Animal Kingdom: Comparative Anatony

• All animals are grouped as either an invertebrate or a vertebrate:

  • 95% of all animals are invertebrate organisms. The animals do not have backbone or vertebral column
  • 5% of all animals are vertebrates. These animals do have a backbone.
• What do animals do to survive?

  All animals have eukaryotic cells with no cell walls

  All animals are heterotrophs

  All animals carry out essential functions
• All animals carry out essential functions such as:

  • Feeding
  • Respiration
  • Circulation
  • Reproduction
  • Excretion
  • Movement
  • Response
• Feeding depend of how they evolve in their niche:

  • Most animals do not absorb food; instead they ingest it
  • Animals range from filter feeder and herbivores to carnivores and from commensalites to parasite.
  • All animals have developed different mouth structures and different digestive systems based on food and environmental adaptations
• Arthtropods are the largest group of invertebrates
• Sea turtles feed on jellyfish (like plastic so they tend to ingest plastic)
• Invertebrates can either have intracellular or extracellular digestion
• Intracellular digestion meaning the food is digested within each individual cell of the organism (dont have digestive tract)

  • Example: Sponges ingest food by phagocytosis
• Extracellular digestion means that digestion occurs inside a digestive tract or cavity, then absorbed into the body.

  • Examples: mollusks, worms, arthropods, echinoderms
• Proventriculus is between the pharynx and the gizzard. it is also called as crop.

  • It is a glandular part of the stomach that may store or commence digestion of food before it progresses to gizzard.
  • It is usually were the digestion primary begins
  • Secretes hydrochloric acid and pepsinogen
• Mammalian Teeth:

  • Incisors: chisel-like incisors are used for cutting, gnawong, and grooming (it can alos be used to identify age)
  • Canine: are pointed teeth. Carnivores use them for piercing, gripping, and tearing. In herbivores, they are reduces or absent.
  • Molar and premolar: molars crush and grind food. The ridged shape of the wolf's molars and premolars allows them to interlock during chewing, like blades of scissors. The broad, flattened molars and premolars of horses are adapted for grinding tough plants
• Turtle have no teeth instead they have tomium
• Woodpeckers' skull is thicker to protect the brain and their tongues have barbs to catch insect
• The digestive system of many vertebrates have organs that are well adapted for different feeding habits
• Carnivores, such as sharks, have short digestive tarcts that produce fast-acting enzymes.
• Meat eaters have fast metabolism and short intestines since they dont digest cellulose and meat is easy to digest
• Herbivores have long intestines that have large colonies of bacteria that help in digesting the cellulose fibers in plants. Their long intestine allows complete digestion of cellulose and they have long metabolism because of cellulose. They have active cecum that store bacteria for digestion
• Respiration in animals depend on the environment.
• Whether they live in water or on land, all animals must respire.
• To respire means to take in oxygen and give off carbon dioxide
• Acid+grind food = maximize digestion
• Expansion of lungs= exchange of gases or air
• Some animals rely on simple diffusion through their skin to respire (amphibians)
• While otherr have developed large complex organ systems for respiration
• Chordates have one or two basic structures for respiration:

  1. Gills- for aquatic chordates
  2. example: tunicates, fish and amphibians
• 2. Lungs- for terrestrial chordates

  Example: adult amphibians, reptilesm birdsm and mammals
• Amphibians respire through their skin
• Birds have one way pathway of air, their lungs dont expand instead they have air sacs. They need to be light to fly at high altitude. They have 7 air sacs, 3 paired, 1 unpair
• Fish respire through their gills. water movement= respiration
• Water flows through the mouth then over the gills where oxygen is removed. Carbon dioxide and water then are pumped out through the operculum
• MOuth- water flows in thorugh the fish's mouth. Muscles pump the water across the gill

  Operculum (gill cover)- water and carbon dioxide are pumpep out through the operculum.

  Gill filament- each gill contains thousands of filaments that absorb oxygen from the water
• Mouth (water with o2)-gills-gill filaments (blood take o2)-operculum (water and co2 pumped out)

  • absorbing free o2 in its blood through its blood through gills or directly through its body surface
• Gill filament provides large surface area for exchange of gases. Large surface area are crucial for aquatic organisms as water contains littel amount of dissolved o2
• Gills are the primary respiratory orogan contains tiny blood vessels
• The basic function of all of the different types of respiratory organ system is to bring oxygen rich air from outside the body through the trachea and into the lungs.

  • This allows for oxygen to reach the bloodstream and carbon dioxide to leave the bloodstream
• As you move from amphibians to mammals the surface area of the lungs increases in order to allow great amount of ggas exchange (or two way flow of air)
• Birds, by contrast, have lungs and air sacs which have only one-way flow of air. This allows them to have consttnat contact with fresh air. This adaptation enables them to fly at high altitudes where there is less oxygen
• Circulation system are the systems used to transport oxygen through the body to the cells so the can perform the essential process of cellular respiration
• Open circulatory system- blood is pumped through a system of vessels. But it is only partially contained in these vessels. Most of the time the blood is pumped through open cavities.

  • This system is beneficial to arthropods and mollusks because the blood comes into direct contact organs
• Open circulatory system- pumps blood into a hemocoel which surrounds the organ, with blood diffusing back to the circulatory system between cells. This mixes the blood with interstitial fluid