Comparative AnatomyComparative AnatomyCirculatory SystemCirculatory System

Kardong Kardong Chapter 12 Chapter 12

Part 13

Cardiovascular SystemCardiovascular System ArteriesArteries

Carry blood away from the Carry blood away from the heartheart

Muscular, elastic fibrous Muscular, elastic fibrous walls (see next figure) walls (see next figure)

Regulates blood pressureRegulates blood pressure Terminate in capillary bedTerminate in capillary bed

VeinsVeins Carry blood toward the Carry blood toward the

heartheart HeartHeart

Modified blood vesselModified blood vessel

Figure 13.1. Cross section of artery and vein.

Arteries, Veins, and Capillaries

Figure 13.2. Blood vessel microanatomy..

Figure 13.3. Basic circulatory pattern of amniote embryo.

Aortic arches- Within pharyngeal arches

Figure 13.4-5. Embryological development of aortic arches (see book figures 12.9 -10).

Aortic arches- Within pharyngeal arches (discussed later)

Portal SystemsPortal Systems

Veins that drain an organ and dump blood Veins that drain an organ and dump blood into another organ instead of heartinto another organ instead of heart

Figure 13.6. Portal systems of craniates.

Portal SystemsPortal Systems (cont’d.) (cont’d.) HepaticHepatic

Drains small intestine into liverDrains small intestine into liver RenalRenal

Drains venous channels of tail into Drains venous channels of tail into kidneyskidneys

HypophysealHypophyseal Drains hypothalamus into sinusoids of Drains hypothalamus into sinusoids of

anterior pituitaryanterior pituitary SmallestSmallest

Figure 13.7. Hepatic and renal portal systems of shark (book figure 12.11).

Portal Systems (cont’d.)Portal Systems (cont’d.)

Figure 13.8. Hypophyseal portal system (book figure 15.15) .

In a typical tetrapod, the heart pumps blood: In a typical tetrapod, the heart pumps blood: By pulmonary arteries, from heart to lungs By pulmonary arteries, from heart to lungs

(blood returns to heart by pulmonary veins)(blood returns to heart by pulmonary veins) By aorta to systemic circulation…By aorta to systemic circulation…

Fish heart – tube-likeFish heart – tube-like 4 chambers: 4 chambers:

Sinus venosusSinus venosus AtriumAtrium VentricleVentricle Conus arteriosusConus arteriosus

HeartHeart

Figure 13.9. Four chambers of heart in most fishes (book figure 12.26).

Fish Heart (cont’d.)Fish Heart (cont’d.)

Fish heart Fish heart Sinus venosusSinus venosus AtriumAtrium VentricleVentricle Conus arteriosus*Conus arteriosus*

Figure 13.10. Fish with four chambered heart (book figure 12.27).

Fish Heart (cont’d.)Fish Heart (cont’d.)

Sinus venosusSinus venosus Thin-walled venous chamberThin-walled venous chamber Receives blood from ducts of Cuvier, coronary Receives blood from ducts of Cuvier, coronary

veins, hepatic veinsveins, hepatic veins AtriumAtrium

Large and thin walledLarge and thin walled Dorsal to ventricleDorsal to ventricle

VentricleVentricle Dumps into conus artriosus- continuous with aortaDumps into conus artriosus- continuous with aorta Chambers separated by valves: sino-atrial note, Chambers separated by valves: sino-atrial note,

sino-ventricular node, semi-lunar valvesino-ventricular node, semi-lunar valve Conus arteriosus (bulbus cordis in embryos)Conus arteriosus (bulbus cordis in embryos)

Short in bony fish and amphibiansShort in bony fish and amphibians Termed Termed bulbous arteriosusbulbous arteriosus (if walls lack cardiac (if walls lack cardiac

muscle, but contains smooth muscle)muscle, but contains smooth muscle) Not found in adult amniotesNot found in adult amniotes

Fish Heart (cont’d.)Fish Heart (cont’d.)

Figure 13.11. Heart chambers, oxygenated blood flow (red), and septum modification .

Phylogeny of the HeartPhylogeny of the Heart

Lungfish and Amphibian vs DogfishLungfish and Amphibian vs Dogfish

Modifications of partial or complete partition Modifications of partial or complete partition in atriumin atrium Left and right atriaLeft and right atria

Advent of lungsAdvent of lungs Double circulationDouble circulation Modification in conus arteriosusModification in conus arteriosus Semi-lunar valve modified to shunt deoxygenated Semi-lunar valve modified to shunt deoxygenated

blood to lungs (spiral valve)blood to lungs (spiral valve)

Spiral ValveSpiral Valve

Figure 13.12. Spiral valve in dipnoans; longitudinal folds of conus lining (book figure 12.29).

