• Maintenance of a constant environment.

*maintained via a negitive feedback system.

~When any variation from normal is brought back w/in range. "Negates Variation."

*As temp goes up the A.C.'s responce is to produce cold air causing the temp. to lower.

*As the temp goes down the A.C.'s responce is to reduce the cold air causing the temp. to go higher.

• Heterotrophic
• Multicellular
• Eukaryotic Cells
• No Cell Wall
• Most move at some point in their life- due to nervous/ muscular tissue. (Exception-sponges)
• All Animals capable of sexual reproduction
   -Simple animals are capable of asexual
• 9 major phyla

1. Increase complexity of the body systems.
2. Habitat- Evolution of animals from a marine habitat to to a land habitat.
3. Reproduction- Sexual/asexual became just sexual.
4. Body Symmetry:
       A. Asymetrical: No cuts can be made to to give mirror images. No symmetry. Ex: Sponge
       B. Radial Symmetry: Mulitple cuts can be made. Ex: Jellyfish
       C. Bilaterial Symmetry: Only 1 cut can be made. Ex: Humans
   (Advantage: provides an area for an inhanced nervious system.)
5. Body Cavity (coelum):  (5th group on tree)
       A. Acoelumate: animals with no body cavity. Ex: Cnidaria and Platyhelmenthes.
       B. Pesudocoelomate: Animals with a partial body cavity. Ex: Nemotodes
       C. Coelumate: Have a true body cavity. Ex: 1st phylum-> Mollusca
   Advantage: Place for organs to be/sit.
    - Digestive system can now be much longer.
    - Reproductive organs can be larger and can produce more gamytes/zygotes. (Cells)

* Developmennt of the circ. system parelled the evolution of the coelum.6.[image]

6. Development of Digestive System in Early Embryo (protostomic/ Deyterosone)

[image]

*Protostoms: The first indentation of the digestive system becomes the mouth.

*Deuterostomes: The first indentation becomes the anus.

-The only deuterstomes are Echinodermadia and Cordadita.

7. Segentation

 -Division of the body into sections.

 -First occurs in phylum Amelida.

 -Advantages:A. Organized development.

                   B. Damage to 1st segment NOT as servre.

                   C. Efficency/ improvements in movement.

1. To sence envirnment using 5 sences.

2. To control/ regulate body activities quickly.

1. C.N.S. -> includes brain/spinal cord.

2. P.N.S. -> includes nerves outside of control nervous systems.

        A. Sensory nerves

        B. Motor nerves

Nerve cell (neuron)

Human Neuron

[image]

1. Resting Neutron

[image]

• positive charge on outside of axon due to Na+
• maintained by Na/K/ATP pump
• "polarized"
• uneaqual distrabution of charge
  

2. Neuron is Stimulated

      A.When the neuron is stimulated: sodium gates open & sodium ions rush into the cell->causes a tempory reversal of charge.
                 -membrane is depolarized.

      B. Neghboring sodium gates are stimulated to open.-> Wave of depolarization is moving down axon termonous.= Action potential.

      C. Preparing to send another impluse: once action passes by, nuron has to restablish the initial changes in order to send another impluse.=repolarization.

         - Acompished by pumping Potasium (K+) out.

         - Neurotransmitters must be broken down or vaccumed up back in axon terminal.

[image]

      D. What happens when action potential gets to the end of the neuron (axon)??

When it comes to an end, it causes vesicles to fuse with cell membrane, causing them to rupture and release neuro transmitters into synapses. Then they defuse across the synapses go across to recptors and will bind to them on the next cell causing it to move.-> impluse to be generated. [image]

       - Chemicals found in vesicles  in the axon terminal neuro transmitters.

[image]

Cerebrum: Frontal Lobe 

                         -thinking, logic, analysis

                         - emotion -(includes motor cortex)

               Parietal Lobe

                         - Speech centers

                         - (includes sensory cortex)

               Occipital Lobe

                         - Vision

               Temporal Lobe

                         - sound/ hearing centers

                         - memory

Cerebellum: -balance

                 - muscle coordination

Brainstem: Medulla Oblongata

                         -Digestion, breathing, blood pressure-uncountous control

                         - Balance

1. Parifera

Characteristics of sponges:

   -Simplest phylum of animals

   -Most are marine: Salt water= 99%, Fresh water= 1%

   -Have a skeletal System

*They are the simplest. Why?

   -Adult is attached to ground (sessile)

   -No symmetry

   -Filter feeders

      *No storage of food

      *No external digestion

      *Limited food source=small foods

   -No muscle or nervous tissue

   -No respritory, circulatory, urinary systems.

   -Capable of asexual reproduction.

2. Cnidaria

Characteristics of Cnidaria:

 Ex: Jellyfish, Coral, Sea Anemony, Sea Fan, Hydra

   -Mostly Marine (except hydra-> fresh water)

   -Tenticles avec stinging cells (nomatisist)

   -2 body forms: medusa and polyp

*Radial symmetry

[image]

Advancements over sponges:

*Have nervous/muscle tissue "Nerve net"

*Have a digestive system (only 1 digestive opening for waste and eating)

*Can eat larger prey

[image]