Physiology The Hypothalamus And Pituitary Gland

Front 1

The pituitary gland, or ____________ , lies in a pocket (the ________ ) of the sphenoid bone at the base of the brain, Just below the brain area called the _________.

Back 1

- hypophysis

- sella turcica

- hypothalamus

Front 2

The pituitary is connected to the hypothalamus by the infundibulum, a stalk containing nerve fibers and small blood vessels.

Back 2

-

-

-

Front 3

In human beings, the pituitary is composed of ?

Back 3

two adjacent lobes called the anterior pituitary (toward the front of the head; also called the adenohypophysis) and the posterior pituitary (toward the back of the head; also called the neurohypophysis).

Front 4

The anterior pituitary is located where and AKA?

Back 4

toward the front of the head; also called the adenohypophysis

Front 5

The posterior pituitary is located where and AKA?

Back 5

toward the back of the head; also called the neurohypophysis

Front 6

The anterior pituitary arises embryologically from _________, while the posterior pituitary is actually

Back 6

- the invagination of the pharynx called Rathke’s Pouch

-an extension of the neural components of the hypothalamus.

Front 7

The axon of the two well-defined clusters of hypothalamic neurons (the supraoptic and paraventricular nuclei) pass down ?

Back 7

the infundibulum and end within the posterior pituitary in close proximity to capillaries.

Front 8

The the supraoptic and paraventricular nuclei do not forma synapse with other neurons. Instead, ...

Back 8

their terminals end directly on capillaries.

Front 9

What is the names of the two well-defined clusters of hypothalamic neurons in the pituitary gland?

Back 9

the supraoptic and paraventricular nuclei

Front 10

In contast to the neural connection btwn the hypothalamus and the posterior pituitary pituitary, There are ______________ btwn the hypothalamus and anterior posterior pituitary. There is, however, ___________.

Back 10

- no important neural connections

-an unusual blood vessel connections.

Front 11

The capillaries at the base of the hypothalamus (the median eminence) does what?

Back 11

recombine to form the hypothalamo-pituitary portal vessels.

Front 12

The term portal denotes blood vessels that _______.

Back 12

connect two capillary beds.

Front 13

What is the name of the capillaries at the base of the hypothalamus?

Back 13

the median eminence

Front 14

The hypothalamo-pituitary portal vessels pass down the stalk connecting _____________ and enter ____________ where they drain into ___________.

Back 14

- the hypothalamus and pituitary

- the anterior pituitary

- a second capillary, bed, the anterior pituitary capillaries.

Front 15

The hypothalamo-pituitary portal vessels offer? This offers the advantage of a rapid response and minimizes the amount of hypothalamic hormone that must be synthesized to reach an effective blood concentration

Back 15

a local route for the blood flow directly from the hypothalamus to the anterior pituitary.

Front 16

The hypothalamo-pituitary portal vessels offers the advantage of?

Back 16

a rapid response and minimizes the amount of hypothalamic hormone that must be synthesized to reach an effective blood concentration

Front 17

The posterior pituitary is really a ?

Back 17

neural extension of the hypothalamus.

Front 18

The hormones of the posterior pituitary are not synthesized in the posterior pituitary itself but in the hypothalamus, specifically in the cell bodies of two hypothalamic nuclei (the supraoptic and paraventricular nuclei) whose axons pass down the neural axons to accumulate at the axon terminals in the posterior pituitary.

Back 18

in the hypothalamus

Front 19

The hormones of the posterior pituitary are not synthesized in the posterior pituitary itself but in the hypothalamus, specifically in

Back 19

the cell bodies of two hypothalamic nuclei (the supraoptic and paraventricular nuclei) whose axons pass down the neural axons to accumulate at the axon terminals in the posterior pituitary.

Front 20

In regards to the hormones of the posterior pituitary, Stimuli (e.g., neurotransmitters) generate...... ; these action potentials propagate __________. The hormone then enters the

Back 20

-action potentials in the neurons

-
to the axon terminals and trigger the release of the hormone by exocytosis

-capillaries to be carried away by the blood returning to the heart.

Front 21

In regards to the hormones of the posterior pituitary, the brain can receive stimuli and respond as if

Back 21

it were an endocrine organ.

Front 22

By releasing its hormones into the general circulation, the posterior pituitary can modify ....

Back 22

the function of distant organs (such as the kidney).

Front 23

The two posterior pituitary hormones are ___.

Back 23

oxytocin and vasopressin

Front 24

Oxytocin stimulates ?

Back 24

contraction of smooth muscle cells in the breasts, which results in milk secretion during lactation, and stimulates contraction of uterine smooth muscle during labor.

