Page 8 - E-Biology Sec.2 2024-2025 U1_Handy

L2: Excretion in man (Kidney and Liver)

2- Human Urinary System

The system that clarifies blood from the nitrogenous wastes,
excess salts & excess water and expels them in the form of urine.

Location: It lies in the abdominal cavity near the backbone.

Structure:

Renal artery carries the Renal vein carries the pure blood
blood with nitrogenous is filtered by the two kidneys to the
wastes to the two kidneys. heart which pumps it to the body.

1- The two kidneys 2- The two ureters

They are bean shaped with (convex They are two narrow tubes
outer part) (concave inner part “pelvis”) emerge from the two kidneys
They are located in the upper part of the and open at the back of the

abdominal cavity at both sides of the bladder “inclined”
backbone.
They pass the urine drop
Its length is 12 cm, width 7 cm & by drop to the bladder.
thickness 3 cm.

3- The urinary bladder 4- Urethra

A small muscular sac has a It is a duct which extends
sphincter muscle to close the outlet from the urinary bladder
of bladder till the accumulation of and opens outside the body.

urine then the bladder contracts. It allows urine to pass
outside the body.
It receives the urine from ureters
and stores it temporarily until it is 7
released outside through urethra.

Second Term