
HOW DO WE REMEMBER ALL THE LIFE
PROCESSES?

H.N.T.R.S.G.E.R.M.R

WHICH ONES HAVE WE COVERED?

NUTRITION & TRANSPORT & RESPIRATION

WHAT’S NEXT ON THE LIST?

WHY ARE WE SKIPPING TO “E”?

EXCRETION


WHAT IS EXCRETION?

DEFINTION 

THE PROCESS BY WHICH METABOLIC WASTES ARE
REMOVED

WHAT IS A METABOLIC WASTE?

PRODUCTS OF THE LIFE PROCESSES (CHEMICAL
REACTIONS) THAT ARE NOT NEEDED BY THE
ORGANISM…IF THEY BUILD UP IN CONCETRATION THEY
CAN BE TOXIC!!


WHAT ARE EXAMPLES OF METABOLIC WASTES?
IN OTHER WORDS, WHAT ARE PRODUCTS OF
REACTIONS IN THE BODY THAT WE DON’T
USE??


THE MAJOR METABOLIC WASTES ARE



CARBON DIOXIDE
WATER
NITROGEN COMPOUNDS (EX. AMMONIA & UREA)

EXCRETION IS THE PROCESS BY WHICH THESE
SUBSTANCES ARE REMOVED FROM THE BODY

HOW IS CARBON DIOXIDE REMOVED?


RESPIRATION / GAS EXCHANGE
SEE THE OVERLAP IN LIFE PROCESSES?


BEFORE WE CONTINUE, EVERYONE MUST BE
WARNED NOT TO CONFUSE
WITH
!!!


EXCRETION IN PROTISTS




DO THEY NEED AN EXCRETORY SYSTEM?
HOW DO THEY GET RID OF CARBON DIOXIDE?
HOW DO THEY GET RID OF WATER?
HOW DO THEY GET RID OF NITROGENOUS
WASTES?


EXCRETION IN HYDRAS?

DO THEY NEED AN EXCRETORY SYSTEM?


EXCRETION IN EARTHWORMS?

DO THEY NEED AN EXCRETORY SYSTEM?

HOW DO THEY REMOVE
CARBON DIOXIDE?

HOW DO THEY REMOVE
NITROGENOUS WASTE?


EXCRETION IN EARTHWORMS

SPECIAL STRUCTURE CALLED A NEPHRIDIA

FILTERS OUT THE NITROGENOUS WASTE FROM THE
BLOOD, THEN SHIPS IT OUT IN THE FORM OF URINE TO
TINY “PORES” IN THE SKIN


EXCRETION IN GRASSHOPPERS?

DO THEY NEED AN EXCRETORY SYSTEM?

HOW DO THEY REMOVE CARBON DIOXIDE?

HOW DO THEY REMOVE NITROGENOUS WASTES?


EXCRETION IN GRASSHOPPERS

MALPIGHIAN
TUBULES
FILTER BLOOD
AND PASS
URIC ACID
TO THE
INTESTINE
TO MIX WITH
FECES


EXCRETION IN HUMANS

DO HUMANS NEED AN EXCRETORY SYSTEM?

HOW DO THEY REMOVE CARBON DIOXIDE?

HOW DO THEY REMOVE NITROGENOUS WASTES?


EXCRETION IN HUMANS

WHERE DO NITROGENOUS WASTES COME FROM?




DETOXIFICATION

REMOVES HARMFUL
SUBSTANCES FROM THE BLOOD
BILE FORMATION

EXCESS BILE IS REMOVED IN
FECES
UREA FORMATION

RESULTS FROM BREAKDOWN
OF AMINO ACIDS


EXCRETION IN HUMANS

WHERE DO NITROGENOUS WASTES COME FROM?

BREAKDOWN OF AMINO ACIDS


EXCRETION IN HUMANS


WHEN AMINO ACID IS BROKEN DOWN, AMMONIA
(NH
3
) IS FORMED…BUT THAT IS TOO POISONOUS
TO BE TRANSPORTED
IN THE BLOOD, SO IT IS
CONVERTED, BY THE
LIVER, INTO A
DIFFERENT
NITROGENOUS COMPOUND
CALLED UREA
UREA IS ABLE TO BE TRANSPORTED IN THE BLOOD,
BUT MUST THEN BE FILTERED OUT TO BE
EXCRETED !!


EXCRETION IN HUMANS

THE URINARY SYSTEM


EXCRETION IN HUMANS


THE URINARY SYSTEM IS RESPONSIBLE FOR
FILTERING UREA OUT OF THE BLOOD FOR IT TO BE
EXCRETED
MAJOR STRUCTURES

KIDNEY** 




FILTER
URETER 

CONNECTING TUBE
BLADDER 

URINE STORAGE
URETHRA 

EXIT TUBE


EXCRETION IN HUMANS

**HOW DO THE KIDNEYS WORK?

N
S
P
H
R
O
THEY CONTAIN
MANY, MANY
N
E


EXCRETION IN HUMANS

NEPHRONS


EXCRETION IN HUMANS

NEPHRON MAJOR STRUCTURES

GLOMERULUS


BALL OF
CAPILLARIES
BOWMAN’S CAPSULE



FILTER
LOOP OF HENLE

REABSORPTION
COLLECTING DUCT

URINE COLLECTION


EXCRETION IN HUMANS

URINARY SYSTEM REMINDER


EXCRETION IN HUMANS

SOME UREA IS LOST IN SWEAT, ALSO


EXCRETION IN HUMANS


THE SKIN’S SWEAT GLANDS PRODUCES SWEAT
WHICH HELPS
REMOVE UREA
*SWEAT IS 99% H
2
O
SWEAT ALSO HELPS
REMOVE EXCESS
HEAT!!


EXCRETION IN HUMANS

EXCRETORY DISORDERS

CIRRHOSIS




JAUNDICE
GOUT
KIDNEY STONES
KIDNEY FAILURE


WHAT’S NEXT ON OUR LIFE PROCESS LIST?

RESPONSE

YOU NEED TO BE ABLE TO MOVE IN ORDER TO
RESPOND…WHICH MEANS YOU NEED…

