Endocrine - Pituitary and Pineal Gland

Question 1

What are the two feedback mechanisms utilized by the endocrine system?

Answer 1

Positive Feedback

Negative Feedback

Question 2

What is the hypophysis?

Answer 2

Pituitary Gland

Question 3

What two glands provide endocrine and neuroendocrine control of other endocrine glands?

Answer 3

Hypothalmus and pituitary gland

Question 4

Is the pituitary gland paired?

Answer 4

No

Question 5

Where is the pituitary gland located in the skull?

Answer 5

Sella turcica

Question 6

What connects the pituitary gland to the hypothalmus?

Answer 6

Infundibular stalk

Question 7

What type of tissue surrounds the pituitary gland?

Answer 7

Dense irregular CT

Continuation of dura mater of the brain

Question 8

What are the two functional components of the pituitary gland?

Answer 8

Adenohypophysis - anterior

Neurohypophysis - posterior

Question 9

What is the adenophysis derived from? The neurohypophysis?

Answer 9

Adenophysis - oral ectoderm

Neurohypophysis - downgrowth of neurectoderm or diencephalon

Question 10

What is Rathke’s pouch?

Answer 10

The invagionation of the ectogerm of the oral cavity during embryology that develops into the adenohypophysis

Question 11

How is endocrine tissue, like that of the pituitary gland, typically organized?

Answer 11

Organized into clumps and cords around fenestrated capillaries

Question 12

What are the three regions of the adenohypophysis? Where are each located?

Answer 12

Pars distalis - anterior most, largest portion
Pars intermedia - thin remnant of posterior all of Pathke’s pouc
Pars tuberalis - collor/sheath around infundibular stalk

Question 13

What are remnants of the Rathke’s pouch lumen called? Where are they found? What are they lined with

Answer 13

Rathke’s cysts
Pars intermedia
Lined with cuboidal epithelium

Question 14

What are chromophiles? Chromophobes?

Answer 14

Chromophiles - cells with secretory granules that pick up dye
Chromophobes - do not have intensely staining secretory granules

Question 15

What are two types of chromophobes found in the adenohypophysis?

Answer 15

Stromal cells

Degranualted chromophiles

Question 16

What are two sub-categories of chromophiles?

Answer 16

Basophils

Acidophils

Question 17

What are the two cells types of acidophils in the anterior pituitary?

Answer 17

Somatotropes

Lactoropes

Question 18

What do somatotropes secrete? What endocrine organ controls this secretion? Which things causes production? Inhibition?

Answer 18

Secrete somatotropin (growth hormone)
Hypothalmus
GHRH - stimulates
Somatostatin - inhibits

Question 19

What do lactoropes secrete? What are they stimulated and inhibited by? Where do each of those come from?

Answer 19

Secrete prolactin
Stimulated by TRH
Inhibited by dopamine

Question 20

What happens to lactorope cells during pregnancy?

Answer 20

Increase in size and number

Question 21

What is the most abundant cell in the adenohypophysis?

Answer 21

Somatotropes

Question 22

What are the three basophil cells in the anterior pituitary?

Answer 22

Corticotropes, gonadotropes, thyrotropes

Question 23

What do corticotropes produce? What stimulates this release? From where?

Answer 23

Adrenocorticotropic hormone (ACTH)
CRH (corticotropin-releasing hormone) stimulates ACTH release. It is produced in the hypothalmus

Question 24

What two hormones are secreted from gonadotropes? controlled by what? From where?

Answer 24

FSH and LH

Controlled by hypothalmus by secretion of GnRH (gonadotropin-releasing hormone)

Question 25

What to thyrotropes produce? What controls this secretion?

Answer 25

Secrete TSH | Controlled by TRH

Question 26

What two parts comprise the neurohypophysis?

Answer 26

Pars nervosa | Infundibulum

Question 27

What two cell types are contained in the neurohypophysis?

Answer 27

Axons of hypothalamic neurons | Pituicytes - glial cells

Question 28

What two things do the hypothalamic neurons secrete into pars nervosa?

Answer 28

Oxytocin | ADH

Question 29

What are Herring bodies?

Answer 29

Large distended axon terminals of hypothalamic neurons located in the pars nervosa of the neurohypophysis

Question 30

What two arteries supply the pituitary?

Answer 30

Superior and inferior hypophyseal arteries

Question 31

What 4 parts are supplies by the superior hypophyseal artery?

Answer 31

Pars tuberalis Infundibulum Median eminence Pars distalis

Question 32

What is the most prominent feature of the hypophyseal blood supply?

Answer 32

Hypophyseal portal system

Question 33

What does the hypophyseal portal vein run between?

Answer 33

Primary capillary plexus to secondary capillary plexus (around pars distalis)

Question 34

What type of capillaries are contained in the capillary plexi?

Answer 34

Fenestrated sinusoidal capillaries

Question 35

What artery supplies the pars nervosa?

Answer 35

Inferior hypophyseal artery

Question 36

Where is the pineal gland located?

Answer 36

Posterior end of third ventricle of the brain

Question 37

What does the pineal gland form as an outcropping of? Similarly to what structure?

Answer 37

Dicephalon | Neurohypophysis

Question 38

What covers the pineal gland?

Answer 38

Pia matter

Question 39

Pia matter extends into the pineal gland as what? What runs in them?

Answer 39

Septa | Blood vessels

Question 40

What are corposa aernacea? Where are they found?

Answer 40

Aggregates of calcium phosphate | Located in pineal gland

Question 41

How do the corposa aernacea change with age?

Answer 41

Increase in number and size with age

Question 42

What two cell types are found in the pineal gland?

Answer 42

Pinealocytes | Glial Cells

Question 43

What are the principal cells of the pineal gland? What did they likely evolve from? They are considered modified ______ cells

Answer 43

Pinealocytes Photoreceptors Neuronal

Question 44

Where are axons located in the pineal gland in relation to the pinealocytes?

Answer 44

Spacers between clusters of pinealocytes

Question 45

Describe the characteristics of the pineolcyte nucleus and nucleolus

Answer 45

Nucleus - large euchromatic | Nucleolus - prominent

Question 46

What do pinealocytes secrete?

Answer 46

Melatonin

Question 47

What tract conveys information about light/dark cycles to the pineal gland?

Answer 47

Retinothalamic tract

Question 48

What controls the systhesis and secretion of melatonin?

Answer 48

NE released by sympathetic neurons

Question 49

What activity does melatonin inhibit?

Answer 49

Steroidogenic activity of gonads is inhibited by melatonin

Question 50

What are the supporting cells of the pineal gland?

Answer 50

Glial cells

Question 51

What percent of the pineal gland is pinealocytes? Glial cells?

Answer 51

Pinealocytes - 90% | Glial cells - 5-10%

Question 52

How do glial cell nuclei compare to pinealocytes?

Answer 52

Smaller and heterochromatic