Chapter 15 - Urinary System Flashcards
What are the Organs of the urinary system ?
Kidneys, ureters, urinary bladder, and urethra
Nephrons are the microscopic functional units of the kidneys
Where is the kidney located
Retroperitoneal in position
Lie behind the abdominal peritoneum
Either side of the vertebral column
Between the levels of the last thoracic vertebra and the third lumbar vertebra
Renal hilum
Concave depression of the kidney faces medially
Renal artery, renal vein, and ureter enter the kidney here
What are the 3 layers in the kidney?
3 layers of tissue surrounding each kidney
Layers protect the kidney against trauma, help give shape, and anchor the kidney
Deepest layer is the renal capsule
Middle layer is the adipose capsule
Outermost layer is the renal fascia
What are the 4 functions of the kidney?
Removing metabolic waste products from the blood
Combined with water and ions to form urine, which is excreted from the body
Hormone secretion (can be used as a doping drug)
Erythropoietin, which stimulates the red bone marrow to produce red blood cells
Enzyme renin, which helps regulate blood pressure and blood volume
Regulate blood pH
Synthesis
Vitamin D
Gluconeogenesis
What is Inner renal medulla-
Divided into triangular-shaped areas known as renal pyramids
Made up of a renal corpuscle and a tubular system
Blood comes in ?
in through renal artery and out through renal vein
Outermost renal cortex-
Covers the pyramids
Portion between pyramids is called a renal column
where most of the nephrons are found
Renal corpuscle
Nephrons are made up of the renal corpuscle and a tubular system
It is composed of a mass or tuft of capillaries called the glomerulus
Capsule that surrounds it is the glomerular capsule, also called Bowman’s capsule
Site of blood filtration
Parenchyma
The cortex and the medulla make it. Solid part of the kidney. Where waste excretion takes place and contains over a million nephrons
Renal tubules
Extend from the Bowman’s capsule and Collect the filtrate
Three parts of tubule Proximal convoluted tubule
Loop of Henle and Distal convoluted tubule
What are collecting ducts?
Distal convoluted tubules from several nephrons merge together to form collecting ducts.
Ducts transport urine to minor and major calyces.
Delivered to the renal pelvis
Empties urine into the ureters
Acute Renal Failure
Decreased or no urine production
Modify the diet to decrease the amount of protein consumed, controlling fluid intake and potassium levels
Sudden loss of kidney function
Chronic Renal Failure
Kidneys slowly lose their ability to function
Diabetes, hypertension, glomerulonephritis, polycystic kidney disease, renal stones, obstruction of the ureters, heart failure, and acute kidney failure
, white spots on the skin or increased pigmentation, hyperkalemia, an increased or decreased urine output,
Polycystic Kidney Disease (PKD)
Disorder in which the kidneys enlarge because of the presence of many cysts within them
Autosomal-dominant
Autosomal-recessive PKD-A rare developmental anomaly
Medications to control anemia and hypertension
kidney failure, and liver disease
Pyelonephritis
Complicated urinary tract infection
Caused by bacteria, bladder infection, renal calculi, or an obstruction of the urinary system ducts
nlarged kidneys, painful urination, and cloudy or bloody urine
Intravenous fluids, analgesics, and antibiotics
Renal Calculi/Kidney or Renal Stones
Gouty arthritis, defects of the ureters, overly concentrated urine, and urinary tract infections
Fever, nausea, severe back or abdominal pain, a frequent urge to urinate, hematuria, and abnormal urinalysis results
Pain medication, intravenous fluids, medications to decrease stone formation, surgery to remove kidney stones, and lithotripsy
Glomerulonephritis
Inflammation of the glomeruli of the kidneys
Bacterial infections, renal diseases, and immune disorders
Drowsiness, coma, seizures, nausea, anemia, hypertension, increased skin pigmentation, abnormal heart sounds, abnormal urinalysis results, hematuria, and decreased or increased urine output
Low-sodium, low-protein diet
Glomerular Filtration
Takes place in the renal corpuscles
Fluid part of blood is forced from the glomerulus into Bowman’s capsule, called glomerular filtrate
Glomerular filtration depends on 3 pressures…which ones? - first stage of urine formation
Takes place in renal corpuscles from glomerulus to bowmans capsule
Glomerular filtration pressure-Blood pressure in the glomerular capillaries
Capsular hydrostatic pressure-Acts in opposition to the glomerular pressure
Blood osmotic pressure - Acts in opposition to the glomerular pressure
How does Sympathetic nervous system (SNS) controls the rate of filtration
If blood pressure or blood volume drops, the SNS causes the afferent arterioles in the kidneys to constrict.
