1- Renal Anat, Phys & urine formation Flashcards
urinary system 4 main component:
kidneys Ureters Bladder Urethra
Kidneys functions
produce urine Blood metabolic balance produce the hormones Produce the enzyme renin
Hormones that are produced by kidney:
erythropoietin calcitriol prostaglandins
Both kidneys located ______
retroperitoneally
Left kidney level:
T11 - L2
Right kidney level:
T12 - L3
What goes through the kidney hilum
renal artery renal vein ureter
the main functional unit of the kidney?
Nephron
Nephron types:
Cortical nephron juxtaglomedullary
Define Cortical nephron
Located mostly within the cortex, and have short length of the loop of Henle
Define juxtaglomedullary
extend deep into the medulla and have long loop of Henle
Movement of waste from blood to kidney is called
Filtration
Filtration occurs in (be specific)
glomerulus
Movement of material from kidney back to body
Reabsorption
Movement from body straight to kidney
Secretion
Secretion occurs in
proximal convoluted
tubule loop of Henle
distal convoluted tubule
Excretion occurs in
collecting duct
minor calyx
major calyx
renal pelvis
20-25% of the blood leaving the left ventricle of the heart enters the kidneys via _____
renal arteries
Blood passes through the kidneys at a rate of
1200 ml/min, or 600 ml/min/kidney.
Afferent arterioles carry blood to the ____
capillary tuft
capillary tuft aka
glomerulus
Efferent arterioles that contain _________
blood that was not filtered
Efferent arterioles blood come from
the peritubular capillaries in the cortex Vasa recta in the medulla
The glomerulus is located between
two arterioles (Bowman’s capsule)
he outer (parietal) layer of Bowman’s capsule is composed of
squamous epithelium (parietal epithelial cells)
he inside (visceral) layer of Bowman’s capsule is composed of
specialized cells “podocytes” (visceral epithelial cells)
space between the outer portion of the capsule and visceral portion of the capsule
Bowman’s space
The filtrate of the blood pools in
Bowman’s space
Glomerular Filtration rate
90-120 ml/min
90-120 ml/min, or one-fifth of the renal plasma, is filtered through the glomeruli forming the _____
ultrafiltrate
GFR estimates how much ________
blood passes through glomeruli each minute
GFR test aka
Clearance test
GFR test (clearance test) measures how well the kidneys are filtering _______ (compound)
creatinine
Def: a waste product of creatine phosphate breakdown in muscles
creatinine
GFR test (clearance test) requires the collection of:
a 24 hour urine sample
blood sample
Define: substances which are almost completely reabsorbed by the renal tubules when their concentration in the plasma is within normal limits
Threshold substances
Glucose appears in the urine when plasma concentration exceeds about
160 to 180 mg/dl
Tubular Function (proximal tubules) absorption
- amino acids, proteins (100%)
- glucose (100%)
- HCO3¯ (90%)
- K⁺, NaCl, Ca (65%)
- H2O (65%)
Which substence that doesn’t get reabsorbed
creatinine
Tubular Function (proximal tubules) secretions
- uric acid
- organic acids (antibiotics)
- creatinine
- hydrogen ion
Tubular Function (loop of Henle): REABSORPES
- H2O
- NaCl (25%)
- Ca⁺⁺, Mg⁺⁺
Tubular Function (loop of Henle): SECRETES
- hydrogen ion
- ammonia
Descending limb of the loop of Henle properties
permeable to water No reabsorption of solutes
Ascending limb of the loop of Henle properties
impermeable to water
hydrogen ion and ammonia are secreted
active reabsorption of solute
Fluid leaving the loop of Henle has a (Higher/lower) osmolality than plasma
Lower
Fluid leaving the loop of Henle has a lower osmolality than plasma because of
lost sodium chloride
Tubular Function (distal tubules) REABSORPES
- NaCl (5%)
- H2O
- Ca⁺⁺
Tubular Function (distal tubules) SECRETES
- K⁺
- H⁺
- urea
Tubular Function (collecting ducts): REABSORPES
- urea
- NaCl (5%)
- H2O
Tubular Function (collecting ducts) EXCRETE
- H2O
- NaCl
- K⁺
- HCO3¯
- creatinine
About ____% of the glomerular filtrate is reabsorbed by the time it reaches the distal tubule
90
blood pH range
7.35 to 7.45
Maintaining the pH regulated by
lungs and kidneys
A region of tissue found in each nephron in the kidney regulates blood pressure, body fluid and electrolytes.