Figure 13.13. Spiral valve in anurans; single flap (book figure 12.30).

Amphibian HeartAmphibian Heart Spiral valve directs Spiral valve directs

oxygenated blood entering oxygenated blood entering ventricle from left atriumventricle from left atrium

Conus (termed truncus Conus (termed truncus arteriosus when greatly arteriosus when greatly reduced)reduced)

Bulbus arteriosusBulbus arteriosus Swelling of ventral aortaSwelling of ventral aorta Smooth muscleSmooth muscle

Figure 13.14. Three chambered frog heart.

Urodele - partially divided circulationUrodele - partially divided circulation Right and left atriumRight and left atrium Sinus venosus dumps into right Sinus venosus dumps into right

atriumatrium Pulmonary veins leave left ventriclePulmonary veins leave left ventricle

Reptile - fully divided circulationReptile - fully divided circulation

Figure 13.15-16. Salamander heart chambers (left) and circulation path (book figures 12.16 and 12.31).

Amphibian Heart (cont’d.)Amphibian Heart (cont’d.)

Reptile HeartReptile Heart Cavum venosum (CV) - internal pocket e.g., turtleCavum venosum (CV) - internal pocket e.g., turtle Blood collected from post cava through sinus Blood collected from post cava through sinus

venosus to precavavenosus to precava To right atriumTo right atrium Venous blood to CVVenous blood to CV Cavum pulmonaleCavum pulmonale Into pulmonary artery to lungsInto pulmonary artery to lungs Oxy. blood returns through pulmonary veins in left atriumOxy. blood returns through pulmonary veins in left atrium Back to CVBack to CV To left and right aortic trunkTo left and right aortic trunk

Figure 13.17. Chelonian heart chambers and circulation path (see book figure 12.33).

Turtle Heart

Squamate Heart

Figure 13.18. Squamate heart chambers and circulation path (book figure 12.35).

Crocodilian HeartCrocodilian Heart

Mechanism for breathing and divingMechanism for breathing and diving Lungs not utilizedLungs not utilized Blood not pumped to lungsBlood not pumped to lungs

Foramen of PanizzaForamen of Panizza Valve between aortic trunks to divert bloodValve between aortic trunks to divert blood Allows left ventricle to pump to both arches when Allows left ventricle to pump to both arches when

right ventricle closedright ventricle closed Underwater right ventricle helps pump Underwater right ventricle helps pump

systemic bloodsystemic blood

DivingDiving

Semilunar valve in right aorta closed when above waterSemilunar valve in right aorta closed when above water Semilunar valve forced open when submerged in water to Semilunar valve forced open when submerged in water to

divert pulmonary circulationdivert pulmonary circulation

(a) (b)

Figure 13.19. Crocodilian blood circulation when (a) diving and when (b) on the surface.

Two Aortic TrunksTwo Aortic Trunks

Figure 13.20. Turtle heart and two aortic trunks emerging . Figure 13.21. Crocodilian foramen of

Panizza connects two aortic trunks at base (see book figure 12.36).

Higher Amniote HeartHigher Amniote Heart

4 chambered heart 4 chambered heart 2 atria and 2 ventricles 2 atria and 2 ventricles

Birds and mammalsBirds and mammals Sinus venosus - 5Sinus venosus - 5thth chamber in reptile heart chamber in reptile heart

Becomes sino-atrial nodeBecomes sino-atrial node In embryo, right and left atria are not separatedIn embryo, right and left atria are not separated

Foramen ovaleForamen ovale Fossa ovalisFossa ovalis

Auricle- flap on side of atriumAuricle- flap on side of atrium

Adult Mammalian HeartAdult Mammalian Heart

Figure 13.22. Adult heart blood flow (see book figure 12.42).

Aortic ArchesAortic Arches

Basic pattern has 6 aortic archesBasic pattern has 6 aortic arches Major arterial channelsMajor arterial channels

Ventral aortaVentral aorta Dorsal aortaDorsal aorta 6 pairs of aortic arches 6 pairs of aortic arches

connects ventral aorta connects ventral aorta and dorsal aortaeand dorsal aortae

Reptiles - additional archReptiles - additional arch

Figure 13.23. Adult heart blood flow (book figure 12.13).

Aortic Arches Aortic Arches (cont’d.)(cont’d.)

Figure 13.25. Ventral perspective of aortic arches (book figure 12.19).