When constriction occurs, glomerular filtration pressure decreases and less glomerular filtrate is formed.
When less glomerular filtrate is formed, less urine is ultimately formed. Allowing the body to retain fluids that are needed to raise blood pressure and volume
What is Tubular reabsorption? 2nd stage of urine formation
Glomerular filtrate flows into the proximal convoluted tubule. All the necessary substances pass through the wall of the renal tubule into the blood of the peritubular capillaries. Water reabsorption varies depending on the presence of two hormones. Antidiuretic hormone (ADH and aldosterone
Tubular secretion 3rd stage of urine formation
Substances move out of the blood in the peritubular capillaries and into the renal tubules.
Secreted substances will be excreted.
Urine is mostly made of water.- Also contains , urea, uric acid, and various ions, creatinine
Glucose and proteins should not be found in the urine
Ureters
Tubes that drain urine from the kidneys, carrying the urine to the bladder.
Long, muscular tubes that propel urine through rhythmic muscular contractions called peristalsis.
Stored in the bladder until its expelled
Urinary Bladder
Distensible (expandable) organ that is located in the pelvic cavity just behind the pubic symphysis
Interior has folds in the mucosa called rugae that allow it to expand
Internal floor contains 3 openings
One for the urethra and one for each ureter
Form a triangle called the trigone
3 layers of bladder?
Innermost layer is mucosa made up of transitional epithelium
Middle layer is the muscular layer- pushes the urine out
Superficial layer is composed of connective tissue
Micturition
Urinary bladder distends as it fills with urine
Distension stimulates stretch receptors in the bladder wall.
Signaling the micturition center in the spinal cord
Parasympathetic nerves stimulate the detrusor muscle.
Begins rhythmic contractions that trigger the sense of the need to urinate
Brainstem and cerebral cortex -Send impulses to voluntarily contract the external urethral sphincter and to inhibit the micturition impulse
Upon the decision to urinate
External urethral sphincter is relaxed and impulses from the pons and hypothalamus start the micturition reflex
Contraction of the detrusor muscle occurs
Urine is expelled through the urethra.
Incontinence
An adult cannot control urination
Medications, excessive coughing, urinary tract infections, nervous system disorders, bladder cancer, prostate problems
Weakness of the urinary sphincters from surgery, trauma, or pregnancy
Primary symptom is the involuntary leakage of urine
Cystitis
Urinary bladder infection
Different types of bacteria or the placement of a catheter in the bladder
Urine is often cloudy and blood may be present in the urine
Antibiotics, pain medication, drink lots of clear liquids, and cranberry juice
When you get older?
Kidneys become smaller with age and are less efficient at filtering blood plasma
Blood flow to the kidneys also decreases
Infections, incontinence, renal calculi, and renal failure become more common as do dysuria, nocturia, and even hematuria
How does ADH regulate urine production?
produced by the posterior pituitary gland —increases the amount of water reabsorbed in the distal convoluted tubule and collecting duct
ADH causes decreased urine volume and decreased plasma osmolarity - Anti diuretic hormone - rid the body of excess fluid
How does aldosterone regulate urine production?
Aldosterone affects sodium, potassium, total fluid in the body, and blood pressure. Aldosterone causes the kidneys to hold onto more sodium, which leads to more water staying in the body. The more fluid the body holds onto, the higher the blood pressure may become. Potassium may decrease as the amount of aldosterone increases.
Lab tests
- Urea (BUN)
- Serum Creatinine
- Creatinine Clearance- blood and urine-24 hr
- Routine Urinalysis and C&S
- Serum Calcium and Phosphate
- Electrolytes –Na, K, Cl
- Urine 24hr protein
- Serum Urate (uric acid)
- Albumin
- Ammonia
- Osmolality
What do nephrons do
filter waste products from blood
what is the proximal convoluted tubule attached to
attached to the bowmans capsule and eventually straightens out to become the loop of henle which then becomes the distal convoluted tubule
what do the distal convoluted tubules form
they form the collecting ducts which collect urine to be delivered to the renal pelvis and empties into the ureter
Urethra
expels urine from bladder to outside
Renal capsule - what layer
deepest layer
protects against trauma
helps give shape
Adipose capsule - what layer
middle layer
made of fat, protects
holds kidney in place
Renal fascia- wht layer
outermost
protecting layer
anchors kidney to the abdominal wall
