The Endocrine System III (Lecture 16)

Question 1

True or False: Secretions by pituitary controlled by hormonal or nervous signals from hypothalamus

Answer 1

True

Question 2

30-40% of anterior pituitary cells are somatotropes that secrete ______.

Answer 2

GH

Question 3

What is the function of somatotropes?

Answer 3

Promote growth of the entire body by affecting protein formation, cell multiplication, and cell division

Question 4

True or False: Growth hormone causes growth of almost all tissues of the body that are capable of growing

Answer 4

True

Question 5

What processes increases the number of cells?

Answer 5

Mitosis

Question 6

True or False: Growth hormone can increase bone length and thickness, cartilage, and muscle cells.

Answer 6

True

Question 7

True or False: Men get their pubertal growth spurt first.

Answer 7

False

Question 8

True or False: After adulthood, most of the bones stopped lengthening, however many soft tissues continue to grow

Answer 8

True

Question 9

What are the three ways that metabolic effects growth hormones

Answer 9

Increased rate of proetin synthesis

Increases utilization of fatty acids

Decreased glucose uptake

Question 10

What are the 6 hormones of growth?

Answer 10

Growth hormone

Somatomedins (insulin-like growth factors)
Insulin

Thyroid hormones

Sex hormones

Growth factors and growth-inhibiting factors

Question 11

True or False: GH stimulates IGF release from liver and other cells

Answer 11

True

Question 12

IGF-1 occurs ______ and IGF-2 occurs _____.

Answer 12

After birth, gestation

Question 13

True or False: IGFs have direct effect on target cells such as hormones and paracrines.

Answer 13

True

Question 14

True or False: GH don’t often occur through IGFs

Answer 14

False, GH effects occur mostly through IGFs

Question 15

Growth hormone releasing hormone (GHRH) in hypothalamus stimulates GH release from ______.

Answer 15

Anterior pituitary

Question 16

True or False: Maximal levels of GH occur during puberty and decrease over time.

Answer 16

True

Question 17

GH is secreted in a ______ pattern

Answer 17

Pulsating

Question 18

What are the 7 factors that increase GHRH release?

Answer 18

Decreases in glucose

Decreases in fatty acids

Increases in amino acids

Sleep

Circadian rhythm

Exercise

Stress

Question 19

What are the most powerful factors affecting growth hormone secretion.

Answer 19

Strenuous exercise and sleep

Question 20

What is the negative feedback loop of growth hormone?

Answer 20

GNRH secreted by hypothalamus

GH secreted by anterior pituitary

Effects liver, tissues, adipose tissue and muscle

In liver, increases insulin-like growth factor secretion which promotes cell division

In tissues, promotes protein synthesis and IGF, in adipose tissue it lower glucose and increases lipolysis in muscle in decreases glucose uptake and increases amino acid uptake
- provides energy and substrates fro growth

Question 21

True or False: Growth hormone promotes protein deposition in tissues.

Answer 21

True

Question 22

What 5 things does growth hormone promote promote in protein deposition in tissues?

Answer 22

Enhancement of amino acid transport through cell membrane

Enhanced RNA translation

Increased nuclear transcription

Decreased catabolism of protein and amino acids

Increased deposition of protein in muscle, cartilage and bone

Question 23

______ are bone makers (deposition), ______ are bone breakers (resorption), ______ are bone maintainers.

Answer 23

Osteoblasts, osteoclasts, osteocytes

Question 24

How does growth hormone affect bone growth width?

Answer 24

Osteoblasts lay down new bone on outer surface

Osteoclasts resorb bone in inner surface of cavity

Question 25

How does growth hormone affect bone growth lenght?

Answer 25

Osteoblasts lay down new bone at epiphyseal plates

Question 26

What are the 4 things that occur in the formation of bone?

Answer 26

Osteoblasts lay down osteoid

Calcification (depositing of calcium phosphate)
Hydroxyapatite
Osteoblast becomes immobilized into an osteocyte

Osteocyte maintains surrounding osteoid

Question 27

What are the 4 things that occur in resorption of bone?

Answer 27

Osteoclasts secrete acid and enzymes

Acid dissolves calcium phosphate crystals

Enzymes degrade osteoid

Calcium and phosphate are released into blood

Question 28

In long bone growth, ______ produce new cartilage in epiphyseal plate, which then makes the ______ widen causing bone to lenghten, ________ then die and ______ replace ______ and lay down bone

Answer 28

Chondrocytes, epiphyseal plate, chondrocytes, osteoblasts, chondrocytes

Question 29

True or False: You can grow after the epiphyseal plate closes.

Answer 29

False

Question 30

______ are required for synthesis of GH and are permissive for GH action.

Answer 30

Thyroid hormone

Question 31

______ is permissive for GH actions

Answer 31

Insulin

Question 32

______ have little role in childhood growth, are important for pubertal growth spurt and actively promote growth during puberty.

Answer 32

Sex hormones

Question 33

______ inhibit growth

Answer 33

Gluccocorticoids

Question 34

______ decrease in secretions of all the anterior pituitary hormones.

Answer 34

Panhypopituitarism

Question 35

True or False, In dwarfism, most instances result from deficiency of the anterior pituitary secretion during childhood

Answer 35

True

Question 36

True or False: Panhypopituitarism dwarfism do not pass through puberty and do not secret sufficient quantities of gonadotropic hormones.

Answer 36

True

Question 37

Gigantism normally results in ______.

Answer 37

Hyperglycemia

Question 38

______ is the condition that results after adolescence, after the epiphyses of the long bones have fused with the shafts resulting from tumour on the anterior pituitary gland.

Answer 38

Acromegaly