ADH sescretion
Osmoreceptors in hypothalamus stimulates:
Posterior pituitary:
releases ADH
ADH targets collecting ducts
water reabsorption goes up
What does ANF exist to do
Protect the heart from high bp
What is ANF’s full name
Atrial natriuretic factor
What effect does ANF have on bp
Lowers it
When is ANF released
by cells in the atria when bp is elevated
What 3 things does ANF do
inhibits Na reabsorption (DCT, collecting duct)
Lowers release of ADH, renin and aldosterone
Induces vasodilation
What hormone is estradiol similar to
Aldosterone
What does progesterone do
Has a minor diuretic effect
What hormone is cortisol similar to
Aldosterone
What is pressure diuresis
When blood volume/pressure goes up, sympathetic output to kidney goes down
What is the result of pressure diuresis
Dilation of afferent arterioles; higher GFR
