Pituitary Hormones and Their Control by the Hypothalamus

Question 1

hormoes released by anterior pituitary with functions

Answer 1

• Growth hormone promotes growth of the entire
body by affecting protein formation, cell multiplication, and cell differentiation.
• Adrenocorticotropin (corticotropin) controls the
secretion of some of the adrenocortical hormones,
which affect metabolism of glucose, proteins, and
fats.
• Thyroid-stimulating hormone (thyrotropin) controls
the secretion rate of thyroxine and triiodothyronine
by the thyroid gland, and these hormones control
the rates of most intracellular chemical reactions in
the body.
• Prolactin promotes mammary gland development
and milk production.
• Two separate gonadotropic hormones, follicles timulating hormone and luteinizing hormone,
control growth of the ovaries and testes, as well as
their hormonal and reproductive activities.

Question 2

hormones released by posterior pituitary and its functions

Answer 2

Antidiuretic hormone (also called vasopressin) controls the rate of water excretion into the urine, thus
helping to control the concentration of water in the
body fluids.
• Oxytocin helps express milk from the glands of the
breast to the nipples during suckling and helps in
the delivery of the baby at the end of gestation

Question 3

five type of cells of anterior pituitary

Answer 3

1. Somatotropes—human growth hormone (hGH)
2. Corticotropes—adrenocorticotropin (ACTH)
3. Thyrotropes—thyroid-stimulating hormone (TSH)
4. Gonadotropes—gonadotropic hormones, which
   include both luteinizing hormone (LH) and folliclestimulating hormone (FSH)
5. Lactotropes—prolactin (PRL)

Question 4

most type of cells in anterior pituitary

Answer 4

are somatotropes 30-40%
( 20% CORTICOTROPES )
3-5% THE REST OF THEM

Question 5

acidophilic tumors

Answer 5

Somatotropes stain strongly with acid dyes and are therefore called acidophils. Thus, pituitary tumors that secrete large quantities of human growth hormone are
called acidophilic tumors.

Question 6

Posterior Pituitary Hormones Are Synthesized by Cell Bodies in the Hypothalamus

Answer 6

hormones are made by large neurons present in hypothalamus, called
magnocellular neurons, located in the supraoptic and paraventricular nuclei of the hypothalamus. The hormones are then transported in the axoplasm of the
neurons’ nerve fibers passing from the hypothalamus to the posterior pituitary gland

Question 7

secretions from posterior pituitary is controlled by

Answer 7

nerve signals that originate in the hypothalamus

Question 8

secretions from anterior pituitary are controlled by

Answer 8

hormones that originate in the hypothalamus called as hypothalamic releasing or hypothalamic inhibitory factors that are conducted to the gland through hypothalamic hypophysial portal vessels

Question 9

median eminence

Answer 9

lower most portion of hypothalamus which connects inferiorly with pituitary stalk and its the functional connection between the hypothalamus and anterior pituitary

Question 10

The major hypothalamic releasing and inhibitory hormones, which are

Answer 10

1. Thyrotropin-releasing hormone (TRH), which
   causes release of thyroid-stimulating hormone
2. Corticotropin-releasing hormone (CRH), which
   causes release of adrenocorticotropin
3. Growth hormone–releasing hormone (GHRH),
   which causes release of growth hormone, and
   growth hormone inhibitory hormone (GHIH), also
   called somatostatin, which inhibits release of growth
   hormone
4. Gonadotropin-releasing hormone (GnRH), which
   causes release of the two gonadotropic hormones,
   luteinizing hormone (LH) and follicle-stimulating
   hormone (FSH)
5. Prolactin inhibitory hormone (PIH), which causes
   inhibition of prolactin secretion

Question 11

which is the only hormone which does not affect the respective targeted gland

Answer 11

GH

Question 12

GROWTH HORMONE PROMOTES

GROWTH OF MANY BODY TISSUES

Answer 12

It causes growth of almost all tissues of
the body that are capable of growing. It promote increased sizes of the cells and increased mitosis, with development of greater numbers of cells and specific differentiation of certain types of cells such as bone growth
cells and early muscle cells.

Question 13

GROWTH HORMONE HAS SEVERAL

METABOLIC EFFECTS

Answer 13

(1) increased rate of protein synthesis in most cells of the body; (2) increased mobilization of fatty acids from
adipose tissue, increased free fatty acids in the blood, and increased use of fatty acids for energy; and (3) decreased
rate of glucose utilization throughout the body.

Question 14

Growth Hormone Promotes Protein

Deposition in Tissues how?

Answer 14

enhances the transportation of amino acids across the cell membrane into the cell increasing concentration of amino acids in cell
enhances translation of rna to form more protein
enhances the transcription of dna to rna
minimizes the breakdown of membrane protein and utilized fatty acid in adipose tissue

Question 15

“Ketogenic” Effect of Excessive Growth Hormone

Answer 15

Under the influence of excessive amounts of growth hormone, fat mobilization from adipose tissue sometimes becomes so great that large quantities of acetoacetic
acid are formed by the liver and released into the body fluids, thus causing ketosis. This excessive mobilization
of fat from the adipose tissue also frequently causes a
fatty liver.

Question 16

what necessary for growth promoting affect of growth hormone and why

Answer 16

carbohydrate and insulin to provide energy needed for metabolism for growth.

Question 17

There are two principal mechanisms of bone growth.

Answer 17

first the growth of bone in length through the epiphyseal plate till the shaft and epiphysis fuse together
second by the work of osteoblast which deposits new bone on old bone and is enhanced by the GH specially in membranous bones

Question 18

GH causes the liver to release what and how it is important

Answer 18

it causes the liver to release Insulin like growth factor which are important for growth

Question 19

syndrome in which igf-1 is missins

Answer 19

Laron syndrome in which there is a mutation in GH receptor and it is unable to stimulate it to make IGF

Question 20

what stimulate the secretion of GH

Answer 20

(1) starvation, especially with severe protein deficiency;
(2) hypoglycemia or low concentration of fatty acids in the blood; (3) exercise; (4) excitement; (5) trauma; and
(6) ghrelin, a hormone secreted by the stomach before
meals. Growth hormone also characteristically increases
during the first 2 hours of deep sleep,

Question 21

Panhypopituitarism

Answer 21

Panhypopituitarism means decreased secretion of all the anterior pituitary hormones. The decrease in secretion may be congenital (present from
birth), or it may occur suddenly or slowly at any time during life, most often resulting from a pituitary tumor that
destroys the pituitary gland.

Question 22

central diabetes insipidus

Answer 22

absence of adh the membrane of collecting ducts and renal tubules become impermeable to water and more water is lose, urine is more diluted in a condition called central diabetes insipidus

Question 23

diseases no flashcard

Answer 23

no