urinary system
ID and name the function of the following urinary organs: kidney,
-regulate water volume and osmolarity in the body
-regulate
concentration of ions
-ensure acid base balance
-excreting
metabolic wastes and drugs/toxins
-produce erythropoietin and
renin that regulate RBC production and BP
-convert vitamin D
actively (produced in skin, inactively, and activates in kidney and
liver)
-filters 200 liters of fluid
Where is the location of the kidney? Be as specific as possible
(retroperitoneal position, right and left lumbar abdominopelvic region).
ID and name the function of the following urinary organs bladder,
-Urinary bladder - temporary storage reservoir for urine➢Muscular sac
for temporary storage of urine
➢Openings for ureters and urethra
➢Layers of bladder wall
i.Mucosa - transitional epithelial
mucosa
ii.Thick detrusor - three layers of smooth muscle
iii.Fibrous adventitia (peritoneum on superior surface only)
➢Collapses when empty; rugae appear
i.Expands and rises
superiorly during filling without significant rise in internal
pressure
ii.Full bladder 12 cm long; holds ~ 500 ml
iii.Can hold ~ twice that if necessary
iv.Can burst if overdistended
ID and name the function of the following urinary organs urethra
-Urethra transports urine out of body➢Muscular tube draining urinary
bladder
➢Sphincters
➢Internal urethral sphincter
i.Involuntary (smooth muscle) at bladder-urethra junction
ii.Contracts to open
➢External urethral sphincter
i.Voluntary (skeletal) muscle surrounding urethra as it passes
through pelvic floor
➢Female urethra (3–4 cm)
➢Male
urethra carries semen and urine
ID the two kinds of nephrons. Where are each located and how are they different anatomically? Which one is more numerous ?
➢ Cortical nephrons—85% of nephrons; almost entirely in cortex
➢ Juxtamedullary nephrons
i. Long nephron loops deeply
invade medulla
ii. Ascending limbs have thick and thin segments
iii. Important in production of concentrated urine
1. Juxtamedulliary- efferent arteriole to vasa recta
2. Cortical- efferent arteriole to peritubular capillaries
.(Juxtamedullary has longer loop of Henle than cortical. However, corticalare much more numerous.Cortical nephrons barely extend into the medulla. Juxtamedullary nephrons extend much further down into the medulla)
ID and name the function of the following urinary organs renal artery,
Name the location and function of the JG cells only in the Juxtaglomerular apparatus.
Jg cells tell when the blood pressure drops
-leads into the renal sinus
-where the ureter, renal blood
vessels, and lymphatics, and nerves all join the kidney
What are the three major processes of urine formation, where do they occur in the nephron and what is going on i.e. where are substances moving during each of the three processes?
1. Filtration(glomarilous) strains toxins out.
2.Reabsorption (mostly in PCT ) body is taking something something out, under hormonal control-ADH, aldosterone), goes back into the body because it is something it needs to keep.(H2O-ADH) Na+ is absorbed.
3. Secretion- Body has too much and wants to get rid of sodium potassium water mostly in the DCT, can happen elsewhere but mostly in the DCT/ACT- then you get urine.
List the pathway of filtrate from the glomerilous until it reaches the collecting duct and forms urine
glomerular capsule (capsular filtrate) → PCT (tubular fluid) → nephron loop → DCT → collecting duct → papillary duct (urine) → minor calyx → major calyx → renal pelvis → ureter → urinary bladder → urethra.
What does a positive vs a negative NFP mean (net filtration pressure)
main point to know is that without blood pressure there is no NFP .
huge amounts of filtrate can be produced even with theusual modest NFP of 10 mm Hg. The opposite side of this“coin” is that a drop in glomerular pressure of only 18% stopsfiltration altogether.The GFR is directly proportionalto the NFP, so any change inany of the pressures acting at the filtration membrane changesboth the NFP and the GFR. In the absence of regulation, an in-crease in arterial (and glomerular) blood pressure in the kid-neys increases the GFR. As we shall see in the next sectionhowever, GFR is tightly regulated.Regulation of Glomerular Filtrati
What is a typical GFR (globular filtration rate)
125 min/ml
Name the parts of the nephron
Be able to ID and give function of the following parts of a nephron: glomerulus, Bowman’s capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct, afferent arteriole, efferent arteriole, peritubular capillary, vasa recta.
