It is system of arteries and consists of all the arteries in body. The arteries are blood vessels which carry blood away from the heart. The arterial system of frog beings with the truncus arteriosus which arises from top right region of ventricle.The truncus arteriosus ascends, get curved towards left and divides into left and right aortic trunks, each aortic trunk divides into three major vessels or aortic arches:
(1)Common carotid arch (2) systemic arch and (3) pulmocutaneous arch.
(1)Common carotid arch (2) systemic arch and (3) pulmocutaneous arch.
1. Common carotid arch: It is a short vessel running forward and outward, but soon divides into 2 branches: external and internal carotid artery.
a. External carotid artery: It is the smaller inner branch carrying blood to the tongue and adjacent parts. It is also called lingual artery.
b.Internal carotid: It is the larger outer branch. At its base a Small swelling called the carotid labyrinth is present. It detects blood pressure and change in concentration of oxygen , carbondioxide and pH in blood. The internal carotid artery divides into 3 branches: a palatine artery to the roof of buccal cavity, a cerebral artery to the brain, and an ophthalmic artery to the eye.
2. Systemic arch: It is the longest of the three arches and with greatest distribution of blood supply. The two systemic arches curve dorsally around the oesophagus and join with each other behind the heart to form the dorsal aorta. In its course each systemic arch gives off 3 arteries:
a. Oesophageal: A small inner artery to oesophagus.
b. Occipito-vertebral: A larger outer branch which immediately divides into an occipital branch to occiput or posterior part of head, and a vertebral branch to vertebral column and spinal cord.
c. Subclavain: It is a large outer artery supplying the shoulder region and passes into the forelimb as brachial artery.
Dorsal aorta: As already said, it is formed by the union of both the systemic arches. It runs posteriorly lying mid-dorsally just beneath the vertebral column. It gives off the following arteries:
a. Coeliaco-mesenteric artery: It is a single large artery arising from the left side of the junction of the two systemic arches. It has two main branches:
a. External carotid artery: It is the smaller inner branch carrying blood to the tongue and adjacent parts. It is also called lingual artery.
b.Internal carotid: It is the larger outer branch. At its base a Small swelling called the carotid labyrinth is present. It detects blood pressure and change in concentration of oxygen , carbondioxide and pH in blood. The internal carotid artery divides into 3 branches: a palatine artery to the roof of buccal cavity, a cerebral artery to the brain, and an ophthalmic artery to the eye.
2. Systemic arch: It is the longest of the three arches and with greatest distribution of blood supply. The two systemic arches curve dorsally around the oesophagus and join with each other behind the heart to form the dorsal aorta. In its course each systemic arch gives off 3 arteries:
a. Oesophageal: A small inner artery to oesophagus.
b. Occipito-vertebral: A larger outer branch which immediately divides into an occipital branch to occiput or posterior part of head, and a vertebral branch to vertebral column and spinal cord.
c. Subclavain: It is a large outer artery supplying the shoulder region and passes into the forelimb as brachial artery.
Dorsal aorta: As already said, it is formed by the union of both the systemic arches. It runs posteriorly lying mid-dorsally just beneath the vertebral column. It gives off the following arteries:
a. Coeliaco-mesenteric artery: It is a single large artery arising from the left side of the junction of the two systemic arches. It has two main branches:
i) the coeliac artery which divides into gastric artery( to stomach) and hepatic artery ( to liver and pancreas) and
ii) the anterior mesenteric artery which divides into spleenic artery(to spleen) and intestinal artery ( to small intestine).
b. Gonadial arteries : A pair of short arteries to gonads, called spermatic artery in male frog and ovarian artery in female frog.
c. Renal arteries : While passing between the two kidneys, dorsal aorta gives 4-6 pairs of small renal arteries in a series into both the kidneys.
d. Posterior mesenteric arteriy: It arises from the posterior end of dorsal aorta, or sometimes from anterior mesenteric artery. It goes to large intestine or rectum.
e. Common iliac arteries: The dorsal aorta finally bifurcates posteriorly into two common iliac artery. Each common iliac artery gives;
• epigastric artery to ventral body wall,
• rectovesicular artery to rectum and urinary bladder and
enters inside the hind limbs of own side as femoral artery which supplies to hip and upper thigh and sciatic artery which supplies to lower leg.
3. Pulmocutaneous arch: It divides into two main arteries, pulmonary artery to the lung and cutaneous artery to skin of dorsal and lateral sides of trunk.
b. Gonadial arteries : A pair of short arteries to gonads, called spermatic artery in male frog and ovarian artery in female frog.
c. Renal arteries : While passing between the two kidneys, dorsal aorta gives 4-6 pairs of small renal arteries in a series into both the kidneys.
d. Posterior mesenteric arteriy: It arises from the posterior end of dorsal aorta, or sometimes from anterior mesenteric artery. It goes to large intestine or rectum.
e. Common iliac arteries: The dorsal aorta finally bifurcates posteriorly into two common iliac artery. Each common iliac artery gives;
• epigastric artery to ventral body wall,
• rectovesicular artery to rectum and urinary bladder and
enters inside the hind limbs of own side as femoral artery which supplies to hip and upper thigh and sciatic artery which supplies to lower leg.
3. Pulmocutaneous arch: It divides into two main arteries, pulmonary artery to the lung and cutaneous artery to skin of dorsal and lateral sides of trunk.