Title: Comparative Anatomy Circulatory System
1Comparative AnatomyCirculatory System
Part 13
2Cardiovascular System
- Arteries
- Carry blood away from the heart
- Muscular, elastic fibrous walls (see next figure)
- Regulates blood pressure
- Terminate in capillary bed
- Veins
- Carry blood toward the heart
- Heart
- Modified blood vessel
Figure 13.1. Cross section of artery and vein.
3Arteries, Veins, and Capillaries
Figure 13.2. Blood vessel microanatomy..
4Aortic arches- Within pharyngeal arches
Figure 13.3. Basic circulatory pattern of
amniote embryo.
5Aortic arches- Within pharyngeal arches
(discussed later)
Figure 13.4-5. Embryological development of
aortic arches (see book figures 12.9 -10).
6Portal Systems
- Veins that drain an organ and dump blood into
another organ instead of heart
Figure 13.6. Portal systems of craniates.
7Portal Systems (cont.)
- Hepatic
- Drains small intestine into liver
- Renal
- Drains venous channels of tail into kidneys
- Hypophyseal
- Drains hypothalamus into sinusoids of anterior
pituitary - Smallest
Figure 13.7. Hepatic and renal portal systems of
shark (book figure 12.11).
8Portal Systems (cont.)
Figure 13.8. Hypophyseal portal system (book
figure 15.15) .
9Heart
- In a typical tetrapod, the heart pumps blood
- By pulmonary arteries, from heart to lungs (blood
returns to heart by pulmonary veins) - By aorta to systemic circulation
- Fish heart tube-like
- 4 chambers
- Sinus venosus
- Atrium
- Ventricle
- Conus arteriosus
Figure 13.9. Four chambers of heart in most
fishes (book figure 12.26).
10Fish Heart (cont.)
- Fish heart
- Sinus venosus
- Atrium
- Ventricle
- Conus arteriosus
Figure 13.10. Fish with four chambered heart
(book figure 12.27).
11Fish Heart (cont.)
- Sinus venosus
- Thin-walled venous chamber
- Receives blood from ducts of Cuvier, coronary
veins, hepatic veins - Atrium
- Large and thin walled
- Dorsal to ventricle
12Fish Heart (cont.)
- Ventricle
- Dumps into conus arteriosus- continuous with
aorta - Chambers separated by valves sino-atrial valve,
atrio-ventricular valve, semi-lunar valve - Conus arteriosus (bulbus cordis in embryos)
- Short in bony fish and amphibians
- Termed bulbous arteriosus (if walls lack cardiac
muscle, but contains smooth muscle) - Not found in adult amniotes
13Phylogeny of the Heart
Figure 13.11. Heart chambers, oxygenated blood
flow (red), and septum modification .
14Lungfish and Amphibian vs Dogfish
- Modifications of partial or complete partition in
atrium - Left and right atria
- Advent of lungs
- Double circulation
- Modification in conus arteriosus
- Semi-lunar valve modified to shunt deoxygenated
blood to lungs (spiral valve)
15Spiral 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).
16Amphibian Heart
- Spiral valve directs oxygenated blood entering
ventricle from left atrium - Conus (termed truncus arteriosus when greatly
reduced) - Bulbus arteriosus
- Swelling of ventral aorta
- Smooth muscle
Figure 13.14. Three chambered frog heart.
17Amphibian Heart (cont.)
- Urodele - partially divided circulation
- Right and left atrium
- Sinus venosus dumps into right atrium
- Pulmonary veins leave left ventricle
- Reptile - fully divided circulation
Figure 13.15-16. Salamander heart chambers
(left) and circulation path (book figures 12.16
and 12.31).
18Reptile Heart
- Cavum venosum (CV) - internal pocket e.g., turtle
- Blood collected from post cava through sinus
venosus from precava - To right atrium
- Venous blood to CV
- Cavum pulmonale
- Into pulmonary artery to lungs
- Oxy. blood returns through pulmonary veins in
left atrium - Back to CV
- To left and right aortic trunk
19Turtle Heart
Figure 13.17. Chelonian heart chambers and
circulation path (see book figure 12.33).
20Squamate Heart
Figure 13.18. Squamate heart chambers and
circulation path (book figure 12.35).
21Crocodilian Heart
- Mechanism for breathing and diving
- Lungs not utilized
- Blood not pumped to lungs
- Foramen of Panizza
- Valve between aortic trunks to divert blood
- Allows left ventricle to pump to both arches when
right ventricle closed - Underwater right ventricle helps pump systemic
blood
22Diving
- Semilunar valve in right aorta closed when above
water - Semilunar valve forced open when submerged in
water to divert pulmonary circulation
(b)
(a)
Figure 13.19. Crocodilian blood circulation when
(a) diving and when (b) on the surface.
23Two 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).
24Higher Amniote Heart
- 4 chambered heart
- 2 atria and 2 ventricles
- Birds and mammals
- Sinus venosus - 5th chamber in reptile heart
- Becomes sino-atrial node
- In embryo, right and left atria are not separated
- Foramen ovale
- Fossa ovalis
- Auricle- flap on side of atrium
25Adult Mammalian Heart
Figure 13.22. Adult heart blood flow (see book
figure 12.42).
26Aortic Arches
- Basic pattern has 6 aortic arches
- Major arterial channels
- Ventral aorta
- Dorsal aorta
- 6 pairs of aortic arches
- connects ventral aorta
- and dorsal aortae
- Reptiles - additional arch
Figure 13.23. Adult heart blood flow (book
figure 12.13).
27Aortic Arches (cont.)
Figure 13.24. Basic pattern of aortic arches and
dorsal aortae.
