The excretory system
Constists of
Urinary system
made of
Kidneys
Location
on both sides at the back of abdomen
Shape
they are bean-shaped
Number
two
Parts
Renal cortex(external part)
Bowman´s capsule
Convoluted tubules
Renal medulla(internal part)
Loop of Henle
Collecting ducts
Renal pelvis(hollow chamber)
Functional unit
nephron*
Function
filter the blood from waste products
Ureters
Shape
two narrow tubes that come out from kidneys/start in the renal pelvis and end in bladder
Function
collect the urine formed by the kidneys and conduit it to the bladder
Bladder
Shape
elastic sac
Function
stores urine until reflex occurs(when it contains a large quality of urine
Urethra
Shape
a conduit that connect bladder with the exterior. At its end there is an sphincter
Fuction
through it urine circulates when micturition* occurs
Micturition*: reflex that makes bladder contract and push the urine out
Sweat glands
Respiratory system
Liver
Functions
Eliminates waste products
Regulates water in tissues
Regulates concentration and minerals in blood
Regulates ph in blood
Nephron*
Bowman´s capsule
a round sac
it surrounds a curly-ip capillary
function: glomerular, filtration
Convoluted tubules
proximal
distal
Function: tubular absorption of substances different from water
Loop of Henle
v-shaped tube between proximal and distal
Function: tubular absorption of water
a few nephrons drain the urine in the same collecting duct which drains into the renal pelvis
Phisiology of urine system: Production of urine
Urine = water + minerals + waste products (urea or uric acid)🡆they come from anmonia from the breaking down of proteins duct aminoacids
Formed in the renal cortex and renal medulla/ drains into the pelvis
prduction occurs in two phases
A) Glomerular filtration
blood that circulates in theglomerulur is filtred. Water and most solutes (with the exception of proteins)enter the Bowman´s capsule
B)Tubular reabsorption
a lot of filtered substances go back into the blood in the surrounding capillaries (reabsorption zone) such as nutrients, water and minerals to keep their levels coonstant
- water is reabsorbed in the loop of Henle
- other substances in the proximal tubule
twisted tubes