Front 25

Although oxytocin is also presenting males, its functions in males are _____.

Back 25

uncertain

Front 26

Vasopressin acts on ?

Back 26

smooth muscle cells around blood vessels to cause muscle contraction, which constricts blood vessels and increases blood pressure.

Front 27

Vasopressin also acts within the kidney to ?

Back 27

decrease water excretion in the urine, thus retaining fluid in the body and helping to maintain blood volume

Front 28

Because of its kidney function, vasopressin is also known as ?

Back 28

anti-diuretic hormones (ADH).

Front 29

Vasopressin and oxytocin are also produced in other areas of the brain and serve in those sites as?

Back 29

neurotransmitter or neuromodulators.

Front 30

How are Hypothalamic neurons different from those that produce the hormones released from the posterior pituitary?

Back 30

secrete hormones that control the secretion of all the anterior pituitary hormones.

Front 31

Hypothalamic neurons are different from those that produce the hormones released from the posterior pituitary; secrete hormones that control the secretion of all the anterior pituitary hormones. Several hypothalamic nuclei sends terminals to ?

Back 31

the median eminence.

Front 32

The hypothalamic hormones that regulate anterior pituitary function are collectively termed?

Back 32

hypophysiotropic hormones or hypothalamic releasing or inhibiting hormones.

Front 33

Hypophysiotropic hormones denotes only those hormones .....

Back 33

from the hypothalamus that influence the anterior pituitary, but they are not categorized as hypophysiotropic hormones.

Front 34

With one exception, each of the hypophysiotropic hormones is the first in a three-hormone sequence:

Back 34

(1)A hypophysiotropic hormone controls the secretion of (2) an anterior pituitary hormone, which controls the secretion of (3) a hormone from some other endocrine gland (this last hormone then acts on its target cells)

Front 35

The adaptive value of three-hormone sequence of hypophysiotropic hormones is that .......

Back 35

they permit a variety of important hormonal feedbacks. They also allow amplification of a response of a small number of hypothalamic neurons into a large peripheral hormone signal.

Front 36

The anterior pituitary secretes at least __ hormones, but __ ___have well-established functions.

Back 36

- eight

- only six

Front 37

All peptides, these six “classical” are

Back 37

- follicle-stimulating hormone (FSH),

-luteinizing hormone (LH)
- growth hormone (GH; aka somatotropin),

- thyroid-stimulating hormone (TSH; aka thyrotropin)

- prolactin

-adrenocorticotropic hormone (ACTH; aka corticotrophin).

Front 38

The following hormones: growth hormone (GH; aka somatotropin), thyroid-stimulating hormone (TSH; aka thyrotropin), prolactin, and adrenocorticotropic hormone (ACTH; aka corticotrophin) are secreted by ...... whereas FSH and LH, collectively termed gonadotropic hormones (aka gonadotropins) because they stimulate .....

The other two peptides in the anterior pituitary, beta-lipotropin and beta-endorphin have unknown physiological effects.

Back 38

- a distinct cell type in the anterior pituitary

- the gonads, are usually secreted by the same cell.

Front 39

FSH and LH, collectively termed ?

Back 39

gonadotropic hormones (aka gonadotropins)

Front 40

gonadotropic hormones (aka gonadotropins) are called that because they stimulate ?

Back 40

the gonads

Front 41

The other two peptides secreted by the anterior pituitary , beta-lipotropin and beta-endorphin have ...... physiological effects.

Back 41

unknown

Front 42

The other two peptides secreted by the anterior pituitary that are not part of the classic six are

Back 42

beta-lipotropin and beta-endorphin

Front 43

The only major function of two of the six is to stimulate their target cells to secrete other hormones (and to maintenance the growth and function of these cells):

Back 43

- Thyroid-stimulating hormone induces the thyroid to secrete thyroxine and triiodothyronime
- Adrenocorticotropic hormone – meaning hormone that stimulates the adrenal cortex- stimulates that gland to secrete cortisol

Front 44

Three other anterior pituitary hormones also stimulate the secretion of another hormone but have an additional function as well.

Back 44

FSH and LH stimulate the gonads to secrete the sex hormones- estradiol and progesterone from the ovaries, or testosterone from the testes – but in addition, they regulate the growth and development of Ova and Sperm

- Growth hormone stimulates the liver to secrete a growth-promoting peptide hormone known as insulin-like growth factor I (IGF-I) and in addition, exerts direct effects on metabolism

Front 45

Growth hormone from the anterior pituitary stimulates?

