Venous system

Venous System

It consists of tubes called veins whose function is to carry blood from the capillaries to the heart. Veins, also like arteries, belong to large and small circulation.

The circuit that ends in the left atrium through the four pulmonary veins carrying arterial blood from the lungs is called small circulation or pulmonary circulation. And the circuit that ends in the right atrium through the vena cavae and the coronary sinus returning with venous blood is called large circulation or systemic circulation.

Some important veins of the human body:

Veins of pulmonary circulation (or small circulation): The veins that carry the blood that returns from the lungs to the heart after hematosis (oxygenation) are called pulmonary veins.

There are four pulmonary veins, two for each lung, one upper right and one lower right, one upper left and one lower left.

The four pulmonary veins will flow into the left atrium. These veins are formed by segmental veins that collect arterial blood from the pulmonary segments.

Veins of systemic circulation (or large circulation): Two large veins flow into the right atrium bringing venous blood to the heart. They are: superior vena cava and inferior vena cava. We also have the coronary sinus which is a large venous conduit formed by the veins that are bringing venous blood that circulated in the heart itself.

Pulmonary Grapes, Upper and Lower Cranes and Coronary Sinus
 
Pulmonary Grapes, Upper and Lower Cranes and Coronary Sinus
Source: NETTER, Frank H .. Atlas of Human Anatomy. 2 ed. Porto Alegre: Artmed, 2000.

Superior Vena Cava: The superior vena cava has a length of about 7.5 cm and a diameter of 2 cm and originates from both brachiocephalic trunks (or right and left brachiocephalic veins).

Each brachiocephalic vein consists of the junction of the subclavian vein (which receives blood from the upper limb) and the internal jugular vein (which receives blood from the head and neck).

Veins in the heart

Inferior Vena Cava: The inferior vena cava is the largest vein in the body, with a diameter of about 3.5 cm and is formed by the two common iliac veins that collect blood from the pelvic region and lower limbs.

Superior and inferior vena cava

Coronary sinus Coronary Sinus and Cardiac Veins:
The coronary sinus is the main vein of the heart. It receives almost all venous blood from the myocardium. It is located in the coronary sulcus opening in the right atrium. It is a broad venous canal to which veins drain. It receives the magma cardiac vein (anterior interventricular sulcus) at its left extremity, the middle cardiac vein (posterior interventricular sulcus) and the small cardiac vein at its right extremity. Several anterior heart veins drain directly into the right atrium.


HEAD AND NECK GRAVES

 HEAD AND NECK GRAVES

 HEAD AND NECK GRAVES

 HEAD AND NECK GRAVES

Skull: The venous network inside the skull is represented by a system of intercommunicating canals called the dura mater sinuses.

Dust Breasts:

These are true tunnels dug into the dura membrane. This is the outermost membrane of the meninges.

These channels are lined by endothelium.

The dural sinuses can be divided into six odd and seven even.

HARD MATER BELLS
 HARD MATER BELLS
Source: NETTER, Frank H .. Atlas of Human Anatomy. 2 ed. Porto Alegre: Artmed, 2000.
HARD MATER BELLS
 HARD MATER BELLS
Source: NETTER, Frank H .. Atlas of Human Anatomy. 2 ed. Porto Alegre: Artmed, 2000.

IMPERTUS BELLS (6): three are related to the cranial calvaria and three to the skull base.

Cranial Calvaria Breasts:

1 – Superior Sagittal Breast: It is located on the upper edge and follows the brain's scythe to its full extent.

2 – Lower Sagittal Sinus: it occupies two posterior thirds of the lower edge of the free part of the brain's scythe.

3 – Straight Breast: situated at the junction of the brain's scythe with the cerebellum tent.

Formerly it receives the inferior sagittal sinus and the great vein of the brain (which is formed by the internal veins of the brain) and later ends at the confluence of the sinuses.

Skull Base Breasts:

1 – Anterior Intravenous Sinus: crosswise connects the two cavernous sinuses. Situated at the top of the Turcic Saddle, passing before and over the pituitary gland.

2 – Posterior Intercavernous Sinus: Parallel to the anterior, it connects the two cavernous sinuses, passing behind and above the pituitary gland.

