THE URINARY SYSTEM Flashcards
filters nitrogenous wastes from the blood and helps regulate water, electrolyte, and acid-base balances
The Urinary System
produced by the kidneys to help regulate blood pressure and produces angiotensin II
Renin
released by the kidneys to stimulate red blood cell production in the bone marrow
Erythropoetin
What are the functions of the kidneys?
- disposes wastes and excess ion
- regulate blood volume and maintain proper balance between water and salts, and between acids and bases
- produce renin and release erythropoetin
- convert vitamin D produced in the skin to it’s active form
What are the organs of the urinary system?
- Kidneys (main organs)
- Paired ureters
- Urinary Bladder
- Urethra
What is the function of the other organs of the urinary system (excluding the the kidneys)?
provide temporary storage for urine or serve as transportation channels to carry it from the kidneys to the outside of the body
Location of the Kidneys
- lie against the dorsal body wall in a retroperitoneal position in the superior lumbar region
- extend from the T12 to the L3 vertebra
behind the parietal peritoneum
retroperitoneal position
Which kidney is lower and why?
the right kidney is slightly lower because it is crowded by the liver
What is the size of the kidneys?
12cm long, 6cm wide, and 3cm thick
medial indentation in the kidneys where several structures such as the ureters, renal blood vessels and nerves enter or exit the kidneys
Renal Hilum
sits on top of each kidney
Adrenal Gland
deepest layer of the kidney; encloses each kidney and gives it a glistening appearance
Fibrous Capsule
middle layer of the kidney; fatty mass that surrounds each kidney and cushions it against blows
Perirenal Fat Capsule
most superficial layer made of dense fibrous connective tissue; anchors kidney and adrenal gland to surrounding structures
Renal Fascia
caused when amount of fatty tissue dwindles and kidneys drop to a lower position; creates problems if the ureters become kinked
Ptosis
happens when urine that can no longer pass through the ureters backs up and exerts pressure on the kidney tissues; can severely damage the kidneys
Hydronephrosis
outer region; dark in colour
Renal Cortex
darker reddish brown area deep to the cortex
Renal Medulla
triangular regions with a striped appearance in the renal medulla
Renal or Medullary Pyramids
separates the renal pyramids
Renal Columns
lateral to the hilum; flat, funnel-shaped tube; continuous with the ureter leaving the hilum
Renal Pelvis
extensions of the pelvis; form cup-shaped drains that enclose the pyramid and collects urine
Calyces
artery supplying each kidney
Renal Artery
structural and functional units of the kidneys; responsible for forming urine
Nephrons
collects fluids from several nephron and conveys it to the calyces and renal pelvis
Collecting Ducts
two main structures of a nephron
renal corpuscle and renal tubule
found in each renal corpuscle; knot of capillaries and specialises in filtration
Glomerulus
part of the renal corpuscle; cup-shaped hollow structure that surrounds the glomerulus
Glomerular Capsule or Bowman’s Capsule
highly modified octopus-like cells that make up the inner visceral layer of the capsule
Podocytes
long branching extensions that intertwine with one another and cling to the glomerulus
Foot Processes
found between foot processes; allow podocytes to form a porous or leaky membrane around the glomerulus ideal for filtration
Filtration Slits
extends from the glomerular capsule and coils and twists before forming a hairpin loop then coils and twists again before entering a collecting duct
Renal Tubule
What are the regions of the renal tubule in order from the glomerular capsule?
- Proximal Convoluted Tubule (PCT)
- Nephron Loop or Loop of Henle
- Distal Convoluted Tubule (DCT)
covers and increases surface tension of tubule cells exposed to the filtrate in the PCT; found in reduced numbers in other parts of the renal tubule
Microvilli
what most nephrons are called; located almost entirely within the cortex
Cortical Nephrons
nephrons situated close to the cortex-medullary junction; nephrons loops dig deep into the medulla
Juxtamedullary Nephrons
feeds the glomerulus; arises from a cortical radiate artery
Afferent Arteriole
receives blood as it leaves the glomerulus
Efferent Arteriole
low-pressure, porous vessels adapted for absorption; receives solutes and water from tubule cells
Peritubular Capillaries
Urine formation is the result of which three processes?
