Transcript Organ Systems in Other Animals

Organ Systems in
Other Animals
Cow, Fish, Frog, Crayfish
Goals

To become aware of the diversity that is present
in members of the animal kingdom.

To compare the organ systems of humans to
other animals.
Digestive System - Cow


Cows are large mammals that mainly eat grass
and plant material.
Plant matter contains cellulose, which is very
hard to break down.
Four Stomachs?


Much chewing is needed to break down plant
fibres.
Four stomach chambers are needed to
completely digest the tough plant cellulose.
Four Stomachs?

Rumen
The largest chamber
 Digests cellulose with the assistance of bacteria.




Reticulum – a secondary chamber that digests
non-plant material
Omasum – absorbs water back into the body.
Abomasum
the “true stomach”
 Digests proteins, fats, and sugars, much like a human
stomach.

In Humans



Human have only one stomach chamber.
We cannot digest cellulose.
It is thought that the appendix was once a
secondary stomach for digesting cellulose.
Respiratory System - Fish


Fish live under water, and do not breathe “air”
Gills are required to absorb dissolved oxygen
directly from the water.
Breathing Water


Gills – network of fanned membranes with
many blood vessels.
O2 is absorbed and exchanged for CO2, much
like in human lungs.
Why are gills fanned out?
The Operculum

Most fish have an operculum, or ‘cheek’ to
pump water through their gills.
Operculum
Sharks do not, and must always be
moving to keep water flowing across
their gills.
Reproductive System - Frog

Frogs are amphibians, which means:
They must live part half of their life in water.
 Lay soft eggs outside of the body.

Laying Eggs


Frogs lay gelatinous strands of eggs in the water
which hatch into tadpoles.
Tadpoles have gills which require them to stay in
the water.
Metamorphosis

As frogs grow, they lose their gills and grow
lungs and limbs.

This allows them to live on land.
Humans


Baby humans are born functionally the same as
adults – just smaller.
Humans give live birth.
Skeletal System
Crayfish

A crayfish is a crustacean with a hard
exoskeleton and many specialized appendages.
6 antennae for smelling
8 legs for walking
(the front two pairs taste food)
Small feathers on the tail
segments for swimming
Two large claws for defense
Many different mouthparts
for handling food
Exoskeleton

All of their appendages are formed of chitin –
the exoskeleton.

Crayfish cannot grow larger than their skeleton
and must moult it regularly.

The crayfish is soft and weak for a short period
while the new skeleton grows.
Moulting
In Humans

The skeleton is within the body.

The body tissues are able to grow around the
skeleton.

Thankfully, you never have to take your bones
out and replace them.