BIOL 1344 Lecture 4: Chapter 21
14 Feb 2017
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Typically larger in diameter than blood capillaries. Overlapping endothelial cells: act as one-way flaps to allow liquid to enter. Anchoring filaments hold endothelial cells to nearby structures. Lacteals capillaries in the gi tract: allow for the absorption of lipid-soluble substances from the gi tract. Interspersed throughout areolar connective tissue in the blood capillary networks (not red bone marrow, spleen or cns: absent in avascular tissues like epithelia or cartilage. Superficial vessels are usually adjacent to superficial veins of the body. Deep vessels are adjacent to deep veins/arteries of the body. Have valves in the lumen: prevents pooling and backflow especially in lower limbs. No pumps are present: relies on contraction of skeletal muscle, pulsatile movement of blood, rhythmic contraction of smooth muscle in larger lymph vessels. Some connect directly to lymphatic organs called lymph nodes. Each removes lymph from a specific region of the body. Jugular head/neck: subclavian upper limbs, breasts, superficial thoracic wall, bronchomediastinal deep thoracic structures.
