Ch. 25 Urinary System HW

Urinary incontinence

(the inability to control urination) is usually a result of weakened pelvic muscles following childbirth or surgery, physical pressure during pregnancy, or nervous system problems.

Calculate the net filtration pressure if capillary hydrostatic pressure is 60 mm Hg, capillary osmotic pressure is 25 mm Hg, and capsular hydrostatic pressure is 10 mm Hg.

60 - (25 + 10) = 25 mm Hg

Tubuloglomerular feedback mechanism

A drop in flow rate through the nephron or a rise in the osmolality of filtrate triggers regulation by this mechanism. -"directed" by the macula densa cells of the juxtaglomerular complex

Anuria

Abnormally low urinary output, may indicate that glomerular BP is too low to cause filtration. Renal failure and anuria can result from situations in which the nephrons stop functioning, including acute nephritis, transfusion reactions, crush injuries.

Blood vessel leading directly into the glomerulus.

Afferent arteriole

Bilirubinuria

Bile pigments in urine -Liver disease(hepatitis, cirrhosis) or obstruction of bile ducts from liver or gallbladder.

If the afferent arteriole constricts while the efferent arteriole remains unchanged, the glomerular filtration rate __________.

Decreases

Suppose that a patient has a failing liver and is unable to make normal levels of albumin for the blood plasma. If all other factors remain the same, what would be the effect on the amount of filtrate produced?

Filtrate production would increase If the liver were making insufficient levels of albumin, which is the most important contributor to the blood's osmotic pressure, the blood's osmotic pressure would drop, leading to a rise in filtrate production.

colloid osmotic pressure(OPgc)

Force that pulls fluid back into the glomerulus from the capsular space. -exerted by the proteins in the blood -30 mm Hg

Glycosuria

Glucose in urine -Diabetes mellitus

Nephrotoxin

Heavy metal, organic solvent, or bacterial toxin that is toxic to the kidneys

The afferent arterioles dilate in response to a fall in blood pressure and __________.

Increases GFR

substance is typically used to measure the GFR

Inulin -plant polysaccharide that has a renal clearance value equal to the GFR

Ketonuria

Ketone bodies in urine -excessive formation and accumulation of ketone bodies, as in starvation and untreated diabetes mellitus

Pyuria

Leukocytes(pus) in urine. -Urinary tract infection

Which of the regions of the nephron do not absorb Na+ by primary active transport?

Loop of Henle, descending limb

Polycystic KD autosomal recessive form

More severe and less common ( 1 in 20,000 people). Almost half of newborns with recessive PKD die just after birth, and survivors generally develop renal failure in early childhood.

Capillaries that surround the tubules of the nephron.

Peritubular capillaries

Which part of the brain controls the micturition (urination) reflex?

Pons

hydrostatic pressure in the capsular space (HPcs)

Pressure exerted by fluid in the glomerular capsule against the fluids coming out of the glomerulus.( pressure exerted by filtrate in the glomerular capsule.) -15 mm Hg

Aldosterone

Promotes reabsorption of Na+ at the distal convoluted tubule. -Decreased blood volume or pressure, or high extracellular K+ concentration (hyperkalemia) can cause adrenal cortex to release Ald. -all but hyperkalemia promote RAA mechanism. - Ald. targets principal cells of collecting ducts and cells of distal DCT. -results in little to no Na+ leaving body in urine - W/o aldosterone about 2% of Na+ filtered daily can be lost which is not compatible with life.

Myogenic mechanism

Property of vascular smooth muscle, contracts when stretched and relaxes when not stretched. -Rising systemic BP stretches muscle in the arteriolar walls, causing afferent arterioles to constrict. - This restricts blood flow in glomerulus and prevents glomerulus BP from rising to damaging levels. -Declining BP causes dilation of afferent arterioles and raises glomerular hydrostatic pressure. -Both help maintain normal NFP and GFR

Proteins in urine

Proteinuria,albuminuria -Nonpathological: excessive physical exertion, pregnancy -Pathological(over 150 mg/day): glomerulonephritis, severe hypertension, heart failure, often sign of renal disease

the primary site of glucose and amino acid reabsorption.

Proximal convoluted tubule

ADH

Regulates water reabsorption at the collecting duct. ADH inhibits diuresis or urine output. ADH makes principal cells more permeable to water with aquaporins. Amount of ADH determines amount of aquaporins. When body is overhydrated ECF osmolarity decreases,decreasing ADH secrtion by posterior pituitary gland= collecting ducts relatively impermeable to water. ADH also increases urea reabsorption by collecting ducts.

