Excretory System

organs in excretory system

liver, skin, lungs

organs in urinary system

bladder, kidney, ureters, urethra

function of kidneys

filter our toxins and waste and reabsorb useful nutrients

other functions of kidneys

gluconeogenesis, produces renin and erythropoietin, activates vitamin D

what is gluconeogenesis?

process of forming new glucose molecules

when does gluconeogenesis occur?

when dietary resources, reserves and blood glucose levels are low

what does renin do?

regulates blood pressure

what does erythropoietin do?

produces red blood cells

what are nephrons?

functional unit of kidney that filters blood

what do collecting ducts do

receives filtrate from nephrons, transports filtrate through medullary pyramids, delivers urine to the calyx

what does the calyx do?

delivers urine to ureters → bladder → urethra

what does fibrous capsule do?

prevents infection from spreading to kidneys

what does the perirenal fat capsule do?

attaches kidney posteriorly and provides cushioning

what does the renal fascia do?

dense connective tissue that anchors kidney and adrenal gland

what is the cause of renal ptosis

significant decrease in fatty capsule

what is renal ptosis

when kidneys drop to inferior position → ureter may twist → urine can’t be transported → urine backs up in kidneys (renal failure)

what does the adrenal gland do?

secretes adrenaline which prepares body for emergency situations

parts of nephron

bowman’s capsule, glomerulus, renal tubule

parts of renal tubule

proximal tube, loop of henle, distal tube

what does the bowman’s capsule do?

surrounds and holds glomerulus

what is the glomerulus

bundle of capillaries at top of tubule

why is the glomerulus porous?

so that substances can pass through

what occurs in renal tubule?

reabsorption and filtration

what does the renal tubule empty in?

collecting duct

what are the three steps of urine formation?

glomerular filtration, tubular reabsorption, tubular filtration

what happens during glomerular filtration

small particle enter glomerulus (water, glucose, amino acids, waste) and large particles remain in blood vessels to maintain osmotic pressure

does glomerular filtration require energy?

no its a passive process

what is tubular reabsorption?

a selective process to reclaim useful materials (glucose and amino acids)

is tubular reabsorption passive or active

depends on material that is reabsorbed

what is the loop of henle?

a U-shaped portion of the kidney tubule in the nephron that connects the proximal and distal convoluted tubules

what does the descending limb of loop of henle do?

reabsorbs water due to ADH which is a hormone

what does the ascending limb of loop of henle do?

reabsorbs only solutes

what happens or non-reabsorbed substances

excess materials and nitrogenous waste products will be secreted

what occurs during tubular secretion

tubules remove unwanted substances directly from blood vessels

why is tubular secretion important?

because if removes toxins and excess materials that were not filtered and regulates blood pH

what causes polycystic kidney disease?

genetic mutation in PKD1 and PKD2 genes

symptoms of polycystic kidney disease

High blood pressure

side/back pain

Blood in urine

Headaches

Kidney stones

diagnostic tests for polycystic kidney disease

• Mri scan

• Ultrasound

• CT scan

how does tolvaptan treat polycystic kidney disease

slows how fast the cysts grow

how do diets treat polycystic kidney disease?

lower blood pressure

cause of hypokalemia

potassium loss from the kidneys or GI tract

symptoms of hypokalemia

• Fatigue 

• Muscle cramps

• Constipation

• Heart palpitations

• Arrhythmia

• Paralysis

• Respiratory failure

diagnostic tests for hypokalemia

• Serum potassium blood test

• EKG

• CMP

how can IV infusions and oral supplemenst treat hypokalemia

replenishes potassium levels

cause of diabetes insipidus

a depletion of arginine vasopressin or the kidneys' being unable

symptoms of diabetes insipidus

• pale urine 

• Bed-wetting.

• Very thirsty

• Weight loss.

• Poor growth.

• Vomiting.

• Irritability.

• Fever.

• Constipation.

• Headache.

• Problems sleeping.

