Comparative Anatomy 1 - University of Rio · PDF fileComparative Anatomy ... April 2, 2013....

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


Comparative Anatomy

• study of similarities and differences between organisms


Circulatory Systems

• function to transport materials throughout body

• types:

• none

• open circulatory system

• closed circulatory system


No Circulatory System

• lower animal phyla - sponges, jellyfish, flatworms

• each cell exposed to water from skin or gastrovascular cavity


No Circulatory System

• Some animals use body cavity to circulate fluids

• Nematodes use pseudocoelom

• Echinoderms use coelom


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)


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


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


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


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


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


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.


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


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.


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)


Respiratory Systems

• function for gas exchange

• exchange regions must be thin, moist, large

• types:

• body surface

• gills

• trachea

• lungs


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.


Gills

• used by larger aquatic organisms - clams, crabs, fish

• consist of thin, branched membranes

• vertebrates - form from pharynx

• inverts - form from body wall


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


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.


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.


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.


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


Comparative Anatomy 1 - University of Rio · PDF fileComparative Anatomy ... April 2, 2013....

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