FINALS: URINARY SYSTEM Flashcards
pH above 7.45
ALKALOSIS
pH below 7.35
ACIDOSIS
arterial pH between 7.35 & 7.0
PHYSIOLOGICAL ACIDOSIS
Systems of 1 or 2 molecules that act to
prevent dramatic changes in H+
concentrations when acids/bases are added
Bind to H+ when pH drops
Release H+ when pH rises
1st line of defense in resisting pH changes
BLOOD BUFFERS
3 MAJOR CHEMICAL BUFFER SYSTEMS:
Bicarbonate buffer system
Phosphate buffer system
Protein buffer system
- Mixture of carbonic acid (H2CO3) & sodium
bicarbonate (NaHCO3) - Bicarbonate ions (HCO3‾) react with strong acids to
change them to weak acids - Carbonic acid dissociates in the presence of a strong
base to form a weak base and water
BICARBONATE BUFFER SYSTEM
prevents excessive water loss in urine
ADH
regulates Na+ content
of ECF
ALDOSTERONE
ALDOSTERONE IS TRIGGERED BY THE?
renin-angiotensin
mechanism
Regulate aspects of homeostasis: water
balance, electrolytes, acid-base balance in
blood, BP (renin) , RBC production (EPO),
activation of vitamin D
Excretes wastes in urine
Lie against the DORSAL body wall in a retroperitoneal position in the superior
lumbar region
Right kidney is slightly lower than the left
Attached to ureters, renal blood vessels, &
nerves at renal hilum
Atop each is an adrenal gland
Adult: 12 cm (5in)long, 6 cm (2.5in) wide, & 3 cm (1in) thick
KIDNEYS
Transport urine from kidneys to urinary
bladder
URETERS
Stores urine & expels it into urethra
URINARY BLADDER
Discharges urine from body
URETHRA
KIDNEY COVERINGS:
- Smooth, transparent sheet of dense
irregular connective tissue that is
continuous with the outer coat of the
ureter
Barrier against trauma & helps MAINTAIN THE SHAPE OF KIDNEY
FIBROUS CAPSULE
KIDNEY COVERINGS:
- Mass of fatty tissue surrounding the
fibrous capsule
Protects the kidney from trauma &
holds it firmly in place within the
abdominal cavity
PERIRENAL FAT CAPSULE
KIDNEY COVERINGS:
- Thin layer of dense irregular connective
tissue
ANCHORS the kidney to the surrounding structures & to the abdominal wall
RENAL FASCIA
RENAL MEDULLA:
Triangular regions with a striped appearance
Renal/medullary pyramids
RENAL MEDULLA:
portions of the renal
cortex that extend between renal
pyramids
Renal columns
RENAL PELVIS: inner collecting tube
- cup-shaped structures that funnel urine towards the renal pelvis
Calyces
The structural and functional units of the
kidneys
Responsible for forming urine
NEPHRONS
TYPES OF NEPHRONS:
Located entirely in the cortex
Includes most nephrons
CORTICAL NEPHRONS
TYPES OF NEPHRONS:
Found at the boundary of the cortex & medulla
JUXTAMEDULLARY NEPHRONS
CAPILLARY BEDS ASSOCIATED WITH
NEPHRONS:
Feeder vessel: afferent arteriole
Receives blood that has passed through
glomerulus: efferent arteriole
GLOMERULUS
CAPILLARY BEDS ASSOCIATED WITH
NEPHRONS:
Arise from efferent arteriole of the glomerulus
Normal, low-pressure capillaries
Attached to a venule
Cling close to the renal tubule
Reabsorb (reclaim) some substances from
collecting tubes
PERITUBULAR CAPILLARIES
Glomerular Filtration Rate (GFR):
125 mL/min
GLOMERULAR FILTRATION:
Filtration occurs through a structure of
three parts:
- The FENESTRATIONS OF THE CAPILLARY
endothelium, which blocks blood cells and
platelets - The THICK, COMBINED BASAL LAMINA, or
GBM, which restricts large proteins and
some organic anions - The FILTRATION SLIT diaphragms between
pedicels, which restrict some small proteins
and organic anions.
1st FUNCTION to be AFFECTED IN RENAL DISEASE
Begins as soon as the filtrate enters PCT
The peritubular capillaries reabsorb
several materials: some water, glucose,
amino acids, ions
Some reabsorption is passive, most is active
TUBULAR REABSORPTION
MATERIALS NOT REABSORBED:
- Nitrogenous waste products
- Urea
- Uric acid
- Creatinine
- Excess water
Tubular reabsorption in reverse
Some materials (H+, K+, creatinine, drugs) move from the peritubular capillaries into the renal tubules
Materials left in the renal tubule move toward the ureter & make their way into the urine.
