Chapter 18 - Urinary System Flashcards
kidneys
A pair of bean-shaped organs on either side of your spine, below your ribs and behind your belly. The kidneys’ job is to filter your blood. They remove wastes, control the body’s fluid balance, and keep the right levels of electrolytes. All of the blood in your body passes through them about 40 times a day.
ureter vs urethra
The ureter is a small tube, or duct, that connects the bladder and kidneys. Urine passes through the ureter from the kidneys to the bladder.
The urethra is the tubular path that connects the bladder to the body’s exterior, allowing urine to exit the body.
The body has two ureters but only one urethra.
How many holes do female genitals have?
Two.
There are two openings in the vulva — the vaginal opening and the opening to the urethra (the hole she pees out of).
The urethral opening is the tiny hole that she pees out of, located just below the clitoris.
The vaginal opening is right below the urethral opening. It’s where menstrual blood leaves the body, and babies are born. A variety of things can go inside the vagina, like fingers, penises, sex toys, tampons, and menstrual cups.
vulva
the outer part of the female genitals
bladder
A hollow muscular organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. It is located in the pelvis in humans.
uremia
also referred to as uremic poisoning
the condition of having high levels of nitrogen-containing waste products in the blood (urea)
urea
a nitrogen-containing waste product normally excreted in urine
retroperitoneal
the anatomical space (sometimes a potential space) behind (retro) the peritoneum
potential space
a space between two adjacent structures that are normally pressed together
appose (verb)
to place in juxtaposition or proximity
juxtaposition
the act or an instance of placing two or more things side by side often to compare or contrast or to create an interesting effect
proximate
- immediately preceding or following (as in a chain of events, causes, or effects)
- very near : CLOSE
- soon forthcoming : IMMINENT
renal fat pad
a heavy cushion of fat that normally encases each kidney and helps hold it in place
hilum
the part of the kidney that the vessels, nerves, and the ureter connect to
renal cortex
the outer part of the kidney
renal medulla
the inner portion of the kidney
renal pyramids
the triangular divisions of the renal medulla of the kidney
renal column
A column-like extension of the renal cortex in the renal medulla
renal papilla (plural: papillae)
the narrow, innermost end of a renal pyramid
renal pelvis
also called kidney pelvis
The area at the center of the kidney. Urine collects here and is funneled into the ureter, the tube that connects the kidney to the bladder.
calyx (plural: calyces)
a division of the renal pelvis (the papilla of a pyramid opens into each calyx)
nephron
The minute or microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule.
renal corpuscle
It is the blood-filtering component of the nephron of the kidney.
It consists of a glomerulus (a tuft of capillaries composed of endothelial cells) and a glomerular (glomerulus-covering) capsule known as Bowman’s capsule.
tuft
(1) a small cluster of elongated flexible outgrowths attached or close together at the base and free at the opposite ends (e.g. grass, hair)
(2) clump, cluster
(3) mound
renal tubule
One of millions of tiny tubes in the kidneys that returns nutrients, fluids, and other substances that have been filtered from the blood (but that the body needs back) back to the blood. The remaining fluid and waste in the renal tubules become urine.
cortical nephrons vs. juxtamedullary nephrons
Cortical nephrons make up 85% of nephrons and are located almost entirely in the renal cortex.
Juxtamedullary nephrons have their renal corpuscles near the junction (juxta) between cortex and medullary layers.
What is the path that filtrated blood plasma takes through the renal tubule?
Filtration of the blood plasma takes place in the renal corpuscle. After leaving the renal corpuscle, the filtrate passes through the renal tubule in the following order:
1. proximal convoluted tubule (found in the renal cortex)
2. loop of Henle (mostly in the medulla)
3. distal convoluted tubule (found in the renal cortex)
4. collecting tubule (in the medulla)
5. collecting duct (in the medulla)
The collecting ducts then descend towards the renal pelvis and empty urine into the ureter.
endothelium
A thin membrane that lines the inside of the heart and blood vessels. It is made up of endothelial cells.
Endothelial cells release substances that control vascular relaxation and contraction as well as enzymes that control blood clotting, immune function and platelet (a colorless substance in the blood) adhesion.
hemodialysis
A procedure where a dialysis machine and a special filter called an artificial kidney, or a dialyzer, are used to clean your blood. To get your blood into the dialyzer, the doctor needs to make an access, or entrance, into your blood vessels. This is done with minor surgery, usually to your arm.
renal failure
Also called kidney failure.
It means one or both kidneys can no longer function well on their own. Sometimes, kidney failure is temporary and comes on quickly. Other times, it is a chronic condition that can get worse slowly over a long time.
continuous ambulatory peritoneal dialysis (CAPD)
It is a new way of treating renal failure.
