13 Urogenital System Flashcards
Functions of the Urinary System
Elimination of waste products like
- Nitrogenous wastes
- Toxins
- Drugs
Functions of the Urinary System
Regulate aspects of homeostasis in terms of
- 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
location of the kidneys
- against dorsal body wall
- at the level of T12 to L13
Location of the Kidneys
The right kidney is slightly _ than
the left
lower
Location of the Kidneys
Attached to ureters, _,
and _ at renal hilus
renal blood vessels
nerves
Location of the Kidneys
Atop each kidney is an _
adrenal gland
Coverings of the Kidneys
- renal capsule
- adipose capsule
Coverings of the Kidneys
Surrounds each kidney
Renal capsule
Coverings of the Kidneys
- Surrounds the kidney
- Provides protection to the kidney
- Helps keep the kidney in its correct location
Adipose capsule
Regions of the Kidney
- renal cortex
- renal medulla
- renal pelvis
Regions of the Kidney
outer region
renal cortex
Regions of the Kidney
inside the cortex
renal medulla
Regions of the Kidney
inner collecting tube
renal pelvis
Kidney Structures
- medullary pyramids
- renal columns
- calyces
Kidney Structures
triangular regions
of tissue in the medulla
Medullary pyramids
Kidney Structures
extensions of cortexlike material inward
Renal columns
Kidney Structures
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
Nephrons
Nephrons are Responsible for forming _
urine
Main structures of the nephrons
- glomerulus
- renal tubule
- A specialized capillary bed
- attached to arterioles on both sides
- maintains high pressure
glomerulus
arterioles in glomerulus
- large afferent arteriole
- narrow efferent arteriole
Glomerulus
Capillaries are
covered with what type of cell
that is from
the renal tubule
podocytes
The glomerulus
sits within a _
(the first part of the
renal tubule)
glomerular capsule
Renal Tubule Components
- Glomerular (Bowman’s) capsule
- Proximal convolutedtubule
- Loop of Henle
- Distal convoluted tubule
2 Types of Nephrons
- Cortical nephrons
- Juxtamedullary nephrons
Types of Nephrons
Found at the boundary of the cortex and
medulla
Juxtamedullary nephrons
Types of Nephrons
- Located entirely in the cortex
- Includes most nephrons
Cortical nephrons
- Arise from efferent arteriole of the glomerulus
- Normal, low pressure capillaries
- Attached to a venule
- Cling close to the renal tubule
- Reabsorb (reclaim) some substances from collecting tubes
Peritubular Capillaries
3 Urine Formation Processes
- filtration
- reabsorption
- secretion
Filtration
- _ passive process
- Water and solutes _ than proteins are forced through capillary walls
- _ cannot pass out to the capillaries
- Filtrate is collected in the _ and leaves via the _
- Nonselective
- smaller
- Blood cells
- glomerular capsule
- renal tubule
Reabsorption
- The _ reabsorb several materials
Some water
Glucose
Amino acids
Ions - Some reabsorption is passive, most is _
- Most reabsorption occurs in the _
- peritubular capillaries
- active
- proximal convoluted tubule
Materials Not Reabsorbed
- nitrogenous waste products
* urea
* uric acid
* creatinine - excess water
Reabsorption in
Reverse
Secretion
Secretion
- Some materials move from the _ into the renal tubules; such as
- Materials left in the renal tubule move toward the _
- peritubular capillaries
- Hydrogen and potassium ions
- Creatinine
- ureter
Characteristics of Urine Used for
Medical Diagnosis
- Colored somewhat yellow due to the pigment urochrome (from the destruction of hemoglobin) and solutes
- Sterile
- Slightly aromatic
- Normal pH of around 6
- Specific gravity of 1.001 to 1.035
Ureter
- Slender tubes attaching the kidney to the bladder
- Continuous with the renal pelvis
- Enter the _ aspect of the bladder
- Runs behind the _
- _ aids gravity in urine transport
posterior
peritoneum
Peristalsis
- Smooth, collapsible, muscular sac
- Temporarily stores urine
Urinary Bladder
Urinary bladder is _ (3 openings)
trigone
2 from ureters
1 to urethra
Urinary Bladder Wall
- _ layers of smooth muscle
(detrusor muscle) - Mucosa made of _ epithelium
- Walls are _ in an empty bladder
- Bladder can expand significantly without increasing _
- Three
- transitional
- thick and folded
- internal pressure
Urethra
- Thin-walled tube that carries urine from the bladder to the outside of the body by _
- Release of urine is controlled by two sphincters
- peristalsis
- internal urethral sphincter -involuntary
- external urethral sphincter - voluntary
Urethra Gender Differences
length
- Females – 3–4 cm (1 inch)
- Males – 20 cm (8 inches)
Urethra Gender Differences
location
- Females – along wall of the vagina
- Males – through the prostate and penis
Urethra Gender Differences
