The transverse foramen (Latin: foramen transversarium) pierces the transverse processes of the seven cervical vertebrae. In the upper six vertebrae, the foramen gives passage to the vertebral artery, vertebral vein, and a plexus of sympathetic nerves. The seventh foramen lacks the artery, but contains the vein and sympathetic nerves.
The superior mesenteric artery supplies the caecum, appendix, ascending colon and right two-thirds of the transverse colon via the ileocolic, right colic and middle colic branches. The ileocolic artery is formed as the distal continuation of the superior mesenteric artery in the root of the small bowel mesentery after the origin of the last ileal artery.
The inferior mesenteric artery is usually smaller in calibre than the superior mesenteric artery, and arises from the anterior or left anterolateral aspect of the aorta at about the level of the third lumbar vertebra, 3 or 4 cm above the aortic bifurcation and posterior to the horizontal part of the duodenum. It descends deep to the peritoneum, initially anterior and then to the left of the aorta. It crosses the origin of the left common iliac artery medial to the left ureter and then enters, and continues in, the root of the sigmoid mesocolon as the superior rectal artery. Distally the inferior mesenteric vein is lateral to it. The principal branches are the left colic, sigmoid (of which there may be several) and superior rectal artery.
The arc of Riolan (AOR) is also known as the meandering mesenteric artery or central anastomotic mesenteric artery.
It is an inconstant artery that connects the proximal superior mesenteric artery (SMA) or one of its primary branches to the proximal inferior mesenteric artery (IMA) or one of its primary branches. It is classically described as connecting the middle colic branch of the SMA with the left colic branch of the IMA. It forms a short loop that runs close to the root of the mesentery.
When present, the AOR is an important connection between the SMA and IMA in the setting of arterial occlusion or significant stenosis. In proximal SMA occlusion, the AOR provides collateral flow from the IMA to the SMA territory. In proximal IMA occlusion, it provides collateral flow from the SMA to the IMA territory. In distal abdominal aortic occlusion it provides collateral flow from SMA to IMA to iliac vessels (via the superior rectal artery) and then to the lower limbs (via the external iliac artery).
*I am not gonna explain the entire anatomy of the knee here, coz u will find that in hundreds of books. I am gonna post a video made by Dr. Bertram Zarins of the Mass General Hospital Sports Medicine Service, which has made me happy (happy because of its simplicity and beauty in explaining the basic anatomy). Sometimes you try explaining hundreds of things to students without a picture or video and they dont get it, but u show them a beautiful video or picture and they dont need you. This is one of those videos. Point to note is that the doctor was trying to explain Anterior cruciate ligament repair here and not anatomy.
Things to understand from this video :
1. The Anterior cruciate ligament ACLoriginates from deep within the notch of the distal femur. Its proximal fibers fan out along the medial wall of the lateral femoral condyle. There are two bundles of the ACL—the anteromedial and the posterolateral, named according to where the bundles insert into the tibial plateau. The ACL attaches in front of the intercondyloid eminence of the tibia, being blended with the anterior horn of the medial meniscus. These attachments allow it to resist anterior translation and medial rotation of the tibia, in relation to the femur.
2.The posterior cruciate ligament (or PCL) is one of the four major ligaments of the knee. It connects the posterior intercondylar area of the tibia to the medial condyle of the femur. This configuration allows the PCL to resist forces pushing the tibia posteriorly relative to the femur.
3. Medial collateral ligament : It is a broad, flat, membranous band, situated slightly posterior on the medial side of the knee joint. It is attached proximally to the medial condyle of femur immediately below the adductor tubercle; below to the medial condyle of the tibia and medial surface of its body. It resists forces that would push the knee medially, which would otherwise produce valgus deformity.
4. Lateral collateral ligament : Rounded, more narrow and less broad than the medial collateral ligament, the fibular collateral ligament stretches obliquely downward and backward from the lateral epicondyle of the femur above, to the head of the fibula below. In contrast to the medial collateral ligament, it is fused with neither the capsular ligament nor the lateral meniscus. Because of this, the lateral collateral ligament is more flexible than its medial counterpart, and is therefore less susceptible to injury.The fibers of the posterior part of the ligament are short and incline backward as they descend; they are inserted into the tibia above the groove for the semimembranosus muscle.The anterior part of the ligament is a flattened band, about 10 centimeters long, which inclines forward as it descends.It is inserted into the medial surface of the body of the tibia about 2.5 centimeters below the level of the condyle. It resists forces that would push the knee laterally, which would otherwise produce a varus deformity. *Other important structures related to knee anatomy are the menisci of the knee and the bursa surrounding the knee, which i am gonna discuss in another post someday.
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Now try answering these Multiple choice questions (mcqs): 1.Posterior Cruciate ligament prevents a.Anterior movement of tibia in relation to femur b.Posterior movement of tibia in relation to femur c.Medial movement of tibia d.Lateral movement of tibia
2.Anterior cruciate ligament prevents a.Anterior movement of tibia in relation to femur b.Posterior movement of tibia in relation to femur c.Medial movement of tibia d.Lateral movement of tibia
3.Medial collateral ligament prevents a.Anterior movement of tibia in relation to femur b.Posterior movement of tibia in relation to femur c.Medial movement of tibia d.Lateral movement of tibia
4.Lateral collateral ligament prevents a.Anterior movement of tibia in relation to femur b.Posterior movement of tibia in relation to femur c.Medial movement of tibia d.Lateral movement of tibia
5.What are the two bundles ACL is made up of a.Anteromedial and posterolateral b.Posteromedial and anterolateral c.Mediolateral and cephalocaudal d.None of the above
The confluence of sinuses or torcular herophili is the connecting point of the superior sagittal sinus, straight sinus, and occipital sinus. It is found deep to the occipital protuberance of the skull. Blood arriving at this point then proceeds to drain into the left and right transverse sinuses.
The superior sagittal sinus often drains into (either exclusively or predominantly) one transverse sinus, and the occipital sinus drains into the other.
Confluence of sinuses
An older term often used for the confluence of sinuses "torcular herophili", describes the veins as a gutter, or canal, and honors Herophilos, the Greek anatomist who was the first to use cadavers for the systematic study of anatomy. This term more precisely refers to the concavity in the bone which is the location of the confluence of sinuses.