Figure 13.24. Basic pattern of aortic arches and dorsal aortae.

Figure 13.26. Left aortic arches (see book figure 12.17).

Aortic Arches Aortic Arches (cont’d.)(cont’d.)

TeleostTeleost 11stst and 2 and 2ndnd arches lost arches lost Dorsal aortae become internal carotidsDorsal aortae become internal carotids

Lung fishLung fish Pulmonary artery from 6Pulmonary artery from 6thth arch arch

TetrapodsTetrapods Pulmonary artery from 6Pulmonary artery from 6thth arch arch 55thth arch lost arch lost

Figure 13.27. Aortic arches, internal carotids (ic) and pulmonary artery (book figure 12.14).

Tetrapod Aortic ArchesTetrapod Aortic Arches

11stst and 2 and 2ndnd arches lost arches lost Dorsal segment dropped between Dorsal segment dropped between

33rdrd and 4 and 4thth arches arches Ductus caroticusDuctus caroticus

Figure 13.28. Adult aortic arches (see book figure 12.17).

Tetrapod Aortic Arches Tetrapod Aortic Arches (cont’d.)(cont’d.)

33rdrd arch extends to internal carotids arch extends to internal carotids Carotid archCarotid arch

Ventral aorta extensionVentral aorta extension External carotidExternal carotid

Common carotid at base between 3Common carotid at base between 3rdrd and and 44thth

Figure 13.29. Aortic arches, internal carotid (ic), external carotic (ec) and common carotid (cc) (book figure 12.14).

Tetrapod Aortic Arches Tetrapod Aortic Arches (con’t)(con’t)

55thth arch lost arch lost Dorsal segment of 6Dorsal segment of 6thth arch lost arch lost 44thth arch - no anterior connection arch - no anterior connection

Aortic arch (systemic arch)Aortic arch (systemic arch) 66thth arch arch

Pulmonary archPulmonary arch Ex: adult anuranEx: adult anuran

Figure 13.30. Adult aortic arches (book figure 14.19).

Figure 13.31. Modifications of aortic arches and dorsal aortae into mature mammalian vascular system.

Aortic Arch SummaryAortic Arch Summary UrodeleUrodele

Ductus caroticusDuctus caroticus Ductus arteriosus Ductus arteriosus

- dorsal segment of 6- dorsal segment of 6thth arch arch ReptilesReptiles

11stst and 2 and 2ndnd arches lost arches lost Ductus caroticus lostDuctus caroticus lost 55thth arch lost arch lost Ductus arteriosus lostDuctus arteriosus lost Additional aortic arch introducedAdditional aortic arch introduced

Arch from left side loops rightArch from left side loops right Arch from right side loops leftArch from right side loops left

Figure 13.32. Modifications of aortic arches and their derivative in anamniotes (book figure 12.14).

Mammalian Aortic ArchesMammalian Aortic Arches 33rdrd, 4, 4thth, 5, 5thth, & 6, & 6thth retained embryonically retained embryonically Adults- 1Adults- 1stst and 2 and 2ndnd dropped dropped 33rdrd carotid arch carotid arch 44thth systemic arch systemic arch 55thth lost lost Dorsal segment of 6Dorsal segment of 6thth lost lost

Retained embryonically- ductus Retained embryonically- ductus arteriosus (ligamentum arteriosum)arteriosus (ligamentum arteriosum) Figure 13.33. Adult aortic

arches (book figure 12.19).

Figure 13.34. Left aortic arches (book figure 12.17).

Bird Aortic ArchesBird Aortic Arches

Right portion of aortic arch is retained and left Right portion of aortic arch is retained and left is lost (opposite to mammals)is lost (opposite to mammals)

Birds have right aortic archBirds have right aortic arch Mammals have left aortic archMammals have left aortic arch

Venous SystemVenous System

Sinus venosus - where all blood Sinus venosus - where all blood returnsreturns Feed by common cardinals and Feed by common cardinals and

subclavian veinssubclavian veins Shark renal portal system - drains Shark renal portal system - drains

blood from tail before entering post blood from tail before entering post cardinal (book figure 12.21)cardinal (book figure 12.21)

Figure 13.35. Modifications of basic venous patterns showing sinus venosus (S) (book figure 12.21).

