fluids and urine (ew) Flashcards
The fluid compartments of the body are all contained in either the _____ or the ______
intracellular compartment, extracellular compartment
:all fluid contained inside cells
* ____ of all body fluids
Intracellular fluid. 2/3
:all fluid outside cells.
* ____ of all body fluids
Extracellular fluid. 1/3
Extracellular fluid is found in a number of sub compartments
Interstitial fluid and intravascular space
between the cells of the body
◦ Most extracellular fluid (¾)
interstitial fluid
mostly blood plasma but also lymph, CSF, synovial fluid, aqueous humor, endolymph and perilymph, pleural fluid, and pericardial fluid
Intravascular fluid space
Babies are more “wet” than adults, with water composing about ___% of total body mass. Women is ____% and Men is ___%
- 60
Fluid moves between compartments based on
Osmotic pressure and hydrostatic pressure
occurs when excess interstitial fluid collects, causing swelling in the tissues.
Edema
Occurs when filtration from intravascular space (primarily capillaries) exceeds reabsorption
Edema
Edema causes include:
◦ increased blood pressure
◦ increased capillary permeability
◦ decreased concentration of plasma proteins
◦ obstruction in lymphatic drainage
Normal fluid intake is through:
*ingestion: ___ (2300mL/day)
* Metabolic synthesis of water. (cellular respiration and dehydration synthesis) _____ (200mL/day)
most. minimal
Normal fluid loss is through:
* The kidneys: ____ (1500mL/day)
* Evaporation from the skin: ____ (600mL/day)
* Respiratory tract:_____ (300mL/day)
* In the feces:____ (100mL/day)
major. minor. minor. minimal
Fluid intake and output (I & O) are balanced through regulation of
Water loss in Kidneys
Water ingestion (thirst)
Water loss through Feces and Sweat in extreme cases
A number of feedback mechanism contribute to balance of daily fluid input and output
Similar mechanisms affect both ____ (ingestion) and _____ output
thirst. kidney
Antidiuretic hormone (ADH) (vasopressin): directly regulates
water loss in the kidneys
Increases permeability of the collecting ducts to water producing a concentrated urine
Antidiuretic hormone (ADH)
(vasopressin)
Na+ and Cl– balance is regulated by 3 hormones (renal absorption and excretion)
- Aldosterone
- Atrial natriuetic peptide
- Angiotensin II
______promote urinary Na+ and Cl– reabsorption (and water by osmosis) when dehydrated
Angiotensin II and aldosterone
_______ promotes excretion of Na+ and Cl– followed by water excretion to decrease blood volume
Atrial natriuretic peptide (ANP)
_____ form when electrolytes dissolve and dissociate
ions
____ are positively charged and ____ are negatively charged
Cations. Anions
Ions (electrolytes) have 4 general functions
- Control osmosis of water between body fluid compartments
- Help maintain the acid-base balance
- Carry electrical current
- Serve as cofactors
The term “milliequivalent” (mEq) is used to measure the ______ of solutes:
osmotic contribution
A major homeostatic challenge is keeping the ________ of body fluids at an appropriate level
H+ concentration (pH)
Because metabolic reactions often produce a huge excess of H+, failure of homeostatic mechanisms would cause the pH of body fluids to quickly ______
fall to a lethal level
In a healthy person, _____, the _____, and the _____ help maintain the pH of systemic arterial blood between 7.35 and 7.45
chemical buffers. lungs. kidneys
: act quickly to temporarily bind excess
H+ or OH -, sequestering (hiding) the highly reactive ions
until they can be permanently excreted
Buffer systems
By increasing the rate and depth of _____, CO2 is exhaled or retained, and blood pH is corrected
breathing
_____ excretion/reabsorption of acidic ions (H+ and NH4+) or basic ions (HCO3 – or OH -) is the slowest mechanism; but is the only way to eliminate acids other than carbonic acid
Kidney.
