Histology of the Pituitary Gland Flashcards Preview

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Flashcards in Histology of the Pituitary Gland Deck (69):
1

Where is the pituitary gland in the brain?

In the sella turcica of the sphenoid bone

2

What is the superior border of the pituitary gland?

Diaphragma sellae and hypothalamus

3

What is the inferior border of the pituitary gland?

Sella turcica

4

What is the lateral border of the pituitary gland?

Cavernous sinus

5

What is the anteroinferior border of the pituitary gland?

Sphenoid sinus

6

What is the anterosuperior border of the pituitary gland?

Optic chiasm

7

What arteries run laterally to the pituitary gland?

Internal carotids

8

What is the large sinus situated inferiorly to the pituitary gland?

Sphenoid sinus

9

What is the clinical relevance of the proximity of the internal carotids to the pituitary gland?

Pituitary adenoma may impinge on internal carotids, causing neurological ssx

10

What is the CN that sits superiorly to the carotid artery at the level of the pituitary?

CN III

11

What is the CN that sits laterally to the carotid artery at the level of the pituitary?

CN IV

12

What is the CN that sits inferior to the carotid artery at the level of the pituitary?

CN VI

13

What arteries supply the anterior cortical border zone (anterolateral regions) of the brain?

ACA and MCA

14

What arteries supply the internal border zone (medial region) of the brain?

ACA
MCA

15

What arteries supply the posterior cortical border zone (posterolateral regions) of the brain?

MCA and PCA

16

How is access gained to the pituitary during surgery?

Go through the nostrils and break through the sphenoid sinus

17

What is primary empty sella syndrome? What is the usual presentation?

Arachnoid mater invades the sella turcica d/t defect in the sellar diaphragm, compressing the pituitary gland posteriorly, and widening the superior opening for the infundibulum


Usually asymptomatic

18

What is secondary empty sella syndrome?

Secondary ESS is the result of the pituitary gland regressing within the cavity after an injury, surgery, or radiation therapy. Individuals with secondary ESS due to destruction of the pituitary gland have symptoms that reflect the loss of pituitary functions, such as the ceasing of menstrual periods, infertility, fatigue, and intolerance to stress and infection.

19

What are the three portions of the anterior pituitary (in order, from superior to inferior)?

Pars tuberalis
Pars intermedia
Pars distalis

20

What are the two portions of the posterior pituitary?

Infundibular stalk
Pars nervosa

21

What is the pars tuberalis?

The "collar" of the anterior pituitary that wraps around the infundibulum

22

What is the neurohypophysis?

Posterior pituitary

23

What is the adenohypophysis?

Anterior pituitary

24

From what layer of the developing fetus does the anterior pituitary gland form? Posterior?

Anterior = oral ectoderm
Posterior = Neuroectoderm

25

What is Rathke's pouch?

a depression in the roof of the developing mouth in front of the buccopharyngeal membrane. It gives rise to the anterior pituitary (adenohypophysis).

26

What part of the developing brain gives rise to the posterior pituitary?

Diencephalon

27

What is the clinical significance of remnants of Rathke's pouch?

The development of a craniopharyngioma

28

What are the two signalling molecules for the development of Rathke's pouch?

Bone morphogenetic protein 4

Fibroblast growth factor 8

29

What is the cause of craniopharyngiomas in children? Adults?

Children = remnants from Rathke's pouch

Adults = Mature cells in the anterior hypophysis

30

What are the inferior hypophyseal arteries a branches of? What do these supply?

-Direct branches of the internal carotid
- Pars nervosa

31

What are the arteries that supply the infundibulum?

Superior hypophysial arteries

32

What is the connection between the superior and inferior hypophysial arteries?

Trabecular arteries

33

What are the arteries that supply the primary capillary plexus of the pituitary, which is located in the infundibulum? What is the function of this plexus?

-Superior hypophysial arteries

-Collect hormones secreted from the hypothalamus

34

What are the veins that drain the primary capillary plexus to the secondary one, which is located in the anterior pituitary?

Portal veins

35

What is the capillary plexus found in the posterior pituitary supplied by?

Inferior hypophyseal arteries

36

What is the normal connective tissue in the pars distalis? What happens to this with the development of a pituitary adenoma?

Reticular

Loss of this CT

37

What is the general layout of the histology of the pituitary gland?

Sinusoidal capillaries broken up by cords of epithelial cells

38

What are the three types of cords of epithelial tissue found in the pituitary?

-Basophils
-Acidophils
-Chromophobes

39

What are the types of hormones that are released by basophils?

Glycoproteins

40

What are the types of hormones that are released by acidophils?

Proteins

41

What are the types of hormones that are released by chromophobes?

none- cell that has discharged its contents

42

Acidophils or basophil: somatotropes? What do these cells secrete?

Acidophils

GH

43

Acidophils or basophil: Mammotrophs (lactotrophs)? What do these cells secrete?

Acidophilic

Prolactin

44

What is the chemical cascade that occurs with GnRH secretion from the hypothalamus?

GnRH stimulates somatotropes to release GH, which increases IGF-1 from the liver.

45

Acidophils or basophil: Corticotrophs? What do these cells secrete?

Basophils
ACTH and Beta-lipotropic hormone

46

Acidophils or basophil: Gonadotropes? What do these cells secrete?

Basophils
LH and FSH

47

Acidophils or basophil: Thyrotropes? What do these cells secrete?

Basophils
TSH

48

What are the only two acidophils in the pars distalis?

Somatotropes and mammotrophs

49

What is the chemical cascade that occurs with TRH/PRH release from the hypothalamus?

PRH/TRH stimulates mammotrophs to secrete prolactin, which increases lactogenesis

50

What is the primary inhibitor of prolactin secretion?

Dopamine

51

What is the major stimulus for prolactin secretion?

baby suckling

52

True or false: there are acidophilic stem cells in the normal pituitary that secrete both GH and prolactin

True, but these are rare

53

True or false: either gonadotropes secrete FSH, or they secrete LH, never both

False, can be both or either/or

54

What are the cells that FSH acts on?

Follicular cells
Sertoli cells

55

What are the cells that LH acts on?

Corpus luteum
Leydig cells

56

What cells does ACTH stimulate?

Two inner regions of the adrenal glands (fasciculata and reticularis)

57

What is the mucoid wedge of the pituitary?

Anterior and medial part of the pituitary that contains ACTH secreting cells and thyrotropes

58

Where are the gonadotropes located in the pituitary?

Anterolaterally

59

Where are the mammotrophs located in the pituitary?

Posteriorly in the anterior pituitary

60

Where are the gonadotrophs located in the pituitary?

Diffusely

61

What is Crooke's hyaline change?

Glassy appearance of corticotrophs d/t excess glucocorticoid production

62

What corticotrophs are not susceptible to the Crooke's hyaline change?

Those that invade the posterior pituitary

63

What is the neurohypophysis? Where do the cell bodies whose axons project into this area reside?

Collection of axons whose cell bodies reside in the supraoptic and paraventricular nuclei of the hypothalamus

64

What are the supporting cells of the neurohypophysis?

Pituicytes

65

What are the Herring bodies found in the neurohypophysis?

Dilated area along the axons from the PVN and SVN that release the ADH/oxytocin

66

What is the function of the Neurohypophysis?

Release of ADH and oxytocin

67

What cells are primarily responsible for the synthesis of oxytocin?

Paraventricular nucleus

68

What cells are primarily responsible for the synthesis of ADH?

Supraoptic nucleus

69

Why is LH low with an FSH secreting tumor?

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