Urinary Outline Flashcards
Albumin/o
Medical Term: Albuminuria
Albumin
Medical Term meaning: Abnormal presence of albumin in the urine
Cyst/o or Vesic/o
Medical Term: Cystitis
Urinary Bladder
Medical Term meaning: Inflammation of the urinary bladder
Glomerul/o
Medical Term: Glomerular
Glomerulus
Medical Term Meaning: referring to the glomerulus
Hydro/o
Medical Term: dehydration
Water
Medical Term Meaning: excessive loss of body water
Lith/o
Medical Term: nephrolithiasis
Stone
Medical Term meaning: prescience of kidney stones
Olig/o
Medical Term: oliguria
Scanty
Medical Term meaning: Scanty urination
Pyel/o
Medical Term: pyelonephritis
Renal pelvis
Medical Term meaning: urinary tract infection that has involved the renal pelvis
Ren/o or Nephr/o
Medical Term: renal
Kidney
Medical Term meaning: referring to the kidney
Trigon/o
Medical Term: trigonal
Trigone
Medical Term meaning: referring to the trigone
Ureter/o
Medical Term: ureteral
Ureter
Medical Term Meaning: referring to the ureter
Urethr/o
Medical Term: urethral
Urethra
Medical Term meaning: referring to the urethra
Urin/o
Medical Term: urinary
Urine
Medical Term meaning: referring to the urine
What is the kidneys function?
“Clear” or clean the blood of many waste products continually produced as a result of metabolism of nutrients in the body cells. Blood enters the nephron where additional waste is secreted into the tubules and substances useful to the body are reabsorbed into the blood.
.Maintains electrolytes, water and acid-base balances in the body.
. Maintenance of a high rate of blood flow and normal blood pressure on the kidneys is essential for the formation of urine.
. Regulates the levels of many chemical substances in the blood such as chloride, sodium, potassium and bicarbonate.
. Regulates the proper balance between body water content and salt by selectively retaining or excreting both substances by demand.
. Secretion of the hormone Erythropoietin (EPO.) regulates red blood cell production
Uremia or uremic poisoning
Waste products from metabolism from nutrients that are not removed from the blood can quickly accumulate to toxic levels
Kidneys location?
Outside the parietal peritoneum and in the retroperitoneal.
Right kidney is under liver pushing it lower than the left. Still protected by the posterior part of the rib cage.
Renal Fat Pad
A heavy cushion of adipose tissue that normally encased each kidney and helps hold it in place.
How much of the total blood pumped by the heart each minute enters the kidneys?
A little more than 20%. The rate of blood flow through the kidneys are among the highest in the body.
Maintenance of a high rate of blood flow and normal blood pressure on the kidneys is essential for the formation of urine.
Hilum
Medial indentation where vessels, nerves and the ureter connect with the kidney.
Kidney structures:
- Renal Cortex
- Renal Medulla
- Renal Pyramids
- Renal Papilla (papillae)
- Renal Pelvis
- Calyx
Renal cortex
The outer part of the kidney
Renal medulla
The inner portion of the kidney
Renal pyramids
The triangular divisions of the medulla of the kidney. Extensions of cortical tissue that dip down into the medulla; between the renal pyramids are called renal columns.
Renal Papilla (papillae)
Narrow, innermost end of a pyramid
Renal Pelvis (aka Kidney Pelvis)
An expansion of the upper end of a ureter (the tube that drains urine into the bladder.)
Calyx (calyces)
A division of the renal pelvis (the papilla of a pyramid opens into each calyx.)
A nephron can be composed of what 2 principle components?
Renal corpuscle & Renal Tubule
Renal corpuscle is made up of:
Glomerular Capsule - cup shaped top of a nephron. The hollow, saclike glomerular capsule surrounds the glomerulus. Also called Bowman capsule.
Glomerulus - a network of blood capillaries tucked into the glomerular capsule.
Why is there high blood pressure in the glomerular capillaries and what creates it?
High pressure is required to filter wastes from blood.
Afferent - delivers blood to the glomerulus which is larger in diameter.
Efferent - drains blood from the glomerulus and is relatively short.
Renal Tubule consist of:
- Proximal Convoluted Tubule (PCT)
- Nephron Loop (Henle Loop)
- Distal Convoluted Tubule (DCT)
- Collecting Duct (CD)
Proximal Convoluted Tubule (PCT)
First segment of a renal tubule. The PCT is called proximal because it lies nearest the tubule’s origin from the glomerular capsule, and it is called convoluted because it has several bends.