Figure 13.25. Ventral perspective of aortic
arches (book figure 12.19).
28Figure 13.26. Left aortic arches (see book
figure 12.17).
29Aortic Arches (cont.)
- Teleost
- 1st and 2nd arches lost
- Dorsal aortae become internal carotids
- Lung fish
- Pulmonary artery from 6th arch
- Tetrapods
- Pulmonary artery from 6th arch
- 5th arch lost
Figure 13.27. Aortic arches, internal carotids
(ic) and pulmonary artery (book figure 12.14).
30Tetrapod Aortic Arches
- 1st and 2nd arches lost
- Dorsal segment dropped between 3rd and 4th arches
- Ductus caroticus
Figure 13.28. Adult aortic arches (see book
figure 12.17).
31Tetrapod Aortic Arches (cont.)
- 3rd arch extends to internal carotids
- Carotid arch
- Ventral aorta extension
- External carotid
- Common carotid at base between 3rd and 4th
Figure 13.29. Aortic arches, internal carotid
(ic), external carotic (ec) and common carotid
(cc) (book figure 12.14).
32Tetrapod Aortic Arches (cont.)
- 5th arch lost
- Dorsal segment of 6th arch lost
- 4th arch - no anterior connection
- Aortic arch (systemic arch)
- 6th arch
- Pulmonary arch
- Ex adult anuran
Figure 13.30. Adult aortic arches (book figure
14.19).
33Figure 13.31. Modifications of aortic arches and
dorsal aortae into mature mammalian vascular
system.
34Aortic Arch Summary
- Urodele
- Ductus caroticus
- Ductus arteriosus
- - dorsal segment of 6th arch
- Reptiles
- 1st and 2nd arches lost
- Ductus caroticus lost
- 5th arch lost
- Ductus arteriosus lost
- Additional aortic arch introduced
- Arch from left side loops right
- Arch from right side loops left
Figure 13.32. Modifications of aortic arches and
their derivative in anamniotes (book figure
12.14).
35Mammalian Aortic Arches
- 3rd, 4th, 5th, 6th retained embryonically
- Adults- 1st and 2nd dropped
- 3rd carotid arch
- 4th systemic arch
- 5th lost
- Dorsal segment of 6th lost
- Retained embryonically- ductus arteriosus
(ligamentum arteriosum)
Figure 13.33. Adult aortic arches (book figure
12.19).
Figure 13.34. Left aortic arches (book figure
12.17).
36Bird Aortic Arches
- Right portion of aortic arch is retained and left
is lost (opposite to mammals) - Birds have right aortic arch
- Mammals have left aortic arch
37Venous System
- Sinus venosus - where all blood returns
- Feed by common cardinals and subclavian veins
- Shark renal portal system - drains blood from
tail before entering post cardinal (book figure
12.21)
Figure 13.35. Modifications of basic venous
patterns showing sinus venosus (S) (book figure
12.21).
38Venus System
- Major venous channels
- Cardinals anterior, posterior, common
- Renal portal
- Lateral abdominals
- Vitellines- associated with hepatic portal system
- Coronary veins
- Additional characteristics of higher vertebrates
- Pulmonary
- Posterior vena cava
-
39Venus System
- Common cardinals - directs blood to sinus
venosus - Anterior cardinals - receives blood from head
- Post cardinals - receives blood from kidneys
- Renal portal - receives blood from caudal vein
- Lateral abdominals- receives blood from
abdominal stream to iliac (lateral wall of
body) - Hepatic portal veins - receives blood from
intestine into liver - Hepatic veins direct blood into sinus venosus
40Modifications to Basic Venous System
- Post cardinal lost in adult anurans
- Post cava- new vessel
- Post cava drains kidneys in turtle
- External iliac vein connects lateral abdominals
and renal portal system
41Modifications to Basic Venous System
- Most mammals lose renal portal system
- Pre-cava- common cardinals in higher verts
- Internal jugular- anterior cardinal veins
- Anterior vena cava- only right pre-cava retained
42Modifications to Basic Venous System
- Azygous- vestige of right post cardinal vein
- Hemiazygous- remnant of left post cardinal
- Inferior vena cava- post cava
(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).
43Azygos and Hemiazygos
Figure 13.37. Ventral view of venous channels of
rabbit (see book figure 12.23).
44Fetal Circulation
Figure 13.38. Circulation of mammalian fetus
(see book figure 12.42).
45Fetal Circulation (cont.)
Figure 13.39. Fetal circulation before birth.
46Fetal Circulation (cont.)
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).
47Fetal Circulation (cont.)
- Oxygenation at placenta
- Umbilical veins supply fetus with oxy. blood
- Vein passes through liver and unites with post
cava - From right atrium, oxy. blood goes 2 directions
- To right ventricle
- To left atrium through foramen ovale
Figure 13.41. Foramen ovale in fetal circulation
system.
48Fetal Circulation (cont.)
- In right ventricle, oxy. blood sent to pulmonary
artery - Lungs nonfunctional
- Ductus arteriosus diverts blood from lungs
Figure 13.43. Left aortic arches with ductus
arteriosus.
Figure 13.42. Adult aortic arches of mammal.
49Circulation At Birth
- Placenta shuts down
- Umbilical vein collapses- near falciform ligament
- Interatrial aperture closes (fossa ovalis)
- Ductus arteriosus closes (ligamentum arteriosum)
- Deoxygenated blood now enters right ventricle,
pulmonary arteries, and continues to lungs - Ductus venosus collapses (ligamentum venosum)
50Figure 13.44. Post birth modifications in fetal
circulation.