2-1-16-Histology Of Pituitary, Hypothalamus, & Pineal (Cole)

Question 1

What are the 2 nuclei of the hypothalamus?

Answer 1

Supraoptic

Paraventricular

Question 2

This hypothalamic nucleus primarily produces ADH

Answer 2

Supraoptic

Question 3

This hypothalamic nucleus primarily produces oxytocin:

Answer 3

Paraventricular

Question 4

The hypothalamus releases ____ which stimulates release of prolactin and thyrotropin (AKA Thyroid Stimulating Hormone)

Answer 4

Thyrotropin-releasing Hormone (TRH)

Question 5

The hypothalamus releases ___ which stimulates release of FSH and LH

Answer 5

Gonadotropin-releasing hormone (GnRH)

Question 6

The hypothalamus releases ___ which stimulates release of ACTH

Answer 6

Corticotropin-releasing hormone (CRH)

Question 7

The hypothalamus releases ___ which stimulates release of GH

Answer 7

Growth hormone releasing hormone (GHRH)

Question 8

The hypothalamus releases ____ which inhibits release of GH and TSH

Answer 8

Somatostatin

Question 9

The hypothalamus releases ___ which inhibits release of Prolactin

Answer 9

Prolactin-inhibiting hormone (PIH) AKA Dopamine

Question 10

The anterior pituitary is stimulated by TRH from the hypothalamus to release ___ which stimulates thyroid production of T3 and T4 thyroid hormones

Answer 10

Prolactin and Thyrotropin (AKA TSH)

Question 11

The anterior pituitary is stimulated by GnRH from the hypothalamus to release ___ which stimulates follicular development (ovaries) and spermatogenesis (testes). ___ is also released from the anterior pituitary in response to GnRH which stimulates ovulation, estrogen production (ovaries) & testosterone production (testes)

Answer 11

FSH and LH

Question 12

The anterior pituitary is stimulated by CRH from the hypothalamus to released ___ which stimulates the adrenal cortex to release cortisol

Answer 12

ACTH

Question 13

Where is the pituitary gland located?

Answer 13

In the SELLA TURCICA within the SPHENOID BONE of the skull. It is posterior to the OPTIC CHIASM

Question 14

____ is dura mater that extends over and covers the pituitary within the sella turcica

Answer 14

Sellar diaphragm

Question 15

___ is a pituitary tumor > 1 cm diameter (macroadenoma) present with symptoms due to mass effect.

Answer 15

Nonfunctional pituitary adenoma

Question 16

Compression of the optic chiasm in nonfunctional pituitary adenoma leads to ___

Answer 16

Bitemporal hemianopsia (issues with peripheral vision)

Question 17

Compression of the pituitary from nonfunctional pituitary adenoma can lead to ____

Answer 17

Hypopituitarism

Question 18

In pituitary embryogenesis, ___ becomes anterior pituitary (adenohypophysis) and ___ becomes posterior pituitary (neurohypophysis)

Answer 18

Oral ectoderm

Neuroectoderm

Question 19

The regressing stalk of Rathke’s pouch can leave residual tissue, which may become a tumor called a _____

Answer 19

Craniopharyngioma

Question 20

___ is a benign childhood brain tumor that is usually suprasellar. It is similar to pituitary adenomas, can compress the optic chiasm and cause bitemporal hemianopsia.

Answer 20

Craniopharyngioma

Question 21

A craniopharyngioma is derived from remnant’s of ___; often contains cystic spaces and calcifications

Answer 21

Rathke’s pouch

Question 22

List the components of the adenohypophysis

Answer 22

Pars distalis (anteior portion)

Pars tuberalis (surrounds infundibular stalk)

Pars intermedia (division between anterior and posterior)

Question 23

List the components of the neurohypophysis

Answer 23

Pars nervosa

Infundibular stalk

Question 24

___ is the largest portion of the pituitary gland (75%) and is made up of Glandular epithelial cells, Fenestrated capillaries (sinusoids), and some CT stroma

Answer 24

Pars distalis (pars anterior)

Question 25

List the Adenohypophysis hormones:

