Urinary system

Urinary system definition and organs involved

organ system responsible for filtering blood, removing waste products, excess water and producing, storing, eliminating urine.

organs involved: kidneys (fliters blood n produce urine)

Ureters (transport urine from the kidneys to the bladder)

Urinary bladder (stores urine)

Urethra (carries urine out of the body)

5 functions of kidneys/regulate homeostatis

1. water balance

2. electrolyte balance

3. acid-base balance in blood

4. blood pressure regulation

5. RBC production

6. Vitamin D activation

Nephron function and main 2 structures

a microscopic structural and functional unit of the kidney responsible for flitering blood and producing urine.

main 2 structures include:

Glomerulus: network of tiny blood capillaries that filters blood. Water and solutes are forced through gaps in the capiliary walls of the glomerulus into the bowmans capsule due to hydrostatic pressure caused by a sudden decrease in blood vessel size. (filterate is called blood plasma without proteins)

Renal tubule: reabsorps useful substances and secretes waste. its a tube that begins at Bowmans capsule and continues towards the collecting duct. There is 3 parts which is proximal convoluted tubule, loop of henle, distal convoluted tubule. Site of tubular reabsorption and secretion into and out of the peritubular capillaries,

3 major renal processes

1. glomerular filteration, water and solutes smaller than proteins are forced through the capillary walls of the glomerular capsule into the renal tubule.

2. Tubular reabsorption: water, glucose, amino acids, and ions are transported out of the filterate into the tubule cells then enter the capillary blood.

3. tubular secretion: additional substances move from the blood into the renal tubule.

Definition of kidney/renal, Ureter, bladder, urethra, urine, filteration

kidney/renal: bean shaped organ that filters blood, remove waste and excess waterand produce urine

Ureter: mascular tube that transports urine fron each kidney to the urinary bladder

bladder: hollow muscular organ that temporarily stores urine until its eliminated from the body (usually holds 500ml but can hold 1L and has 3 layers)

Urethra: a tube that carries urine from the bladder out of the body

urine: a liquid waste produced by kidneys, containing water, urea, salts etc (more than 30ml/hr)

Filteration: process of seperating water and small dissolved substances from the blood while retaining blood cells and most proteins.

solutes normally found in urine

sodium and potassium ions, urea, uric acid, creatinine, ammonia, bicarbonate ions

what are the 3 main fluid compartments that water occupies

1. Intracellular fluid: fluid inside cells

2. extracellular fluid: fluids outside cells; includes blood plasma, interstital fluid, lymph, and transcellular fluid

3. Plasma blood is extracellular fluid but accounts for 3L of total of body water (links internal and external enviroment)

what is ADH

ADH is antidiurectic hormone that is primarly responsible for reabsorption of water and electrolytes by the kidneys which prevents excessive water loss in urine. Released from the posterior pituitary gland, more will be released when bp drops.

Renin-aldosterone mechanism

When cells in the kidney are stimulated by low blood pressure, the enzyme renin is released into the blood. Renin leads to the production of angiotension II, which causes vasoconstriction and aldosterone release from the adrenal cortex. Result is increase in blood volume and blood pressure.

Aldosterone promotes reaborption of sodium ions back into the blood in the renal tubules.

Anuria, haematuria, oliguria, nocturia, dysuria, proteinuria, cystitis, diuretic definitions

Anuria: little to no urine production

haematuria: blood present in urine

Oliguria: abormally low urine output

nocturia: waking up during the night to urinate

Dysuria: pain or discomfort when urinating

Proteinuria: protein present in the urine

Cystitis: Inflammation of the bladder, usually caused by a bacterial infection

Diuretic: a substance or medication that increases urine production

Urinary tract infection (UTI) and 3 types, common wit?

presence of microorganisms in any urinary system stucture.

3 types:

cytisis: in the bladder

pyelonephritis: in kidney

urethritis: in urethrea

common with:

urinary retention, idwelling catherter, diabetes, older people/women

signs/symptoms include urgency, frequency, dysuria, nocturia, pain, cloudy urine, offensive odour

Urinary retention

Being unable to empty bladder completely which leads to increased risk of UTI and overflow incontinence. Causes are post surgery, medication, post catherter removal, trauma, enlarged prostate. Symptoms include pain, palpable bladder above pubis

Benign prostatic hyperplasia (BPH) definition, sign symptoms, causes

Enlargement of the prostate. common in men n over 50. puts pressure on urethra and prevents complete emptying of the bladder. Symptoms UTI, haematuria, Oliguria, difficultly starting urination, slow emptying, frequency

Renal calculi definition signs symptoms cause

Hard deposits of minerals and salts that form inside the kidneys. Occurs when uric salts form crystals which precipitate in the renal pelvis. Cuases dehydration, diet, hereditary. symptoms are painful when passed through the ureter walls or lodged in ureter, haematuria, UTIs

Acute renal failure definition signs causes

Kidneys suddenly being unable to filter blood usually due to reduced blood flow in the kidneys. Causes include trauma, infection, surgical shock, heart failure, medications

Chronic renal failure definition sign cause

slow and progressive loss of kidney function, intially kidneys hyper-filterate to compenstate for loss of nephrons but it only causes further damage. patients dont experience symptoms until 80% of function is lost. symptoms include diabetes, severe hypertension, high bp, headache, nausea, anorexia