Exam 24: Circulation

Tree-climbing snakes spend a considerable amount of time in vertical rather than horizontal orientation. In what way might you expect the circulatory system of tree-climbing snakes to differ from that of ground-dwelling snakes?

In vertebrate animals, functional separation of deoxygenated and oxygenated blood

Within the lymphatic system in vertebrates

Refer to the following diagram showing the relative composition of the walls (endothelium, elastin fibres, smooth muscle, collagen fibres) of four different types of vessels in the vertebrate circulatory system. Diagram 1 is most likely

In diastole

How many separate atria are present in the hearts of modern amphibians?

In embryonic birds, how many circulatory loops to the placenta are there?

Which of the following statements about vertebrate circulation is true?

The Starling Principle states

The major arteries in vertebrates

In the heart of a fish, a one-way valve prevents the back flow of blood from the

Where is the mammalian heart cycle initiated?

Which of the following vessels carries blood at the lowest pressure?

The pattern of circulation in a submerged crocodile is most like the pattern of circulation in a

Countercurrent heat exchange

Which of the following statements about open circulatory systems is true?

An increase in sympathetic input and a decrease in parasympathetic (vagal) input to the heart causes

In animal cells, diffusion is only effective

Circulation in amphibians has which of the following features?

At the arteriole end of a capillary the