A&P2.12 - Urinary System Flashcards
Urinary System
List the major structures/organs of this system
- Kidneys
- Ureters
- Urinary bladder
- Urethra
Urinary System
List the major processes and important aspects of this system
- Urine production
- Urine
- Micturition
- Water balance
- Electrolytes
What are the kidneys?
functional unit of the urinary system
Kidneys
Describe the size, shape and location of these structures
Size: 4-5” long (bar of soap)
Shape: kidney bean shape
Location: Inferior, posterior rib cage
* L side slightly higher/R slightly lower due to the liver sitting above it
Kidneys
List the different functions
- Regulation:
** Blood volume and composition
** Blood pH
** Blood pressure - Stimulation of red blood cell production
Functions of the Kidney
Blood volume and composition
- Cells in hypothalamus sense changes in solute concentration of blood & stimulate kidney to respond
- increased concentration = retain H20
- decreased concentration = expel H20
Functions of the Kidney
Regulation of blood pH
By excreting or holding onto H+ ions, kidneys regulate blood’s pH
Acidic = expel H+
Basic = retain H+
Body pH range is 7.35-7.45
Functions of the Kidney
Regulation of Blood Pressure
- Kidneys can affect fluid volume of blood which determines blood pressure.
- Kidneys also secrete renin (enzyme) to induce vasoconstriction when BP is low
Functions of the Kidney
Stimulation of RBC Production
- Kidneys produce erythropoetin (hormone) that stimulates RBCs in red bone marrow => increased availability of hemoglobin
Kidneys - External Anatomy
List the different structures involved
- Renal hilus
- Renal capsule
- Adipose capsule
- Renal fascia
Kidneys - External Anatomy
Renal hilus
- Vertical cleft on medial side of kidney
- Entrance for blood vessels, nerves & tubes
Kidneys - External Anatomy
Renal capsule
Outer covering of CT that surrounds kidney and protects against infection (or spreading of)
Kidneys - External Anatomy
Adipose capsule
- covering of adipose tissue on outside of renal capsule
- Provides cushion & insulation for kidneys
- Anchors kidney to posterior abdominal wall
Kidneys - External Anatomy
Renal fascia
- Outermost layer of CT that runrs through the adipose capsule
- Creates structure and groups kidneys to adrenal glands
Kidneys - Internal Anatomy
List the 3 distinct regions of the internal kidney
- Cortex
- Medulla
- Pelvis
Kidneys - Internal Anatomy
List all of the structures involved in this region
- Renal cortex
- Renal medulla/pyramids
- Minor calyces
- Major calyces
- Renal pelvis
Kidneys - Internal Anatomy
Renal cortex
- Outermost region of internal portion
- Contains bulk of nephron
Kidneys - Internal Anatomy
Renal medulla/pyramids
- Deep to cortex
- Contains urine and collecting tubes
Kidneys - Internal Anatomy
Minor calyces
Urine drains from collecting tubes (specifically from renal papillae) into these structures and then drains into major calyces
Kidneys - Internal Anatomy
Major calyces
Receive urine from minor calyces before draining into renal pelvis
Kidneys - Internal Anatomy
Renal pelvis
- Lateral to hilus
- A smooth ms, funnel-shaped tube that leads into ureters
- Peristalsis (automatic smooth ms contraction) occurs here
Kidney
Blood Supply
- Kidneys need healthy blood spply to monitor and regulate
- 25% of cardiac output will arrive @ kidneys via renal arteries
- Once filtered, blood is delivered back to the heart via inferior vena cava
Kidney
Nephron
- Made up of blood vessels and tubes
- Produces urine
- Each kidney has over 1 million
- Made up of 2 regions
** Glomerulus
** Renal tubule
Kidney - Nephron
Glomerulus
- A collection of blood capillaries
- Blood filtratin occurs here
- Runs on hydrostatic pressure from blood pressure
Kidney - Nephron
Renal Tubule
- 1.25” long
- Made of 5 parts
- A tube of epithelial tissue which collects by-product of filtered blood => makes adjustments to produce urine
Kidney - Nephron - Renal Tubule
List the 5 regions of this structure
- Glomerular capsule
- Proximal convoluted tubule
- Loop of Henle or Nephron loop
- Distal convoluted tubule
- Collecting tubes
Kidney - Nephron - Renal Tubule - 5 Parts
Glomerular Capsule
Epithelial capsule surrounding glomerulus
Kidney - Nephron - Renal Tubule - 5 Parts
Collecting Tubes
Collect urine and deliver it to minor and major calyces
Urine Production
List the 3 steps of this process
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
Urine Production
Glomerular Filtration
- Blood is filtered through glomerulus by hydrostatic pressure
- Water & solutes are removed
- Formed elements & proteins remain in blood
Urine Production
Tubular Reabsorption
- 99% of H20 is reabsorbed back into blood along w/ some organic elements and electrolytes
- Only 1% of filtrate reamins
Urine Production
Tubular Secretion
Some waste still remaining in blood is secreted into renal tubule
Describe urine and some basic facts/characteristics of it
- Clear, yellowish fluid
- 95% water w/ electrolytes, wastes, uric acid & some drugs
- 1-2L expelled per day
- Solutes we should not see:
** RBCs (bleeding)
** WBCs (infection)
**Protein (pregnancy, high BP)
** High glucose (diabetes)
Ureters
- Long, thin tubes that drain urine from renal pelvis & bring to urinary bladder
- Outer layer is a smooth ms (peristalsis) which contracts every 10-20 seconds
Urinary Bladder
- Posterior to pubic symphysis
- A smooth ms, collapsible sac
- Stores 800-1,000mL of urine
- Urge to urinate occurs around 200mL to give us time in case unable to go immediately
- Stretch of walls causes internal sphincter to relax; we can control external sphincter
Urethra
- Mucous membrane lined structure that carries urine to outside of the body
- MM lining helps to prevent infection
Define micturition
Urination
Water Balance
List the different aspects of this
- Amount of H20 in body
- Muscle vs. fat
- Sources of water
- Elimination of water
Water Balance
Amout of H20 in Body
Average adult has about 40L of H20 in the body at any given time
Water Balance
Muscle vs. Fat
Muscle = 65% H20
Fat = 20% H20
Water Balance
This is a constant, ever-changing balance because…
Water is constantly moving back and forth between two main compartments of the body (always following salt and protein):
- intracellular
- extracellular
Intracellular = 2/3 of 40L distributed w/in cells
Extracellular = 1/3 of 40L outside of cells as interstitial fluid
Water Balance
Sources of Water
- Liquids consumed = 60%
- Food = 30#
- Metabolism = 10% (byproduct of aerobic cellular respiration)
Water Balance
Elimination of Water
Determind by osmotic pressure flow of H20 from high to low concentration
Electrolytes
Charged particles necessary for conduction of electrical signals
Ex:
- Sodium
- Magnesium
- Potassium
Massage & The Urinary System
Massage over kidneys
Deep pressure and tapotement are precautionary
Massage & The Urinary System
Massage and dialysis
Increased venous return may add additional stress to kidneys
Manual lymphatic drainage (MLD) is contraindicated to as not to overload kidneys and heart
