Excretory System Flashcards
includes what the excretory system is, the formation of urine, and kidney disorders
Why is a real kidney better than dialysis treatment?
even though dialysis enables people with kidney diseases to continue daily activities, it is neither a cure nor a long-term solution
- individuals with 10% or less kidney function will eventually have to replace their kidneys as a real kidney does a better job at filtering wastes and keeping you healthy
What is the collecting duct
part of the nephron; function is passive reabsorption of water by osmosis
What is a dialysis?
a procedure that removes wastes and excess fluid from the blood when kidney function is lost due to renal failure
- the diffusion of dissolve substances through a semipermeable membrane
What is peritoneal dialysis?
type of renal dialysis that utilizes the lining of the intestines, called the peritoneum, as the dialysis membrane to remove waste and excess fluid from the blood when kidney function is lost
What are the 4 main steps of urine formation?
- Glomerular Filtration
- Tubular Reabsorption: proximal tubule & Loop of Henle
- Tubular Secretion: Distal tubule
- Water Reabsorption: Collecting Duct
What is diabetes insipidus?
- when ADH activity is insufficient, causing excessive urination (about 4L to 8L a day)
- intense thirst but water is excreted more quickly than consumed, leading to severe dehydration & ion imbalances
what is the urinary system’s function?
- excretion of urea and uric acid
- maintain water balance
What are the advantages and disadvantages of peritoneal dialysis?
ADVANTAGES:
- fewer restrictions on diet & fluid intake
- longer-lasting kidney function
- can be carried out at home or any place that is clean
DISADVANTAGES:
- risk for infections
- development of a weakness in the abdominal muscles
- needs to be done daily; strict schedule
What happens if there is dehydration
- blood plasma is too concentrated
- osmotic pressure increases
- osmoreceptors in hypothalamus send impulses to pituitary gland
- pituitary releases antidiuretic hormone (ADH) which acts on kidneys to increase permeability of the distal tube and the collecting duct
action: more water is reabsorbed into the blood, lowering osmotic pressure
What is the origin of waste and organ of excretion for ammonia?
origin of waste: deamination of amino acids by the liver
organ of excretion: kidneys
What are kidney stones?
the development of crystalline formations due to excess calcium in the urine; also formed because of UTI’s or insufficient water consumption
symptoms: severe back pain, blood in urine, nausea, fever, cloudy/smelling urine, vague pain
treatment: can pass through on their own, medications, ultrasound shock waves, surgery
What is the origin of waste and organ of excretion for lactic acid
origin of waste: products of anaerobic respiration
organ of excretion: liver
What are the advantages and disadvantages of hemodialysis?
ADVANTAGES:
- helps control blood pressure and balance important minerals (ex. potassium, sodium)
- effectively removes waste products, toxins, and excess fluid
DISADVANTAGES:
- strict renal diet & fluid restrictions are required
- risk for infection
- could cause low BP, shortness of breath and nausea
What is the composition of urine? What should it not include?
96% water, 2% urea, and 2% other molecules like uric acid, ammonia, sodium, etc.
SHOULD NOT INCLUDE GLUCOSE
What is Brights Disease/Nephritis?
tissues in the kidney become inflamed and have problems filtering waste from the blood
symptoms: blood in urine, decreased urine output, swelling of the body, high BP and pelvis pain
treatment: antibiotics, medication, diet changes, dialysis or kidney transplant
what can end stage renal failure be cured by?
kidney transplant
give an overview of the excretion process
- kidneys filter blood
- ureter conducts waste to bladder
- bladder stores urine
- urethra voids the urine from the bladder
Whats the fourth step, “Water Reabsorption”, of urine formation about?
- passive reabsorption of water occurs here, depending on the concentration of the blood plasma
- if too concentrated from dehydration, more water is reabsorbed back into the surrounding capillaries
- if plasma is not concentrated, less water is reabsorbed
- process is under hormonal control: ADH
- as it leaves, filtrate only consists 1% of the original volume that entered the glomerulus and this is called URINE
What are the wastes that need to be removed from the body?
- products like ingested toxins, alcohol, and heavy metals via the liver
- products of protein metabolism such as urea (made from ammonia) and uric acid (breakdown of nucleic acids)
- metabolic wastes:
- excess proteins become carbohydrates
- amino group removed via deamination
- ammonia released as a byproduct
- in the liver, 2 ammonia molecules combine with CO2 to form urea
What are afferent arterioles?
part of the nephron; carry blood to the glomerulus
What is the long-term disadvantage of having a kidney transplant? How is this disadvantage overcome?
infections & cancer; can be overcome by antibiotics, medication, and maintaining a healthy lifestyle
What is the origin of waste and organ of excretion for carbon dioxide?
origin of waste: waste product of cellular respiration
organ of excretion: lungs
What happens if blood plasma is too dilute?
