BIOM 3200 Lecture Notes - Lecture 6: Theca Interna, Tunica Externa, Common Iliac Artery

• School: University of Guelph
• Department: Biomedical Sciences
• Course: BIOM 3200
• Professor: Saleh

Document Summary

Interna has 3 layers: endothelium (lines blood vessel lumina, basement membrane (glycoproteins, elastic lamina (layers of elastin) Veins: venules are smallest veins & they receive deoxygenated blood from tissue capillaries. Joins successive venules to form medium, then large sized veins completing venous circuit by returning deoxygenated blood to right atrium of heart. Low venous pressure is insufficient to return blood to heart, however as (cid:448)ei(cid:374)s pass th(cid:396)u skeletal (cid:373)us(cid:272)les, the(cid:455)(cid:859)(cid:396)e (cid:373)assaged & s(cid:395)ueezed (cid:271)(cid:455) muscle creating blood flow to heart. One-way flow to heart thru veins: skeletal muscle squeeze veins while contracting, creating a 1-way blood flow back to heart, venous valves impede blood to go backwards. Capillaries: smallest blood vessels of the body & characterized by thin walls that are ideal for tissue exchange. Local microenvironmental cues, nervous & endocrine mechanisms control tone of precapillary sphincters, ultimately controlling blood flow to organs.