Nephron Loop (Henle Loop)
The extension of the proximal tubule into the renal medulla. Observe that the nephron loop consists of a straight descending limb, a hairpin turn and a straight ascending limb.
Distal Convoluted Tubule (DCT)
The part of the tubule distal to the ascending limb of the nephron loop. The DCT extends from the ascending limb to the collecting duct.
Collecting duct (CD)
A straight (that is, not convoluted) part of a renal tubule. Distal tubules of several nephrons join to form a single collecting duct.
How does urine leave the nephron?
From the collecting ducts exits from the pyramid through the papilla and enters the calyx and renal pelvis before flowing into the ureter.
Cortical nephron
When located high in the cortex which is typical of about 85% of all nephrons. Nephrons in this group are located almost entirely in the renal cortex.
Juxtamedullary Nephrons
Are the remainder type of nephrons apart from the cortical. They have their renal corpuscles near the junction (juxta) between cortex and medullary layers. The nephron loops dip far into the medulla.
Juxtamedullary Nephrons have an important role in concentrating urine.
Juxtaglomerular Apparatus (JG)
The cells also function in the blood volume and blood pressure regulation. When blood pressure is low, which often occurs when blood plasma volume is low, these JG cells secrete an enzyme that triggers a system to restore normal blood volume and pressure.
Erythropoietin (EPO)
As a response to hypoxia a deficiency of oxygen in the body, the erythropoietin is sent to the red bone marrow, where it stimulates the production of erythrocytes (red blood cells.) The additional erythrocytes increases the ability of the blood to absorb and transport oxygen to oxygen-starved tissues.
What organ is often considered to be the most important homeostatic organ in the body.
Kidneys
How does the nephrons form urine?
By way of a combination of 3 blood-balancing processes:
1. Filtration
2. Reabsorption
3. Secretion
Filtration
Of water and dissolved substances out of the blood in the glomeruli into the glomerular capsule.
If the glomerular blood pressure drops below a certain level, filtration and urine formation cease.
What is the rate of Glomerular filtration?
125 mL/min resulting in about 180 L (nearly 50 gallons) being produced everyday by the kidneys.
About 120 L of that water is reabsorbed by osmosis in the proximal tubule. The proximal tubules also reabsorb about 2/3’s of most ions , as well as nearly all of the small organic molecules
Reabsorption
Water & dissolved substances out of kidney tubules back into the blood. This prevents substances needed by the body from being lost in the urine. Usually, up to 99% of water, sodium, and chloride filtered out of glomerular blood is retrieved from tubules - along with 100% of glucose and other small organic molecules.
Where does Reabsorption begin?
In the proximal convoluted tubules and continues in the nephron loop, distal convoluted tubules, and collecting duct.
What substances are reabsorbed?
Water, glucose and other nutrients like sodium and other ions.
Where are sodium ions actively being transported back into the blood?
The tubular fluid in all segments of the kidney tubule except the collecting duct.
Sodium reabsorption and how it uses the Countercurrent mechanisms
In the nephron loop dipping far into the medulla is a countercurrent flow where filtrate returns back up the nephron loop transporting large amounts of sodium & chloride into the interstitial fluid of the medulla. Making the medulla very salty (hyperosmotic) which promotes osmosis of water into them.
Countercurrent mechanisms
Maintain hyperosmotic conditions in the medulla. By maintaining this the kidney is able to concentrate urine by reabsorbing more water by osmosis.
How is the amount of sodium reabsorbed determined?
Depends on the body’s intake ex.
> sodium intake = < amount reabsorbed & greater the amount excreted in the urine
< sodium intake = > amount reabsorbed from the kidney tubules & less secreted in the urine
How is chloride absorbed?
Chloride ions passively move into the blood because they carry a negative electrical charge. The + charged sodium ions that have been reabsorbed and moved into the blood “attract” the - charged chloride ions from the tubule fluid into the peritubular capillaries.
Glucose reabsorption
Filtered glucose is reabsorbed by the proximal tubules into peritubular capillary blood.
No valuable nutrient is wasted by being lost in the urine.
Sodium-Glucose molecules travels in the tubule wall and passively reabsorb by “tag along” with sodium being reabsorbed into the blood.
Transport Maximum (Tmax)
The largest amount of any substance that can be moved by a cellular transporter (pump or carrier) at one time, determined mainly by the number of available transporters of that substance.
Renal Threshold
When the amount of a substance that I’d normally fully reabsorbed from tubular fluid (such as glucose) increases above this “threshold” level, the kidney tubules are unable to reabsorb all of it and the substances “spill over” into the urine.
Glycosuria
Glucose in the urine; a sign of diabetes mellitus.
