Body Areas copyright cmassengale

Body Surfaces Dorsal – back or upper surface Ventral – belly or lower surface Anterior – head or front end Posterior – tail or hind end opposite the head copyright cmassengale

Surfaces (Most Animals) DORSAL POSTERIOR ANTERIOR VENTRAL copyright cmassengale

Symmetry copyright cmassengale

Body Symmetry Symmetry is the arrangement of body parts around a central plane or axis Asymmetry occurs when the body can’t be divided into similar sections (sponges) copyright cmassengale

Body Symmetry copyright cmassengale

Radial Symmetry Radial symmetry occurs when body parts are arranged around a central point like spokes on a wheel (echinoderms) Most animals with radial symmetry are sessile (attached) or sedentary (move very little) copyright cmassengale

Bilateral Symmetry Occurs when animals can be divided into equal halves along a single plane Organisms will have right and left sides that are mirror images of each other More complex type of symmetry Animals with bilateral symmetry are usually motile (they move) Animals have an anterior and posterior end Show cephalization (concentration of sensory organs on the head or anterior end) copyright cmassengale

copyright cmassengale

Segmentation copyright cmassengale

Segmentation Occurs whenever animal bodies are divided into repeating units or segments Found in more complex animals Earthworms show external segmentation Humans show internal segmentation (backbone) copyright cmassengale

Body Layers All worms, mollusks, arthropods, echinoderms, and vertebrates have three cell layers Ectoderm Endoderm Mesoderm copyright cmassengale

Animal Systems copyright cmassengale

Basic Animal Systems Chart Organ/Structures Purpose and Process Endocrine Glands (thymus, thyroid, pancreas…) Production of hormones. Hormones are produced in one location and arrive at another via the circulatory system. Digestive Mouth, esophagus, stomach, liver, small intestine, large intestine, rectum, anus To extract nutrients from food. Mouth and stomach allow for mechanical breakdown, small intestine removes nutrients from food through diffusion, large intestine removes excess water through osmosis. Respiratory Trachea, lungs, diaphragm To oxygenate blood and remove carbon dioxide. Processes occur through diffusion. Circulatory Heart, arteries, veins, capillaries Provide transport of molecules through blood that is pumped through the body. Molecules move through diffusion. Excretory Kidneys, bladder, ureters, urethera Remove metabolic wastes/salt/excess water to maintain homeostasis. Process are done through osmosis/diffusion. Reproductive Ovaries, uterus, vagina, penis, testicles For creating offspring.

Digestive Systems All animals are heterotrophs (ingest their food) Animals with a one-way digestive system have a mouth and an anus Food enters the mouth, continues in one direction through the digestive tract, and wastes leave through the anus Includes annelids, arthropods, & vertebrates copyright cmassengale

Circulatory Systems Transports oxygen & nutrients to cells Carries away wastes & carbon dioxide from cells Responds to changing demands by increasing or decreasing heart rate and blood flow in order to maintain homeostasis. Sponges, cnidarians, & flatworms do NOT have circulatory systems copyright cmassengale

Respiratory System Helps maintain homeostasis by allowing gas exchange (intake of oxygen/release of carbon dioxide). Responds to changing demands by increasing or decreasing breathing rate. Gases can diffuse across moist surfaces (earthworms) Gills filter O2 from water (aquatic animals) Lungs take O2 from air (terrestrial animals) Gills copyright cmassengale

Excretory System Excretion is the removal of nitrogen wastes from the body Diffusion is used by simple aquatic animals Terrestrial animals remove wastes with Kidneys May be paired (most vertebrates) copyright cmassengale

VERTEBRATE SYSTEMS System Description Function Skeletal Endoskeleton of bone and/or cartilage Provides support and protection Muscular Contractile tissue attached to bone or cartilage; some are part of internal organ walls Enables animals to move; protects some organs Integumentary Body covering of skin, hair, nails, scales, or feathers Provides support & protection; involved in excretion, respiration, and perception Digestive Tube extending from mouth to anus; includes mouth, esophagus, stomach, intestines, rectum, liver, pancreas, and gall bladder Prepares food for use by the animal's cells; removes solid wastes from the body Respiratory Gills or lungs and associated structures Exchanges gases between the animal and it's environment Circulatory Closed system of blood vessels with 2, 3, or 4 chambered hearts; includes arteries, veins, capillaries, and blood Carries blood from the heart to the rest of the body, transports gases, nutrients and wastes. Excretory Includes the kidneys, urinary bladder, ureters, and urethra; skin, lungs, and gills may also be involved Removes wastes from the body Nervous Brain, spinal cord, nerves, and senses Monitors the environment; controls & coordinates many body functions Reproductive Females - ovaries, fallopian tubes, uterus, vagina Males - testes, prostate, penis Produces and carries eggs & sperm; allows for internal or external fertilization & development Endocrine Glands - Thyroid, parathyroid, adrenals, pancreas, gonads, and pituitary Secretes chemicals (hormones) that regulate body growth, reproduction & development

Animal Reproduction Reproduction is the process by which organisms make more of their own kind All animals reproduce by sexual reproduction - produce eggs and sperm Some animals also use asexual reproduction - creating identical offspring copyright cmassengale

Types of Animal Asexual Reproduction Regeneration or Fragmentation is the breaking off of pieces and the re-growth of a new organism Found in simple animals like Sponges and Flatworms Budding occurs in hydra whenever a growth on the parent is released Creates a clone copyright cmassengale

Parthenogenesis – females produce eggs that develop unfertilized into female organisms Komodo dragon is an example copyright cmassengale

Hermaphrodites are animals like earthworms that produce BOTH eggs and sperm Most hermaphrodites do NOT fertilize their own eggs Mate to exchange sperm copyright cmassengale

Fertilization External – sperm and eggs are released into water where they are fertilized Internal – sperm and egg are fertilized inside the female animal’s body copyright cmassengale