Excretory system

organs that remove waste

lungs

liver

Sweat glands

kidneys

Excretion

Removal of the wastes of metabolism from the body

lungs waste

carbon dioxide (produced by body cells) during cellular respiration

liver waste

bile, urea ( basic)

Sweat glands waste

sweat (by-products of metabolism- salts, urea lactic acid)

kidney waste

nitrogenous wastes ,urea, uric acid and creatinine

urea production

liver ( from breakdown amino acids)

process that makes urine

deamination

Nephron

functional part of the kidney surrounded by blood capillaries

steps of deamination

kidney length

11 cm

nephron

functional unit of kidney, where the urine is formed

processes of the formation of urine by the nephrons

glomerular filtration

selective reabsorption

secretion by tubules.

1. where does glomerular filtration take place

renal corpuscle when fluid is forced out of the blood and is collected by the glomerular capsule

afferent arteriole

leads into the glomerulus ( wide diameter)

efferent arteriole

leaves glomerulus ( narrow diameter) - increasing blood pressure

filtrate

liquid from water and dissolved blood components forced through high pressure forces into differentially permeable cell membranes and into the capsule.

renal corpsuscle walls

capillary wall

capsule wall

Filtrate components

H20

salts

amino acids

creatine

urea

hormones

reason why blood is forced out of blood capillaries into glomerular capsule

higher blood pressure ( Differently permerable membrane)

reason why RBC, WBC and plasma proteins can’t travel through capilliaries

molecules to large

only 20 filtered through

What is found at the top of the kidneys

adernal glands

2. Reabsorption

Selective reabsorption - returning filtrate to blood from peritubular capillaries

carried out by cells lining renal tubule

Reason reabsorption happens

components of plasma are filtered through from capillilaries of the glomerulus are useful for the body.

Materials reabsorbed in selective reabsorption

H20

glucose

amino acids

ions

waste ( urea)

facultative reabsorption

hormonal control of reabsorption ( active process)

3. Tubular Secretion

add materials to filtrate from the blood.

materials added for Tubular secretion

potassium

hydrogen ion

creatinine,

drugs (penicillin)

2 main effects of tubular secretion

1. maintains blood pH ( removes H+ and NH4+)

2. Maintains urine pH ( adds H+ and NH4+)

what happens to urine after tubular secretion

1. Urine drains from collecting ducts to renal pelvis

How urine get to the ureter

pushed by ureteral peristalsis

where is urine stored

urinary bladder - pushed by pelvic muscles

Urine Composition doesn’t have

little protein

no glucose

where does urine colour come from

bile pigments

Urine Composition

H20 - 96%

urea -2%

various ions - 1.5%

other 0.5%

kindney stones

solid crystals built up inside the kidneys (reneal pelvis)

kidney stones cause

insufficient diet - Urine becomes to concentrated.

Ca,K, Na, PO43 - becomes to acidic and crystallises

small kidney stones

passes down the ureter and out of the body through the urethra unnoticeable

treatment for small kidney stones

take pain relief and muscle relaxants

big kidney stones

get stuck in the ureter, bladder or urethra, causing intense pain.

treatment big kidney stones

sounds was to break it apart or physically removed during surgery.

Kidney failure

affect the glomeruli, lose their ability to excrete waste and to control the level of fluid in the body ( can’t filter blood)

Kidney failure causes

diabetes, high blood pressure, or diseases that slowly destroy the nephrons i

maintence of healthy kidneys

regulate diet

drink water

not to much alcohol

no smoking

no performance enhancing drugs

Treatment for kidney failure

Dialysis

kidney transplant

Dialysis

method of removing wastes from the blood when kidney failure occurs ( kidney failure)

different Dialysis

1. Peritoneal dialysis

2. Haemodialysis

Peritoneal dialysis

using the peritoneum as a membrane across which

waste can be removed in abdominal cavity.

Peritoneal dialysis function

catheter is placed through the wall of the abdomen and fluid passes through (no waste)

conc difference, wastes will diffuse out of the blood into the fluid

Haemodialysis

passing the blood through an artificial kidney or dialysis machine.

Haemodialysis function

passes through fine tubes before being immersed in fluid.( no waste)

conc difference, wastes will diffuse out of the blood into the fluid