Download Animal Kingdom: Comparative Anatomy

Lecture 20: Comparative anatomy
What do animals do to survive?
All Animals
have
are
carry out
Eukaryotic
cells
Heterotrophs
Essential
functions
with
such as
No cell walls
Feeding
Respiration
Circulation
Excretion
Response
Movement
Reproduction
Invertebrate feeding and digestion:
 Invertebrates can either have intracellular or extracellular digestion:
 Intracellular meaning that food is digested within each individual
cell of the organism.

Examples: Sponges
 Extracellular means that digestion occurs inside a digestive tract or
cavity, then absorbed into the body.

Examples: mollusks, chordates, arthropods, echinoderms
Invertebrate digestive systems:
Section 29-2
Intestine
Gizzard
Crop
Mouth/anus
Pharynx
Mouth
Gastrovascular
cavity
Anus
Gastrovascular
cavity
Annelida
Coelenterata
Pharynx
Crop
Anus
Pharynx
Mouth
Mouth/anus
Flatworm
Stomach
and
digestive glands
Rectum
Intestine
Arthropoda
Vertebrate digestive systems:
 The digestive systems of many vertebrates have organs that are well
adapted for different feeding habits.
 Carnivores, such as sharks have short digestive tracts that produce fastacting digestive enzymes.
 Herbivores have long intestines that have large colonies of bacteria
that help in digesting the cellulose fibers in plant tissues.
The
Digestive
Systems
of
Vertebrates
Section 33-3
Esophagus
Stomach
Intestine
Liver
Gallbladder
Pancreas
Cloaca
Crop
Gizzard
Cecum
Rectum
Shark
Salamander
Lizard
Pigeon
Cow
Respiration in animals:
Aquatic invertebrates:
 Some respire through diffusion through their skin and others use gills.
Terrestrial Invertebrates:
 There are many different respiratory organs in terrestrial invertebrates:
 Spiders use parallel book lungs.
 Insects use openings called spiracles where air enters the body and
passes through tracheal tubes for gas exchange.
 Snails have a mantel cavity that is lined with moist tissue and an
extensive surface area of blood vessels.
Invertebrate respiratory systems:
Tracheal
tubes
Gill
Siphons
Movement of water
Spiracles
Mollusk
Insect
Airflow
Spider
Book
lung
Vertebrate respiratory systems:
 Chordates have one of two basic structures for respiration:
• Gills – for aquatic chordates.
Example: fish and amphibians.
• Lungs - for terrestrial chordates.
Examples: adult amphibians, reptiles, birds, and mammals.
Vertebrate Gills:
 Water flows through the mouth then over
the gills where oxygen is removed.
 Carbon dioxide (CO2) and water are then
pumped out through the operculum.
Vertebrate Lungs:
Nostrils, mouth, and throat
Trachea
Lung
Air sac
Salamander
Lizard
Primate
Pigeon
Invertebrate circulatory systems:
Open circulatory systems:
 The blood is pumped through open cavities.
 This system is found in arthropods and mollusks.
Closed circulatory systems:
 A closed system forces blood through vessels that extend
throughout the body of the organism.
 Since the system is “closed” the blood never leaves the vessels.
 This system is found in Annelids and chordates.
Invertebrate Circulatory Systems:
Section 29-2
Heartlike structure
Hearts
Small vessels in tissues
Blood
vessels
Heart
Sinuses
and organs
Heartlike
structures
Insect:
Open Circulatory System
Blood
vessels
Annelid:
Closed Circulatory System
Vertebrate circulatory systems:
 Chordate circulatory systems range from a single loop system (found
in organisms with gills) to double loop systems.
Single-Loop Circulatory System
Fishes
Double-Loop Circulatory System
Most Reptiles
Crocodilians, Birds, and Mammals
Aquatic Invertebrate excretion:
 Some aquatic invertebrates diffuse ammonia out their bodies into the
surrounding water where it is diluted and carried away.
 Example: sponges, coelenterate, and some round worms.
 Other aquatic invertebrates swell up with water, dilute the wastes and
excrete the wastes through tiny pores in their skin.
Terrestrial Invertebrate excretion:
 Many terrestrial invertebrates convert ammonia into urea.
 Urea is a simpler nitrogenous compound that is much less toxic than
ammonia.
 This urea is eliminated from the body in urine.
Invertebrate
Excretory
Systems
Section 29-2
Flatworm
Flame cells
Excretory tubules
Excretory pore
Flame cell
Excretory tubule
Nephridia
Digestive tract
Annelid
Malpighian tubules
Arthropod
Vertebrate Excretion:
 Aquatic
vertebrates:
Most
of
the
nitrogenous wastes (including large
amounts of
ammonia, NH3) leave
by diffusion out of the gills.
 Terrestrial vertebrates: rely on the
kidney’s to filter the urea and send it out
in urine.
Nervous system:
 All animals respond to their environment through specialized cells
called nerve cells.
 In most animals, nerve cells hook together to form the nervous
system.
 Nervous systems can range from fairly simple to extremely complex.
Section 29-2
Invertebrate Nervous Systems
Arthropod
Brain
Ganglia
Ganglia
Brain
Flatworm
Mollusk
Vertebrate Nervous Systems