______ occurs whenever CO2 accumulates
because of hypoventilation. (a condition that occurs when your lungs can’t remove all of the carbon dioxide produced by your body)
Respiratory acidosis
____occurs whenever non-respiratory acids accumulate, as seen in diabetic ketoacidosis or aspirin overdose. (The buildup of acid in the body due to kidney disease or kidney failure)
Metabolic acidosis
______ occurs whenever too much CO2
is lost because of hyperventilation
Respiratory alkalosis
occurs whenever non-respiratory acids are lost, which happens infrequently
Metabolic alkalosis
Structures of the urinary system
kidneys, ureters, bladder and urethra
function or urinary sys is that it maintains homeostasis of:
blood volume, pressure, pH, and electrolytes (Na+, K+, Ca 2+, Cl-, HPO4-3, Mg2+, HCO3-)
Another function is:
Reabsorbing glucose, excretes wastes, and releases certain hormones like renin and EPO
bean-shaped organs located just above the waist between the peritoneum and the posterior wall of the abdomen (in the retroperitoneal space).
kidneys
kidneys are partially protected by the ______ pairs of ribs.
eleventh and twelfth
Because of the liver, the right kidney is
slightly _____ than the left.
lower
(approximately 25 cm long) originates near the hilum of each kidney and travels to the base of the bladder. Renal blood vessels also emerge from the hilum
ureter
the duct by which urine passes from the kidney to the bladder
ureter
allows urine to be excreted from the bladder
urethra
the filtration to form urine. receives most of the blood flow, & is mostly concerned with reabsorbing filtered material
renal cortex
collects and excretes urine. a highly metabolically active area, which serves to concentrate the urine.
medulla
8 to 18 conical subdivisions within the
medulla contain the kidney’s secreting apparatus and tubules. is responsible for filtering the blood and removing waste products from the body
renal pyramids
lines of blood vessels and fibrous material which anchor the cortex.
renal columns
Renal papilla: medullary pyramids empty urine into
minor and major calyces (cuplike structures)
Once the filtrate enters the calyces, it is _____ because no further reabsorption occurs.
urine
Urine drains from the major calyces into the _____ and then out through the ureter
renal pelvis
contains part of the renal pelvis, the calyces, and branches of the renal blood vessels and nerves
renal sinus
: transport urine from the renal pelvis of the kidneys to the bladder using _________.
No anatomical valve between the ureter and the bladder.
ureters: . peristaltic waves, hydrostatic pressure and gravity
hollow, distensible muscular organ,
capacity that averages 700-800mL
urinary bladder
emptying the bladder.
micturition or urination:
◦ When volume increases, ______ send signals to a micturition center in the _____ triggering a spinal reflex – the micturition reflex.
◦ In early childhood, we learn to initiate and stop the reflex voluntarily.
stretch receptors. spinal cord.
: tube from the internal urethral orifice in the bladder floor to the exterior.
* In males, it is also used to discharge semen.
urethra
the _____ and ______ enter the kidney (the parenchyma) at the hilum
renal artery and renal vein
Blood flow path:
renal artery
afferent arterioles
glomerular cappilaries
efferent arterioles
pertibular capillaries
renal vein
is the functional unit of the kidney.
nepheron
what makes up the nepheron and what do they do
blood vessels and tubules. collect filtrate from blood and turn it into urine
Each nephron receives one _____, Leading to a ball-shaped capillary network called the ______.
afferent arteriole. glomerulus
The glomerular capillaries then reunite to form an ______ that carries blood out of the glomerulus.
efferent arteriole
Renal Corpuscle consists of two structures:
glomerular capillaries and glomerular capsule
(Bowman’s capsule) – a double- walled epithelial cup that surrounds the glomerular capillaries
glomerular capsule
: modified simple squamous epithelial cells called podocytes.
* wrap around the single layer of endothelial cells of the glomerular capillaries
* inner wall of capsule.
* Fenestrations, pores
visceral layer
simple squamous epithelium
* outer wall of capsule.