Venus SystemVenus System

Major venous channelsMajor venous channels Cardinals: anterior, posterior, commonCardinals: anterior, posterior, common Renal portalRenal portal Lateral abdominalsLateral abdominals Vitellines- associated with hepatic portal systemVitellines- associated with hepatic portal system Coronary veinsCoronary veins

Additional characteristics of higher vertebratesAdditional characteristics of higher vertebrates PulmonaryPulmonary Posterior vena cavaPosterior vena cava

Common cardinals - directs blood to sinus Common cardinals - directs blood to sinus venosusvenosus

Anterior cardinals - receives blood from headAnterior cardinals - receives blood from head Post cardinals - receives blood from kidneysPost cardinals - receives blood from kidneys Renal portal - receives blood from caudal veinRenal portal - receives blood from caudal vein Lateral abdominals- receives blood from Lateral abdominals- receives blood from

abdominal stream to iliac (lateral wall of body)abdominal stream to iliac (lateral wall of body) Hepatic portal veins - receives blood from intestine into liverHepatic portal veins - receives blood from intestine into liver Hepatic veins – direct blood into sinus venosusHepatic veins – direct blood into sinus venosus

Venus SystemVenus System

Modifications to Basic Modifications to Basic Venous SystemVenous System

Post cardinal lost in adult anuransPost cardinal lost in adult anurans Post cavaPost cava- new vessel- new vessel

Post cava drains kidneys in turtlePost cava drains kidneys in turtle External iliac veinExternal iliac vein connects lateral abdominals and connects lateral abdominals and

renal portal systemrenal portal system

Most mammals lose renal portal systemMost mammals lose renal portal system Pre-cava- common cardinals in higher vertsPre-cava- common cardinals in higher verts Internal jugular- anterior cardinal veinsInternal jugular- anterior cardinal veins Anterior vena cava- only right pre-cava retainedAnterior vena cava- only right pre-cava retained

Modifications to Basic Modifications to Basic Venous SystemVenous System

Modifications to Basic Modifications to Basic Venous SystemVenous System

Azygous- vestige of right Azygous- vestige of right post cardinal veinspost cardinal veins

Hemiazygous- remnant of Hemiazygous- remnant of left post cardinalleft post cardinal

Inferior vena cava- post Inferior vena cava- post cavacava

(a) (b)

Figure 13.36. Ventral view of anterior venous channels of cat and human (a) and ventral view of azygos of rhesus monkey (b).

Azygos and HemiazygosAzygos and Hemiazygos

Figure 13.37. Ventral view of venous channels of rabbit (see book figure 12.23).

Fetal CirculationFetal Circulation

Figure 13.38. Circulation of mammalian fetus (see book figure 12.42).

Fetal Circulation Fetal Circulation (cont’d.)(cont’d.)

Figure 13.39. Fetal circulation before birth.

Fetal Circulation Fetal Circulation (cont’d.)(cont’d.)

Figure 13.40. Pre birth fetal circulation: liver (I), inferior vena cava (II), rt. atrium (III), lt. atrium (IV), ductus arteriosus into descending aorta (see book figure 12.42).

Fetal Circulation Fetal Circulation (cont’d.)(cont’d.)

Oxygenation at placentaOxygenation at placenta Umbilical veins supply fetus with Umbilical veins supply fetus with

oxy. bloodoxy. blood Vein passes through liver and Vein passes through liver and

unites with post cavaunites with post cava From right atrium, oxy. blood goes From right atrium, oxy. blood goes

2 directions2 directions To right ventricleTo right ventricle To left atrium through To left atrium through

foramen ovaleforamen ovale

Figure 13.41. Foramen ovale in fetal circulation system.

Fetal Circulation Fetal Circulation (cont’d.)(cont’d.)

In right ventricle, oxy. blood sent to pulmonary arteryIn right ventricle, oxy. blood sent to pulmonary artery Lungs nonfunctionalLungs nonfunctional Ductus arteriosus diverts blood from lungsDuctus arteriosus diverts blood from lungs

Figure 13.42. Adult aortic arches of mammal.

Figure 13.43. Left aortic arches with ductus arteriosus.

Circulation At BirthCirculation At Birth

Placenta shuts downPlacenta shuts down Umbilical vein collapses- near falciform ligamentUmbilical vein collapses- near falciform ligament Interatrial aperture closes (fossa ovalis)Interatrial aperture closes (fossa ovalis) Ductus arteriosus closes (ligamentum arteriosum)Ductus arteriosus closes (ligamentum arteriosum) Deoxygenated blood now enters right ventricle, Deoxygenated blood now enters right ventricle, pulmonary pulmonary

arteries, and continues to lungsarteries, and continues to lungs Ductus venosus collapses (ligamentum venosumDuctus venosus collapses (ligamentum venosum))

Figure 13.44. Post birth modifications in fetal circulation.