In the anatomy of both humans and animals, the concept of "brachiocephalic trunk" stands out. Let's talk about this in more detail today.
General concept
The name of this body speaks for itself. The trunk of the brachiocephalic moves from the aorta along the midline of the sternum. Then it rises obliquely, then back and up, and at the level of the clavicular joint it is divided into two arteries. It is located in front of the trachea, which in children is covered by the thymus gland, and has a short length of three to four centimeters.
In infants it often divides the cephalad into a sternoclavicular articulation in the anterior triangle of the neck.
Human trunk
In humans, this organ has the structure described above. This is, as a rule, a short and thick vessel, which branches into two right arteries, which are covered on both sides - on the right and in front - by the pleura. There is no such artery in the left side of the human body. Otherwise, this vessel is called the brachycephalic trunk (from the Latin name) or namelessartery.
In humans, some diseases may be associated with the brachiocephalic trunk. Among them are the following:
- atherosclerosis (accumulation of cholesterol and fat on the inner walls of the arteries);
- birth defects;
- hemangiomas (a benign tumor that develops from small blood vessels);
- arterial injury;
- aneurysms (expansion of the lumen by two or more times);
- obliterating lesion of the branches of the arch (impaired vascular patency, which leads to ischemia of the brain and limbs (upper)).
If there are problems with this vessel, you should contact an angiosurgeon.
Animal trunk
The anatomy of the brachiocephalic trunk is as follows. It differs from the human one in that it goes to the entrance to the chest cavity and already there it is divided into two left arteries (right in humans). This occurs at the level of the second thoracic vertebra.
In some animals, for example, in a dog and a pig, there is no trunk of the brachiocephalic, instead of it there are two left arteries that come out of the aortic arch. From one of the arteries, called the brachiocephalic, the carotid arteries depart, which carry blood to the head of animals. The exception is the horse, which has several other small arteries branching off from it.
The trunk of the brachiocephalic provides blood to the head, neck, thoracic limbs, part of the chest wall.
In some cases, from this trunk to the lower part of the thyroid gland is the lower thyroidartery. Thanks to the trunk, the lack or absence of one of the vessels of the thyroid gland can be compensated.
Trunk branches
There are specific characteristic differences in the order of vessels originating from the subclavian arteries. The following branches depart from the arteries:
- The rib-cervical trunk supplies blood to the muscles of the neck and withers. It departs together with such arteries as the deep cervical and vertebral (in ruminants and pigs), or only the first of them (in carnivores). In horses, this trunk is an independent branch.
- The deep cervical artery supplies the "extensors" of the head and neck. It diverges in the cervical muscles, its direction is cranial. On the neck, like the vertebral branch, it forms the 2nd collateral. In pigs and dogs, this artery is a branch of the costocervical trunk.
- The vertebral artery is a steam room. It also goes cranially. Having reached the atlas, it releases branches into the muscles and spinal cord, exits through a hole in the first cervical vertebra (atlas) of animals and forms large blood flow paths on the neck (called a collateral). In cattle, it departs along with the above branches. And in carnivores, it is the first blood vessel that departs from the subclavian artery.
- The brachial artery (otherwise called the superficial cervical artery) provides blood to the muscles of the neck, dewlap, and also the entrance to the chest. In a pig, the thyroid trunk departs from it.
- Internal and external mammary arteries. The inner one is directed caudally along the surface of the sternum, reaches the seventh rib and branches. Her ultimatethe vessel is represented by the musculophrenic artery. Then it goes down and supplies blood to the muscles of the abdominal cavity, in pigs and carnivores also to the mammary gland. The external artery bypasses the first rib and branches deep into the pectoralis muscle. This artery is rather poorly developed.
Further on, the brachiocephalic trunk of animals, continuing with the left arteries, becomes the axillary arteries. They are also the main source of blood supply to the chest limbs.
