The pineal gland and adrenal gland both develop from different embryonic tissues. The pineal gland develops from neuroectoderm of the posterior diencephalon roof, while the adrenal glands develop from both neural crest ectoderm and intermediate mesoderm. The pineal gland secretes melatonin which is influenced by light exposure and regulates circadian rhythms. The adrenal glands secrete cortisol and aldosterone which regulate stress responses and electrolyte balance. Both glands are susceptible to teratogens during development and can develop tumors or experience dysfunction later in life.

1. EMBRYOLOGY OF PINEALAND
ADRENAL GLAND
Department of Human Anatomy, Ahmadu Bello University,
Zaria.
By
ZACHARIAH Richard

2. PINEAL GLAND
2

3. INTRODUCTION
• The pineal gland, also known
as the pineal body, conarium,
epiphysis cerebri or the third
eye, is a small endocrine gland
in the vertebrate brain
• The shape of the gland
resembles a pine cone, hence
its name(Macchi et al., 2004).
(Illu, 2012.)
3
FIG. 1: Showing the location of the pineal gland

4. DEVELOPMENT OF THE PINEAL GLAND
• (7th-8th week) Develops from neuroectoderm of
posterior portion of roof of diencephalon, remains
attached to brain by a short stalk (Davies et al., 2012 ).
(Bowen et al.,2011). 4FIG. 2: Showing the human fetus

5. 5
Figure 3: A, External view of the brain at the end of the fifth week. B, Similar view at 7 weeks.
C, Median section of this brain showing the medial surface of the forebrain and midbrain. D,
Similar section at 8 weeks.
(www.studentsconsult.com)

6. 6
Fig. 4: A, Drawing of the medial surface of the forebrain of a 10-week embryo showing
the diencephalic derivatives and the pineal gland
(www.studentsconsult.com)

7. Fig. 5: A schematic figure to show the pineal gland derived from the walls of the fore-brain
7
(Wilhelm, 2003)

8. 8
Fig. 6: Schematic diagram showing the evagination of the pineal gland
(www.slideshare.com)

9. 9
(www.slideshare.com)
Fig. 7: Schematic diagram showing the Diencephalon where the pineal gland developed

10. SECRETIONS
Melatonin
Was discovered by Arone Lerner in 1958
• Melatonin secretions starts at 3-4 months of age
• Peak levels at 1-3 years of age
• Slightly lower levels through adulthood
10

11. PRODUCTION
• Melatonin is produced by pinealocytes in the pineal
gland (located in the brain) and also by the retina,
lens and GI tract.
11

12. • Production of melatonin by the pineal gland is under the
influence of the suprachiasmatic nucleus (SCN) of the
hypothalamus which receives information from the retina
about the daily pattern of light and darkness
12
FIG. 8: Showing the mechanism of melatonin secretion
(Hardeland, 2005)

13. 13
FIG. 9: Showing the role of suprachiasmatic nucleus
(Hardeland, 2005)

14. TERATOGENS
• Alcohol
• Vitamin B12
• Caffeine
• Cigarettes
14

15. CLINICAL CORRELATES
• Calcification
Calcification of the
pineal gland is typical
in young adults, and
has been observed in
children as young as
two years of age
(Zimmerman et
al.,2012). (www.pinterest.com)
15
FIG. 10

16. Pineal hyperplasia
• An abnormal condition caused by overgrowth of the
pineal gland. It is characterized by;
• Dry skin, hirsutism, teeth develop prematurely and are
malformed. External genitalia may reach adult size by 4
years of age.
16
(www.pinterest.com)FIG. 11: Malformed and Premature development of teeth

17. 17
ADRENAL
GLAND

18. INTRODUCTION
• The adrenal glands develop from two separate
embryological tissues; the neural crest ectoderm and
the intermediate mesoderm.
18FIG. 12: Showing the development of adrenal gland

19. DEVELOPMENT OF ADRENAL GLAND
19
(Barwick et al., 2005)
FIG. 13: Showing fetal development
Late Fetal Period - differentiates to form cortical zones
Birth - zona glomerulosa, zona fasiculata present
Year 3 - zona reticularis present (Barwick et al., 2005)

20. (Barwick et al., 2005)
20
FIG. 14; Showing the development of the Adrenal gland

21. 21
Fig. 15: Schematic drawings illustrating development of the suprarenal glands. A, At 6 weeks,
showing the mesodermal primordium of the fetal cortex. B, At 7 weeks, showing the addition
of neural crest cells. C, At 8 weeks, showing the fetal cortex and the early permanent cortex
beginning to encapsulate the medulla. D and E, Later stages of encapsulation of the medulla by
the cortex. F, Newborn infant showing the fetal cortex and two zones of the permanent cortex.
G, At 1 year, the fetal cortex has almost disappeared. H, At 4 years, showing the adult pattern
of cortical zones. Note that the fetal cortex has disappeared and that the gland is much smaller
than it was at birth (F).
(www.studentsconsult.com)

22. 22
FIG. 16: Hormones of the adrenal gland

23. FUNCTIONS OF ADRENAL HORMONES
23

24. TERATOGENS
• Caffeine
• Cigarettes
24

25. CLINICAL CORRELATES OF ADRENAL GLAND
Cushing's syndrome
• Is the manifestation
of glucocorticoid
excess. It can be the
result of a prolonged
treatment with
glucocorticoids or be
caused by an
underlying disease
(Longo et al., 2012).
25
FIG. 17

26. Addison's disease
• Addison's disease refers to primary hypoadrenalism, which
is a deficiency in glucocorticoid and mineralocorticoid
production by the adrenal gland. (Longo et al., 2012).
26
FIG. 18

27. Adrenal tumors
• Adrenal tumors are
commonly found during
medical imaging. They are
seen in around 3.4% of CT
scans (Nieman, 2010)
• In most cases they are benign
adenomas (Mantero et al.,
2000).
• Adrenal carcinomas are very
rare, with an incidence of 1
case per million per year
(Longo et al., 2012).
27
Scottmillermd.com
FIG. 19

28. SUMMARY
• The pineal gland develops from neuroectoderm of
posterior portion of roof of diencephalon
• The adrenal glands develop from two separate
embryological tissues; the neural crest ectoderm and
the intermediate mesoderm.
28

29. REFERENCES
Longo, D; Fauci, A; Kasper, D; Hauser, S; Jameson, J;
Loscalzo, J (2012). Harrison's Principles of Internal
Medicine (18th ed.). New York: McGraw-Hill.
Melmed, S; Polonsky, KS; Larsen, PR; Kronenberg, HM
(2011). Williams Textbook of Endocrinology (12th ed.).
Saunders.
Miller, WL; Auchus, RJ (2011). "The molecular biology,
biochemistry, and physiology of human steroidogenesis
and its disorders.". Endocrine Reviews. 32 (1): 81–151.
29

30. Moore KL, Dalley AF, Agur AM (2013). Clinically Oriented
Anatomy, 7th ed.
Melmed, S; Polonsky, KS; Larsen, PR; Kronenberg, HM
(2011). Williams Textbook of Endocrinology (12th ed.).
Saunders
Nieman, LK (2010). "Approach to the patient with an
adrenal incidentaloma.". The Journal of Clinical
Endocrinology and Metabolism. 95 (9): 4106–13.
Ross M, Pawlina W (2011). Histology: A Text and Atlas
(6th ed.). Lippincott Williams & Wilkins. pp. 708, 780.
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31. THANK YOU
FOR
LISTENING
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