Function of; glomerilous
Function of;bowmnan's capsule
Bowman's capsule (or the Bowman capsule, capsula glomeruli, or glomerular capsule) is a cup-like sac at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine. A glomerulus is enclosed in the sac.
Function of;PCT proximal convoluted tubule
Function of;Loop of Henle
Descending Limb of Loop of Henle
Ascending Limb of Loop of Henle
Function of;Distal Convluted tubule DCT
Function of;collecting duct
collecting ducts, each of which receives filtrate frommany nephrons, run through the medullary pyramids and givethem their striped appearance. As the collecting ducts approachthe renal pelvis, they fuse together and deliver urine into the mi-nor calyces via papillae of the pyramids
Function of;afferent arteriole
The afferent arteriole carries blood from the renal artery into the glomerulus, where it divides to form a circulatory network. At the distal end of the glomerulus, the capillaries rejoin to form the efferent arteriole through which blood leaves the glomerulus.
Function of;efferent arteriole
The efferent arterioles are blood vessels that are part of the urinary tract of organisms. The efferent arterioles form from a convergence of the capillaries of the glomerulus. They play an important role in maintaining the glomerular filtration rate despite fluctuations in blood pressure. they are smaller in diameter than afferents thus create resistance.
Function of;peritubular capillary
The peritubular capillariesarise from the efferent arteriolesdraining the glomeruli. These capillaries cling closely to adja-cent renal tubules and empty into nearby venules. They are low-pressure, porous capillaries that readily absorb solutes andwater from the tubule cells as these substances are reclaimedfrom the filtrate
Function of;vasa recta
bundles of long straight vessels called vasa recta(vasah rektah; “straight ves-sels”) that extend deep into the medulla paralleling the longestloops of Henle. The thin-walled vasa recta play an importantrole in forming concentrated urine,
Name the location and function of the JG cells only in the Juxtaglomerular apparatus.
????? One per nephron
➢ Important in regulation of rate of
filtrate formation and blood pressure
➢ Contains
i.
Chemoreceptors; sense NaCl content of filtrate
ii.
Mechanoreceptors; sense blood pressure in afferent arteriole
On what specific spot of the nephron do ADH and aldosterone work?
What are the ascending and the descending loops of Henle permeable/impermeable to?
How does ADH affect urine concentration?
A hormone released from the pituitary gland that causes water reabsorption in the kidneys, thus concentrating the urine
What is a diuretic and name some examples
➢ Chemicals that enhance urinary output
i. ADH inhibitors,
e.g., alcohol
ii. Na+ reabsorption inhibitors (and resultant H2O
reabsorption), e.g., caffeine, drugs for hypertension or edema
How does alcohol affect ADH?
Inhibits body from absorbing ADH
What are abnormal ingredients in urine?
protein (albumen), wbc, rbc, glucose
What are the normal ingredients in urine?
urea, uric acid, na,k, nitrogenous waste,
What is the pathway of urine from the collecting ducts to the urethra?
collecting ducts, papillary ducts, minor calyx, major calyx, renal pelvis,ureter,bladder,urethra,urethral orifice
What is the anatomical term for urination?
XXVI. Micturition
➢Urination or voiding
➢Three simultaneous events must occur
i.Contraction of detrusor by ANS
ii.Opening of internal
urethral sphincter by ANS
iii.Opening of external urethral
sphincter by somatic nervous system
➢Reflexive urination
(urination in infants)
➢Pontine control centers mature between
ages 2 and 3
What kinds of muscles are found in the detrusor, internal urethral sphincter, and external urethral sphincter ?
The urethral sphincter is crucial for the maintenance of urinary continence [1,2]. The urethral sphincter refers to one of the following muscles [3]: 1) the internal urethral sphincter (IUS), which consists of smooth muscle and is continuous with the detrusor muscle and under involuntary control, and 2) the external urethral sphincter (EUS), which is made up of striated muscle and is under voluntary control.
What are the standard physical characeristics of urine?
color,odor,PH, specific gravity?
