Getting rid of wastes

Getting Rid of Wastes

All greens you can see here do it every time.

Even this wild-looking domestic cat does it, secretly.

Well, this proud-looking dog does it, publicly.

Even small insects, such as this bee, does it.

Believe

And

it or

not…

This man did it, too. Several times.

And admit it.

youdo it too.

Every

Of thAT

hour

day

every

minute

Of thAT

HOUR

EVERY

second

Of that

minute

You do

excretion

So, what is this

excretion

all about?

excretion is simply the

“elimination of metabolic wastes”.

These metabolic wastes are:

Carbon dioxide and water

Excess nitrogen

solutes

produced by the body in some ways.

But why do we,

animals,

need to excrete?

Here’s why..

To get rid 0f the

metabolic wastes

and

To regulate the

concentration of

solutes and water to

achieve osmoregulation

Vocabulary check:

Osmoregulation is the ability to regulate water and solute concentrations.

What will happen if we don’t do excretion?

Hmm..It’s either of the two

You’ll

burst

Just like the fate of this balloon.

Or..

You’ll be

+ ed

And, I hate to break it up to you but

Both of these

leads to..

orto make it more clearer

So, how does

excretion

made possiblein animals?

This is made possible by an

organ systemthat allows organisms to

excrete metabolic wastes,

at the same time,

regulates the concentration

of solutes and water

in their body.

This organ system is known as

the

Excretory system

At the end of this lesson, we will be able to

• Know the structure and structure of

different excretory organs/systems

• Determine the different types of

excretory organs in animals

• To identify the different nitrogen

excretion in animals

• Medical aspects concerning excretory

organs

So, let’s begin.

There are two types of excretory organs in animals:

one, for the two, for the

and

generalized

excretory

for

organs

invertebrates

The

Contractile

vacuoles

for

Protozoa

Cnidarians

Echinoderms

Sponges

Meet Mr. Protozoa

He uses contractile vacuole in excreting.

This is his contractile vacuole.

It fuses with the membrane of the protozoan and the water is expelled to the environment.

ATP is required for both entry of water into the vacuole and for the emptying process.

The

nephridia

for

rotifers

annelids

larval mollusk

flatworms

Annelid worms

Vocabulary Check:

Nephridia are tubular excretory organ found in many invertebrates .

There are two types of nephridia

protenephridia is the primitive kind.

Greek protos, first + nephros, kidney

metanephridia is the advanced kind.

Greek meta, after + nephros, kidney

Here is Ms. Flatworm.

She uses protonephridia.

This is what a protonephridia look like

They exist as closed, or blind-ended, tubules, and which do not connect with the coelomic cavity.

Vocabulary check:

Coelomic cavity is a body cavity formed in animals which is lined

with mesodermal tissue.

The cell which forms the tip of the blind-ended tube is ciliated. If it contains a single cilia it is called a solenocyte, whereas if it contains several cilia it is called a flame cell.

Identify the parts.

Here’s how it works.

Cilia within the tubules beats up

Body fluid is drawn to the tip of the tubule

Fluid passes to the cell membrane

Ultrafiltration occurs

Reabsorption and secretion

Excretory pores

Ultrafiltration : filtration of body fluids which results in the formation of a protein-free filtrate, i.e. the filter allows all molecules, with the exception of proteins, pass through it.

On the other hand, Sir Annelid worm here uses

metanephridia

And this what it looks like.

They have a ciliated opening called the nephridiostomeand which ends in pores which open to the external environment, called nephridiospores.

Blood enters the membrane Ultrafiltration occurs

Fluid produced enter coelomicspace

Fluid enters metanephridiathrough nephridiostomes

Initial urine goes reabsorption and secretion

Hypoosmotic urine leaves through nephridiospores


Hypoosmotic: less concentrated

The

Malphigian

tubules

insectsfor

Lady butterfly here

has malphigian tubules

Here’s a Malphigian tubule.

They have a closed end which lies in the fluid-filled activity known as the hemocoel, and an open end which opens into the gut between the midgut and the rectum.

K+ ions, Na+ ions, nitrogenous waste products and amino

acids enters the tubules

Urine enters the midgutand rectum

Solute and water reabsorption

Urine is excreted – semi-solid


There is a tremendous amount of water reabsorption in the rectum and the uratesprecipitates as uric acid.

The

Crustacean

Green

glands

for crustaceans

My friend, Crab, has this

Crustacean green glands

or antennal glands

Here’s a crustacean green gland

(Find it, actually. It’s green.)

Consists of blind-ending sac called the end sac connected to a tubule, the nephridial canal, which terminates in a region called the bladder which exits to the external environment via an excretory pore situated near at the base of the antenna.

Coelomic fluid surrounds end sac

Coelomic fluid is filtered and stored in antennal glands

Initial urine is producedUrine passes through

nephridial canal

Bladder Excretory pore


initial urine produced doesn’t have substances with high molecular weight, such as proteins

water and solutes are reabsorb in nephridial canal

organs

Excretory

specialized

for

vertebrates

The

Respiratory

system

for

Amphibians

Mammals

Reptiles

Birds

fish

You might be wondering why

the respiratory system

included here.

If you are

then, you must have forgotten that

the respiratory system

excrete

Carbon dioxide

and

Carbon

dioxide

Belongs to the

Metabolic

wastes

So, I heard you’re familiar with

The respiratory system

It is responsible for providing oxygen and for the elimination of carbon dioxide.