Due to the renal threshold being reach with an increase of blood glucose concentration.
Diabetes Mellitus (DM)
Due to the renal threshold being reach with an increase of blood glucose concentration. There are not enough sodium-glucose transporters to handle the excess glucose immediately. Then there will be glucose in the urine which is Glycosuria.
What happens when glucose is retained in the urine?
High glucose concentration in the tubular filtrate means that less water will leave the tubules by osmosis.
Thus urine is dilute and has a higher than normal volume resulting in Polyuria an excessive urination which this then results in increased loss of water from the body, triggering thirst called Polydipsia.
Polyuria
Unusually large amounts of urine
Polydipsia
excessive and ongoing thirst
Secretion
Of hydrogen ions, potassium ions, and certain drugs from blood into kidney tubules.
What is secretion opposite of?
Reabsorption, it’s the reverse version.
Whereas reabsorption moves substances out of the urine into the blood, secretion move’s substances out of the blood into the urine.
What function does tubular secretion serve?
Remove or “clear” the blood of excess potassium and hydrogen ions, certain drugs including penicillin and phenobarbital and numerous wastes such as urea, uric acid, and creatinine.
Where do substances that are secreted from peritubular blood enter?
The proximal tubule and, to a lesser extent, the distal convoluted tubule and collecting ducts.
Potassium is an exception where is is secreted into the collecting ducts in and exchange with sodium.
Diuretic Drugs
Stimulate the production of urine which decreases the volume of potassium ions. It increases secretion of potassium into tubular fluid and thus it’s excretion in the urine.
Sodium secretion
Is located in the distal convoluted tubules and collecting ducts. Sodium secretion is dependent on hormones..
Ammonia secretion
Ammonia is secreted passively by diffusion
Why is kidney tubule secretion crucial?
It maintains the body’s fluid, electrolytes, and acid-base balance.
Antidiuretic hormone (ADH)
“Water-retaining hormone” or “urine-decreasing hormone”
Is secreted from the posterior pituitary gland which decreases the amount of urine by making collecting ducts permeable to water. This is an example of regulating water reabsorption.
Why is maintaining a hypertonic (salty) medulla due to the countercurrent mechanisms of the nephron loop & it’s capillaries important?
Maintains a hypertonic medulla allows ADH to have a greater effect in concentrating urine, thereby conserving the body’s valuable water.
Aldosterone hormone
“Salt- and water-retaining hormone”
Is secreted by the adrenal cortex that stimulates the kidney tubules to reabsorb & retain sodium ions and water at a faster rate which reduces urine volume.
What happens when blood volume and pressure drop below normal?
Is first sensed by cells in the JG apparatus which then release an enzyme Renin that initiated the renin-angiotensin-aldosterone system (RAAS.)
renin-angiotensin-aldosterone system (RAAS)
Produces construction of blood vessels and thus raised blood pressure.
Also triggers adrenal gland secretion of aldosterone which increases total blood volume and contributes to a rise in blood pressure.
Atrial Natriuretic Hormone (ANH)
“Salt- and water-losing hormone”
Secreted from the heart’s atrial wall, has opposite effect of aldosterone. Stimulates kidney tubules to secrete more sodium and thus loose more water which increases urine volume.
What does the body secrete depending on the homeostatic balance of body fluids at any particular moment?
ADH Antidiuretic Hormone, Aldosterone and ANH Atrial Natriuretic Hormone.
Anuria
Absence of urine
Oliguria
Scanty amount of urine
Polyuria
Unusually large amount of urine
What is the normal adult urine output in a day?
About 1,500 to 1,600 mL a day
Ureters
Urine drains out of the CD’s of each kidney into the renal pelvis and down the ureter into the urinary bladder.
What lines both the ureters and each renal pelvis?
The mucous membrane features easily stretchable stratified transitional epithelium.
The ureter has a thick, muscular wall to be assist in moving urine down the ureters into the bladder & is richly supplied with sensory nerve endings.
Renal colic
Pain caused by the passage of a kidney stone.
Where is the urinary bladder located?
When empty it lies in the pelvis just behind the pubic symphysis.
When full it projects upwards into the lower portion of the abdominal cavity. In women it sits in-front of the uterus & in men it rests on the prostate.
What is the bladder lined with to make it well suited to expand and hold variable amounts of urine and to then contract to empty itself.
Elastic fibers and involuntary muscles fibers in the wall. The mucous membrane-contains transitional epithelium line the urinary bladder. This lining is attached to the deeper muscular layer so the bladder can wrinkle and be in folds called rugae when empty.