Glomerular Filtration, Tubular Reabsorption, and Tubular Secretion
nonselective, passive process where water and solutes smaller than proteins are forces through the capillary walls and pores of the glomerular capsule into the renal tubule
Glomerular Filtration
fluid in the capsule; essentially blood plasma without blood proteins
Filtrate
abnormally low urinary output between 100 and 400 ml/day
Oliguria
abnormally low urinary output less than 100 ml/day
Anuria
begins when filtrate enters the PCT; water, glucose, amino acids, and needed ions are transported out of the filtrate into the tubule cells and then enters into the capillary blood
Tubular Reabsorption
H+, K+, creatinine, and drugs are removed from the peritubular blood and secreted by tubule cells into the filtrate; important for getting rid of substances not already in the filtrate
Tubular Secretion
poorly or not reabsorbed; tend to remain in high concentrations in urine excreted from the body
Nitrogenous Wastes
formed by the liver as an end product of protein breakdown when amino acids are used to produce energy
Urea
released when nucleic acids are metabolised
Uric Acid
associated with creatine metabolism in muscle tissue
Creatinine
what remains of the filtrate; contains nitrogenous wastes and unneeded or excess substances
Urine
pigment that results from the body’s destruction of hemoglobin; causes urine to be yellow
Urochrome
compares how much heavier urine is than distilled water
Specific Gravity
condition where the kidney loses its ability to concentrate urine
Chronic Renal Failure
kidney inflammation that causes production of concentrated urine with a high specific gravity
Pyelonephritis
Substance: Glucose
Name of Condition: Glycosuria
Causes:
-Nonpathological: excessive intake of sugary foods
-Pathological: diabetus mellitus
Substance: Proteins
Name of Condition: Proteinuria or Albuminuria
Causes:
-Nonpathological: physical exertion, pregnancy
-Pathological: glomerulonephritis, hypertension
Substance: Pus (WBCs and bacteria)
Condition: Pyuria
Cause: urinary tract infection (UTI)
Substance: Red Blood Cells
Condition: Hematuria
Causes: bleeding in the urinary tract (due trauma, kidney stones, infection)
Substance: Hemoglobin
Condition: Hemoglobinuria
Causes: various causes such as transfusion reaction, hemolytic anemia
Substance: Bile pigment
Condition: Bilirubinuria
Cause: Liver disease (hepatitis)
carry urine from the kidneys to the bladder
Ureters
how smooth muscle layers in ureter walls propel urine
Peristalsis
crystals formed by solutes such as uric acid salts that precipitate in the renal pelvis when urine becomes extremely concentrated
Renal Caliculi or Kidney Stones
What causes caliculi formation?