Back 45

- the liver to secrete a growth-promoting peptide hormone known as insulin-like growth factor I (IGF-I) and in addition, exerts direct effects on metabolism

Front 46

Prolactin is unique among the anterior pituitary hormones in that

Back 46

its major function is not to exert control over the secretion of a hormone by another endocrine gland.

Front 47

Prolactin most important action is to stimulate?

Secondary action of Prolactin?

Back 47

- development of mammary glands and milk lactation,

- prolactin exerts a secondary action to inhibit gonadotropin secretion, thus decreasing fertility when a woman is breast-feeding.

Front 48

In the male, prolactin may facilitate several components of

Back 48

reproductive function, although its precise roles are uncertain

Front 49

Secretion of the anterior pituitary hormones is largely regulated by ________ produced by and collectively called ?

Back 49

- hormones

- the hypothalamus

- the hypophysiotropic hormones

Front 50

Hypophysiotropic hormones are secreted by _________ that originate in ..... and terminate in ?

Back 50

-neurons

-discrete areas of the hypothalamus

-the median eminence around the capillaries that origins of the hypothalamopituitary portal vessels.

Front 51

With hypophysiotropic hormones, The generation of action potentials in these neurons causes them to secrete

Back 51

-their hormones, much as action potentials cause other neurons to release neurotransmitters by exocytosis.

Front 52

Hypothalamic hormones, enter the ____________ and are carried by the ......... to the ?

Back 52

-capillaries

-hypothalamo-pituitary portal vessels

-anterior pituitary.

Front 53

When the hypothalamic hormones act upon the various anterior pituitary cells to control ?

Back 53

-their hormone secretions.

Front 54

hypothalamic neurons secrete hormones in a manner identical to ?

Back 54

that described previously for the hypothalamic neurons whose axons end in the posterior pituitary.

Front 55

the hormones that are made in hypothalamic neurons, travel ...., and are released...?

Back 55

-down axons to the neuron terminals

-in response to action potentials in the neurons.

Front 56

Two critical differences, distinguish the two pituitary hormone systems:

Back 56

- 1) The axons of the hypothalamic neurons that secrete the posterior pituitary hormones leave the the hypothalamus and end in the posterior pituitary, whereas those that secrete the hypophysiotropic hormones remain in the hypothalamus, ending in the median eminence.

- (2) Most of the posterior pituitary capillaries into which the posterior hormones are secreted immediately drain into the main blood stream, which carries the hormones to the heart for distribution to the entire body.

Front 57

The hypophysiotropic hormones enter capillaries ...... , but empty into ......., which carry them to the?

Back 57

- in the median eminence of the hypothalamus that do not directly join the main bloodstream

- the hypothalamo-pituitary portal vessels

-anterior pituitary.

Front 58

If a cell has an appropriate receptor for a given hypophysiotropic hormone, that cell will respond by

Back 58

increasing or decreasing the secretion of its pituitary hormone.

Front 59

If a pituitary hormone is secreted, it will diffuse into ?

Back 59

the same capillaries that delivered the hypophysiotropic hormone. .

Front 60

If a pituitary hormone is secreted, it will diffuse into the same capillaries that delivered the hypophysiotropic hormone. These capillaries then drain into ..... , where the pituitary hormones .....?

Back 60

- veins, which enter the systemic circulation

- can come into contact with their target cells.

Front 61

The anterior pituitary is exposed to ....... of the hypophysiotropic hormones than those existing in the general bloodstream

Back 61

- much higher plasma concentrations

Front 62

There are multiple discrete hypophysiotropic hormones, each secreted by ....... and influencing the release of ?

Back 62

- a particular group of hypothalamic neurons

-one or, in at least one case, two of the anterior pituitary hormones.

Front 63

Each hypophysiotropic hormone is named for ?

Back 63

-the anterior pituitary hormone whose secretion is controls.

-

-

Front 64

secretion of ACTH (corticotrophin) is stimulated by ?

Back 64

-corticotrophin-releasing hormone (CRH)

Front 65

secretion of growth hormone is stimulated by

Back 65

-growth hormone-releasing hormone (GHRH)

Front 66

secretion of thyroid-stimulating hormone (thyrotropin) is stimulated by

Back 66

-thyrotropin-releasing hormone (TRH)

Front 67

secretion of both luteinizing hormone and follicle-stimulating hormone (the gonadotropins) is stimulated by?

Back 67

gonado-tropin-releasing hormone (GnRH)

Front 68

Two of the hypophysiotropic hormones do not stimulate the release of an anterior pituitary hormone but rather inhibit its release.

