Question

In a study entitled Sleep Disorders in Children with Incidental Pineal Cyst on MRI: A Pilot Study by Del Rosso, et al. involving children aged 6–12 years, who were referred for evaluation of headaches, tics, or syncope, and had an incidental pineal cyst on an otherwise normal brain MRI, it was found out that school-age children with pineal cysts have significantly increased levels of sleepiness and difficulty with sleep initiation and maintenance than those with normal MRI.

6. Describe the gross anatomy of the pineal gland.

7. Enumerate the different types of cell of the pineal gland.

8. In the study, propose a logical reason why children who have incidental finding of pineal cyst on brain MRI had significantly increased levels of sleepiness and difficulty with sleep initiation than those with normal MRI.

9. How does pineal gland play a role in jet lag syndrome?

10. Enumerate the tumors that may arise from the pineal gland.

Answer 1

6.  PINEAL GLAND ANATOMY

The pineal gland is an endocrine gland that is located inside the diencephalic part of the forebrain.It mainly controls the circardian rhythm of the body.It is also called the epiphysis cerebri.The gland is an extension of the roof of the 3rd ventricle of the brain.

• The pineal stalk is formed by the Habenular and posterior commissures.
• The Habenular commissure forms a part of the superior lamina of the stalk and the posterior commissure is a part of the inferior lamina.
• The space between the two laminae is called the pineal recess. This communicates with the hypothalamic sulcus and the third ventricle anteriorly
• Blood supply is through the branches of the posterior cerebral arteries.
• Nervous innervations:
  • Sympathetic- from the superior cervical ganglion
  • .Parasympathetic innervation- from the pterygopalatine and otic ganglia .
  • Neurons from the trigeminal ganglion also supply the gland with nerve fibers which contain the neuropeptide PACAP.

7. The different type of cells inside the pineal gland are

• Pinealocytes-They form about 95% of the cells inside the pineal gland.Thet secrete melatonin which regulate the circardian rhythm of the body
• interstitial cells
• perivascular phagocytes
• corpora arenacea (brain sand) bodies
• pineal neurons