Trigone
Smooth triangular area on the wall of the urinary bladder that is free from rugae. It’s lining membrane is tightly fixed to the deeper muscle coat. Expanding between the 2 ureter openings and to the point of exit of the urethra below.
The ureters enter the wall of the bladder at an angle which prevents back flow of urine into the ureters from a full bladder.
Urethra
A narrow tube used as a passageway for elimination of urine; in males, also acts as a genital duct that carries sperm to the exterior.
What path does urine take to leave the body?
Urine passes from the bladder, down the urethra and out of its external opening, the urinary meatus.
Because the same mucous membranes lines each renal pelvis, the ureters and the bladder extending down into the urethra what can happen during during an infection in the urethra?
An infection can spread upward from the urethra to the urinary tract.
Example cystitis
Cystitis
Inflammation of the urinary bladder
What is the difference between the urethra in males vs females?
In women the tube is only about 4cm (1 1/2 inches) long. In women the urethra is a part of only the urinary tract.
In men it’s about 20cm (8 inches) long. In men the urethra has 2 functions 1. It’s a terminal portion of the urinary tract 2. It’s is a passageway for movement of the reproductive fluid (semen) from the body.
What terms refer to the passage of urine from the body or the emptying of the bladder?
Micturition, Urination and Voiding
Micturation
Urination, voiding.
The use of internal urethral sphincter & external urethral sphincter to act as valves that guard the pathway leading from the bladder exit. When contracted, both sphincters seal off the bladder and allow urine to accumulate without leaking to the exterior.
Internal urethral sphincter
Located at the bladder exit and is involuntary
External urethral sphincter
Circles the urethra just below the neck of the bladder. Is also composed of striated muscle and is under voluntary control.
Is used during emptying reflex when the bladder is full. If the muscle is relaxed during this reflex, micturition occurs. Also through voluntary choice to empty bladder. Otherwise it can suppress the emptying reflex until the bladder is filled to capacity with urine and the losses control.
How much urine does the bladder hold until the sensation to void begins and when micturition occurs?
The muscular wall of the bladder permits this organ to accommodate a considerable volume of urine with very little increase in pressure until a volume of 300 to 400 mL is reached.
The need to void may be noticed at volumes of 150mL, but micturition in adults does not normally occur much below volumes of 350mL.
Emptying reflex
Nerve impulses are transmitted to the 2nd, 3rd and 4th sacral segments of the spinal cord as the bladder wall stretches. This reflex causes contractions of the muscle of the bladder wall and relaxation of the internal sphincter. Urine then enters the urethra.
If the external sphincter is relaxed, micturition occurs or also through voluntary choice. Otherwise it can suppress the emptying reflex until the bladder is filled to capacity with urine and the losses control.
How does highly centers in the brain function in micturition?
By integrating bladder contraction and internal and external sphincter relaxation, with the cooperative contraction of pelvic and abdominal muscles.
Urinary retention
Is a condition in which no urine is voided. The kidneys produce urine, but the bladder cannot empty itself.
Urinary suppression
The kidneys do not produce any urine, but the bladder retains the ability to empty itself.
What problems happen with micturition when it’s working as a complex system, homeostatic control?
15 million adults and about 15-20% of that being children experience some degree of enuresis and voiding dysfunction. People over the age of 60 are especially at risk, with elderly women affected almost twice often as men.
Urinary Incontinence or Enuresis
Refers to involuntary voiding or loss of urine. It occurs most often in an older child or adult.
Urge Incontinence
Is associated with smooth muscle over activity in the bladder wall.
Stress Incontinence
Is often used to describe the type of urine loss associated with laughing, coughing, or heavy lifting. It is a common problem in women with weakened pelvic floor muscles following pregnancy.
Overflow incontinence
Is characterized by intermittent dribbling of urine. It results from urinary retention and overdistended bladder - a common problem in men with an enlarged prostate gland.
Reflex incontinence
Occurs in the absence of any sensory warning or awareness. It is common in nervous system disorders such as stroke, Parkinsonism, or spinal cord injury.
If totally cut off from spinal innervation, the bladder musculature acquired some automatic action, and periodic but unpredictable voiding occurs - a condition called neurogenic bladder.
Neurogenic Bladder
Disorder of the bladder that results in loss of control of normal voiding; due to disruption of nervous input to the bladder.
Nocturnal enuresis
Bed wetting at night often occurs in a child who is beyond the age when voluntary bladder control is expected. Incidence is higher in boys than in girls and is often due to maturational delay of the complex urinary reflexes needed for voluntary control of micturition.
Urinalysis
Clinical laboratory testing of urine samples