TUBULAR SECRETION
major site for
removal of nonfiltered substances
Proximal Convoluted Tubule
TUBULAR SECRETION 2 MAJOR FUNCTIONS:
- REGULATION OF THE ACID-BASE BALANCE
in the body through the secretion of
hydrogen ions. - ELIMINATION OF WASTE PRODUCTS not
filtered by the glomerulus
24 HOURS:
Kidneys filters ________of blood plasma
150-180 L
24 HOURS:
Only about ___of urine are produced
1-18 L
2 slender attaching the kidney to the bladder
25-30 cm (10-12 in) long & 6 mm (1/4 in) in
diameter
Peristalsis (contraction of smooth muscle
layers in their walls) aids gravity in urine transport
Small valvelike folds of bladder mucosa: prevents urine from flowing back into the ureter
URETERS
Smooth, collapsible, muscular sac
Temporarily stores urine
TRIGONE (3 openings)
- 2 ureters openings (ureteral orifices)
- Single opening of urethra (internal urethral
ORIFICE: drains the bladder
Males: prostate gland surrounds the neck of
the bladder
3 layers of smooth muscle (detrusor muscle)
Mucosa made of TRANSITIONAL EPITHELIUM
Walls are thick & folded in an empty bladder
Bladder can expand significantly W/OUT INCREASING INTERNAL PRESSURE
URINARY BLADDER
Thin-walled tube that carries urine by
peristalsis from the bladder to the outside of
the body
Release of urine is controlled by 2
sphincters:
- INTERNAL URETHRAL SPHINCTER
(involuntary): smooth muscle
- EXTERNAL URETHRAL SPHINCTER
(voluntary): skeletal muscle
URETHRA
Act of emptying the bladder
MICTURITION (VOIDING)
Volume of urine in the bladder exceeds
200-400 mL
2 sphincters control the flow of urine from
the bladder, both must open to allow
voiding:
- relaxed after stretching of the bladder
INTERNAL URETHRAL SPHINCTER
2 sphincters control the flow of urine from
the bladder, both must open to allow
voiding:
must be voluntarily relaxed
EXTERNAL URETHRAL SPHINCTER
Falling/floating kidney, is an inferior
displacement/dropping of the kidney
Cause: Kidney is not securely held in place
by adjacent organs/its covering of fat
Dangerous because the ureter may kink &
block urine flow—exerts pressure on kidney
tissue (hydronephrosis)
NEPHROPTOSIS
Abnormally low urinary output (100-400 mL/day)
Indicates that glomerular BP is too low to
cause filtration
Other causes: transfusion reactions & acute
inflammation/from crush injuries of the
kidneys
OLIGURIA
less than 100 mL
ANURIA
Formed by the occasional precipitation & solidification of the crystals of salts present in urine
Commonly contain crystals of calcium
oxalate, uric acid or calcium phosphate
RENAL CALCULI (KIDNEY STONES)
Decrease/cessation of glomerular filtration
Kidneys abruptly stop working entirely
Main feature: suppression of urine flow
(oliguria/anuria)
ACUTE RENAL FAILURE
Infection of a part of the urinary
system/presence
- Symptoms: DYSURIA (painful urination),
urinary urgency & frequency, fever
URINARY TRACT INFECTION (UTI)
inflammation of urethra
URETHRITIS
inflammation of urinary bladder
CYSTITIS
kidney inflammation
PYELONEPHRITIS/PYELITIS
Unable to voluntarily control the external
sphincter
Normal in infants & children 2-3 years old
TYPES:
- Stress incontinence
- Urge incontinence
- Overflow incontinence
- Functional incontinence
INCONTINENCE
Bladder is unable to expel its contained urine
Causes:
- After surgery in which anesthesia has been
given
- Hyperplasia (enlargement) of prostate gland
URINARY RETENTION
ADH is not released, huge amounts of very
dilute urine (25 L/day) flush from the body
day after day
Can lead to severe dehydration & electrolyte
imbalances
Always thirsty & have to drink fluids almost
continuously to maintain normal fluid balance
DIABETES INSIPIDUS
Hypoaldosteronism
Have polyuria (excrete large volumes of
urine) & lose tremendous amounts of salt & water to urine
ADDISON’S DISEASE
Degenerative condition, 1 or both kidneys enlarge & have many blisterlike sacs (cysts) containing urine
ACUTE POLYCYSTIC KIDNEY DISEASE
Condition found in male babies only
Urethral orifice is located on the ventral
surface of the penis
HYPOSPADIAS
Inflammation of the kidney that involves the
glomeruli
Common cause: allergic reaction to the
toxins produced by streptococcal bacteria
that have recently
GLOMERULONEPHRITIS
The thickening and loss of function in the
GBM produced as part of the systemic
microvascular sclerosis in diabetes mellitus
Is the leading cause of (irreversible) endstage kidney disease in the United States,
treatment requires either a kidney transplant
or regular artificial hemodialysis
DIABETIC GLOMERULOSCLEROSIS
One of the most common problems caused by sickle cell disease
Occurs when the affected erythrocytes sickle in the vasa recta, because of the low oxygen tension there.
The nephropathy results from renal infarcts, usually within the renal papillae or pyramids
SICKLE CELL NEPHROPATHY
can cause an unstable
urothelium, with benign urothelial changes
involving hyperplasia or metaplasia
Chronic cystitis
is usually some form of
transitional cell carcinoma arising from
unstable urothelium.
Bladder cancer