NUTRITION IN ANIMALSTypes of digestive systems

WHAT IS DIGESTION? Digestion is the mechanical and chemical

breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones.

TYPES OF DIGESTION IN ANIMALS: . External digestion is more primitive, and

most fungi still rely on it.[3] In this process, enzymes are secreted into the environment surrounding the organism, where they break down an organic material, and some of the products diffuse back to the organism gastrovascular cavity:Extracellular digestion takes place within this cavity. It has only one opening to the outside that

functions as both a mouth and an anus.

INTERNAL DIGESTION Animals form a tube in which internal

digestion occurs, which is more efficient because more of the broken down products can be captured, and the internal chemical environment can be more efficiently controlled.[4]

STAGES IN THE DIGESTIVE PROCESS Breaking these large molecules into smaller

components involves: Ingestion: the intake of food movement: propels food through the digestive

system secretion: release of digestive juices in response to a

specific stimulus digestion: breakdown of food into molecular

components small enough to cross the plasma membrane

absorption: passage of the molecules into the body's interior and their passage throughout the body

elimination: removal of undigested food and wastes

CUTANEUS RESPIRATION: GAS EXCHANGE IS CARRIED OUT THROUGH THE SKIN. The Body Surface: moist skin Flatworms and annelids use their outer

surfaces as gas exchange surfaces. Earthworms have a series of thin-walled blood vessels known as capillaries. Gas exchange occurs at capillaries located throughout the body as well as those in the respiratory surface.

Adult Amphibians use their skin as a respiratory surface.

RESPIRATION IN ANIMALS: A WAY TO INTAKE OXYGEN- BRANCHIAL RESPIRATION

GILLS AND TRACHEAE: TRACHEAL RESPIRATION. TRACHEAE END IN ORIFICES CALLED SPIRACLES

GILLS IN FISH: FISH NEED TO MOVE IN ORDER TO TAKE OXYGEN.

PULMONARY RESPIRATION: LUNGS Internal cavities which have very thin, damp

walls full of blood vessels. Movements: inhalation and exhalation (Inhalar y exalar) Vertebrates and some invertebrates like

terrestrial snails. http://

www.youtube.com/watch?feature=player_embedded&v=obnAWTWdV7c

http://www.youtube.com/watch?v=rNTEOCFmOIQ

CIRCULATORY SYSTEM: IT CARRIES OXYGEN AND NUTRIENTS TO THE CELLS AND REMOVES CARBONDIOXIDE AND WASTES Types: 1. Open circulatory system: the heart pumps

the fluid through the body cavity directly to the organs. (Molluscs and arthropods)

2. Closed circulatory system: The blood always circulates inside blood vessels pumped by a heart. Simple (fish) and double (mammals)

Simple: the blood passes once through the heart and the gills.

Double: the blood passes through the heart twice. First loop: heart-lungs-heart

Second loop: heart-body-heart

OPEN AND CLOSE CIRCULATORY SYSTEMS

SIMPLE AND DOUBLE CLOSE CIRCULATORY SYSTEMS:

EXCRETION: THE PROCESS OF COLLECTING WASTE PRODUCTS AND EXPELLING THEM OUTSIDE. Carbon dioxide: respiratory system Ammoniac and urea: excretory system

Some animals expel wastes directly through the

pores (sponges) Insects: Malpighian tubules Vertebrates: Kidneys, ureteres, bladder and

urethra.

VERTEBRATES: KIDNEYS

FLAT WORMS: DIRECTLY TRHOUGH THE PORES, CONDUCTS (B)

INSECTS: MALPIGHIAN TUBULES