Back 68

- Somatostatin (SS)

- Dopamine (DA)

Front 69

Somatostatin (SS) inhibits ?

Back 69

the secretion of growth hormone.

Front 70

Dopamine (DA), tonically inhibits?

Back 70

the secretion of prolactin.

Front 71

Growth hormone is controlled by two hypophysiotropic hormones?

Back 71

Somatostatin (SS) inhibits the release and growth hormone releasing hormone, which stimulates it.

Front 72

The rate of growth hormone secretion depends, therefore, upon the .....as well as.....?

Back 72

- releative amounts of the opposing hormones released by the hypothalamic neurons,

- upon the relative sensitivities of the anterior pituitary to them.

Front 73

All of the known hypophysiotropic hormones also occur in locations other than the hypothalamus, particularly ...?

Back 73

in the other areas of the central nervous system, where they function as neurotransmitters or neuromodulators, and in the GI tract.

Front 74

The one hypophysiotropic hormone that is not a peptide is ?

Back 74

- dopamine

- which is a amine and a member of the catecholamine family.

Front 75

What controls secretion of the hypophysiotropic hormones?

Back 75

Some of the neurons that secrete hypophysiotropic hormones may possess spontaneous activity but firing of most of them requires neural and hormonal input.

Front 76

Neurons of the hypothalamus receive stimulatory and inhibitory synaptic input from ..... and specific neural pathways influence ..?

Back 76

- virtually all areas of the central nervous system

- the secretion of the individual hypophysiotropic hormones.

Front 77

A large number of neurotransmitters (ex. The catecholamines and serotonin) are released ; not surprisingly, therefore, drugs that influence these neurotransmitters can alter...?

Back 77

- at the synapse on the hormone-secreting hypothalamic neurons

-the secretion of the hypophysiotropic hormones.

Front 78

Corticotropin-releasing hormone (CRH) from the hypothalamus stimulates ...... to secrete .... which in turn stimulates the adrenal cortex to secrete ...

Back 78

-

- the anterior pituitary

- ACTH

- cortisol.

Front 79

A wide variety of sensory stimuli resulting from physical or emotional stress act _______ to the hypothalamus to increase CRH secretion, and therefore, ....?

Back 79

-via neural pathways

- ACTH and cortisol secretion.

-

Front 80

Even in the absence of stressful stimuli, cortisol secretion varies in a regular manner during a 24 hour period because ...

Back 80

neural rhythms within the central nervous system also impinge upon the hypothalamic neurons that secrete CRH.

Front 81

A prominent feature of each of the hormonal sequences initiated by the hypophysiotropic hormone is?

Back 81

negative feedback exerted upon the hypothalamo-pituitary system by one or more of the hormones in its sequence

Front 82

The hormonal sequencing is effective in ..?

Back 82

dampening hormonal responses- that is, in limiting the extremes of hormone secretory rates.

Front 83

The situation described for cortisol, in which the hormone secreted by the third endocrine gland in a sequence exerts a negative feedback effect over the anterior pituitary and/or hypothalamus, is known as

Back 83

a long-loop negative feedback.

Front 84

This type of feedback (long-loop negative feedback) exists for...?

Back 84

each of the three-hormone sequences initiated by a hypophysiotropic hormone.

Front 85

Long-loop feedback does not exist for ______ since ........ meaning, it does not participate in a three-hormone sequence.

Back 85

-prolactin

-this is one anterior pituitary hormone that does not have major control over another endocrine gland

Front 86

there is negative feedback in the prolactin system, for this hormone itself acts .....?

Back 86

upon the hypothalamus to stimulate the secretion of dopamine, which then inhibits the secretion of prolactin.

Front 87

The influence of an anterior pituitary hormone on the hypothalamus is known as

Back 87

a short loop negative feedback.

Front 88

Like ......, several other anterior pituitary hormones, including , ________ also exert such feedback on the hypothalamus.

Back 88

- prolactin

- growth hormone

Front 89

Keep in mind that there are many stimulatory and inhibitory hormonal influences on the ..............other than those that fit the feedback patterns.

Back 89

hypothalamus and/or anterior pituitary

Front 90

a hormone that is not itself in a particular hormonal sequence may ?

Back 90

nevertheless exert important influences on the secretion of the hypophysiotropic or anterior pituitary hormones in that sequence.

Front 91

estrogen markedly enhances the secretion of prolactin by the anterior pituitary, even though .

Back 91

estrogen secretion is not normally controlled by prolactin

Front 92

the sequences we have been describing should not be viewed as

Back 92

isolated units.