
The lymphatic vessels (or lymph vessels or lymphatics) are thin-walled vessels (tubes), structured like
blood vessel
Blood vessels are the structures of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away from ...
s, that carry
lymph. As part of the
lymphatic system, lymph vessels are complementary to the
cardiovascular system
The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...
. Lymph vessels are lined by
endothelial cells, and have a thin layer of
smooth muscle
Smooth muscle is an involuntary non- striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit ...
, and
adventitia that binds the lymph vessels to the surrounding tissue. Lymph vessels are devoted to the
propulsion
Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from ...
of the lymph from the
lymph capillaries, which are mainly concerned with the absorption of
interstitial fluid
In cell biology, extracellular fluid (ECF) denotes all body fluid outside the cells of any multicellular organism. Total body water in healthy adults is about 60% (range 45 to 75%) of total body weight; women and the obese typically have a l ...
from the tissues. Lymph capillaries are slightly bigger than their counterpart
capillaries
A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: ...
of the vascular system. Lymph vessels that