1. Blood Vessels Arteries carry blood away from heart Ventral aorta
Dorsal aorta
Aortic arches between the two

4. Key Points
There are 7 visceral arches and yet the previous slide only showed 6 aortic arches, why?

5. Ventral aorta & Aortic Arches
Fish
Afferent branchial artery
Gill capillaries
Efferent branchial artery
Teleosts – 1 & 2 are gone
Lungfish – Pulmonary artery is branch from 6th aortic arch – efferent region

8. Tetrapod Ventral Aorta & Aortic Arches
General pattern
6 arches in embryo
1 & 2 rapidly regress
Internal carotid artery is formed from arch 3 plus paired dorsal aortae
Fifth aortic arch is gone in most

10. Tetrapod Ventral aorta & Aortic Arches
Pulmonary artery is a branch from arch 6
Common carotid artery is from ventral aorta
External carotid artery is from common carotid artery

12. Amphibian Ventral Aorta & Aortic Arches
Urodeles have ductus caroticus present meaning blood in arch three can go cranial or caudal
Anurans have no ductus caroticus, so that blood in third aortic arch can only go towards the head

14. Reptile Ventral Aorta & Aortic Arches
Two aortic trunks from conus arteriosus – sends blood to arch 3 and 4
One pulmonary trunk from conus arteriosus – sends blood to 6th aortic arch
Otherwise similar to amphibians

16. Birds & Mammals Ventral Aorta & Aortic Arches
One aortic trunk that sends blood to arches 3 and 4
One pulmonary trunk sends blood to arch 6
Fourth Aortic Arch
Right side stays in birds
Left side stays in mammals
Right side of 4th arch becomes subclavian A. in mammals

19. Bird & Mammal Ventral Aorta & Aortic Arches
Ductus arteriosus is in fetus only. It is a bypass of blood from the pulmonary trunk to the aorta
Carotids have same general pattern

20. Key Points
Why would the mammalian fetus need a bypass from the pulmonary trunk to the aorta?

21. Dorsal Aorta General Pattern
Paired in head & pharynx in embryo and stays paired in adult as internal carotid arteries
Single in trunk
Becomes the caudal artery

23. Key Points
Where do you find the caudal artery in the shark? Compare its location with the notochord and the nerve cord.

24. Dorsal Aorta Ventral Visceral branches
Celiac A. supplies stomach, pancreas, liver
Mesenteric A. supplies intestine (may be more than one)

26. Dorsal Aorta
Lateral visceral branches
Urogenital

28. Dorsal Aorta Somatic branches to skin, spine, muscles
Subclavian A  Brachial A. supplies arm
Iliac A  Femoral A. supplies leg

31. Veins
Veins start as capillaries and carry blood towards the heart

32. Key Points Define artery Define capillary Define vein Define trunk
Define sinus

33. Cardinal Stream Sharks Common Cardinal Vein
Anterior cardinal vein – drains head
Posterior cardinal vein drains kidney, body wall, gonads, and most of body except digestive structures

35. Key Points
Trace the blood flow from the shark’s kidney to its ventral aorta.

36. Cardinal Stream Amphibians
Most of postcardinal disappears in anurans, but persists in urodeles

38. Cardinal Stream Amniotes
Postcava (=inferior vena cava = caudal vena cava)
Takes the place of the Posterior Cardinal Vein
Drains some of hindlimbs in crocodiles, all of hindlimbs in mammals and eventually drains most of trunk and tail, in addition to hind limbs

41. Cardinal Stream in Amniotes
Azygous/Hemiazygous
From R. Posterior Cardinal V.
Provides alternate route from structures caudal to diaphragm
Mammals only

44. Cardinal Stream in Amniotes
Precava (= superior vena cava = cranial vena cava)
From Common Cardinal Vein
In cats and humans, Right Precava persists and lose most of left.

47. Cardinal Stream in Amniotes
Internal Jugular Vein
Drains brain
From the Anterior Cardinal Vein

49. Key Points
Trace the blood flow from the brain of a crocodile to the sinus venosus.

50. Renal Portal Stream
A Portal is a vein that begins and ends in a capillary bed
Fish – drains tail to kidney
Amphibians – drains hindlimbs to kidneys
Reptiles and birds – bypasses kidneys and goes to postcava
Mammals –not present

52. Key Points
Where are the capillary beds for the Renal Portal Veins in the shark?

55. Abdominal Stream Sharks Lateral abdominal Veins are paired
Iliac V. from pelvic fins
Subclavian V from pectoral fins eventually to common cardinal V.

57. Key Points
Trace the blood flow from the shark’s pectoral fin back to the sinus venosus of the heart.

58. Abdominal Stream Amphibians
Ventral – single vessel, not paired as in fish
No connection to forelimbs

60. Abdominal Stream Reptiles Paired abdominal V
No connection to forelimbs

62. Abdominal Stream Mammals In fetus only
Umbilical Vein becomes the round ligament of the liver in the adult
Ductus venosus is a bypass of the liver and becomes the ligament venosum as a remnant in the adult

64. Key Points
Summarize the evolutionary trend for venous drainage of the forelimb.
Shark
Anurans
Amniotes

68. Key Points
Summarize the evolutionary trend of venous drainage of the hindlimbs
Fish
Amphibians
Reptiles
Mammals

76. Hepatic Portal Stream & Hepatic Sinuses
All vertebrates have this
Similar in all
What is a sinus?

77. Hepatic Portal Stream & Hepatic Sinuses
Vitelline V. from yolk sac to heart early in development
Subintestinal Vein from digestive visceral to vitelline Vein

80. Hepatic Portal Stream & Hepatic Sinuses
Hepatic Portal System – develops from one Vitelline V. and Subintestinal V.
Hepatic Sinuses – develop within liver from vitelline veins

82. Mammalian Fetal Circulation
Ductus venosus is bypass of liver
Ductus arteriosus and foramen ovale of interatrial septum are bypasses of lungs

83. Key Points Why is there a liver bypass in mammal fetus?
Why is there a lung bypass in mammal fetus?