Comparative Anatomy 1Biology 2
Tuesday, April 2, 2013
all cellssugar + O2 CO2+H2O +Eamino acids NH3+ urea
sugars carbsfatty acids fatsamino acids proteins
Respiratory System
CirculatorySystem
Endocrine System
Integumentary, Skeletal and Muscular Systems
Nervous System
CO2
CO2
CO2
O2
O2
O2
O2
Excretory System
H2O, Salt
Digestive System
fecesfood
Protection, Support and Movement
hormones
control
controlby electrical
signal
NH3
NH3
NH3
carbs sugarsfats fatty acids
proteins amino acids
sugar
Reproductive System
perpetuatespecies
eggs/spermTuesday, April 2, 2013
Homeostasis
• regulating internal environment at relatively stable conditions (e.g. T, H2O, BP)
Sensormonitors
parameter
Regulatory Centerinterprets data
Effectorresponds
Negative Feedback
Tuesday, April 2, 2013
Comparative Anatomy
• study of similarities and differences between organisms
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Circulatory Systems
• function to transport materials throughout body
• types:
• none
• open circulatory system
• closed circulatory system
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No Circulatory System
• lower animal phyla - sponges, jellyfish, flatworms
• each cell exposed to water from skin or gastrovascular cavity
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No Circulatory System
• Some animals use body cavity to circulate fluids
• Nematodes use pseudocoelom
• Echinoderms use coelom
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Open Circulatory System• see handout and figures in textbook
• fluid (hemolymph) not completely contained in vessels
• heart pumps hemolymph into blood vessels which deliver hemolymph to the tissue spaces
• Other vessels pick up fluid and carry through gills or other respiratory structures
• vessels eventually return fluid to pericardial cavity
• blood reenters heart through valved openings called ostia
• found in arthropods, molluscs (except cephalopods)
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Closed Circulatory System
• fluid (blood) completely contained within vessels
• blood flows from heart to arteries to capillaries to veins
• exchange of gases and , food and waste takes place in capillaries
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Annelids
• e.g. earthworms
• have a closed circulatory system
• they have 5 hearts which are enlarged, muscular blood vessels around the anterior gut.
• a dorsal blood vessel carries blood anteriorly and a ventral blood vessel carries blood posteriorly
Tuesday, April 2, 2013
Cephalopod Molluscs
• e.g. squid (see diagram in handout and lab)
• have a closed circularoty system
• 2 gill hearts pump blood to gills where blood picks up oxygen
• Blood flows from gills to a central system heart which pumps blood to the rest of body.
• Deoxygenated blood from all other organs flows back to gill hearts
Tuesday, April 2, 2013
Closed Circulatory System
• Vertebrates have a cardiovascular system consisting of a heart, arteries, veins and capillaries.
• The number of chambers in the heart increase from fish through birds/mammal evolution
• Circulation also progresses from a single loop to a double loop system
Tuesday, April 2, 2013
Fish
• See handout and textbook figures• Fish have a 2 chambered heart consisting of an atrium and a ventricle• The ventricle pumps blood to the gills where it picks up oxygen.•Blood flows from the gills to other parts of the body where oxygen is released and carbon dioxide and other wastes are picked up•Blood returns to the heart at the atrium
Tuesday, April 2, 2013
Amphibians• See handout and textbook figures• Amphibian circulation has 2 loops:
•Pulmonary circuit from the heart to the lungs and back •System circuit from the heart to the rest of the body and back.
• Amphibians have a 3 chambered heart consisting of right and left atria and a ventricle• Blood enters the heart at the right atrium and flows into the ventricle•The ventricle pumps blood into vessels that go to the lungs and the rest of the body.•Oxygenated blood from lungs flow into the left atrium and then the ventricle where it is mixed with deoxygenated blood.
Tuesday, April 2, 2013
Birds & Mammals
• See handout and textbook figures• Have pulmonary and systemic circuits• Have a 4 chambered heart consisting of right and left atria and right and left ventricles• The oxygenated blood is always on left side of heart and the deoxygenated blood is always on right side • There is no mixing of oxygenated and deoxygenated blood in heart - more efficient•Allows for endothermic lifestyle
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Reptiles
• See handout and textbook figures• System is similar to birds and mammals only the ventricle is only partly divided so there is some mixing of oxygenated and deoxygenated blood. Thus system is not as efficient.
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Control
• See textbook figures• The heart has a pacemaker (SA node) in the right atrium which sends out a signal causing the atria to contract.• The signal reaches the AV node which after a brief delay passes the signal to the ventricles causing them to contract at the same time•These electrical signals can be seen on an EKG (electrocardiogram)
Tuesday, April 2, 2013
Respiratory Systems
• function for gas exchange
• exchange regions must be thin, moist, large
• types:
• body surface
• gills
• trachea
• lungs
Tuesday, April 2, 2013
Body Surface
• Gases are exchanged across thin body surface
• Found in sponges, jellyfish, flatworms, roundworms, segmented worms.
• Starfish have dermal papulae between their skeletal plates and also use the thin tube feet for gas exchange.
Tuesday, April 2, 2013
Gills
• used by larger aquatic organisms - clams, crabs, fish
• consist of thin, branched membranes
• vertebrates - form from pharynx
• inverts - form from body wall
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Countercurrent Exchange
If same direction:
100 90 80 70 60 50
0 10 20 30 40 50
Opposite direction:
100 80 60 40 20 10
90 70 50 30 10 5
Increases efficiency
• blood flow opposite water flow
Tuesday, April 2, 2013
Tracheal System
• see figures in handout and textbook
• found in terrestrial arthropods, well-developed in insects
• Spiracles are openings to the system found on the abdomen.
• A network of trachea branch throughout the body
• Trachea end in tracheoles that are very thin and allow for gas exchange directly with tissues.
• Muscle movement moves air through the system.
Tuesday, April 2, 2013
Book Lungs
• found in spiders in anterior portion of abdomen
• Consist of thin membranes stacked like pages of a book
• Spiders also have a primitive tracheal system.
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Vertebrate Lungs• form as outgrowths of pharynx
• found in amphibians, reptiles, birds, mammals
• note increase in folding/surface area in evolution from amphibians to reptiles to mammals
• trachea - tube from mouth to lungs
• bronchi - tubes that branch from trachea into lungs
• bronchial tree - system of branching tubes within lungs
• alveoli - air sacs. These are surrounded by blood capillaries for oxygen exchange.
Tuesday, April 2, 2013
Birds• See handout and text diagrams
• Birds have a more efficient system than mammals with a one way flow
• Have anterior and posterior air sacs in addition to lungs.
• It takes 2 inhales and 2 exhales to move air through.
• No mixing of oxygenated and deoxygenated air.trachea
lungs
anteriorair sacs
posteriorair sacs
inhale 1
exhale 1inhale 2
exhale 2
Tuesday, April 2, 2013