In vivo measurement of dimensions of veins with implications regarding control of venous return.
D000818:Animals; D001775:Blood Circulation; D004285:Dogs; D005239:Fear; D008099:Liver / Q000033:anatomy & histology; D005082:Physical Exertion; D012769:Shock / Q000628:therapy; D013154:Spleen / Q000033:anatomy & histology; D014680:Veins / Q000033:anatomy & histology*; D014683:Vena Cava, Superior / Q000033:anatomy & histology; D014690:Venous Pressure