Urinary System Flashcards
What are the 8 functions of the urinary system?
- Formation of calcitriol
- Production and release of erythropoietin
- Regulation of ion levels and acid–base balance
- Control of blood pressure
- Involvement in gluconeogenesis
- Elimination of metabolic waste and biologically active molecules
- Anatomical variations and anomalies of kidneys
- Supportive structures surrounding kidneys
What is calcitriol?
A hormone formed by the kidneys that regulates calcium levels in the body.
What is erythropoietin?
A hormone produced by the kidneys that stimulates red blood cell production.
How do the kidneys regulate ion levels?
By balancing electrolytes such as sodium, potassium, and calcium.
What role do the kidneys play in blood pressure control?
They regulate blood volume and release hormones that influence blood pressure.
What is gluconeogenesis in relation to the kidneys?
The process of producing glucose from non-carbohydrate sources in the kidneys.
What types of waste do the kidneys eliminate?
- Urea
- Uric acid
- Creatinine
- Certain drugs
- Certain bioactive substances
What is renal ptosis?
A condition where a kidney drops from its normal position.
Describe the retroperitoneal position of the kidneys.
The kidneys are located behind the peritoneum along the posterior abdominal wall.
What are the major anatomical parts of the kidney?
- Renal cortex
- Renal medulla
- Renal pyramids
- Renal columns
- Renal papillae
- Renal lobes
- Renal pelvis
- Minor calyces
- Major calyces
What is the nephron?
The functional unit of the kidney responsible for urine formation.
What are the two types of nephrons?
- Cortical nephrons
- Juxtamedullary nephrons
What is the function of the collecting ducts?
To transport urine from the nephrons to the renal pelvis.
Describe the juxtaglomerular apparatus.
It regulates blood pressure and filtration rate in the kidneys.
What is the flow order of blood through the kidney?
- Renal artery
- Segmental artery
- Interlobar artery
- Arcuate artery
- Interlobular artery
- Afferent arteriole
- Glomerulus
- Efferent arteriole
- Peritubular capillaries
- Vasa recta
- Interlobular vein
- Arcuate vein
- Interlobar vein
- Renal vein
What are the three processes of urine formation?
- Filtration
- Reabsorption
- Secretion
What is glomerular filtration?
The process of filtering blood to form urine in the glomerulus.
What occurs during tubular reabsorption?
Substances are reabsorbed from the tubular fluid back into the blood.
What is tubular secretion?
The process of transferring substances from the blood into the tubular fluid.
What are the components of the filtration membrane?
- Endothelium
- Basement membrane
- Visceral layer of the glomerular capsule (podocytes)
Define glomerular hydrostatic pressure.
The pressure exerted by blood in the glomerulus that drives filtration.
What is the net filtration pressure?
The pressure that determines the rate of filtration in the glomerulus.
What is glomerular filtration rate (GFR)?
The rate at which blood is filtered in the glomeruli of the kidneys.
What factors affect GFR?
- Blood pressure
- Blood volume
- Hormonal regulation
What intrinsic controls affect GFR?
- Myogenic mechanism
- Tubuloglomerular feedback mechanism
What hormones influence GFR?
- Renin (angiotensin II)
- Atrial natriuretic peptide (ANP)
What is the transport maximum?
The maximum rate at which a substance can be reabsorbed.
What is renal threshold?
The plasma concentration at which a substance begins to appear in urine.
What is glucosuria?
The presence of glucose in urine, often due to high blood sugar.
List substances regulated in renal reabsorption.
- Na+
- H2O
- K+
- Ca2+
- PO43−
- HCO3−
- H+
What are the mechanisms for adjusting urine concentration?
- Countercurrent multiplier mechanism
- Countercurrent exchange mechanism
What is the significance of urine concentration adjustment?
It allows the body to conserve water and maintain homeostasis.
What are renal calculi?
Kidney stones formed from minerals and salts in urine.
What is a urinary tract infection (UTI)?
An infection in any part of the urinary system.
Define micturition.
The process of urination or expelling urine from the bladder.
What is the primary function of the kidneys?
Filter blood, remove waste products, and convert the filtrate into urine.
What is the role of the ureters in the urinary system?
Transport urine to the urinary bladder.
What is the function of the urinary bladder?
An expandable, muscular sac that stores urine until it is eliminated.
What is the purpose of the urethra?
Eliminate urine from the body.
What metabolic wastes do the kidneys help eliminate?
Urea and uric acid.
How do the kidneys regulate ion levels in the blood?
By regulating Na+, K+, Ca2+, and PO43− ion levels.
What is the role of the kidneys in maintaining acid-base balance?
Altering H+ and HCO3− levels in the blood.
How do the kidneys contribute to blood pressure regulation?
By excreting excess fluid and releasing renin.
What is renin and its function?
An enzyme required for angiotensin II production, which increases blood pressure.
What types of molecules do the kidneys eliminate besides waste?
Biologically active molecules such as hormones and drugs.
What hormone do the kidneys secrete in response to low blood oxygen levels?
Erythropoietin.
What is the function of erythropoietin?
Stimulates red bone marrow to increase erythrocyte formation.
What hormone synthesis is involved in calcium absorption?
Calcitriol.
What process may the kidneys engage in to maintain glucose levels?
Gluconeogenesis.
Fill in the blank: The kidneys convert filtrate into _______.
urine
True or False: The urinary bladder is a non-expandable sac.
False
Where is the left kidney located in relation to the vertebrae?
Between the T12 and L3 vertebrae
How does the position of the right kidney compare to the left kidney?
Approximately 2 cm inferior to the left kidney
In what anatomical space are the kidneys located?