ADH does not get released which allows more water to be excreted in the urine, increasing osmotic pressure
whats a urinary tract infection (UTI)?
an infection in the urinary system, usually caused by bacteria
symptoms: painful burning sensation during urination, frequent urination, bloody urine, upper or lower back pain
treatment: antibiotics, kidney infection surgery, fluid consumption
Whats a diuretic? Give an example.
a substance that increases urine production to help remove excess water/fluid and salts from the body
ex. ethanol in alcoholic beverages
What is a nephron?
- unit of filtration
- found in the kidneys; filters and reabsorbs various substance from the blood and produces urine
What organ regulates water balance and osmotic pressure? How is it regulated?
kidneys
special osmoreceptors located in the hypothalamus sense changes in osmotic pressure and coordinate a hormonal response: antidiuretic hormone
What is the origin of waste and organ of excretion for bile pigments
origin of waste: breakdown of red blood cell pigment, hemoglobin
organ of excretion: liver
What is the origin of waste and organ of excretion for urea
origin of waste: deamination of amino acids by the liver
organ of excretion: kidneys
Whats the third step, “Tubular Secretion” of urine formation about?
- here hydrogen ions and potassium ions are actively secreted into the tubule from the blood capillaries
- this process is under hormonal control to help maintain blood pH
- acid base buffer system:
~ if the blood is too acidic, more H+ is excreted from body
~ if blood is too basic, H+ is not excreted. Urine is slightly acidic.
describe the importance of water
- average adult loses 2L per day
- a 1% decrease in body water causes thirst
- a 5% decrease causes extreme pain & collapse
- a 10% decrease causes death
What’s the second step, “Tubular Reabsorption”, of urine formation about?
- proximal tubule uses active transport to reabsorb sodium ions, glucose & other solutes into blood capillaries
- water follows the ions and is reabsorbed by osmosis
Loop of Henle:
- descending portion is full permeable to water; slightly to sodium
~ due to increasing salty environment in the inner medulla region, water leaves the filtrate and is absorbed back into blood
~ this increases sodium ion concentration within the tubule (filtrate) - ascending part is impermeable to water; slightly to ions, allows sodium ions to pass back into the blood
- near the top, sodium ions are actively transported out (maintains saltiness of medulla region)
What is the distal tubule?
part of the nephron; passively reabsorbs water and solutes, and secretes various substances
- lies between the loop of Henle and collecting dust
What is excretion?
the process of separating wastes from body fluids (blood) and eliminating them
Whats the first step, “Glomerular Filtration”, of urine formation about?
- Blood carrying water and wastes enters the bowman’s capsule
- the glomerulus filters out water, solutes, urea, and uric acid which forms a fluid called FILTRATE
- impermeable large proteins & red blood cells remain behind in the blood
What is the origin of waste and organ of excretion for solid waste
origin of waste: by-product of digestible and indigestible material
organ of excretion: large intestine
What is the glomerulus?
a high-pressure capillary bed enclosed by the Bowman’s capsule; walls of the glomerulus act like filtering devices
What is the origin of waste and organ of excretion for uric acid
origin of waste: products of the breakdown of nucleic acids, such as DNA
organ of excretion: kidneys
What is PKD - polycystic kidney disease?
a genetic disorder in which cysts grow in the kidneys, impairing proper function
symptoms: abdominal pain, blood in urine, excessive urination drowsiness, joint pain, high BP
treatment: medication, blood pressure control, fluid intake, antibiotics, dietary changes, dialysis or kidney transplant if serious
What is the proximal tubule?
part of the nephron; responsible for active reabsorption of water and solutes, as well as secretes hydrogen ions
What is the loop of Henle?
in the nephron; tubular portion which helps reabsorb water and ions
- lies between the proximal tubule and distal tubule
What is hemodialysis?
type of renal dialysis that utilizes an artificial membrane in an external device and is connected to an artery and vein in a person’s ARM to remove excess fluid from the blood
what is urine formation dependent on?
concentration gradients
What are efferent arterioles?
part of the nephron; carry blood away from the glomerulus
describe the location of the proximal and distal tubules
proximal - closer to glomerulus
distal - farther from glomerulus
what is the importance of kidneys?
- to eliminate harmful waste
- to balance blood pH
- to maintain water balance
- maintains ion balance and osmolarity
