Urinary system Flashcards
Functions of the Urinary System (2)
Elimination of waste products;
Regulate aspects of homeostasis
Elimination of waste products (3)
Nitrogenous wastes
Toxins
Drugs
urinary system Regulate aspects of homeostasis: (6)
Water balance
Electrolytes
Acid-base balance in the blood
Blood pressure
Red blood cell production
Activation of vitamin D
Organs of the Urinary system
Kidneys
Ureters
Urinary bladder
Urethra
Against the dorsal body wall
At the level of T12 to L3
kidneys
Attached to ureters, renal blood vessels,
and nerves at renal hilus
Atop each is an ___
kidney; adrenal gland
Coverings of the Kidneys
Renal capsule
Adipose capsule
covering that Surrounds each kidney
Renal capsule
Surrounds the kidney
Provides protection to the kidney
Helps keep the kidney in its correct location
Adipose capsule
Regions of the Kidney (3)
__- outer region
___-inside the cortex
___-inner collecting
tube
Renal cortex;
Renal medulla;
Renal pelvis
Kidney Structures (3)
Medullary pyramids
Renal columns
Calyces
– triangular regions
of tissue in the medulla
Medullary pyramids
– extensions of cortex
like material inward
Renal columns
– cup-shaped structures that
funnel urine towards the renal pelvis
Calyces
Blood Flow in the Kidneys
aorta;
renal artery;
segmental artery;
lobar artery;
interlobar artery;
arcuate artery;
interlobular artery;
afferent arteriole;
glomerulus (capillaries);
efferent arteriole;
peritubular capillaries and vasa recta;
interlobular vein;
arcuate vein;
interlobar vein;
renal vein;
inferior vena cava;
The structural and functional units of the kidneys; Responsible for forming urine
nephrons
Main structures of the nephrons
Glomerulus
Renal tubule
specialized
capillary be; Attached to
arterioles on both
sides (maintains
high pressure)
Glomerulus
___afferent
arteriole
___efferent
arteriole
Large;
Narrow
Capillaries are
covered with
____from
the renal tubule
glomerulus; podocytes
The glomerulus
sits within a
______
(the first part of the
renal tubule)
glomerular capsule
Renal Tubule (4)
Glomerular (Bowman’s) capsule;
Proximal convoluted tubule;
Loop of Henle
Distal convoluted tubule
Types of Nephrons (2)
Cortical nephrons
Juxtamedullary nephrons
Located entirely in the cortex
Includes most nephrons
Cortical nephrons
Found at the boundary of the cortex and
medulla
Juxtamedullary nephrons
Arise from efferent arteriole of the glomerulus
Normal, low pressure capillaries
Peritubular Capillaries
Attached to a venule; Cling close to the renal tubule; Reabsorb (reclaim) some substances
from collecting tubes
Peritubular Capillaries
Urine Formation Processes (3)
Filtration
Reabsorption
Secretion
Nonselective passive process; Water and solutes smaller than proteins are forced through capillary walls; Blood cells cannot pass out to the
capillaries
Filtration
Filtrate is collected in the ___ and leaves via the ___
glomerular capsule; renal tubule
reabsorption:
The ___ reabsorb several
materials (4)
peritubular capillaries;
Some water
Glucose
Amino acids
Ions
Somere absorption is ___, most is ___
Most reabsorption occurs in the ____
passive; active;
proximal convoluted tubule
Materials Not Reabsorbed (2)
-Nitrogenous waste products (3)
Urea
Uric acid
Creatinine
-Excess water
Some materials (2) move from the
peritubular capillaries into the renal tubules
Hydrogen and potassium ions
Creatinine
Materials left in the renal tubule move
toward the ___
ureter
Characteristics of Urine Used for Medical Diagnosis (5)
color (yellow due to urochrome and solutes);
Sterile
Slightly aromatic
Normal pH of around 6
Specific gravity of 1.001 to 1.035
Slender tubes attaching the kidney to
the bladder
Ureters
Continuous with the renal pelvis; Enter the posterior aspect of the bladder
ureter
Runs behind the peritoneum
___aids gravity in urine transport
ureter; Peristalsis