function
- Females – only carries urine
- Males – carries urine and is a passageway for sperm cells
Both sphincter muscles must open to
allow _
Micturition (Voiding)
Micturition - process of urine excretion
Micturition (Voiding)
- The _ is relaxed after stretching of the bladder
- Activation is from an impulse sent to the spinal cord and then back via the _ nerves
- The external urethral sphincter must be _ relaxed
- internal urethral sphincter
- pelvic splanchnic
- voluntarily
Maintaining Water Balance
Normal amount of water in the human
body
- Young adult females – 50%
- Young adult males – 60%
- Babies – 75%
- Old age – 45%
Water is necessary for many body
functions and levels must be maintained
body fluids
- intracellular fluid - inside cells
- extracellular fluid - outside cells; interstitial fluid and blood plasma
Distribution of Body Fluid
- intracellular fluid -
- extracellular fluid -
- interstitial fluid -
- blood plasma -
total body water vol = 40 L, 60% body weight
* 25L, 40% BW
* 15L, 20% BW
* 12L, 80% of ECF
* 3L, 20% of ECF
The Link Between Water and Salt
Changes in _ balance causes water to move from one compartment to another
* Alters _
* Can impair the activity of cells
electrolyte
blood volume and blood pressure
Maintaining Water Balance
Water _ must equal water output
intake
Maintaining Water Balance
Sources for water intake
- Ingested foods and fluids
- Water produced from metabolic processes
Maintaining Water Balance
Sources for water output
- Vaporization out of the lungs
- Lost in perspiration
- Leaves the body in the feces
- Urine production
Maintaining Water Balance
_ urine is produced if water intake
is excessive
dilute
Maintaining Water Balance
Less urine (_) is produced if
large amounts of water are lost
concentrated
Maintaining Water Balance
Proper concentrations of various
_ must be present
electrolytes
Regulation of Water and Electrolyte Reabsorption
Regulation is primarily by hormones
* _ prevents excessive water loss in urine
* _ regulates sodium ion content of extracellular fluid
* Triggered by the _ mechanism
- Antidiuretic hormone (ADH)
- Aldosterone
- renin-angiotensin
Regulation of Water and Electrolyte Reabsorption
Cells in the kidneys and hypothalamus
are _ monitors
active
Maintaining Acid-Base Balance in Blood
Blood pH must remain between 7.35
and 7.45 to maintain homeostasis
if not_
Alkalosis - above 7.45
Acidosis - below 7.35
Maintaining Acid-Base Balance in Blood
Most ions originate as _ of
cellular metabolism
byproducts
Maintaining Acid-Base Balance in Blood
Most acid-base balance is maintained
by the _
kidneys
Maintaining Acid-Base Balance in Blood
Other acid-base controlling systems
- blood buffers
- respiration
Molecules react to prevent dramatic changes in hydrogen ion (H+) concentrations
how?
blood buffers
- Bind to H+ when pH drops
- Release H+ when pH rises
Blood Buffers
Three major chemical buffer systems
- Bicarbonate buffer system
- Phosphate buffer system
- Protein buffer system
The Bicarbonate Buffer System
mixture of?
- carbonic acid (H2CO3) and sodium bicarbonate (NaHCO3)
The Bicarbonate Buffer System
Bicarbonate ions (HCO –) react with
_ acids to change them to _ acids
strong
weak
The Bicarbonate Buffer System
Carbonic acid dissociates in the presence of a _ to form a _ and water
strong base
weak base
Respiratory System Controls of Acid-Base Balance
Carbon dioxide in the blood is converted to _ and transported in the plasma
bicarbonate ion
Respiratory System Controls of Acid-Base Balance
Increases in hydrogen ion concentration produces more _
carbonic acid
Respiratory System Controls of Acid-Base Balance
Excess hydrogen ion can be blown off with the release of _ from the lungs
carbon dioxide
Respiratory System Controls of Acid-Base Balance
Respiratory rate can rise and fall depending
on changing _
blood pH
Renal Mechanisms of Acid-Base Balance
- _ bicarbonate ions if needed
- _ new bicarbonate ions if needed
- Urine pH varies from _
- Excrete
- Conserve or generate
- 4.5 to 8.0
Developmental Aspects of the Urinary System
Functional kidneys are developed by
the _ month
third
Developmental Aspects of the Urinary System
Urinary system of a newborn
- Bladder is small
- Urine cannot be concentrated
Developmental Aspects of the Urinary System
Control of the voluntary urethral
sphincter does not start until age _
18 months
Developmental Aspects of the Urinary System
Urinary infections are the only common
problems before _
old age
Aging and the Urinary System
There is a progressive decline in urinary
function as we _
age
Aging and the Urinary System
The _ shrinks with aging
bladder
Aging and the Urinary System
Urinary retention is common in _
males
