Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of...

23
Animal Body Plans Chapter 3, Zoology

Transcript of Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of...

Page 1: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

Animal Body PlansChapter 3, Zoology

Page 2: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANIMAL BODY DESIGNS

Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make up separate organs. And organs make up separate organ systems.

Page 3: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANIMAL BODY SYMMETRY

Symmetry in animals refers to the way in which a plane or planes can divide the body.

Animals with radial symmetry can be divided into similar halves by more than two planes. (examples include jellyfish, sea urchins, sea anenomes etc.)

Animals with bilateral symmetry can be divided into equal left and right halves along the mid-sagittal plane. Animals with bilateral symmetry also exhibit cephalization ( they have a head with a brain).

Page 4: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANIMAL BODY SYMMETRY

Page 5: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANATOMICAL ORIENTATION

When studying the anatomy of animals, it is necessary to use terminology to describe directions, planes, and points of reference.

Anterior/Posterior: A direction on an animals body referring to towards the head and/or tail.

Dorsal/Ventral: A direction on an animals body referring to towards the spine and/or belly.

Medial/Lateral: A direction referring to towards or away from the midline or mid-sagittal plane of the body.

Distal/Proximal: A direction referring to farther away from and closer to another point of reference.

Page 6: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANATOMICAL ORIENTATION

Sagittal plane: An imaginary line or axis that goes through the body separating left and right halves.

Frontal plane: An imaginary line or axis that goes through the body separating dorsal and ventral halves or sections.

Transverse plane: An imaginary line or axis that goes through the body separating anterior and posterior halves or sections.

Oral/Aboral: Animals with radial symmetry, oral refers to the mouth side, aboral is opposite of oral.

Page 7: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANATOMICAL ORIENTATION

Page 8: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANATOMICAL ORIENTATION

Page 9: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

EARLY EMBRYONIC DEVELOPMENT

After fertilization of an egg occurs, the egg becomes a zygote. A zygote then begins dividing in a process called cleavage.

Some animals (like echinoderms and chordates) exhibit radial cleavage, in which the cleavage planes are symmetrical.

Other animals (like molluscs and annelids) exhibit spiral cleavage, in which the cells divide in a spiral asymmetrical pattern.

Page 10: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

RADIAL VS. SPIRAL CLEAVAGE

Page 11: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

BODY PLAN DEVELOPMENT

Cleavage continues to occur until the dividing cells begin to form a fluid-filled ball of cells called a blastula.

Inside the blastula is a fluid-filled cavity called a blastocoel.

In most animals, the blastula develops into a two-layered organism called a gastrula. The gastrula is made up of two layers called the endoderm and ectoderm. Later on these will form the outer and inner tissues and organs of the body.

Page 12: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

EARLY EMBRYONIC DEVELOPMENT IN ANIMALS

Page 13: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

BODY CAVITIES

The gastrocoel (cavity inside the gastrula) develops into digestive cavity in most adult animals.

Some animals such as the sea anemone never advance beyond the gastrula stage.

In the sea anemone, the opening or blastopore becomes the opening to the gastrovascular cavity.

In most animals a third germ layer develops after the gastrula stage called the mesoderm.

Page 14: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

BODY CAVITIES

In some animals, the mesoderm lies along the outer edge of the ectoderm, but not along the endoderm. These types of organisms are referred to as pseudocoelomate, meaning “false coelom”.

In other animals, mesoderm completely fills the blastocoel or internal body cavity. This type of body cavity is without a coelom. These organisms are referred to as acoelomate.

Page 15: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

BODY CAVITIES

Page 16: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

BODY CAVITIES

And lastly the body cavity of most animals are eucoelomate or “true coelomate”. Usually the cavity is just referred to as simply a coelomate body cavity. In this body plan, the mesoderm completely lines the endoderm and ectoderm, and a new fluid filled cavity forms within the mesoderm.

A true coelom or body cavity allows much more flexibility and space for internal organs.

Larger and more complex organisms have a coelomate body cavity.

Page 17: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

BODY CAVITIES

Page 18: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

DEVELOPMENT OF ANIMALS AND THEIR BODY CAVITIES

In coelomate animals if the coelom forms from mesoderm spreading out in the blastopore region, this pattern of coelom development is called schizocoelous development.

In coelomate animals if the coelom forms from pouches that pinch off from a region of the endoderm and enlarge to form the coelom, this pattern of coelom development is called enterocoelous development.

Page 19: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANIMAL DEVELOPMENT

Page 20: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

ANIMAL DEVELOPMENT

Another main difference in the way animals develop is the development of the blastopore, or the opening that forms the mouth or anus.

In protostomes, which means “mouth first”, the blastopore develops into the mouth. (found in annelids, mulluscs, and arthropods).

In deuterostomes, which means “mouth second”, the blastopore develops into the anus. (found in echinoderms and chordates).

Page 21: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

PROTOSTOMES VS. DEUTEROSTOMES

Page 22: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

THE DEVELOPMENT OF TISSUES

Eventually the germ layers (ectoderm, endoderm, and mesoderm) begin to specialize to form tissues. All of the body tissues of animals are comprised of one of the four basic tissue types.

Epithelial tissue Connective tissue Muscular tissue Nervous tissue

Page 23: Animal Body Plans Chapter 3, Zoology. ANIMAL BODY DESIGNS Animals are made up of a complex system of cells. Cells make up separate tissues. Tissues make.

BODY TISSUES