superior colliculus

Examples of superior colliculus in the following topics:

• Oculomotor (III) Nerve

  • It enters the orbit via the superior orbital fissure and controls most of the eye's movements, including constriction of the pupil and maintaining an open eyelid by innervating the levator palpebrae superiors muscle.
  • The oculomotor nucleus originates at the level of the superior colliculus.
  • The muscles it controls are the striated muscle in the levator palpebrae superioris and all extraocular muscles, except for the superior oblique muscle and the lateral rectus muscle.
  • It then divides into two branches that enter the orbit through the superior orbital fissure, between the two heads of the lateral rectus (a muscle on the lateral side of the eyeball in the orbit).
  • Here the nerve is placed below the trochlear nerve and the frontal and lacrimal branches of the ophthalmic nerve, while the nasociliary nerve is placed between its two rami (the superior and inferior branch of oculomotor nerve).

• Visual Processing

  • Another important visual route is a pathway from the retina to the superior colliculus in the midbrain, where eye movements are coordinated and integrated with auditory information.

• Midbrain

  • The tectum (Latin for "roof") is formed by the superior and inferior colliculi and comprises the rear portion of the midbrain.
  • The superior colliculus regulates preliminary visual processing and eye movement, while the inferior colliculus is involved in auditory processing.

• The Role of the Basal Ganglia in Movement

  • Eye movement is influenced by an extensive network of brain regions that converge on a midbrain area called the superior colliculus (SC).

• Thalamus

  • Similarly, the medial geniculate nucleus acts as a key auditory relay between the inferior colliculus of the midbrain and the primary auditory cortex.

• Ischium

  • Situated below the ilium and behind the pubis, the superior portion of this bone forms approximately one third of the acetabulum, which articulates with the femoral head to form the hip joint.
  • The ischium is divisible into three portions; the body, and the superior and inferior rami.
  • The body contains a prominent spine that is the origin for the gemellus superior muscle.
  • The superior ramus of the ischium extends inferiorly and posteriorly from the body.
  • The inferior ramus of the ischium is thin and flattened and ascends from the superior ramus of the ischium to join the inferior ramus of the pubis.

• Anatomy of the Pancreas

  • The uncinate process emerges from the lower part of head, and lies deep to superior mesenteric vessels.
  • The superior pancreaticoduodenal artery from gastroduodenal artery and the inferior pancreaticoduodenal artery from superior mesenteric artery run in the groove between the pancreas and the duodenum and supply the head of pancreas.
  • The body and neck of the pancreas drain into splenic vein; the head drains into the superior mesenteric and portal veins.
  • Lymph is drained via the splenic, celiac and superior mesenteric lymph nodes.
  • 1: Head of pancreas 2: Uncinate process of pancreas 3: Pancreatic notch 4: Body of pancreas 5: Anterior surface of pancreas 6: Inferior surface of pancreas 7: Superior margin of pancreas 8: Anterior margin of pancreas 9: Inferior margin of pancreas 10: Omental tuber 11: Tail of pancreas 12: Duodenum.

• Pubis

  • The pubic bone is divisible into a body, a superior ramus, and an inferior ramus .
  • The rough superior edge of the corpus, known as the pubic crest, ends laterally in the pubic tubercle.
  • The superior pubic ramus is one third of the pubic bone.
  • It passes laterally and downward from the medial end of the superior ramus, and becomes narrower as it descends and joins with the inferior ramus of the ischium below the obturator foramen.
  • (1) sacrum, (2) ilium, (3) ischium, (4) pubis: 4a-body; 4b-superior ramus; 4c-inferior ramus, (5) pubic symphisis, (6) acetabulum, (7) obturator foramen, (8) coccyx, (red dotted line) linea terminalis.

• False and True Pelves

  • The false (greater) pelvis is larger and superior to the true (lesser) pelvis where the pelvic inlet is located.
  • The true (or lesser) pelvis is bounded in front and below by the pubic symphysis and the superior rami of the pubis; above and behind, by the sacrum and coccyx; and laterally, by a broad, smooth, quadrangular area of bone, corresponding to the inner surfaces of the body and superior ramus of the ischium, and the part of the ilium below the arcuate line.
  • The greater pelvis (yellow) is larger and superior to the lesser pelvis (red) where the pelvic inlet is located.

• Autonomic Plexuses

  • The autonomic plexuses include the cardiac plexus, the pulmonary plexus, the esophageal plexus, and abdominal aortic plexus, and the superior and inferior hypogastric plexuses.
  • It is formed by the superior cardiac branch of the left sympathetic trunk and the lower superior cervical cardiac branch of the left vagus nerve.
  • It is situated on the sides and front of the aorta, between the origins of the superior and inferior mesenteric arteries.
  • The superior hypogastric plexus (in older texts, hypogastric plexus or presacral nerve) is a plexus of nerves situated on the vertebral bodies below the bifurcation of the abdominal aorta.