Venous System of Frog
Venous System of Frog
It is the system of veins and venacava which is superficially situated and carry deoxygenated blood from different parts of the body to heart, except pulmonary veins.
Venous system consists of following parts:
- Pulmonary venous system
- Systemic venous system
- Portal venous system
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Pulmonary venous system
It consists of pulmonary veins which brings oxygenated blood from lungs to heart.
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Systemic venous system
It consists of anterior venacava called pre-cavals and one posterior venacava called post cavals.
a. Anterior venacava/ precaval
These are two large veins (right and left precavals) and collect blood from anterior parts of the body.
Each precaval is formed by the union of three veins:
i. External jugular: It collects blood from the tongue and lower jaw.
It is formed by the union of the lingual and mandibular veins.
- Lingual vein- brings blood from the floor of mouth and tongue.
- Mandibular vein- collects blood from lower jaw.
ii. Innominate: formed by the union of subscapular and internal jugular vein.
- Subscapular vein- collects blood from arms and shoulder of fore limbs.
- Internal jugular vein- collects blood from brain, eye and skull.
iii. Subclavian- it is formed by the union of branchial and musculo-cutaneous vein.
- Branchial vein- collects blood from the arm pit and fore limbs.
- Musculo-cutaneous vein- collects blood from muscle and skin of the body.
b. Posterior venacava or post caval
It is a large vein that opens into the posterior end of sinus venosus and collects blood from posterior part of the body (liver, kidney, viscera and hind limb).
It runs more or less parallel and ventral to the dorsal aorta. It can be distinguish from dorsal aorta by its much greater diameter and darker color.
It consists of following veins-
i. Renal vein- arise from the inner side of kidney and open into posterior venacava at different levels. It collects blood from the kidneys.
ii. Gonadial vein- It collects blood from gonads (testis and ovary). In male they are known as spermatic vein and in the females frog they are known as ovarian veins.
iii. Hepatic vein- There are two hepatic veins- right and left. They collects blood from liver. They open into postcaval vein before it joins sinus venosus.