AnTomy

1. ANATOMY
OF
THE PITUITARY
GLAND
Who suffer (s) from pituitary disturbances?
1) Soldier # 1
2) Soldier # 2
3) Soldier # 3
4) Soldiers # 1 & 3
1
2
3

2. OBJECTIVES
At the end of the lecture, students should be
able to:
 Describe the position of the pituitary gland.
 List the structures related to the pituitary
gland.
 Differentiate between the lobes of the gland.
 Describe the blood supply of pituitary gland &
the hypophyseal portal system.

3. § Introduction
1. The “master gland”— controls three
other endocrine glands
2. Better to think of the pituitary
gland as the relay center—
3. Its function covers both
endocrine target glands and
nonendocrine target glands
2-3

4. PITUITARY GLAND
(HYPOPHYSIS CEREBRI)
It is a small oval structure of 1 cm in diameter.
It doubles its size during pregnancy.

6. PITUITARY GLAND
(POSITION)
It lies in the hypophyseal fossa of the body of
sphenoid bone, between optic chiasma (anteriorly) &
mamillary bodies (posteriorly).
Mamillary body
Optic chiasma
Body of sphenoi

7. PITUITARY GLAND
(POSITION)
It lies in the middle cranial fossa
It is well protected in sella
turcica of body of sphenoid
Sella turcica

8. PITUITARY GLAND
(POSITION)
A fold of dura mater (Diaphragma sellae) covers the pituitary
gland & has an opening for passage of infundibulum (pituitary
stalk) connecting the gland to hypothalamus.
Infundibulum

9. PITUITARY GLAND
X-RAY SKULL: LATERAL VIEW
SAGITTAL SECTION OF HEAD &
NECK
Hypophyseal fossa
Sphenoidal air sinus
Pituitary
gland

10. IMPORTANT RELATIONS
SUPERIOR: Diaphragma sellae
INFERIOR: Sphenoidal air sinuses
LATERAL: Cavernous sinuses

11. Hypothalamus and pituitary
gland

12. SUBDIVISIONS OF PITUITARY
GLAND
The gland is subdivided into:
1) Anterior lobe (adenohypophysis): true gland, secretes hormones
2) Posterior lobe (neurohypophysis): connected to hypothalamus
through hypothalamo-hypophyseal tract, stores hormones secreted
by hypothalamic nuclei
Hypothalamo-hypophyseal
tract

13. § Pituitary Gland (Hypophysis)
 Suspended from hypothalamus by stalk
(infundibulum)
 Location and size
 housed in sella turcica of sphenoid bone
 1.3 cm diameter
 Adenohypophysis (________ pituitary)
 arises from hypophyseal (Rathke’s) pouch (outgrowth
of pharynx); Fig. 2.1 and x
 Neurohypophysis (________ pituitary)
 arises from brain;
 Magnocellular neurons– supraoptic and paraventricular
nuclei; Nerve endings?
17-13

14. BLOOD SUPPLY OF PITUITARY
GLAND
ARTERIES: Superior & inferior hypophyseal arteries (branches
of internal carotid artery)
VEINS: hypophyseal veins drain into cavernous sinuses.
Cavernous sinuses

15. 2-15





16. ARTERIES OF PITUITARY
GLAND
The inferior hypophyseal: supplies posterior lobe of pituitary gland.
The superior hypophyseal: supplies infundibulum & forms a capillary
network from which vessels pass downward & form sinusoids into the
anterior lobe of pituitary gland (hypophyseal portal system).
a hypothalamo-
hypophseal
portal vessel
Infundibulum

17. ANTERIOR LOBE OF
PITUITARY
Hormone-releasing &
inhibiting factors
produced by
hypothalamus use
hypophyseal portal
system of vessels to
reach the anterior lobe of
pituitary gland
Hypophyseal portal
system

18. Anterior pituitary
 Anterior pituitary: connected to the
hypothalamus by hypothalmoanterior pituitary
portal vessels.
 The anterior pituitary produces six peptide
hormones:
 prolactin, growth hormone (GH),
 thyroid stimulating hormone (TSH),
 adrenocorticotropic hormone (ACTH),
 follicle-stimulating hormone (FSH),
 luteinizing hormone (LH).

19. 1. FSH (follicle stimulating hormone)
2. LH (luteinizing hormone)
The above two are called gonadotropins
3. TSH (thyroid stimulating hormone, thyrotropin)
4. ACTH (adrenocorticotropic hormone)
5. GH (growth hormone; somatotropin or somatotropic
hormone)
6. PRL (prolactin)
 Tropic (trophic) hormones-- target other
endocrine glands to release their own
hormones;
§ Hormones secreted by anterior pituitary

20. 


2-20

21. Too Much Growth Hormone
 GIGANTISM IN CHILDREN
 skeletal growth; may
grow
up to 8 ft. tall and > 300 lbs
 ACROMEGALY IN ADULTS
 enlarged feet/hands,
thickening of bones,
prognathism, HTN, wt. gain,
H/A, visual disturbances,
diabetes mellitus,
enlargement of the heart and
liver

22. What assessment findings would the nurse
document?

24. S & S Anterior Pituitary
HYPOfunctioning
 GH
 FSH/LH
 Prolactin
 ACTH
 TSH

25. § Glycoprotein hormone family– TSH, FSH, LH
1. TSH– to stimulate the secretion of thyroid
hormone
2. FSH & LH– important for the function of the
testes and the ovaries
 FSH– growth of ovarian follicles and formation of
sperm
 LH (in women)– induce ovulation and the
formation of the corpus luteum; stimulate the
ovarian production of estrogen and progesterone
 LH (in men)– stimulates the production of
Testosterone; what cells?

26. Regulation
of
gonadotropi
n secretion

27. Prolactin
 Stimulates breast development and
lactogenesis
 May be involved in development of Leydig
cells in pre-pubertal males
 Immunomodulatory effects– stimulates T cell
functions
 Prolactin receptors in thymus

28. POSTERIOR LOBE OF
PITUITARY
Axons of supraoptic
& paraventricular cells
of hypothalamus send
their secretion
(neurosecretion) to
posterior lobe of
pituitary gland
through hypothalamo-
hypophyseal tract
Hypothalamo-
hypophyseal tract

29. § The Posterior Pituitary
2-29

30.  OT (oxytocin) and ADH
produced in hypothalamus
transported by hypothalamo-
hypophyseal tract to posterior lobe
(stores/releases hormones)
§ Posterior Pituitary Hormones
2-30

31. Hormone Actions: Posterior Lobe
 ADH (Antidiuretic Hormone)
 Target organ/tissue-- ?
  water retention, reduce urine
 also functions as neurotransmitter
 Oxytocin
 labor contractions, lactation (milk ejection)
 possible role in
 sperm transport . . .
 emotional bonding
2-31

32. 1. 3.
2.
2-32
3 hormonal families of the
anterior lobe: Table 2.1
(ALL proteins)

33. THANK YOU
&
BEST WISHES
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