Smooth, collapsible, muscular sac; Temporarily stores urine
Urinary Bladder
___– three openings
Two from the ___
One to the ___
Trigone;
ureters;
urethrea
Urinary Bladder Wall:
Three layers of smooth muscle
(___ muscle)
Mucosa made of ____
detrusor;
transitional epithelium
Walls are thick and folded in an empty bladder
Bladder can expand significantly without
increasing internal pressure
Urinary Bladder Wall
Thin-walled tube that carries urine from
the bladder to the outside of the body by
peristalsis
Urethra
urethra Release of urine is controlled by two
sphincters:
Internal urethral sphincter (involuntary)
External urethral sphincter (voluntary)
Urethra Gender Differences
Length:
___– 3–4 cm (1 inch)
___– 20 cm (8 inches)
Females;
Males
Urethra Gender Differences
Location
Females– along ____
Males– through the ___
wall of the vagina;
prostate and penis
Urethra Gender Differences
Function
Females– only carries __
Males– carries ___and is a ___
urine;
urine; passageway for sperm cells
Both sphincter muscles must open to
allow __
Micturition (Voiding)
The ____is relaxed
after stretching of the bladder
internal urethral sphincter
Activation is from an impulse sent to the
___and then back via the ____
spinal cord;
pelvic splanchnic nerves
The external urethral sphincter must be ___relaxed
voluntarily
Normal amount of water in the human
body
Young adult females– __%
Young adult males– __%
Babies– __%
Old age– ___%
50;
60;
75;
45
Distribution of Body Fluid
Extracellular fluid volume= __L, __% body weight
-Interstitial fluid volume= __L, __% of ECF
- Plasma volume= _L, __% of ECF
Intracellular fluid volume= __L, __% body weight
Total body volume=__L, __% body weight
15, 20 bw;
12, 80 ecf;
3, 20 ecf;
25, 40 bw;
40, 60 bw
Sources for water intake
(2)
Ingested foods and fluids
Water produced from metabolic processes
Sources for water output (4)
Vaporization out of the lungs
Lost in perspiration
Leaves the body in the feces
Urine production
___is produced if water intake
is excessive
Dilute urine
___ is produced if
large amounts of water are lost
(concentrated) urine
Regulation of Water and Electrolyte Reabsorption hormones (2)
Antidiuretic hormone (ADH);
Aldosterone
this hormone prevents
excessive water loss in urine
Antidiuretic hormone (ADH)
this hormone regulates sodium ion content of
extracellular fluid
Aldosterone
aldosterone is Triggered by the ___
mechanism
rennin-angiotensin
Cells in the __ and __
are active monitors of Regulation of Water and Electrolyte
Reabsorption
kidneys and hypothalamus
Blood pH must remain between ___ to maintain homeostasis
7.35
and 7.45
___– pH above 7.45
___– pH below 7.35
Alkalosis;
Acidosis
Most ions originate as byproducts of
cellular metabolism
Most acid-base balance is maintained
by the ___
kidneys
Other acid-base controlling systems (2)
Blood buffers
Respiration
Molecules react to prevent dramatic
changes in hydrogen ion (H+)
concentrations
Blood Buffers
Blood Buffers:
___to H+ when pH drops
___H+ when pH rises
Bind ;
Release
Three major chemical buffer systems
Bicarbonate buffer system
Phosphate buffer system
Protein buffer system
Mixture of carbonic acid (H2CO3) and
sodium bicarbonate (NaHCO3)
Bicarbonate Buffer System
___ react with
strong acids to change them to weak
acids
Bicarbonate ions (HCO–)
___ dissociates in the presence
of a strong base to form a weak base and
water
Carbonic acid
___ in the blood is converted to
___ and transported in the
___
Carbon dioxide;
bicarbonate ion;
plasma
Increases in hydrogen ion concentration
produces more ___
carbonic acid
Respiratory rate can rise and fall depending
on changing ___
blood pH
Urine pH varies from ___
4.5 to 8.0
Functional kidneys are developed by
the __month
third
Control of the voluntary urethral
sphincter does not start until age ___
18 months
_____ is common in males
Urinary retention
