Question

Who discovered blood capillaries?
(a) William Harvey
(b) Girolamo Fabrici
(c) Marcello Malpighi
(d) Robert Brown

Answer 1

Hint: A blood capillary is the smallest of blood vessels. A blood capillary is 5 to 10 µm in diameter.

Complete Answer:
A blood capillary has a wall that is as thick as a single layer of squamous endothelial cells. The blood capillaries transfer blood between arterioles and venules. Blood capillaries are sites for exchange of many substances with the interstitial fluid surrounding these capillaries.
Girolamo Fabrici contributed to the field of surgery. Girolamo Fabrici thoroughly studied the formation of a fetus. He also studied the structures of various parts of the body like the oesophagus, intestines and stomach. Girolamo Fabrici studied the distinct appearance of the eyes. He also studies the peculiarities of the ears and the larynx.
Marcello Malpighi was an Italian physician and biologist. He is considered to be the Father of Physiology and Histology. Marcello Malpighi was the first person to visually observe the blood capillaries in 1661. Marcello Malpighi also found the link between arteries and veins.
Robert Brown was a Scottish botanist. Robert Brown was one of the first people to give a detailed description of the cell nucleus. He researched his observation of a peculiar motion called the Brownian motion.
William Harvey was an English physician. William Harvey was the first researcher to describe the systemic circulation of blood in the human body. William Harvey stated the presence of blood capillaries in the human circulatory system.

Therefore, blood capillaries were discovered by William Harvey. Hence, the correct option is (a) William Harvey.

Note:
Blood capillaries are formed by the process of vasculogenesis during the early embryonic stage. The formation of blood capillaries from pre-existing blood vessels is called angiogenesis.