Animal SystemsPage 738: Body Symmetry

&Chapters 27 through 28

What is an animal?Scientific Definition

Animal: eukaryotes that are multicellular heterotrophs that do not have a cell wall.Characteristic So the are not…Eukaryotic Prokaryotes (Bacteria or Archaea)Multicellular ProtistsHeterotrophic Plants and algaeAbsent Cell Wall Plants, algae, or fungi

FYI… • 3-30 million species • 97% of all species are invertebrates

Invertebrates

• The vast majority of animals are Arthropods (1,170,000 to 10 million species)

• Of all invertebrates, the insects (part of the arthropods) are by far the most numerous. About 1-30 million+ species

• For comparison, chordates (including mammals) consist of about 75,000 species

Arthropods

ChordatesArthro + pod Arthropod

“jointed”+ “foot” or “leg”“jointed leg”

Some terms used to describe animals

Body Symmetry• Asymmetrical = without symmetry• Radial Symmetry =

symmetry around a central axis• Bilateral Symmetry

–can be divided into symmetrical halves on either side of a plane

Examples of Asymmetrical

Animals

Porifera (Sponges)

This is a cut out piece for

marketing uniformity

Radial Symmetry

Animals with Radial

Symmetry

Examples of Animals with Bilateral Symmetry

Body Orientation (used in humans)• The Anatomical Position: The

anatomical position describes a person that is standing erect with the feet facing forwards, arms hanging to the sides, and the palms of the hands facing forward. Directional terms are always from the patient’s perspective. When we refer to the right side we are referring to the patient’s right side

Do not let this intimidate you…

=

Body Planes of Animals(including humans)

Term DefinitionSagittal(or Median)

Divides the body into right and left halves

Frontal(or Coronal)

Divides the body into anterior and posterior halves

Transverse(or Horizontal)

Divides the body into superior and inferior halves

Directional Terms• Right and left – Refers to the

Patient’s right or left side • Proximal – Near, closer to the origin

Distal – Away from, farther from the origin

• Lateral – Toward the side, away from the mid-lineMedial – Toward the mid-line, middle, away from the side

Directional Terms• Superior – Above, Over

Inferior – Below, Under• Anterior – In front of, front

Posterior – Behind, toward the rear

• Ventral – Toward the bellyDorsal – Toward the back

Directional Terms Quick CheckTerm Definition

1 Superior2 Inferior3 Anterior4 Posterior5 Lateral6 Medial7 Proximal8 Distal9 Ventral10 Dorsal

Directional Terms Quick CheckTerm Definition

1 Superior Above, Over2 Inferior Below, Under3 Anterior In front of, front4 Posterior Behind, toward the rear5 Lateral Toward the side, away from the mid-line6 Medial Toward the mid-line, middle, away from the

side7 Proximal Near, closer to the origin8 Distal Away from, farther from the origin9 Ventral Toward the belly10 Dorsal Toward the back

Other animal examples…

Vocabulary

1. Anatomical Position2. Anterior3. Asymmetrical4. Bilateral Symmetry5. Distal6. Dorsal7. Frontal (or Coronal)8. Inferior9. Lateral

10.Medial11.Posterior12.Proximal13.Radial Symmetry14.Right and left15.Sagittal (or Median) 16.Superior17.Transverse (or Horizontal)18.Ventral

Due tomorrow at the beginning of class:

1.Write a story using seven of these words (as they are used in biology) EXCLUDING right and left.

2.No definitions in your story.3.I must be able to tell that you know what the word

means from the story.4.No more than one vocabulary word in a sentence.5.If I can’t read your handwriting, I wont.

In other words TYPE IT or write legibly.6.No legible first name, last name, OR period = LATE