Human Excretory System - Life Processes, Class 10 Science Video Lecture

excretion the biological process
involved in the removal of harmful
metabolic wastes from the body is called
excretion as in other processes like
nutrition respiration transportation
different organisms use different
strategies to do excretion in case of
unicellular organisms wastes are removed
from body surface into the surrounding
water by the process called diffusion
but in case of multicellular organisms
specialized organs are evolved to
perform excretion excretion in human
beings
the chief organ that is involved in
excretion is kidneys the excretory
system of human beings consists of one a
pair of kidneys right kidney and left
kidney - a pair of ureters right dorita
and left ureter 3 a urinary bladder for
a urethra kidneys are located in the
abdomen on either side of the backbone
kidney is a basic filtration unit it
consists of very thin wall blood
capillaries each capillary cluster is
associated with cup-shaped
end of a tube that collects filtered
urine each kidney has large number of
filtration units called nephrons pack
close together the waste products are
nitrogenous wastes that are collected
from the blood in the form of urine the
produced urine passes through ureters
into urinary bladder the urine is stored
in the urinary blood
and the urine is released to outside
through urethra now let us learn how
during is produced the process of urine
formation takes place in three steps one
filtration two reabsorption three
secretion filtration the nitrogenous
wastes such as urea uric acid are
removed from blood in the kidneys the
process of uric formation takes place in
nephron reabsorption some substances
like glucose amino acids salts and major
water which are filtered along with
nitrogenous wastes are reabsorbed the
amount of water reabsorbed depends on
excess water and dissolved wastes along
with wastes secretion reabsorbed
components of wastes are secreted into
the blood when the urine flows through
the tubular part of nephron in the
kidney mechanism of urination the urine
formed in kidney enters into a lung tube
called ureter the one end of the ureter
is connected to kidney and the other end
is connected to urinary bladder urine is
stored in the urinary bladder until the
pressure of urinary bladder leads to
urge to pass urine when it reaches the
pressure to urge to pass it urine passes
out through urethra how can we hold
urine until it reaches to the urge to
pass urine as urinary bladder is
muscular and it is under the control of
nervous system we can usually control
too
to urinate the process of passing up
urine is called as urination