Parietal layer
act as a filtration (dialysis) membrane
festrations (pores)
Filtered fluid passes into the renal tubule, which has three main sections:
- the proximal convoluted tubule (PCT)
- the loop of Henle
- the distal convoluted tubule (DCT)
distal convoluted tubules of several nephrons empty into a single
collecting duct
Collecting ducts Unite into several hundred large _______ which drain into the minor calyces, major calyces, renal pelvis, and ureters.
papillary ducts
_______ descends into the renal medulla
Descending limb of the loop of Henle:
The loop of henle turns and returns to the renal cortex as _______
the ascending limb
the descending limb is made out of:
simple squamous epithelium
◦ “thin” (composed of a simple squamous epithelium) or
◦ “thick” (composed of simple cuboidal to low columnar cells).
◦ Some nephrons contain both thick and thin ascending limbs.
The ascending limb:
Two populations of Nephrons: __________. length of the loop of Henle thin segments in the ascending limb,
cortical and juxtamedullary
make up about 80–85% of the 1 million microscopic nephrons that comprise each kidney.
Cortical nephrons
cortical nepherons
* Renal corpuscles far from medulla
* short loops of Henle that penetrate only a _____ into the medulla.
* ascending limbs of loops of Henle consist of only a _____ segment, lacking any ____ portions.
* receive their blood supply from peritubular capillaries that arise from ______ arterioles.
small way. thick. thin. efferent
The other 15–20% of the nephrons are
juxtamedullary nephrons
- juxtamedullary nephrons renal corpuscles lie deep in the cortex, close to the _____.
- long loops of Henle that extend into the _____ of the medulla.
- The ascending limbs of loops of Henle consist of _____ segments.
- receive their blood supply from the vasa recta that arise from _____ capillaries
medulla. deepest region. both thin and thick. peritubular
_____ nephrons perform excretory and regulatory functions of a kidney
cortical
_____ nephron is involved in concentrating or diluting urea.
juxtamedullary
The production of urine involves:
Glomerular filtration, Tubular reabsorption, and Tubular secretion
fluid filtered from the blood to the glomerulus
◦ glomerular filtration rate (GFR): amount of filtrate formed in all the renal corpuscles of both kidneys each minute
Glomerular filtration
returning important substances from the filtrate back to the body
Tubular reabsorption:
the movement of waste materials from the body to the filtrate.
Tubular secretion
Glomerular filtration is the formation of a protein-free filtrate (ultrafiltrate) of ____ across the glomerular membrane
plasma
main force that “pushes” water and solutes through the filtration membrane (promotes filtration). *Primary determinant of amount of filtrate
Blood hydrostatic pressure
rom the capsular space (opposes filtration)
Capsular hydrostatic pressure
osmotic pressure of plasma proteins “pulling” on water (opposes filtration).
Blood osmotic (oncotic) pressure:
Final part of the ascending limb of the loop of Henle contacts the afferent arteriole for that renal corpuscle.
* Columnar tubule cells in this region are the _____
macula densa
Wall of the afferent arteriole contains ______ (JG) cells: modified smooth muscle fibers
juxtaglomerular
Juxtaglomerular apparatus (JGA):
juxtaglomerular cells and macula densa
Regulation of the GFR (Glomerular filtration)
- Renal autoregulation: by kidneys
- Neural regulation: by the ANS
- Hormonal regulation: by angiotensin II and atrial natriuretic peptide (ANP)
______ of GFR occurs by two means:
* Stretching in the glomerular capillaries or pressure and flow monitored in the JGA, causes
* afferent arterioles to constrict (decreasing blood flow and GFR) or dilate (increasing blood flow and GFR) appropriately
Renal autoregulation
: sympathetic ANS fibers cause vasoconstriction
Neural regulation
Two hormones contribute to regulation of GFR
: * vasoconstrictor of both afferent and
efferent arterioles (reduces GFR).
:* ANP causes the glomerulus to relax
increasing the surface area for filtration.
Angiotensin II:
Atrial natriuretic peptide (ANP). (released under high bp):
