Central Endocrine Glands

Question 1

What are the central endocrine glands? Where are they located?

Answer 1

secrete hormones that target peripheral endocrine glands in addition to non-endocrine tissue
-pituitary gland (anterior and posterior)
-hypothalamus and pineal gland

Question 2

Which of the central endocrine glands have solely endocrine functions and which have mixed functions?

Answer 2

-pituitary gland (solely endocrine function)
- hypothalamus and pineal gland (mixed functions)

Question 3

What are tropic hormones?

Answer 3

hormones with the primary function of regulation secretion of another hormone
- also maintain the structure of target peripheral gland or cause it to grow (trophic action)

Question 4

What is the anatomical difference between the anterior and posterior pituitary gland?

Answer 4

anterior (separate endocrine gland, containing endocrine cells, controlled by hormones secreted from hypothalamus)
posterior (anatomical extension of hypothalamus, neurosecretory cells directly reach down to it)

Question 5

What brain area projects to the posterior pituitary? Does this same area also project to
the anterior pituitary?

Answer 5

hypothalamus connects directly only to the posterior pituitary gland

Question 6

What are the two hormones released from the posterior pituitary gland, and what do
they do?

Answer 6

vasopressin: released in order to conserve H2O, increases reabsorption of H2O in the kidney, minor role in regulation bp cia arteriolar smooth muscle contraction.

oxytocin: stimulates uterine contractions during childbirth, stimulates ejection of milk from mammary glands during breastfeeding, cognitive effects (bonding btwn mother and infant, possibly btwn couples)

Question 7

What are hypophysiotropic hormones? Where are they released from?

Answer 7

hormones that inhibit or promote the release of anterior pituitary hormones, released from the hypothalamus (some control the release of multiple)

Question 8

what do somatotropes secrete?

Answer 8

growth hormone

Question 9

what do thyrotropes secrete?

Answer 9

thyroid stimulating hormone (TSH)

Question 10

what do corticotropes secrete?

Answer 10

adrenocorticotropic hormone (ACTH)

Question 11

what do gonadotropes secrete?

Answer 11

follicle-stimulating hormone (FSH) and luteinizing hormone (LH)—called gonadotropins

Question 12

what do lactotropes secrete?

Answer 12

prolactin (PRL)

Question 13

What is the hypothalamic-hypophyseal portal system? How is it different than regular
capillary beds?

Answer 13

: hypothalamic capillary bed that recombines into portal vessels to anterior pituitary, where re-branches out into secondary capillary bed

Question 14

What is a 3-hormone chain of command? Where are each of the three hormones
secreted?

Answer 14

three hormones are secreted to bring about wanted change.
1.) corticotropin-releasing hormone
2.) adrenocorticotropic hormone
3.) cortisol

Question 15

How does the negative feedback loop of the 3-hormone chain of command work?

Answer 15

the last hormone released keeps all hormones at their set point

Question 16

What are the four things that allow normal growth to occur?

Answer 16

1.) genetics
2.) adequate diet
3.) freedom from chronic disease and stress
4.) normal level of growth influencing hormones

Question 17

How many growth spurts occur during childhood? What are they?

Answer 17

two
1.) between 0-2, GH
2.) adolescence (puberty), estrogen and testosterone

Question 18

What particular hormones increase during growth spurts?

Answer 18

growth hormone, sex hormones

Question 19

Is growth hormone secreted in adults? What are its metabolic effects?

Answer 19

yes
1.) enhances breakdown of triglycerides in adipose tissue (increases fatty acid blood levels)
2.) increases glucose output by liver (increases glucose blood levels, decreases glucose muscle reuptake)
3.) stimulates amino acid uptake and protein synthesis, especially in muscle

Question 20

What causes secretion of IGF-1? What does IGF-1 do?

Answer 20

:insulin-like growth factor 1
- promotes growth of soft tissue by hypertrophy(size) and hyperplasia(#) of cells

Question 21

Growth obviously includes lengthening bones. During growth, do bones also widen? Do
soft tissues grow, or just bones?

Answer 21

bones and soft tissue grow in length and width

Question 22

What does hypertrophy mean? How about hyperplasia?

Answer 22

hypertrophy: increasing size of cells
hyperplasia: increasing number of cells

Question 23

What are osteocytes, osteoblasts, and chondrocytes?

Answer 23

osteocytes: mature bone cells
osteoblasts: immature bone cells
chondrocytes: makes up cartilage, secrete extracellular matrix, division controlled by GH (via IGF-1 release)

Question 24

What is an epiphyseal plate?

Answer 24

the growth plate, made of cartilage and converted to bone following puberty

Question 25

How does bone lengthening occur? Why does it stop at the end of puberty?

Answer 25

by laying layers of cartilage on top of epiphyseal plate, while transforming the bottom of the plate into bone
-stops when estrogen causes ossification of epiphyseal plate

Question 26

What changes in growth hormone levels would cause dwarfism?

Answer 26

disruption in secretions or responsiveness to GH

Question 27

What changes in growth hormone levels would cause gigantism?

Answer 27

overproduction of GH during childhood

Question 28

What changes in growth hormone levels would cause acromegaly?

Answer 28

onset of GH overproduction during adulthood
- continued growth in bone width (not length), skin and connective tissues

Question 29

What does the suprachiasmatic nucleus (SCN) do? What does the pineal gland do in
relation to it?

Answer 29

: area of hypothalamus that serves as master biological clock over body’s daily rhythm
- SCN entrained to circadian rhythms via melatonin secreted from pineal gland in the brain (Pineal gland increases melatonin secretion in the dark)

Question 30

What hormone does the pineal gland secrete?

Answer 30

melatonin

Question 31

what hypophysiotropic hormone promote the release of GH? Which inhibits the release of GH?

Answer 31

promotes: growth hormone-releasing hormone

inhibits: somatostatin