• Vision problems

diagnostic tests for diabetes insipidus

• Water Deprivation Test

• MRI Scan

• Urinalysis

how does DDAVP treat DI

acts as a synthetic hormone to reduce urine production

another treatment for DI

monitoring fluid intake

cause of cystitis

E. Coli bacteria, inflammation, drugs, radiation, foreign bodies, chemicals

symptoms of cystitis

• Strong urge to urinate

• Pain when urinating

• Passing small amounts of urine

• Blood in the urine 

• Passing cloudy or strong-smelling urine

• Pelvic discomfort

• A feeling of pressure in the area below your belly button 

• Low-grade fever

diagnostic tests for cystitis

Urine analysis and Imaging like x-ray or ultrasound

treatments for cystitis

Antibiotics to treat infection

Drinking fluids to flush out substances irritating the bladder.

cause of kidney stones

When urine contains more crystal-forming substances like calcium oxalate, calcium phosphate and uric acid.

symptoms of kidney stones

• pain in the side and back, below the ribs.

• Pain in lower stomach area and groin.

• Burning feeling while urinating

diagnostic test for kidney stones

• Blood tests

• Urine tests

• CT scans

• Genetic testing

treatment for kidney stones

1. Drinking water to prevent stones from forming

2. Pain relievers to relieve pain caused by stones. 

3. alpha blocker - relaxes muscles of ureter to help pass stone.

what is renal failure?

when the kidneys no longer function

what is required for someone with renal failure?

dialysis

reasons for kidney transplant in united states

hypertension and diabetes

how does cancer cause renal failure?

high mitotic rate of cells causes cell lysis → more work for kidneys to cleanup

requirements for kidney donors and recipients

not diabetic

not hypertensive

healthy BMI

cancer free

infection free

what does a transplant team include?

transplant surgeon, nephrologist, tranplant coordinators, dietician, social worker

how does a social work contribute during kidney transplant?

help iwth support at home, transportation, finances, insurance

is there a greater risk for renal failure if you are a living donor?

no

cadaveric adult kidney donation

each kidney goes to 1 recipient

cadaveric pediatric donor

due to size, both kidneys go to same recipient

how long does a cadaveric kidney donation last?

8-14 years

how long does a living kidney donation last?

15+ years

first transplant criteria

myst be an A, B, O blood type compatible

second transplant criteria

check HLA matches

3 HLAs for kidneys

A, B, and DR

inheritance pattern for HLAs

2 alleles for each antigen - each child has a 3 antigen match with each parent

what is a “perfect match”

when donor and recipient have same 6 HLAs

can you do a kidney transplant with no HLA match?

yes

third transplant criteria

must have a negative cross-match - confirm antibodies do not exist in recipient

what happens in the antibodies exist in recipient of kidney

the body would reject the organ

causes of preformed antibodies?

previous organ transplantation, blood transfusion, pregnancy

what are standard criteria donors

young healthy people (under 60)

what are expanded criteria donors?

older than 60 years old

what are CDC high risk donors

young donors with high risk behaviors

other two categories of wait lists for kidney transplant

living donors and living donors paired exchange

do you take out the original kidney during transplantation?

only if it is diseased or infected

where is the new kidney located

in the anterior pelvic cavity attached to ureters, arteries and veins

survival rate of kidney transplantations on immunosuppressants?

greater than 90%

what do cyclosporine and prograft do?

they inhibit T-cell proliferation (mitosis

what does cellcept do?

blocks DNA synthesis in T-cells → lowers ability for T-cells to divide

side effects of sterroids?

weight gain, hypertension, depression and bone loss

why are steroid controversial immunosuppressants for kidneys?

because their side effects can damage new organ

what causes glucose in urine?

diabetes mellitus

what causes ketone bodies in urine?

excessive formation of ketone bodies

what causes wbcs and bacteria in urine?

glomerulonephitis

what is glomerulonephitis?

inflammation and damage to the kidney's glomeruli

what causes red blood cells in urine?

bleeding in urinary tract

what causes bile pigments in urine?

liver disease

what is the first part of urinalysis

direct visual observation

how does normal urine appear?

normal urine appears a clear yellow

cause of turbidity?

excessive cellular material or protein

what can cause reddish urine color

fod dye, eating beets, a drug, or presence of hemoglobin or myoglobin

what are ketones?

chemicals produced by the liver when the body breaks down fat for energy