Under normal resting conditions, the __________ arteries deliver one-fourth of the total cardiac output (about 1200 ml) to the kidneys each minute.

Renal

Which process results in increased blood pressure in response to hormone release?

Renin-angiotensin-aldosterone mechanism - Drop in systemic BP triggers the release of an enzyme by the kidneys, which triggers this system

Macula Densa cells

Specialized chemoreceptors that monitor the NaCl content of the filtrate entering the DCT. -tall closely packed cells in ascending limb of nephron loop that lies adjacent to granular cells.

Juxtaglomerular (Granular) cells

Specialized mechanoreceptors that sense the BP in the afferent arteriole. Enlarged smooth muscle cells with prominent secretory granules containing the enzyme renin.

Urinary Retention

The bladder is unable to expel its contained urine. Common after general anesthesia or hypertrophy of the prostate.

Glomerular hydrostatic pressure (HPgc)

The force of blood against the walls of the glomerular capillaries. -55 mm Hg

Glomerular hydrostatic pressure (HPgc)

The force of blood against the walls of the glomerular capillaries. -essentially glomerular BP -55 mm Hg -high b/c capillaries are drained by high-resistance efferent arteriole w/ smaller diameter than the afferent arteriole that feeds them. -Results in filtration along entire glomerular capillary and reabsorption does not occur as it would in other capillary beds.

Angiotensin II

a powerful vasoconstrictor that also stimulates the secretion of aldosterone

Renal Infarct

an area of dead, or necrotic, renal tissue due to blockage of the vascular supply to the kidney or hemorrhage. A common cause of localized renal infarct is an obstructed interlobar artery.

Nocturnal enuresis (NE)

an inability to control urination at night during sleep; bed-wetting. In children over 6, it is called primary NE if control has never been achieved and secondary NE if control was achieved and then lost.

During reabsorption of water in the proximal convoluted tubule, what causes water to diffuse from the lumen into the interstitial space?

an increase in the osmolarity of the interstitium

Urinary incontinence may occur if a person has ______.

an overactive detrusor muscle

The energy needed for secondary active transport is provided by the __________.

concentration gradient established by Na+

Polycystic KD autosomal dominant form

cysts develop in the kidney though they develop so slowly they often are not noticed until about 40 years of age. -less severe form of PKD, much more common( 1 in 500 people).

Hypospadias

found in male infants only, is the most common congenital abnormality of the urethra. It occurs when the urethral orifice is located on the ventral surface of the penis. This problem is corrected surgically when the child is around 12 months old.

Your patient's urinalysis shows a large amount of protein in the urine. This suggests a problem in the ____________

glomerulus

important sign of renal trauma

hematuria (blood in the urine) Lower parts of the kidneys, especially the right kidney are susceptible to blunt trauma. The renal artery is vulnerable as well.

Hemoglobinuria

hemoglobin in the urine -transfusion reaction, hemolytic anemia, severe burns, etc.

The most important factor affecting the net filtration pressure in the glomerulus is __________.

hydrostatic pressure in the glomerulus

Acute glomerulonephritis (GN)

inflammation of the glomeruli, leads to increased permeability of the filtration membrane.

Pyelonephritis refers to __________.

inflammations or infections that affect the kidney, may lead to kidney damage if left untreated. Usually successfully treated by antibiotics.

Loop diuretics

inhibit formation of the medullary gradient

What does a high concentration of NaCl in the renal tubule at the juxtaglomerular apparatus (JGA) most likely indicate?

insufficient NaCl reabsorption due to high GFR

When the concentration of ADH increases, __________.

less urine is produced

If the osmotic pressure in the glomerular capillaries increased from 28 mm Hg to 35 mm Hg, would net filtration increase or decrease?

net filtration would decrease -osmotic pressure opposes filtration

Dysuria

painful urination

Creatinine is a

protein metabolite found in skeletal muscle and excreted in urine.

Granular cells of the juxtaglomerular apparatus (JGA) regulate GFR indirectly through which mechanism?

renin-angiotensin mechanism

Cystocele

the herniation of the urinary bladder into the vagina; a common result of tearing of the pelvic floor muscles during childbirth

The reason glucose is detected in the urine of individuals with uncontrolled diabetes is because __________.

the transport maximum for glucose reabsorption has been exceeded

Overflow incontinence

urine dribbles from the urethra whenever the bladder overfills.