3 – Basilar Plexus: It is a venous canal plexus that is located in the occipital cleavage.

This plexus leads to the posterior intercavernous and inferior petrous sinuses (right and left).

Pair Breasts: are situated at the base of the skull.

1 – Sphenoparietal Sinus: occupies the posterior edge of the minor wing of the sphenoid bone.

2 – Cavernous Sinus: anteroposteriorly, it occupies each side of the turgical saddle.

It previously receives the ophthalmic vein, the deep middle vein of the brain and the sphenoparietal sinus, and then continues with the upper and lower petrous sinuses.

3 – Upper Petrosal Sinus: extending from the cavernous sinus to the transverse sinus, it is located at the upper edge of the petrous temporal part.

4 – Lower Petrosal Sinus: It originates at the posterior end of the cavernous sinus and receives part of the basilar plexus, ending in the superior bulb of the internal jugular vein.

5 – Transverse BreastIt originates at the confluence of the sinuses and runs through the transverse groove of the occipital bone to the petrous temporal base, where it receives the superior petrous sinus and continues with the sigmoid sinus.

6 – Sigmoid Sinus: occupies the groove of the same name, which makes a true & #8220; S & #8221; at the posterior border of the petrous part of the temporal, ending in the superior bulb of the internal jugular vein after crossing the jugular foramen.

The internal jugular vein continues the sigmoid sinus, and the inferior petrous sinus runs through the jugular foramen to flow into that vein.

7 – Occipital Sinus: It originates near the foramen magnum and is located on either side of the posterior edge of the cerebellum scythe.

It later ends at the confluence of the breasts at the level of the internal occipital protuberance.

Face: Usually the superior thyroid, lingual, facial and pharyngeal veins anastomose to form a common trunk that will flow into the internal jugular vein.

The pterygoid plexus collects blood from the vascularized territory through the maxillary artery, including all teeth, maintaining anastomosis with the facial vein and cavernous sinus.

The various branches of the pterygoid plexus anastomose with the superficial temporal vein to constitute the retromandibular vein.

This retromandibular vein that will unite with the posterior auricular vein to give rise to the external jugular vein.

The orbital cavity is drained by the superior and inferior ophthalmic veins that will flow into the cavernous sinus.

The superior ophthalmic vein maintains anastomosis with the onset of the facial vein.

Neck: Down the neck, we find four pairs of jugular veins. These jugular veins are called internal, external, anterior and posterior.

Internal Jugular Vein: will anastomose with the subclavian vein to form the venous brachiocephalic trunk.

External Jugular Vein: flows into the subclavian vein.

Anterior Jugular Vein: It originates superficially at the level of the suprahyoid region and ends at the termination of the external jugular vein.

Posterior Jugular Vein: It originates in the vicinity of the occipital and descends posteriorly to the neck to flow into the venous brachiocephalic trunk. It is deeply situated.

Superior Vena Cava Branches

Thorax and Abdominal Grapes

Chest: We found two main exceptions:

& #8211; The first refers to the coronary sinus that opens directly into the right atrium.

& #8211; The second different venous disposition is the azygos system.

The veins of the azygos system collect most of the venous blood from the chest and abdomen walls. From the abdomen venous blood rises through the ascending lumbar veins; of the chest is collected mainly by all the posterior intercostal veins.

The azygos system forms a true & #8220; H & #8221; ahead of the vertebral bodies of the thoracic portion of the spine.

The right vertical branch of & #8220; H & #8221; It is called azygos vein.

The left vertical branch is subdivided by the horizontal branch into two segments, one upper and one lower.

The inferior segment of the left vertical branch is constituted by the hemiazygos vein, while the superior segment of this branch is called accessory hemiazygos.

The horizontal branch is anastomotic, linking the two segments of the left branch with the right vertical branch.

Finally the azygos vein will flow into the superior vena cava.

Abdomen: In the abdomen, there is a very important venous system that collects blood from the abdominal viscera to carry it to the liver. It is the portal vein system.

The portal vein is formed by the anastomosis of the splenic vein (collects blood from the spleen) with the superior mesenteric vein.

