Australia is of Africa and India .. ..Russia EU symbiotic jugular vein Juggalos
- any of several large veins in the neck, carrying blood from the head and face.
Veins of the Head and Neck
The external jugular vein is the most important vein draining blood from the head and neck in the rat, in contrast to man where the internal jugular is the most important vein. In the rat, the external jugular vein collects blood from the posterior and anterior facial veins. The posterior facial vein drains the retroglenoid vein (internal maxillary vein in Greene’s terminology: Greene, 1935) and the superficial temporal vein that drains the scalp. The anterior facial vein appears at the corner of the mouth and collects blood from the face and lower jaw. The external jugular and axillary veins join to produce the subclavian veins, which in turn join with the smaller internal jugular veins to form the anterior (cranial) venae cavae. The entry of the venae cavae into the right atrium is complicated. The right anterior vena cava opens into the anterior of the right atrium; the left anterior vena cava continues in a posterior direction, crossing ventral to the arch of the aorta before entering the right atrium in company with the posterior (caudal) vena cava. The left anterior vena cava receives blood from the azygous vein, which in turn receives blood from the hemiazygous vein (on the right in the rat) that has crossed the midline (Halpern, 1953b).
The Cardiovascular System
Robert Lewis Maynard, Noel Downes, in Anatomy and Histology of the Laboratory Rat in Toxicology and Biomedical Research, 2019..
Figure 2.29. The caudal branch of the medial saphenous vein can be used for intravenous injection or blood drawing. A: The needle is inserted proximal to the calcaneus at the caudal side of the calf. B: Caudal view of the left skinned hind limb showing the medial saphenous vein (white arrows) running distally in the midline between both parts of the gastrocnemius muscle (gm). At the level of the knee, the vein passes by the popliteal lymph node (black arrowhead). More proximally, the sciatic nerve (black arrow) runs adjacent to the vein.
for positioning and the use of ultrasound to guide insertion). The head is turned slightly away from the side of insertion; turning the head too far to the side may compress the vein and move the vein in closer proximity to the carotid artery.
Locate the apex of a triangle formed by the two bellies of the sternocleidomastoid muscle. This point is usually where the external jugular vein crosses the sternocleidomastoid muscle or the midpoint between the mastoid process and the sternal notch.
Palpate the carotid artery. Introduce the needle just lateral to this artery at an angle of 30 degrees to the skin surface. If the internal jugular vein is superficial, a less acute angle may be indicated. While continuously aspirating, advance the needle toward the ipsilateral nipple a distance of no more than 2.5 cm. If no blood is freely obtained, slowly withdraw the needle while maintaining aspiration. The needle can compress the vessel on entry, and it straightens during withdrawal, allowing free aspiration of blood.
Once venipuncture is accomplished, carefully remove the syringe and occlude the end of the needle (to prevent entraining air if the child is breathing spontaneously) until a flexible guidewire is inserted (see Fig. 49.2).54 The wire should advance easily. However, if the wire cannot be advanced, the needle has passed out of the vessel lumen or its tip rests against the vessel wall. In this situation, the wire and needle should be withdrawn simultaneously to avoid shearing the wire. If the wire passes without difficulty, then cannulation proceeds as demonstrated in Figs. 49.2 and 49.4. The location of the catheter tip should be confirmed with a radiologic study and optimally repositioned as necessary (see Fig. 49.3).
Suture the catheter in place, and protect the area with an occlusive dressing.
Hypertonic Saline
The sclerosing effect of HS was examined histologically in the external jugular vein of the dog by Kern and Angle62 and in human varicose veins by McPheeters and Anderson.52 These investigators noted endothelial damage with thrombus formation within 1 hour of injection, with ultimate conversion into a fibrous cord within 2 to 4 weeks. This was confirmed in the rabbit ear vein model43 both clinically and histologically. Examination of the marginal ear vein 1 hour after exposure to HS 23.4% demonstrated complete endothelial destruction (Fig. 7.17).
However, subsequent evaluation of HS 11.7% in the rabbit ear vein model57 demonstrated an immediate thrombosis that lasted only 48 hours before complete normalization. Endothelial destruction was patchy at 1 hour with perivascular and intraluminal margination of polymorphonuclear cells and eosinophils. There was no evidence of extravasation of RBCs in the veins injected with HS 11.7%, whereas extravasation was noted in 30% of vessels injected with HS 23.4%. Therefore, the degree of endothelial damage and resulting extravasation of RBCs is proportional to the concentration of HS used in injury reaction
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