Frequent bacterial infections of the urinary tract, urinary retention, and alkaline urine
noninvasive procedure that uses ultrasound waves to shatter caliculi
Lithostripy
smooth, muscular sac that stores urine temporarily
Urinary Bladder
two ureter openings
Ureteral Orifices
singular opening of the urethra which drains the bladder
Internal Urethral Orifice
smooth triangular region of the bladder outlined by its three openings; where infections tend to persist
Trigone
surrounds the neck of the bladder where it empties into the urethra
Prostate
collective term for three layers of smooth muscle on the bladder wall
Detrusor Muscle
epithelium of detrusor muscle
Transitional Epithelium
thin-walled tube that carries urine by peristalsis from the bladder to the outside of the body
Urethra
at the bladder-urethra junction; keeps urethra closed when urine is not being passed
Internal Urethral Sphincter
formed by skeletal muscle as the urethra passes through the pelvic floor; voluntarily controlled
External Urethral Sphincter
inflammation of the urethra
Urethritis
inflammation of the bladder
Cystitis
kidney inflammation
Pyelonephritis or Pyelitis
Symptoms of UTI
dysuria, urinary urgency and frequency, fever, cloudy or blood-tinged urine
painful urination
Dysuria
act of emptying the bladder
Micturition or Voiding
transmits impulses to the sacral region of the spinal cord and back to the bladder
Pelvic Splanchnic Nerves
occurs when a person is unable to voluntarily control the external sphincter
Incontinence
bladder is unable to expel its container urine
Urinary retention
enlargement of an organ or tissue
Hyperplasia
slender, flexible tube inserted through the urethra to drain the urine and prevent bladder trauma from excessive stretching
Catheter
Three major factors that affect the composition of blood:
diet, cellular metabolism, and urine output
Four major roles of the kidneys:
- excreting nitrogen-containing wastes
- maintaining water balance of the blood
- maintaining electrolyte balance of the blood
- ensuring proper blood pH
percentage of water in young adults
60% in men, 50% in women
percentage of water in babies
75%
percentage of water in old age
45%
What is the full flow of blood through the kidneys?
Aorta - Renal Artery - Segmental Artery - Interlobar Artery - Arcuate Artery - Cortical Radiate Artery - Afferent Arteriole - Glomerulus - Efferent Arteriole - Cortical Radiate Vein - Arcuate Vein - Interlobar Vein - Renal Vein - Inferior Vena Cava
universal body solvent within which all solutes are dissolved
water
fluid compartment where two-thirds of body fluid is contained within the living cells
intracellular fluid (ICF)
includes all body fluids located outside the cells
extracellular fluids
What are the fluids involved in ECF?
blood plasma, interstitial fluid (IF) between cells, lymph, and trancellular fluid (cerebrospinal and serous fluid, the humours of the eye, etc.)
fluids in chambers lined with epithelium
transcellular fluid
“highway” that links the internal and external environment
plasma
driving force for water intake
thirst mechanism
highly sensitive cells in the hypothalamus that activates the hypothalamic thirst center
osmoreceptors
How can water leave the body?
- vaporize out of the lungs (insensible water loss)
- lost in perspiration
- leaves the body in stool
How do the kidneys regulate fluid volume?
- if large amounts of water is lost, kidneys produce less urine
- if water intake is excessive, kidneys produce more urine
hormone that prevents excessive water loss in the urine; causes duct cells to reabsorb more water
antidiuretic hormone (ADH)
huge amounts of very dilute urine (25 ml/day) is flushed from the body
diabetus insipidus
What are the effects of diabetus insipidus?
- severe dehydration and electrolyte imbalances
- always thirsty and needs to drink fluids almost continuously to maintain normal fluid balance
happens when potassium ions in the ECF is low; muscle cells are unable to repolarize properly
muscle cramps
hormone produced by the adrenal cortex that is a major factor in regulating sodium ion content of the ECF and in the process, helps regulate the concentration of other ions
aldosterone
electrolytes most responsible for osmotic water flow
sodium ions
the most important trigger for aldosterone release
renin-angiotensin mechanism
mediates the renin-angiotensin mechanism
juxtaglomerular (JG) apparatus of the renal tubules
acts on the blood vessels to cause vasoconstriction and on the adrenal cortical cells to promote aldosterone release
angiotensin II
alert sympathetic nervous system centers if the brain to cause vasoconstriction via release of epinephrine and norepinephrine; major focus is blood pressure regulation
baroreceptors
people with this disease have polyuria; lose tremendous amounts of salt and water to urine
Addison’s Disease
when one excretes large amounts of urine
polyuria
when pH of arterial blood rises above 7.45
alkalosis
when pH of arterial blood is below 7.35
acidosis
any arterial pH level between 7.0 and 7.35
physiological acidosis