The peritoneum is a natural filter, with a rich supply of tiny blood vessels (capillaries), which lines a space in your body called the peritoneal (or abdominal) cavity. During peritoneal dialysis between one to three litres of fluid is put into the space through a catheter (a permanent soft, flexible plastic tube) attached to your abdomen. The fluid (known as dialysate) then sits there for several hours whilst waste products pass from the capillaries into the liquid. It is then drained out into an empty bag and thrown away.
The process of adding fresh liquid and draining out used liquid is called a dialysis ‘session’ or ‘exchange’. It is usually performed four times a day, every day, and each session takes about 40 minutes.
juxtaglomerular apparatus
A structure in the kidney that regulates the function of each nephron, the functional units of the kidney. The juxtaglomerular apparatus is named because it is next to (juxta) the glomerulus.
The juxtaglomerular apparatus consists of three types of cells:
1. the macula densa, a part of the distal convoluted tubule of the same nephron
2. juxtaglomerular cells, (also known as granular cells) which secrete renin
3. extraglomerular mesangial cells
renin
an enzyme secreted by and stored in the kidneys which promotes the production of the protein angiotensin
angiotensin
a protein hormone that causes vasoconstriction and an increase in blood pressure
mesangial cells
Specialized cells in the kidney that make up the mesangium of the glomerulus; the primary function of mesangial cells is to remove trapped residues and aggregated protein from the basement membrane thus keeping the filter free of debris.
(Basement membrane in this case refers to glomerular basement membrane (GBM).)
mesangium
a thin membrane that gives support to the capillaries surrounding the tubule of a nephron
glomerular basement membrane (GBM)
a key component of the glomerular capillary wall that is essential for kidney filtration
erythropoietin (EPO)
It is a hormone. During hypoxia (a deficiency of oxygen in the body) erythropoietin is released into the bloodstream by the kidneys. EPO travels in the bloodstream to the red bone marrow, where it stimulates the production of additional erythrocytes (red blood cells). The additional erythrocytes increase the ability of the blood to absorb and transport oxygen to oxygen-starved tissues.
four blood-balancing processes
There are four basic processes in the formation of urine:
1. Filtration: the mass movement of water and solutes from plasma to the renal tubule that occurs in the renal corpuscle. About 20% of the plasma volume passing through the glomerulus at any given time is filtered. This means that about 180 liters of fluid are filtered by the kidneys every day.
2. Reabsorption: the movement of water and solutes from the tubule back into the plasma
3. Secretion: The secretion of additional substances into the tubular fluid. This enhances the kidney’s ability to eliminate certain wastes and toxins. It is also essential to regulation of plasma potassium concentrations and pH.
4. Excretion: Excretion is what goes into the urine, the end result of the above three processes.
(amount excreted = amount filtered - amount reabsorbed + amount secreted)
renal threshold
The concentration of a substance dissolved in the blood above which the kidneys begin to remove it into the urine. In other words, if something exceeds the renal threshold, it is put into the urine.
One example is glucose. The most common reason for the glucose renal threshold ever being exceeded is diabetes; the condition is called glycosuria.
glycosuria
Glucose in the urine, a well-known sign of diabetes mellitus.
diuretic
any substance that promotes diuresis, the increased production of urine
hypertonic vs hypotonic
with salt in the solution
The hypertonic is more salty and the hypotonic is less salty.
renin-angiotensin-aldosterone system (RAAS)
A hormone system within the body that is essential for the regulation of blood pressure and fluid balance. The system is mainly comprised of the three hormones renin, angiotensin, and aldosterone. Primarily it is regulated by the rate of renal blood flow.
atrial natriuretic hormone (ANH)
A hormone secreted from the heart’s atrial wall. ANH stimulates kidney tubules to secrete more sodium and thus lose more water. It also increases urine volume as a result. Its main function is to lower blood pressure and to control electrolyte homeostasis.
natriuresis
adjective: natriuretic
excessive loss of sodium in the urine
anuria vs oliguria vs polyuria
- Anuria—absence of urine
- Oliguria—scanty amount of urine
- Polyuria—unusually large amount of urine
I&O
Abbreviation used in clinical medicine to indicate the measurement of fluid intake and urine output over a period of time.
Because a change in urine volume or output is a significant indicator in many types of fluid alterations and diseases, measurement of both fluid intake and fluid output (urine volume) over a specified period of time, often abbreviated as I & O, is a common practice in clinical medicine.
renal calculi
Also called kidney stones.
Kidney stones are hard deposits of minerals and acid salts that stick together in concentrated urine. They can be painful when passing through the urinary tract.
lithotripsy
A procedure that uses shock waves to break up stones in the kidney and parts of the ureter (tube that carries urine from your kidneys to your bladder). After the procedure, the tiny pieces of stones pass out of your body in your urine.