Answer 25

``` FSH LH ACTH TSH Prolactin GH ``` FLAT PiG

Question 26

___ cells of the pars distalis (pars anterior) have granules in the cells that readily take up H&E stain. These cells are divided into acidpohils and basophils

Answer 26

Chromophils (CHroma=color + philein=to love)

Question 27

___ cells of the pars distalis (pars anterior) do not take up stain and lack affinity. The nuclei are the only visible component and do NOT produce hormones (unknown function)

Answer 27

Chromophobes

Question 28

____ stain with basic dye (purple/blue and darker with H&E) ____ stain with acidic dye (Pink with H&E)

Answer 28

Basophils Acidpohils

Question 29

Gonadotrophs synthesize ____ Corticotrophs synthesize ____ Thyrotrophs synthesize ____

Answer 29

Gonadotropins (FSH, LH) Adenocorticotropin (ACTH) Thyrotropin (TSH)

Question 30

Mammotrophs synthesize ____ Somatotrophs synthesize ____

Answer 30

Prolactin GH

Question 31

Gonaotrophs, corticotrophs, and thyrotrophs stain with ____ Mammotrophs and somatotrophs stain with ___

Answer 31

Basic dye Acidic dye

Question 32

___ stimulates ovarian follicle maturation and estrogen production in females; it stimulates sertoli cells to produce sperm in males

Answer 32

FSH

Question 33

FSH can be feedback inhibited by ___

Answer 33

Inhibin and by estrogen in females

Question 34

___ triggers ovulation and stimulates ovarian production of estrogen and progesterone in females; it promotes Leydig cell production of testosterone in males

Answer 34

LH

Question 35

LH is feedback inhibited by ___

Answer 35

Estrogen & progesterone in females and testosterone in males

Question 36

___ stimulates the adrenal cortex to release glucocorticoids and androgens

Answer 36

ACTH

Question 37

ACTH is feedback inhibited by ___

Answer 37

Glucocorticoids (i.e., cortisol)

Question 38

___ stimulates thyroid gland to release T3 and T4 --> Control of metabolism

Answer 38

TSH

Question 39

TSH is feedback inhibited by ___

Answer 39

Thyroid hormones (T3 and T4)

Question 40

___ stimulates milk production and promotes lactation

Answer 40

Prolactin

Question 41

Prolactin inhibits GnRH and thus, ___ and ___

Answer 41

FSH LH

Question 42

Prolactin is feedback inhibited by ___

Answer 42

PIH --> dopamine

Question 43

___ indirectly stimulates overall growth of bone and soft tissue via production of Insulin-like growth factors 1 (IGF-1) aka Somatomedin

Answer 43

GH

Question 44

GH is feedback inhibited by:

Answer 44

- Somatostatin - Feedback inhibition by GH and IGF-1 - Hyperglycemia, hyperlipidemia, obesity, emotional deprivation

Question 45

___ is between pars distalis and pars nervosa and has an unknown function. It frequently has a cleft (remnant of Rathke's) and consists of small basophils and colloid-filled follicles lined by pale cuboidal cells

Answer 45

Pars intermedia

Question 46

___ suspends the pituitary gland from the hypothalamus

Answer 46

Infundibulum

Question 47

___ surrounds the infundibular stalks (part of anterior pituitary) and is a component of the infundibulum

Answer 47

Pars tuberalis

Question 48

___ is the neural portion of the infundibulum and is part of the posterior pituitary

Answer 48

Infundibular stalk

Question 49

___ is a thin neural stalk connecting the median eminence of the hypothalamus to the pars nervosa

Answer 49

Infundibular stalk

Question 50

What are the 2 parts of the infundibular stalk?

Answer 50

Median eminence and Infundibular process

Question 51

What are the neurohypophysis hormones?

Answer 51

ADH and Oxytocin

Question 52

___ of the pars nervosa are glial-like cells and appear to support numerous unmyelinated nerve fibers traveling from the hypothalamus

Answer 52

Pituicytes

Question 53

___ of the pars nervosa are expanded axon terminals filled with the stored neurohypophysis hormones (ADH and oxytocin)

Answer 53

Herring bodies

Question 54

____ is primarily produced by the supraoptic nucleus in the hypothalamus and regulates serum osmolarity (via V2-receptors in DCT and CD --> causes water retention and concentrates urine. It is also a potent vasoconstrictor at high doses (via V1-receptors)

Answer 54

ADH

Question 55

ADH release is regulated by ___

Answer 55

Hypothalamic osmoreceptors and baroreceptors

Question 56

