Module 5 - The Urinary System

functions of the urinary system

regulate blood volume, regulate bp, regulate water loss/osmolarity, regulate plasma electrolytes/ions, stabilize blood ph, regulate blood glucose levels, excrete wastes while conserve nutrients, produce hormones

what are the main urinary organs

kidneys, ureters, urinary bladder, urethra

describe the kidneys

bean shaped, fist sized, retroperitoneal: behind the peritoneum towards your back

describe the ureters

connects kidneys to bladder

describe the urinary bladder

holds urine before elimination

describe the urethra

external opening of urinary system

what are the 3 regions of the kidneys

renal cortex, renal medulla, renal pelvis

the outer layer of kidney that has a capsule is the

renal cortex

the inner layer of the kidney that consists of cone shaped masses called renal pyramids is the

renal medulla

the part that is at the center of the kidney and leads into the ureters at the hilum is the

renal pelvis

describe the path of urine drainage

papillary duct in renal pyramid, minor calyx, major calyx, renal pelvis, ureter, urinary bladder

what makes up the external renal anatomy

renal fascia (outer), adipose capsule (middle), renal capsule (inner)

renal fascia function

anchors kidney to abdominal wall

adipose capsule function

protects

renal capsule function

serves as barrier

ureters __ urine and they travel from __ to __

transport; renal pelvis; bladder

what stores urine

urinary bladder

what structures does the urinary bladder contain

rugae, trigone, neck, internal urethral sphincter, detrusor muscle

what layer in the bladder upon contraction, causes elimination

detrusor muscle

the __ eliminates urine

urethra

the urethra is longer in..

males

what sphincter does the urethra pass thru

external urethral sphincter

urination is aka

micturition, euresis, voiding

at how much urine do stretch receptors fire and bladder contracts

200-400 ml

both sphincters need to be __ for elimination

relaxed

what part of the brain controls urination

thalamus

what does the brain do when it comes to urination that children do?

control the reflex for a better time to go

__ can open whether you want them to or not

sphincters

disorders: incontinence

inability to control urination voluntarily, due to trauma/childbirth/stress/aging

disorders: nephrolithiasis

kidney stones/renal calculi, seen on xrays, broken by lithotripsy or by surgery

disorders: nephroptosis

falling kidney, occurs in thin people with too little adipose in capsule layer, may cause ureter to kink up and urine backs up, too much pressure on kidney

disorders: uti

infection/presence of microbes, painful/burning urination, urgent/frequent urination, low back pain, types: urethritis, cystitis, pyelonephritis

uti: urethritis

infection of urethra

uti: cystitis

infection of bladder

uti: pyelonephritis

infection of kidneys

disorders: glomerulonephritis

due to allergic reaction to toxins from strep, inflammation of glomeruli causes swelling w blood/damages vessels/blood and proteins leak out, may lead to chronic renal failure

disorders: uremia

urea and other waste products that are normally excreted into urine are retained in blood

disorders: hematuria

blood in urine, causes: uti, nephrolithiasis, pkd, trauma, cancer of kidney/prostate/bladder, bph, vigorous exercise, ideopathic (unknown)

disorders: nephrotic syndrome

increased permeability of filtration=loss of albumin causes hypoalbuminemia, liver fails to produce enough proteins, causes edema/proteinuria/hyperlipidemia, linked with dm/sle/cancers/aids

disorders: polycystic kidney disease (pkd)

genetic disorder with malformed tubules and cysts, increased apoptosis=esrd

disorders: bladder cancer

greater in males, painless hematuria, usually linked to smoking, common in people exposed to chemicals in painting/leather/rubber/aluminum industries

when kidneys are unable to filter this leads to

renal failure

disorders: acute renal failure

kidneys suddenly stop, causes oliguria or anuria due to low blood volume/stones/nsaids/antibiotics, edema/acidosis happen, anemia due to low epo production, vitamin d not converted to calcitriol which means no calcium absorption

chronic renal failure

progressive and irreversible decline in gfr, due to chronic dz: pkd, glomerulonephritis, pyelonephritis, 3 stages

