COMPARING HUMAN BLOOD VESSELS TO THOSE OF OTHER VERTEBRATES

In human embryos, blood flows from the heart through a ventral aorta through a series of aortic arches to the dorsal aorta which then runs inferiorly along the posterior side of the body.

archesembryonic heart

These aortic arches do not exist in human adults. Are there similar structures in primitive chordates and fish?

Chordate and shark

archesshark

In humans, oxygenated blood reaches the brain from the carotid and vertebral arteries (the internal carotid branches from the common carotid and the vertebral branches from the subclavian). So other vertebrates possess these vessels?

turtle and cat

turtlecat

opossum

opossumopossum

In humans, venous blood from the upper body returns to the heart from a single superior vena cava. The superficial portion of the head and the brain are drained through the external and internal jugular veins, respectively.

opossum

opossumopossum

cat

cat

cat

WHAT SPECIFIC SIMILARITIES AND DIFFERENCES DID YOU NOTICE BETWEEN THE HUMAN STRUCTURES AND THOSE OF OTHER VERTEBRATES? HOW DO THESE STRUCTURAL SIMILARITIES/DIFFERENCES COMPARE TO SIMILARITIES/DIFFERENCES IN LIFESTYLE? WHAT MAKES HUMANS UNIQUE? WHAT RELATIONSHIPS BETWEEN ORGANISMS DO YOU FEEL ARE SUPPORTED BY YOUR COMPARISONS OF THEIR FEATURES? WHAT FEATURES DO YOU FEEL DEFINE A PARTICULAR GROUP?
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