The device used to do this is called a lithotriptor.
renal colic
It is pain caused by the passage of a kidney stone.
The term “colic” is used because of its similarity to painful cramps sometimes experienced in the muscle layers of the colon.
pubic symphysis
a joint that sits centered between the pubic bones
prostate
The prostate is a walnut-sized gland located between the bladder and the penis. The prostate is just in front of the rectum. The urethra runs through the center of the prostate, from the bladder to the penis, letting urine flow out of the body.
The prostate secretes fluid that nourishes and protects sperm. During ejaculation, the prostate squeezes this fluid into the urethra, and it’s expelled with sperm as semen.
trigone
a triangular region or tissue, particularly the area at the base of the urinary bladder, between the openings of the ureters and urethra
urinary meatus
also known as the external urethral orifice
It is the opening of the urethra. It is the point where urine exits the urethra in males and in females and where semen exits the urethra in males.
orifice
an opening, as of a pipe or tube, or one in the body, such as a nostril or the anus
cystitis
inflammation of the bladder, usually caused by a bladder infection
infection control manager
A person who develops and implements infection control policies designed to reduce or eliminate outbreaks in a facility.
epidemiology
the branch of medical science that investigates all the factors that determine the presence or absence of diseases and disorders
micturition
another name for urination
voiding
another name for urination or defecation
urethral sphincter
A muscular structure that regulates the outflow of urine from the bladder into the urethra. There are 2 urethral sphincters: the external and internal urethral sphincters.
When contracted, both sphincters seal off the bladder and allow urine to accumulate without leaking to the exterior. The internal urethral sphincter is involuntary, and the external urethral sphincter is composed of striated muscle and is under voluntary control.
emptying reflex
A reflex involved in urination.
As the bladder wall stretches, nerve impulses are transmitted to the second, third, and fourth sacral segments of the spinal cord, and an emptying reflex is initiated. The reflex causes contraction of the muscle of the bladder wall and relaxation of the internal sphincter. Urine then enters the urethra. If the external sphincter, which is under voluntary control, is relaxed, urination occurs. Voluntary contraction of the external sphincter suppresses the emptying reflex until the bladder is filled to capacity with urine and loss of control occurs. Contraction of this powerful sphincter also abruptly terminates urination voluntarily.
urinary retention vs urinary suppression
Urinary retention is a condition in which no urine is voided. The kidneys produce urine, but the bladder, for one reason or another, cannot empty itself.
In urinary suppression the opposite is true. The kidneys do not produce any urine, but the bladder retains the ability to empty itself.
enuresis
Involuntary urination, especially by children at night.
Nocturnal enuresis, or bed-wetting at night, is the most common type of elimination disorder.
Daytime wetting is called diurnal enuresis.
Some children experience either or a combination of both.
urinary incontinence
The loss of bladder control, or being unable to control urination.
Urge incontinence occurs when you have a strong, sudden need to urinate that is difficult to delay. It is associated with smooth muscle overactivity 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 an 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 usually occurs in people with a neurological condition or those with a spinal cord problem.
distended
enlarged, expanded, or stretched out (as from internal pressure)
neurogenic bladder
A condition in which problems with the nervous system affect the bladder and urination. Conditions like stroke and Parkinson’s disease can result in neurogenic bladder. Treatment options include drug therapy and surgery.
proteinuria
The presence of plasma proteins in the urine. It is sometimes an indication of renal disease, but can also be caused by heavy exercise.
nephropathy
It is the deterioration of kidney function. The final stage of nephropathy is called kidney failure or end-stage renal disease (ESRD). According to the CDC, diabetes is the most common cause of ESRD.
urinalysis
The physical, chemical, and microscopic examination of urine.
creatinine
A byproduct of a chemical compound called creatine, which helps muscles get the energy that they need. As a waste product, creatinine is filtered out of the blood by the kidneys and removed from the body in urine. A creatinine test measures the amount of this chemical in either the blood or urine.
uric acid
A waste product found in blood. It’s created when the body breaks down nitrogen-containing chemicals called purines. Most uric acid dissolves in the blood, passes through the kidneys and leaves the body in urine. Food and drinks high in purines also increase the level of uric acid.
ammonia
It is a colorless gas made up of nitrogen and hydrogen with a distinct odor. It is a building-block chemical and a key component in the manufacture of many products people use every day. It occurs naturally throughout the environment in the air, soil and water and in plants and animals, including humans. The human body makes ammonia when the body breaks down foods containing protein into amino acids and ammonia, then converting the ammonia into urea.
building block
a unit of construction or composition
especially: something essential on which a larger entity is based
heterocyclic compound
also called ring structure
It is a cyclic compound that has atoms of at least two different elements as members of its ring(s).
cyclic compound
a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring
