Human Excretory urinary System

The kidney- grade 11

Structure of the urinary excretory system

This system includes 4 main organs:

Excretory

system

Kidneys

ureters

Urethra

Bladder

Main function of the urinary System

The human excretory system functions to remove waste from the human body.

During urination animals get rid of nitrogenous waste products of metabolism, including ammonia, urea, and uric acid.

The internal & external structures of a kidney

The flow of urine inside the kidney

Glomerulus

Renal tubules

Renal pelvis

Renal calicesUreter

Purpose of a kidney

Filters blood, redirecting wastes as urine through the ureter and to the urinary bladder and out of the body via urethra.

Each kidney consists of millions of nephrons – the fundamental units of the kidney

Structure of a nephron

What is a nephron?

A functional unit of a kidney.

Blood enters the nephron

at the Bowman’s

capsule and is filtered by

the glomerulus, a

ball of capillaries.

Bowman’s capsule collects filtrate, plasma

forced out of the blood.

Filtrate passes

through the entire

nephron becoming

modified into urine.

Blood Flow through the Kidneys

Blood enters via

renal arteryArterioles Nephron Renal

corpuscle

The 3 processes of blood purification inside the kidneys.

Filtration – blood is filtered through the glomerulus,

allowing small substances to pass further; ions, urea and

amino acids. All these substances make up a fluid

called filtrate.

Reabsorption – Small solutes such as

water, nutrients, and salts are reabsorbed

and then urine remains.

Secretion – Substances including H+, potassium, and

ammonium ions enter the tubules as part of

urine.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Renal tubuleExcretion

Filtration

Reabsorption to blood

Secretion from blood

Glomerulus

Bowman'scapsule

The remaining urine goes to the collecting duct and into the ureters, the

bladder and out of the body via the urethra.

Normal & abnormal flow of urine

References

The slides above have been re-purposed from the following presentation links from slideshare:

http://www.slideshare.net/itutor/excretory-system-23183659?qid=6d3c0d3b-e56c-4c57-83c0-98fbae82b3eb&v=qf1&b=&from_search=1

http://www.slideshare.net/jgthatsme/excretory-system?qid=9ee1584a-3dda-4d5a-b11b-e75b5400133f&v=qf1&b=&from_search=1

http://www.slideshare.net/132cool/excretory-system-8430788?qid=81f3882c-84d0-46f6-867b-782728c2fc79&v=default&b=&from_search=12

THE END!201125991

Ledwaba .M