Pituitary Gland

Question 1

Location of pituitary gland

Answer 1

Sphenoid b. of skull

Question 2

Pituitary gland origin

Answer 2

1. Ectoderm from roof of oral cavity grows upward as Rathke’s pouch → becomes residual cleft
2. Neuroectoderm from diencephalon grows downward → becomes posterior pit.

Question 3

Residual cleft is seen between?

Answer 3

Pars distalis and pars nervosa

Question 4

Parts of anterior pit.

Answer 4

1. Pars distalis (most important)
2. Pars tuberalis
3. Pars intermedia

Question 5

Parts of posterior pit.

Answer 5

1. Pars nervosa

2. Infundibular stalk

Question 6

Structure of pars distalis

Answer 6

Parenchyma of cords/clusters associated with sinusoids

Question 7

Sinusoids are what type of epithelial cells?

Answer 7

Fenestrated

Question 8

2 types of cells in pars distalis

Answer 8

1. Chromophobes (non-staining)

2. Chromophils (acidophils or basophils)

Question 9

Roles of chromophobes

Answer 9

1. Supporting cells
2. Stem cells
3. Degranulated chromophils

Question 10

Acidophils produce?

Answer 10

1. Growth hormone (somatotrophs)

2. Protactin (lactotrophs)

Question 11

Basophils produce

Answer 11

1. TSH (thyrotrophs)
2. Gonadotropic hormones LH and FSH (gonadotrophs)
3. ACTH (corticotrophs)

Question 12

Pars tuberalis forms?

Answer 12

Infundibulum (collar around neural stalk)

Question 13

Pars intermedia secretes?

Answer 13

1. MSH (melanocyte stimulating hormone)

2. ACTH

Question 14

Adenohypophysis means?

Answer 14

Anterior pit.

Question 15

How does hypothalamus control anterior pit.?

Answer 15

1. Hormones synthesized by secretory neurons
2. Stored in axon terminals extending into infundibular stalk
3. When stimulated → discharge into capillaries and median eminence
4. Travel via hyophyseal portal system to secondary capillary plexus

Question 16

What is secondary capillary plexus?

Answer 16

Capillaries in pars distalis

Question 17

Somatostatin

Answer 17

Inhibits somatotropic hormone release

Question 18

Hormones synthesized in the hypothalamus are stored in the?

Answer 18

Posterior pit.

Question 19

What is the neurohypophysis?

Answer 19

Pars nervosa + pituitary stalk

Question 20

Neurohypophysis contains?

Answer 20

Numerous unmyelinated axons → their cell bodies are in the hypothalamus

Question 21

Herring bodies

Answer 21

Acidophilic acuumulations of hormones and carrier proteins in the pars nervosa

(within terminal ends of axons from hypothalamus)

Question 22

Pituicytes

Answer 22

Cells in pars nervosa which act like neuroglia

Question 23

Oxytocin and ADH are made in the _____ and stored in the ____

Answer 23

Hypothalamus

Stored in pars nervosa

Question 24

Vasopressin =

Answer 24

ADH (anti-diuretic hormone) → decreases urination