Urinary (Lecture) Flashcards
Main long term organ for maintaining blood pressure:
kidneys
Organs of the urinary system:
kidneys, ureters, urinary bladder (urocyst), urethra, specialized blood vessels
Two regions of the kidney:
renal cortex (outer), renal medulla
What part of the kidney forms a network of tubes?
Renal pyramids
The tubes that form the renal pyramids are called:
collecting ducts
Basic structural and functional unit of the kidney:
nephron
You have about ____ number of nephrons at birth.
three million
Parts of nephron in macro:
renal corpuscle and tubular component
Network of capillaries tucked into Bowman’s capsule:
glomerulus
Structure that holds the blood vessels:
Bowman’s capsule or glomerular capsule
Three basic functions of the nephron:
glomerular filtration, tubular reabsorption, tubular secretion
Urine formation requires what three steps?
glomerular filtration, tubular reabsorption, tubular secretion
Blood vessel that feeds into the glomerulus:
afferent arteriole
Filtering takes place in the:
glomerulus
Blood vessel that drains the glomerulus:
efferent arteriole
Efferent arteriole feeds into the:
peritubular capillaries (surround the nephron)
The peritubular capillaries feed into the:
veins…renal vein and eventually the inferior vena cava
Reabsorption and secretion occur in the:
nephron and peritubular capillaries (allows the kidneys to carry out its function)
The filtering membrane is a combination of:
Bowman’s capsule and blood vessels of the glomerulus
Three components of the filtering membrane:
capillary endothelium, basement membrane, podocyte cells that form filtration slits (trap medium sized proteins)
What is the first step in urine formation?
glomerular filtration
Term for the transfer of fluid and solutes from the glomerular capillaries into Bowman’s capsule due to pressure gradient:
glomerular filtration
Movement of molecules from high pressure to low pressure:
filtration
Examples of passive biotransport:
diffusion, osmosis, filtration
What do you need for filtration (basics):
pressure and a selectively permeable membrane
“cells with feet”
podocytes
What is filtered by glomerular filtration (stays in blood)?
cells, proteins, and protein-bound substances
What gets through filtration by glomerular filtration?
water, electrolytes, low-weight molecular substances
The driving force that creates the pressure needed for filtration is mainly from:
blood (pressure)
Pressure of plasma is called:
blood hydrostatic pressure
If anything affects ____ it will effect filtration.
pressure
Chief indicator for how well the kidneys are functioning: volume of plasma filtered from both kidneys per minute:
Glomerular Filtration Rate
Normal GFR (prevents uremia if functioning properly)
125ml/min
Plasma volume is filtered approximately ____ times per day.
60
Many of the wastes accumulated in the body are _____ which are produced by the body.
metabolic wastes
When metabolic rate goes up you produce ____ waste products and need to _____ glomerular filtration.
more; increase
When substances cannot be reabsorbed quickly enough and are lost in the urine:
GFR is too high
When everything is reabsorbed, including wastes that are normally disposed of:
GFR is too low
Three mechanisms that control the GFR primarily by controlling blood pressure:
renal autoregulation, hormonal, neural
Network of structures next to the glomerulus that carries out the process of filtration control by carrying out renal autoregulation:
juxtaglomerular complex
What system monitors the pressure for filtration?
juxtaglomerular complex
What monitors how much urine/fluid flows past the distal convoluted tubule?
macula densa
What monitors how much urine/fluid flows through the distal convoluted tubule?
macula densa
Special smooth muscle cells that release hormones (factors) if pressure has dropped:
juxtaglomerular cells
When the juxtaglomerular cells relax, the afferent arteriole _____ allowing more blood to enter the glomerulus. Thus causing the ____ arteriole to _____.
relax (dilate); efferent; constrict
Backup of fluid in the glomerulus:
backpressure (increases blood being filtered and waste products being removed)
Process of self control by the glomerulus:
autoregulation
Allows the kidney to maintain its own pressure despite systemic pressure reading:
autoregulation
Kidneys can only _____ pressure they can’t create it.
adjust
If the autoregulatory component doesn’t work, the kidney can produce ____.
hormones (usually due to a drop in blood pressure which leads to a drop in filtration)
Hormone released by kidney:
renin
Renin mixes with chemicals from the liver and creates:
angiotensin
Angiotensin is converted by the lungs to:
angiotensin II
Target tissues of angiotensin:
blood vessels (arterioles)–cause arterioles in body to vasoconstrict (largest influence on pressure–increases blood pressure), brain (hypothalamus triggers thirst to increase blood volume), adrenal gland (adrenal cortex–triggers release of aldosterone)
increasing blood pressure, increases:
filtration
Hormone that causes you to retain sodium which results in retaining water:
aldosterone
Chain of events caused by angiotensin:
increase blood pressure, increase water retention, increase filtration–to remove waste at a normal rate to maintain homeostasis
ace-inhibitor
blocks lungs from creating angiotensin so blood pressure isn’t raised
What always follows salt?
H2O
Process where water carries the solutes back to the bloodstream
solvent drag
solvent =
water
solute =
sodium, potassium, magnesium
Solvent drag can’t be activated without the:
sodium-potassium ion pump
What hormone triggers sodium and water reabsorption?
aldosterone
Aldosterone comes from:
adrenal glands
Method for getting rid of chemicals that can’t fit through the filtering membrane, waste products (additional uric acid and urea), H+, ammonia, nitrogen, excess potassium
tubular secretion
How does the nephron maintain/prevent large fluctuations in pH of the blood?
tubular secretion (prevents acidosis and alkalosis)
What two processes control the composition and volume of urine?
tubular reabsorption and tubular secretion
micturition
process of removing urine from the body
Sphincters of the bladder:
internal urethral sphincter, external urethral sphincter
The internal urethral sphincter is made of:
smooth muscle (involuntary)
The external urethral sphincter is made of:
skeletal muscle (voluntary)
Muscular wall of the bladder is called:
detrusor muscle
The wall of the bladder contains:
specialized stretch receptors
Voluntarily choosing to retain urine causes what to contract?
external urethral sphincter
Which urethral sphincter is involuntary?
internal urethral sphincter
Where is the micturition reflex center?
sacral region of the spinal cord (in the event of a spinal cord injury, the brain never receives messages to control the external urethral sphincter)
The renal corpuscle contains what two structures?
Bownman’s capsule and glomerulus
The renal tubule contains what four segments?
proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting tubule
Movement of substances out of the renal tubules into the peritubular capillaries:
reabsorption
The process by which substances move into urine forming in the distal and collecting tubules from blood in the peritubular capillaries:
secretion