We all know how it works.

Nose Larynx Trachea

Bronchi Bronchioles Alveoli sacs

Nose Larynx

Trachea Bronchioles Bronchi

The exchange of gases occurs in the alveoli sacs wherein the carbon dioxide from the deoxygenated blood diffuses inside its capillaries and is eliminated through the nose.

The

Digestive

system

for

Amphibians

Mammals

Reptiles

Birds

fish

The digestive system

obviously, helps excrete

Metabolic wastes

ike this.Just

The digestive system

Produces feces – waste materials that consist largely of undigested foods, digestive juices, mucus, and bacterium

Mouth Esophagus Stomach

Small intestineLarge intestine Rectum

Anus


equals

The

skin

for

Amphibians

Mammals

Reptiles

Birds

fish

The skin,

like everyone says, is the largest outer organ in an animal’s body.

Because it covers everything in them to protect the animal and for the regulation of temperature in their bodies.

The skin,

contains 1.6 to 4 million of sudoriferous glands or sweat glands.

Sweat glands: small tube-shaped gland in the skin of most parts of the body from which sweat is released

The

liver

for

Amphibians

Mammals

Reptiles

Birds

fish

Cells under the eccrine sweat glands produces sweat

Moves to the coiled duct connected to the skin

Salts are reabsorbedSweat surfaces and

evaporates

Sweat: mixture of salt and water, with little amounts of metabolic wastes that are produced when someone’s body is hot or due to anxiety, fear, illness or strenuous activity


Do you know why the

The liver

is included here?

Because it excretes metabolic wastes to form bile to be used by the body in emulsifying fats.

Bile is released to emulsify fats

The gall bladder produces the mucous, salts and bile salts, proteins, hormones and enzymes for the bile

Blood enters the liver through hepatic artery

Blood enters the lobules

Wastes are removed, bile is produced

Bile goes to the gall bladder

The

kidney

for

Amphibians

Mammals

Reptiles

Birds

fish

The are

- shaped organs

and are the major/main excretory organ used by the vertebrates . They are responsible in removing wastes in the body and in regulating the amount of fluids in the body

Nephron is its functional unit. It filter the blood and cause wastes to be removed as urine.

Nephron performs ultrafiltration,secretion and absorption.

Filtration occurs in Malphigianbody, which is composed of a tuft of capillaries called glomerulus together with the cupped end of the renal tubule called Bowman’s capsule.

Loop of Henle is the region of the nephron of a kidney where the production of concentration gradients allows the kidney to produce concentrated urine.

Blood enters the renal artery

Arterioles Capillaries of glomerulus

Bowman’s capsule , where ultrafiltration

occursRenal tubuleUrine is produced

Renal cavity ureters Bladder

Urethra


Other functions of the kidney

Regulates the water on the blood through antidiuretic hormones; also called vasopressin

Helps regulating the blood’s sodium and potassium through hormone aldosterone

Adjusts the acid-base balance

Secretes the hormone erythropoietin that influences the production of red blood cells

On the past slides, you learned that animals excrete

the excess nitrogen…

These metabolic wastes are:

Carbon dioxide and water

Excess nitrogen

solutes

produced by the body in some ways.

So , what are these

Excess nitrogen

all about?

It all starts with this statement:

AnimAls cAn’t excrete excess Amino Acids

Therefore, these amino acids are subsequently metabolized to produce glucose. This is called deamination and it

leads to the production of ammonia.

And take note:

Ammonia is a

highly toxic

compound.

So, it’s very dangerous to animals.

And they have to deal with that newly-formed substance.

They deal with it in three ways:

By excreting it unchanged

By converting it to urea

before excreting it

By converting it to uric acid

and then excreting it

Animals who excrete

ammonia unchanged are the

Aquatic animals

and they are called Ammonotelic.

Because ammonia is soluble in water, it easily diffuses through the gills to the immediate environment.

The term uricotelic,

applies for the terrestial animals,

that excrete ammonia through urea.

This one’s and other mammals are uricotelic. Urea is very common and abundant in their urine.

And lastly, animals who excrete ammonia in the form of

Uric acid are called

Uricotelic.

These three are uricotelic.

Excreting is very important to an animal

especially on humans.

But there are those times wherein excreting is very hard to do.

Just like having..

Urinary tract infections

which are usually caused by bacteria.

This usually cause pain in urinating.

And it actually can cause..

Kidney stones

which are small, crystallized substances, such as calcium, that form in the kidney or other parts of the

urinary tract.Treatment is to get rid of these stones before things get worse.

And some people, unfortunately,

can’t Perspire.

They have

Anhidrosis.

Their sweat glands don’t work properly and it’s genetic.

There’s no treatment. Just the lifestyle.

So

Do you know now what is

Excretory system,

and its importance ?

its different structures

I hope you do.

Because without it…

You’ll be

dead

now.

by

teehee

References

• Ian Kay, “Introduction to Animal Physiology”, 1998, pp. 160-174

• "Liver." Microsoft® Encarta® 2009 [DVD]. Redmond, WA: Microsoft Corporation, 2008.

• "Kidney." Microsoft® Encarta® 2009 [DVD]. Redmond, WA: Microsoft Corporation, 2008.

• Edelson, Richard L. "Skin." Microsoft® Encarta® 2009 [DVD]. Redmond, WA: Microsoft Corporation, 2008.

Technology

Getting rid of wastes