The splenic vein, before anastomosing with the superior mesenteric vein, receives the inferior mesenteric vein.

Once constituted, the portal vein also receives the left gastric veins and the prepiloric vein.

When approaching the hepatic hilum, the portal vein forks into two branches (right and left), thus penetrating the liver.

Within the liver, the portal vein branches form a true network.

They will branch into smaller and smaller caliber venules until capillarization.

Then the capillaries are again constituting venules that come together successively to form the hepatic veins which will flow into the inferior vena cava.

The right gonodal vein will flow at an acute angle into the inferior vena cava, while the left will flow perpendicularly into the renal vein.

SUMMARY THE HEPATIC SYSTEM: The hepatic portal circulation diverts venous blood from the gastrointestinal organs and spleen to the liver before returning to the heart. The hepatic portal vein is formed by the union of the superior and splenic mesenteric veins. The superior mesenteric vein drains blood from the small intestine and parts of the large intestine, stomach and pancreas. The splenic vein drains blood from the stomach, pancreas and parts of the large intestine. The inferior mesenteric vein, which flows into the splenic vein, drains parts of the large intestine. The liver receives arterial (own hepatic artery) and venous (hepatic portal vein) blood at the same time. Finally, all the blood comes out of the liver through the hepatic veins that flow into the inferior vena cava.

GRAVES FORMING THE VEIN DOOR & #8211; HEPATIC SYSTEM
 
GRAVES FORMING THE DOOR VEIN - HEPATIC SYSTEM
Source: NETTER, Frank H .. Atlas of Human Anatomy. 2 ed. Porto Alegre: Artmed, 2000.
VEHICLES FORMING THE UPPER CAVA VEIN AND THE HEPATIC SYSTEM
 VEHICLES FORMING THE UPPER CAVA VEIN AND THE HEPATIC SYSTEM
Source: NETTER, Frank H .. Atlas of Human Anatomy. 2 ed. Porto Alegre: Artmed, 2000.

TOP MEMBER TRACKS

TOP MEMBER TRACKS

TOP MEMBER TRACKS

The deep veins of the upper limbs follow the same path as the arteries of the upper limbs.

The superficial veins of the upper limbs:

The cephalic vein originates from the network of venules in the lateral half of the hand region. In its upward course it passes to the anterior face of the forearm, which runs from the radial side, up the arm where it occupies the lateral bicipital groove and then the deltopectoral groove and then deepens, perforating the fascia, to flow into the axillary vein.

The basilic vein originates from the network of venules in the medial half of the dorsal region of the hand. Upon reaching the forearm it passes to the anterior face, which rises from the ulnar side. In the arm, it runs through the medial bicipital groove to the middle of the upper segment, as it deepens and punctures the fascia, leading to the medial brachial vein.

The median forearm vein begins with the palmar venules and runs up the anterior aspect of the forearm, parallel to and between the cephalic and basilic veins.

Near the flexor area of the forearm, the median forearm vein forks, giving the median cephalic vein that runs obliquely upward and laterally to anastomose with the cephalic vein, and the basilic median vein that runs obliquely upward and medially to anastomose with the basilic vein.

LOWER MEMBERS

LOWER MEMBERS
LOWER MEMBERS

Scheme of the Bottom Cava Branches

The deep veins of the lower limbs follow the same path as the arteries of the lower limbs.

The Superficial Veins Of The Lower Limbs:

Great Saphenous Vein: It originates in the venous network of the dorsal region of the foot, bordering the medial border of this region, passes between the medial malleolus and the tendon of the anterior tibial muscle and rises up the medial aspect of the leg and thigh.

In the vicinity of the root of the thigh, it bends deeper and goes through a hole in the fascia lata called the saphenous hiatus.

The Small Saphenous Vein: it originates in the region of venules on the lateral margin of the dorsal region of the foot, passes behind the lateral malleolus and rises along the midline of the posterior aspect of the leg to the vicinity of the knee flexion fold, where it deepens to flow into a of the popliteal veins.

The small saphenous vein communicates with the great saphenous vein through several anastomotic branches.

Structures of
Cardiovascular system
Blood

Heart

Blood vessels

Arterial system