Animal Body

Systems

Objectives…(At the end of this lecture you should be able to):

Summarize the functions of the digestive, respiratory, circulatory, nervous, skeletal and excretory systems.

Compare a gastro vascular cavity with a one-way digestive system.

Differentiate open from closed circulatory systems.

Distinguish asexual from sexual reproduction.

Body Systems are specialized

to carry out different tasks

Simple animals like sponges carry out the many tasks of living with little specialization in the cells of their body.

More complex animals have evolved tissues and organs that are specialized to perform specific functions.

Body Systems are specialized

to carry out different tasks

Seven important functions of these

tissues and organs are : Digestion

Respiration

Circulation

Conduction of nerve impulses

Support

Excretion

Reproduction

Digestion

Purpose: Obtain energy &

nutrients

Sponges digest their food with their body cells

Simple animals, such as flatworms, have a gastro vascular cavity: a digestive cavity with only one opening.

More complex animals, like us, have a digestive tract with two openings: mouth and anus.

Respiration

Purpose: Exchange oxygen and

carbon dioxide gases

Can only take place across a

moist surface.

In simple animals like jellyfish

gasses are exchanged directly

with their environment through

diffusion.

More complex animals have

specialized respiratory

structures like gills or lungs.

Circulation

Purpose: Transport oxygen and nutrients to the other parts of the body

There are 2 types of circulatory systems:

Open: heart pumps fluid containing oxygen through a series of vessels & is dumped into the body cavity.

Closed: heart pumps blood through a system of blood vessels. The blood stays in the vessels the whole time.

CLOSED:

OPEN:

Conduction of

nerve impulses

Purpose: Coordinate the

activities in an animal’s body

and allow animal to sense

and respond to environment.

Simple animals, like hydra,

have little coordination

among their nerve cells.

Complex animals, like

grasshoppers, have nerve

cords/ganglia & a brain.

Support: Skeletal

Purpose: Provide a framework that supports the body.

Many soft-bodied invertebrates have a hydrostatic skeleton made of water like a filled water balloon.

Other invertebrates, such as insects & crabs, have an exoskeleton: a rigid external skeleton.

Complex animals, like dogs, have an endoskeleton: hard material such as bone embedded within the animal.

Excretion

Purpose: Removal of wastes from cellular metabolism (CO2, ammonia, etc.)

Simple aquatic invertebrates & some fishes pass it through their skin/gills by diffusion.

More complex animals have specialized excretory structures like kidneys.

Reproduction

Purpose: produce offspring to ensure that the species survives

Two types of reproduction: Asexual: does not involve fusion

of two gametes. EX: A sponge can reproduce by

fragmenting its body. Sea anemones pull apart into 2 individuals

Sexual: a new individual is formed by the union of a male and female gamete. EX: egg + sperm = fertilization =

blastula

Is this sexual or asexual

reproduction?

Fun & Funky Fact:

Sea “horse” reproduction

Pregnant sea horse fathers give birth. A female sea horse

inserts her eggs into a pouch on the male’s abdomen, where they are fertilized. The male incubates the eggs until they are fully developed and then gives birth to tiny sea horses.

Fertilization

There are two types of fertilization:

External: occurs outside the body EX: Most aquatic animals simply

release the male and female gametes near one another in the water, where fertilization occurs…..think opening scene of Finding Nemo….they were outside the mom.

Internal: occurs inside the females body EX: Animals that live on land don’t

have water so the gametes would dry out. Internal fertilization allows it to take place in a moist environment.

Objectives… (At the end of this lecture you should be able to):

•Summarize the functions of the digestive,

respiratory, circulatory, nervous, skeletal and

excretory systems.

•Compare a gastro vascular cavity with a one-

way digestive system.

•Differentiate open from closed circulatory

systems.

•Distinguish asexual from sexual reproduction.

Quick Test

Which two body systems in most

animals are involved in taking up

oxygen from the environment and

transporting oxygen to body cells?

a) Digestive & Respiratory

b) Respiratory & Circulatory

c) Circulatory & Nervous

d) Nervous & Excretory

The correct answer is:

Today’s classwork:

Directed Reading Worksheet

(page 5)

Use your notes &/or Chapter 27,

Section 2 to complete this in full

sentences.

This is an independent assignment &

Is due before you leave