Download Biology 2

Comparative Anatomy 1
Biology 2
Tuesday, April 2, 2013
CO2
Integumentary, Skeletal and
Muscular Systems
O2
Respiratory System
CO2
Protection, Support
and Movement
O2
CO2
all cells
CO2+H2O +E
NH3+ urea
sugar + O2
amino acids
sugars
fatty acids
amino acids
carbs
fats
proteins
Reproductive
System
perpetuate
species
Tuesday, April 2, 2013
O2
Circulatory
System
NH3
sugar
food
Excretory
System
NH3
H2O, Salt
NH3
Nervous
System
control
by electrical
signal
eggs/sperm
O2
hormones
Digestive System
carbs
sugars
fats
fatty acids
proteins amino acids
feces
Endocrine
System
control
Homeostasis
• regulating internal environment at relatively
stable conditions (e.g. T, H2O, BP)
Negative Feedback
Sensor
monitors
parameter
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Regulatory Center
interprets data
Effector
responds
Comparative Anatomy
• study of similarities and differences between
organisms
Tuesday, April 2, 2013
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)
Tuesday, April 2, 2013
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
Tuesday, April 2, 2013
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.
Tuesday, April 2, 2013
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
• blood flow opposite water flow
If same direction:
Opposite direction:
100 90 80 70 60 50
100 80 60 40 20 10
0 10 20 30 40 50
90 70 50 30 10 5
Increases efficiency
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.
Tuesday, April 2, 2013
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.
inhale 1
posterior
air sacs
exhale 1
Tuesday, April 2, 2013
lungs
trachea
exhale 2
anterior
air sacs
inhale 2