Question

Fetal Pig Anatomy Question Part 1

A. Which type of vessels, arteries or veins, has more muscle fibers? What is the functional significance of this?

B. In general, we have no conscious control over smooth muscle or cardiac muscle function, whereas we can consciously control to some extent all skeletal muscles. Can you consciously control your breathing? What does this tell you about the muscle type of the diaphragm?

C. What is a portal system?What organs does the hepatic portal system connect in adults? What is the purpose of this system?

D. The ductus arteriosus and the ductus venosus are two key vessels in the fetal circulation that are absent in the adult circulation. What are their functions in the fetus? Why are they necessary?

Answer 1

A. Arteries have more muscles than veins. They have smaller, rounder lumens than veins. Muscular arteries have more smooth muscles in their tunica media. Arteries have more muscles because they experience higher blood pressure since they transport blood directly from the heart.

B. We can consciously control our breathing rate but only for a few seconds. So, the muscles of our diaphragm are smooth muscles as they are involuntary in nature.

C. A Portal system is a system in which blood goes to heart after passing through any other organ. The hepatic portal system is a series of veins that carry blood from the capillaries of the stomach, intestine, spleen and pancreas to capillaries in the liver.

D. Ductus arteriosus moves the blood from the pulmonary artery to the aorta and ductus venosus shunts blood from umbilical vein to inferior vena cava. They help in an efficient supply of blood in the fetus.