Vein Anatomy

Fig. 18.1. Venous anatomy in digital subtraction angiography (DSA) in lateral projection. FV, frontal veins PV, parietal veins OV, occipital veins SSS, superior sagittal sinus ISS, inferior sagittal sinus TS, transverse sinus SIS, sigmoid sinus IJV, internal jugular vein SS, straight sinus CS, confluens sinuum VL, vein of I.abbe SV, sylvian vein CS, cavernous sinus VG, vein of Galen 1CV, internal cerebral vein IJV, internal jugular vein...

The venous anatomy is very variable. Venous blood flows centrally via the deep cerebral veins and peripherally via the superficial cerebral veins into the dural venous sinuses, which lie between the outer and meningeal inner layer of the dura and drain into the internal jugular veins (Stam 2005) (Fig. 4.4). The cerebral veins do not have valves and are thin walled, and the blood flow is often in the same direction as in neighboring arteries. There are numerous venous connections between the cerebral veins and the dural sinuses, the venous system of the meninges, skull, scalp, and nasal sinuses, allowing infection or thrombus to propagate between these vessels. 

All C4 plants show Kranz anatomy. The bulk of the photosynthetic tissue is concentrated in two layers around the vascular bundles the irmer bundle-sheath layer and the outer mesophyll layer. C4 leaf veins show up as a darker green than the rest of the leaf you can usually spot this just by holding a leaf upto the light. 

Kato R, Lickfett L, Meininger G, et al. Pulmonary vein anatomy in patients undergoing catheter ablation of atrial fibrillation lessons learned by use of magnetic resonance imaging. Circulation 2003 107 2004-10. 

Scharf C, Sneider M, Case I, et al. Anatomy of the pulmonary veins in patients with atrial fibrillation and effects of segmental ostial ablation analyzed by computed tomography. J Cardiovasc Electrophysiol 2003 14 150-5. 

The conduit characteristics of the venous system primarily depend on the anatomy of the system. Valves in the veins of the limbs are crucial for reducing the pressure in dependent parts of the body. Even small movements from skeletal muscle activity tend to compress the veins and move blood toward the heart. A competent valve then blocks back flow, thus reheving the pressure when the movement stops. Even a few steps can reduce the transmural venous pressure in the ankle from as much as 100 mmHg to about 20 mmHg. Without this mechanism, transcapillary movement of fluid into the extravascular spaces results in edema. Varicose (swollen) veins and peripheral pooling of blood can result from damage to the venous valves. During exercise, the rhythmic contraction of the skeletal muscles, in conjunction with venous... 

Patient Anatomy 7.2.7 Vein Anatomy 1.2.1.1 Subclavian Vein... 

Fig. 8.1. Diagram of anatomy of the gastric varices and collateral vessels. AdV, adrenal vein BaC, balloon catheter CV, coronary vein IpVy inferior phrenic vein IVCy inferior vena cava G-RSy gastro-renal shunt GVy gastric varices MC, microcatheter PcVy pericardiacophrenic vein PGVy posterior gastric vein PVy portal vein RVy renal vein SGV, short gastric vein Spy spleen SpVy splenic vein...

Variant anatomy of the ovarian arteries includes the gonadal artery originating from the renal artery in about 20% of individuals [2]. Very rarely the artery arises from the adrenal, lumbar, or iliac arteries [2]. In some cases, the right ovarian artery passes behind the cava and over the right renal vein. The left ovarian artery will occasionally also pass over the left renal vein [2], There is very rarely a common trunk of left and right gonadal arteries, and occasionally there are multiple gonadal arteries. 

The diverse metabolic activities of the liver make it susceptible to solvent induced in-jiuy, particularly from reactive intermediates which damage cellular macromolecules. The microscopic anatomy of the liver provides an explanation for this susceptibility. The basic unit of the liver is the hepatic lobule which consists of a central vein surrounded radially by sinusoids of liver cells (hepatocytes). Portal triads consisting of a hepatic artery, a hepatic vein and a bile canniliculus are located at the periphery. Liver cells closest to the vascular... 

Fig. 2.2a-c. A 47-year-old, obese patient. Pelvic scan obtained 70 s after intravenous contrast medium administration. Note that there is still incomplete opacification of the pelvic veins. There is strong perfusion of the myometrium and the zonal anatomy of the uterus is clearly seen in all three planes axial (a), coronal (b), sagittal (c). The ovarian vein on the left is dilated by vari-cosis and shows more pronounced enhancement due to reflux from the left renal vein. The intestinal tract was opacified with water and mannitol... 

Fig. 15.6. Volume-rendered dataset of the pulmonary veins after removing the vertebral column. The image displays nicely the anatomy, such as the main left and right, upper, low and lower pulmonary veins, as well as the accessory vein in the left upper field (arrow)...

Fig. 20.1. Hepatic segmental anatomy. RHP right hepatic vein MHP middle hepatic vein LHV left hepatic vein RPV right portal vein LPV left portal vein...

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