juxtaglomerular apparatus (JGA)
JGA is a microscopic structure in the kidney that regulates the function of each _____
nephron
The three cellular components of JGA :
the macula densa
juxtaglomerular cells
mesangial cells
macula densa is located at
the distal convoluted tubule
smooth muscle cells of the afferent arteriole known as
juxtaglomerular cells
juxtaglomerular cells produce and secrete
renin
mesangial cells secrete
erythropoietin
Renin is secreted and reacts with the precursor ____
angiotensinogen in the blood
Renin convert angiotensinogen into
angiotensin I
Angiotensin I passes through the
Lungs
Angiotensin I interacts with which enzyme
angiotensin converting enzyme (ACE)
ACE converts Angiotensin I to
angiotensin II
Angiotensin II function
vasoconstriction
trigger aldosterone
trigger antidiuretic hormone
aldosterone is secreted by
adrenal glands
aldosterone increases ______ reabsorption
sodium
antidiuretic hormone aka
vasopressin
antidiuretic hormone is secreted by
posterior pituitary gland
Aldosterone is secreted by
adrenal cortex (zona glomerulosa)
Aldosterone effect on blood sodium
increases blood sodium reabsorption in the distal tubules
Aldosterone effect on BP
raises blood pressure
Aldosterone enhances potassium/sodium ions in the _______ of nephrons
distal tubules
Insufficient ADH results in
diabetes insipidus (DI)
Syndrome of Inappropriate ADH Secretion AKA
SIADH-syndrome
SIADH-syndrome Is characterized by
excessive release of ADH
continued secretion of ADH in spite of plasma
hypotonicity normal or expandedplasma volume
80% of this syndrome is caused by
small cell lung carcinoma
small cell lung carcinoma aka
oat cell carcinoma
SIADH-syndrome May result from complication of
Brain injury
tumor growth
certain medications
SIADH-syndrome results in
high plasma volume
low serum osmolarity
low plasma sodium (hyponatremia)
high urine osmolarity
higher than normal urine sodium
In general, increased ADH causes water retention without
extracellular fluid volume expansion and without edema or hypertension
When hyponatremia is severe, symptoms of______ become prominent
cerebral edema
cerebral edema symptoms
irritability
confusion
seizures
coma
Excreted as urine average
1 ml/min
Dehydration reduces urine production to
0.3 ml/min
Excessive hydration increases urine production to
15 ml/min
Average adult urine daily volume of urine
1200-1500 ml
More urine is produced during (day/night)
day
Normal total urine range may be from
600-2000 ml/24 hr
Def: is an abnormal increase in the volume of urine hours)
Polyuria
Polyuria is found in pt’s with
diabetes insipidus
diabetes mellitus
Polyuria frequncy (ml/day)
2500 ml and > per 24
Def: is a decrease in urinary volume
Oliguria
Oliguria occurs in Pt’s with
shock and acute glomerulonephritis
In an adult Oliguria frequently defined as being (ml/day)
< 400 ml/24 hr
Def: designates the complete suppression of urine formation
Anuria
Anuria defined as being (ml/day)
< 75 ml/24 h during 2 to 3 consecutive days
In 24 hours the body excretes Approximately ____ g of dissolved material
60g
half of excreted dissolved material is
urea
abnormal compounds/elements in urine
Bilirubin
Blood
Glucose
Ketone bodies
Porphyrins
Protein
sediment Final Urine Composition
Cells Crystals Casts
renal disorders that help in diagnosing
cystitis nephritis
cystitis is the inflammation of
bladder
nephritis is the inflammation of
kidney
nephritis with bacterial infection is called
pyelonephritis
nephritis without bacterial infection is called
glomerulonephritis