➢Color and transparency
i.Clear
ii.Cloudy may indicate
urinary tract infection
iii.Pale to deep yellow from urochrome
iv.Pigment from hemoglobin breakdown; more concentrated urine →
deeper color
v.Abnormal color (pink, brown, smoky)
vi.Food
ingestion, bile pigments, blood, drugs
➢Odor
i.Slightly
aromatic when fresh
ii.Develops ammonia odor upon standing as
bacteria metabolize solutes
iii.May be altered by some drugs and
vegetables
➢pH
i.Slightly acidic (~pH 6, with range of 4.5
to 8.0)
ii.Acidic diet (protein, whole wheat) → ↓ pH
iii.Alkaline diet (vegetarian), prolonged vomiting, or urinary
tract infections → ↑pH
What is the anatomical term for urination?
XXVI. Micturition
➢Urination or voiding
➢Three simultaneous events must occur
i.Contraction of detrusor by ANS
ii.Opening of internal
urethral sphincter by ANS
iii.Opening of external urethral
sphincter by somatic nervous system
➢Reflexive urination
(urination in infants)
➢Pontine control centers mature between
ages 2 and 3
What kinds of muscles are found in the detrusor, internal urethral sphincter, and external urethral sphincter ?
The urethral sphincter is crucial for the maintenance of urinary continence [1,2]. The urethral sphincter refers to one of the following muscles [3]: 1) the internal urethral sphincter (IUS), which consists of smooth muscle and is continuous with the detrusor muscle and under involuntary control, and 2) the external urethral sphincter (EUS), which is made up of striated muscle and is under voluntary control.
How does sympathetic stimulation affect the detrusor, 2 sphincter muscles, and external urethral?
inhibits detrusor contraction, internal urethral sphincter closes,sometic reflex contracts external urethral sphincter, will not pee
How does parasympathetic stimulation affect the detrusor, 2 sphincter muscles, and external urethral?
excites the detrusor muscles, inhibits internal urethral sphincter, ok to pee
What is Hypocalcemia?
Possible causes?
Consequences?
1. Hypocalcemia is when calcium level in the blood is to low
2.
Possible cause: burns, vit. D deficiency, renal rubular disease, renal
failure.
3.Consequences: tingling of fingers, tremors, skeletal
muscle cramps, tetany, convulsions, depressed excitablility of heart,
osteomalacia, and fractures
What is Hypercalcemia?
Possible causes?
Consequences?
1. Hypercalcemia is when calcium level in the blood is to high.
2. Possible causes: hyperparathyroidism, excessive vit.D,
prolonged mobility
3.Consequences: decreased neuromuscular
excitability, cardiac arrhythmias, and arrest
What is Hypochloremia?
Possible causes?
Consequences?
1. Hypochloremia is when chlorine levels in the blood are to low.
2. Possible causes: Metabolic alkalosis(due to vomiting or
ingesting to much alkaline substances)or aldosterone deficiency
3.Consequences: no direct clinical symptoms
What is Hyperchloremia?
Possible causes?
Consequences?
1. Hyperchloremia is when chlorine levels in the blood are to high
2. Possible causes: dehydration
3. Consequences: no direct
clinical symptoms
What is Hypokalemia?
Possible cause?
Consequence?
1. Hypokalemia is when blood potassium level is to low.
2.
Possible Causes: GI tract disturbances, starvation, diuretic therapy.
3. Consequences: Cardiac arrhythmias, muscle weakness
What is Hyperkalemia?
Possible cause?
Consequence?
1. Hyperkalemia is when blood potassium level is to high
2.
Possible cause: renal failure, deficit of aldosterone
3.
Consequences: Nausea, vomiting, diarrhea, Bradycardia, cardiac arrhythmias.
What is Hyponatremia?
Possible causes?
Consequesnce?
1.Hyponatremia is when sodium ion concentrate is plasma is below
normal.
2.Possible Cause: solute loss or water retention
3. Consequences: Impacts nervous system, neurologic disfunction
What is Hypernatremia?
Possible Causes?
Consequences?
1. Hypernatremia is elevated sodium in the blood
2. Possible
cause: could be because of dehydration
3. Concequence:Nervous
system impact, thirst, dehydration leads to confusion and lethargy
progressing to coma.