3 stages of chronic renal failure

1. up to 75% nephron loss: diminished renal reserve 2. 75-90% nephron loss: renal insufficiency 3. greater than 90% nephron loss: esrd

describe hemodialysis

3-6 hrs, multiple days a week, blood passes through tubing and comes in contact with solution that cleans blood, not permanent treatment and eventually needs kidney transplant, kidney transplants more successful from family member

how many nephrons per kidney

1m

what do nephrons produce

urine

where do nephrons receive their blood supply from

renal artery

the portion entering the nephron is the __ arteriole

afferent

the afferent arteriole enters at the __ and then leaves thru the __ arteriole

glomerulus; efferent

blood surrounds nephron with the __ and __ before returning to renal vein

peritubular capillary network; vasa recta

what is around the glomerulus?

glomerular capsule

what is glomerular capsule made of

squamous epithelium that allows diffusion/osmosis, aka glomerular filtration

proximal convoluted tubules

lined with cuboidal epithelium; microvilli allow reabsorption of filtrate components, in renal cortex

what comes after PVT?

loop of nephron

parts of loop of nephron? describe each

descending limb where water can leave and ascending limb with salts that dips into medulla

what comes after the nephron loop? where / function

distal convoluted tubule that enters medulla and back into cortex; perform tubular secretion, connects proximal and distal convoluted tubules

DCT eventually enter the __ and then __ enter the __

collecting ducts; minor/major calyx; renal pelvis

3 steps of urine formation

filtration, reabsorption, secretion

force of bp controls what step of urine formation

filtration

removal of water from filtrate and returns it to the blood describes what step of urine formation

reabsorption

what happens during secretion of urine

removal of larger materials and wastes

list renal blood flow

oxygenated: aorta, renal artery, segmental arteries, interlobar arteries, arcuate arteries, cortical radiate arteries, afferent arterioles, glomerular capillaries, efferent arterioles, peritubular capillaries (vasa recta in medulla), deoxygenated: cortical radiate veins, arcuate veins, interlobar veins, renal veins

filterable components of urine

water, nitrogenous wastes, nutrients, electrolytes/salts

nonfilterable components in urine

blood cells and large proteins

is there more filtrate or urine per day?

filtrate

what makes up filtrate?

mostly water, nitrogenous wastes, glucose, amino acids, electrolytes, small plasma proteins

what makes up normal urine

water, urea, uric acid, creatinine, ammonia, electrolytes, pigment

what is abnormal in urine

glucose, amino acids, proteins, blood, toxins, calculi

what is normal urine volume in a day

1-1.8 liters

normal color of urine

pale to dark yellow

normal pH for urine

slightly acidic

normal turbidity of urine

transparent/clear, slightly cloudy, very cloudy and turbid urine shows problems

what odor does normal urine have

slight ammonia

sweet/fruity odor in urine is a sign of

diabetes

foul odor in urine is sign of

uti

what tests are included in urinalysis

glucose, ph, bilirubin, protein, ketone bodies, urobilinogen, specific gravity, nitrites, blood, leukocytes

glucose in urine or glucosuria is caused by

diabetes or stress

ketone bodies in urine or ketonuria is caused by

diabetes, anorexia, starvation, stress

what can cause rbc’s in urine

acute inflammation, trauma, tumors, kidney disease, menstrual blood

wbc’s in urine or pyuria is caused by

infection

what bacteria is often found in urine

e coli

fungal often found in urine

candida albicans

protozoan in urine

trichomonas vaginalis

what is urobilinogenuria

broken down hemoglobin

what causes urobilinogen in urine of urobilinogenuria

hemolytic/pernicious anemia, hepatitis, jaundice, cirrhosis, chf, mono

what causes albumin in urine of abuminuria

excessive levels show increased permeability; due to increased bp, injury or irritation by toxins, ether or heavy metals

what are casts in urine

hardened masses in tubules

the amount of filtrate kidneys produce per minute is known as

glomerular filtration rate

average glomerular filtration rate (GFR)

125ml

what if glomerular filtration rate (GFR) is too high

too much filtrate too fast causes poor absorption

what if glomerular filtration rate (GFR) is too low

filtrate moves too slow and too much absorption occurs

what controls glomerular filtration rate (GFR)

autoregulation, hormonal regulation, autonomic regulation

what hormones control glomerular filtration rate (GFR)

renin, anp, bnp

during tubular reabsorption, molecules __ and __ move across the __

actively; passively; tubules

first, Na+ is __ reabsorbed, Cl- follows __, now h2o follows __ to keep solutions isotonic

actively; passively; passively

during tubular reabsorption, glucose and amino acids return to blood via __

capillary network

reabsorbed filtrate components

water (most), nutrients, salts (required)

nonreabsorbed filtrate components

water (some), nitrogenous waste, salts (excess)