___ is primarily produced by paraventricular nucleus of the hypothalamus and functions to contract smooth muscle, i.e., uterine contractions during labor & after to contract uterus back down to normal size as well as facilitate milk ejection via breast myoepithelial cells

Answer 56

Oxytocin --> "Feel good hormone"

Question 57

Pituitary blood supply is via ___ artery

Answer 57

Internal carotid

Question 58

___ arteries are off of the internal carotid artery and supply median eminence and infundibulum ___ arteries are off of the internal carotid arterty and supply the pars nervosa

Answer 58

Superior hypophyseal Inferior hypophyseal

Question 59

Superior hypophyseal arteries give rise to the ___ which collects hypothalamic releasing and inhibitory hormones

Answer 59

Primary capillary plexus

Question 60

The primary capillary plexus is drained by ___ veins and delivers blood into the secondary capillary plexus (in pars distalis). These collect anterior pituitary secretions and sends them into circulation via fenestrated capillaries

Answer 60

Hypophyseal portal

Question 61

Inferior hypophyseal arteries give rise to the ___ which supplies and collects hormones from posterior pituitary (ADH and oxytocin) and sends them into circulation via their own hypophyseal veins

Answer 61

3rd capillary plexus

Question 62

Outline the venous drainage of the anterior pituitary gland secreting hormones:

Answer 62

Anterior pituitary gland secretes hormones --> diffuse into capillaries --> venous sinuses (petrosal and cavernous)

Question 63

Outline the venous drainage of the posterior pituitary secreting hormones:

Answer 63

Posterior pituitary gland secretes hormones --> diffuse into capillaries --> hypophyseal veins --> venous sinuses (petrosal and cavernous)

Question 64

The pineal glands develops from a posterior outpocketing of the roof of the ____

Answer 64

Diencephalon in midline of 3rd ventricle

Question 65

___ main functions are to manufacture melatonin and serotonin

Answer 65

Pineal gland

Question 66

The pineal gland does not have a direct nerve connection to the brain. Rather, it is regulated postganglionic sympathetics from ___

Answer 66

Superior cervical ganglion

Question 67

The pineal gland contains a capsule derive from ___ and is made up of pinealocytes, neuroglial cells, calcified granular material (brain sand), and contains NO NEURONS

Answer 67

Pia mater

Question 68

___ are neuron-like, have large, pale, irregular nuclei, are regulated by B-adrenergic receptors, and their main function is production of melatonin and serotonin

Answer 68

Pinealocytes

Question 69

___ are interstitial cells, have smaller and dense nuclei, and support pinealocytes

Answer 69

Neuroglial cells

Question 70

Melatonin is synthesized from this AA:

Answer 70

Tryptophan

Question 71

Melatonin acts to delay sexual development until puberty by inhibiting __ and __ secretion

Answer 71

GnRH GH

Question 72

When puberty arrives, melatonin production will ___

Answer 72

Decrease

Question 73

Pineal tumors are linked to ___

Answer 73

Precocious puberty (Decreases melatonin --> early sexual maturity)

Question 74

Melatonin can be used for treatment of:

Answer 74

Jet lag --> disrupted circadian rhythm Seasonal affective disorder --> help regulate emotional responses due to decreased daylight during winter Insomnia

Question 75

Where is the location of the hypothalamus?

Answer 75

Floor of the DIENCEPHALON Forms part of the wall of the 3rd ventricle

Question 76

___ is characterized by a delayed/absent puberty and anosmia (no sense of smell), hypogonadotrophic hypogonadism, and prevents migration of GnRH neurons to arcuate nucleus and olfactory neurons to olfactory bulb

Answer 76

Kallman syndrome

Question 77

___ is due to loss of feedback control of GH secretion or to GH-secreting tumor in the pituitary (adenoma)

Answer 77

Pituitary gigantism

Question 78

___ is due to an excessive adult production of GH. It is characterized by growth of the face (prognathism), hands and feet, and increase in viscera and is due to loss of feedback control of GH secretion or to GH-secreting tumor in the pituitary.

Answer 78

Acromegaly

Question 79

___ is growth retardation resulting in abnormally short adult stature. It is caused by a variety of hereditary and metabolic disorders.

Answer 79

Pituitary dwarfism--> caused by insufficient GH Problem can be in hypothalamus or pituitary