Retroperitoneal space
What covers only the anterior surface of the kidneys?
Parietal peritoneum
What is the function of the kidney’s fibrous capsule?
Maintain shape, protect from trauma, and prevent infectious pathogen insult
What type of connective tissue composes the kidney’s fibrous capsule?
Dense irregular connective tissue
What provides cushioning to the kidneys?
Perinephric fat layer
What is the renal fascia?
Dense irregular connective tissue layer that anchors the kidney to surrounding structures
What is the paranephric fat layer?
Outermost layer of the kidney composed of adipose connective tissue that provides cushioning
What condition is referred to as renal ptosis?
Drop or inferior movement of the kidney
What can cause renal ptosis?
Loss of support from the adipose connective tissue layer due to extreme weight loss or in the elderly
What may happen to the ureter as a result of renal ptosis?
It may kink, causing a decrease or blockage of urine flow
What is hydronephrosis?
Back up of urine into the kidney due to blockage
What can untreated hydronephrosis lead to?
Renal failure
What is renal ptosis?
Renal ptosis occurs when there is a drop or inferior movement of the kidney
Renal ptosis can lead to complications such as hydronephrosis.
What causes renal ptosis?
Renal ptosis may be due to loss of support from the adipose connective tissue layer as a result of:
* Extreme loss of weight
* Anorexia nervosa
* Aging
What complication can arise from renal ptosis?
The ureter may kink, causing a decrease or blockage of urine flow from the kidney to the urinary bladder.
What can happen if urine backs up into the kidney due to renal ptosis?
It can cause hydronephrosis, which if not treated, will lead to renal failure.
True or False: Renal ptosis can lead to hydronephrosis.
True
Fill in the blank: Renal ptosis occurs when there is a drop or _______ movement of the kidney.
[inferior]
What is renal agenesis?
The failure of the kidney to develop.
Renal agenesis can lead to various health complications depending on whether one or both kidneys are affected.
What is a pelvic kidney?
When the kidney fails to migrate from the pelvic cavity into the abdominal cavity.
This may result in complications related to urinary function and kidney positioning.
What is a horseshoe kidney?
When the inferior portion of both kidneys fuse.
This condition can affect kidney function and is often associated with other anatomical anomalies.
What are supernumerary kidneys?
When more than two kidneys develop.
Supernumerary kidneys can vary in function and may lead to urinary tract complications.
What is the outer region of the kidney’s parenchyma called?
renal cortex
What is the inner region of the kidney’s parenchyma called?
renal medulla
What are the extensions of the cortex that project into the medulla called?
renal columns
What are subdivisions of the renal columns called?
renal pyramids
What is the portion of the kidney where the external edge of the medulla meets the cortex called?
corticomedullary junction
What is the medially directed tip of the renal pyramid called?
renal papilla
The parenchyma can also be divided into _______ consisting of a renal pyramid, portions of adjacent renal columns, and the renal cortex external to the pyramid base.
8–15 renal lobes
What is the medially located space in each kidney called, which serves as the urine drainage area?
renal sinus
The renal sinus is organized into _______.
minor calyces, major calyces, and a renal pelvis
How many funnel-shaped minor calyces are associated with each renal pyramid?
8–15
What do several minor calyces merge to form?
two to three major calyces
What do the major calyces merge to form at the medial edge of the kidney?
a large funnel-shaped renal pelvis
What structures are housed within the space around the renal pelvis?
renal artery, renal vein, lymph vessels, nerves, and a variable amount of fat
What is the microscopic filtration unit of the kidney called?
Nephron
What are the two major structures that each nephron consists of?
- Renal corpuscle
- Renal tubule
Where do the renal corpuscles and most of the renal tubules reside?
Cortex of the kidney
What is the bulbous region of a nephron located within the renal cortex called?
Renal corpuscle
What two structures compose the renal corpuscle?
- Glomerulus
- Glomerular capsule
What is the glomerulus comprised of?
Conglomeration of capillary loops (glomerular capillaries)
How does blood enter and exit the glomerulus?
- Enters by afferent arteriole
- Exits through efferent arteriole
What is another name for the glomerular capsule?
Bowman capsule
What are the two layers of the glomerular capsule?
- Internal, permeable visceral layer
- External, impermeable parietal layer
What is the space between the visceral layer and parietal layer of the glomerular capsule called?
Capsular space
What are the two poles of the renal corpuscle?
- Vascular pole
- Tubular pole
What type of epithelium composes the renal tubule?
Simple epithelium on a basement membrane
What are the three continuous sections of the renal tubule?
- Proximal convoluted tubule (PCT)
- Nephron loop
- Distal convoluted tubule (DCT)
What is the first region of the renal tubule that is lined with simple cuboidal epithelium and apical microvilli?
Proximal convoluted tubule (PCT)
What are the two limbs of the nephron loop called?
- Ascending limb
- Descending limb
What type of epithelium lines the thin segments of the nephron loop?
Simple squamous epithelium
What type of epithelium lines the thick segments of the nephron loop?
Simple cuboidal epithelium
What is the region of the renal tubule that originates from the thick ascending limb of the nephron loop?
Distal convoluted tubule (DCT)
How many types of nephrons are there?
Two types
What are nephrons with a relatively short nephron loop that make up the bulk of the cortex called?
Cortical nephrons
What percentage of nephrons are cortical nephrons?
About 85%
What are nephrons with relatively long nephron loops that aid in the establishment of salt concentration gradients called?
Juxtamedullary nephrons
True or False: Juxtamedullary nephrons help regulate urine concentration by ADH.
True
