export_endocrine 3

Question 1

3 things that happen in growth

Answer 1

1) increase amount of cells
2) increase size of some cells

3) inc bone length and thickness

Question 2

what hormones promote growth?

Answer 2

• GH (postnatal)
• insulin (fetal)
• TH (permissive)
• testosterone/estrogen (puberty)

Question 3

effects of cortisol on growth

Answer 3

inhibits

Question 4

where is GH secreted from?

Answer 4

anterior pituitary

Question 5

what controls release of GH?

Answer 5

inc GHRH and dec somatostatin (hypothalamus)

Question 6

effects of GH

Answer 6

• inc cell size
• in cell number
• stim glycolysis and dec glucose uptake to adipos and skeletal
• liver secret higher levels of IGF1 –> inc blood glucose

> cartilage growth

> bone and tissue growth

Question 7

IGF act as ___ and ___

Answer 7

hormone and paracrine

Question 8

what increased GHRH secretion?

Answer 8

exercise, stress, fasting, low plasma glucose, sleep

Question 9

what are negative feedbacks on GHRH secretion?

Answer 9

• plasma GH

- plasma IGF-1 (and neg on GH release)

Question 10

disorders from GH levels

Answer 10

• dwarfism (deficiency in childhood)
• gigantism (over-secretion in child)

-acromegaly (oversec as adult)

Question 11

laron dwarfism

Answer 11

abnormal GH receptor - IGF1 not secreted

Question 12

GH used as therapy for

Answer 12

-adults with pituitary disease

Question 13

GH in elderly

Answer 13

• inc muscle mass, dec fat

- inc cancer risk bc of prolif cells

Question 14

what drives bone growth?

Answer 14

• GH and local IGF1

- thyroid hormones and sex hormones

Question 15

when does bone growth stop?

Answer 15

when osteoblasts overtake condroblasts

Question 16

what is Ca bound to?

Answer 16

albumin (40%)

phosphate/citrate (10%)

Question 17

what does Ca mediate?

Answer 17

• parathyroid gland (PTH)
• kidney (vitD)
• bone
• parafollicular C cells (calcitonin)

Question 18

vitamin D

Answer 18

promotes absorption of Ca from gut

Question 19

PTH

Answer 19

• produced by parathyroid
• responds to low Ca

-stim kidney to hydroxylate vit D

–> reabsorb Ca and excrete PO4

-osteoclastic resorption of bone (breakdown bone)

Question 20

how does Ca control PTH?

Answer 20

Ca binds to receptor –> inhibits PTH secretion

Question 21

how does PTH inc osteoblast activity?

Answer 21

• INDIRECTLY through paracine factor
• talks to osteoblasts

-clasts secrets acid around cell to allow Ca to flow into blood

Question 22

calcitonin

Answer 22

• produced by thryroid
• inhibts osteoclast resorption of bone
• inc renal Ca excretion
• non essential
• treats osteoporosis

Question 23

vit D sources

Answer 23

• food
• UV light

-liver then kidney activate

Question 24

fxn of vit D

Answer 24

• stim osteoblasts

- inc GI absorption of Ca

Question 25

too much vit D problems?

Answer 25

high levels of Ca in blood

Question 26

osteoporosis

Answer 26

• low bone mass
• bone resorption>depostion
• estrogen therapy –> stim breast cancer?
• bisphosphonates- kill osteoclasts (not good remodeling)

Question 27

fxns of TH

Answer 27

• required to synth GH

- permissive for GH actions

Question 28

how does insulin play into growth?

Answer 28

permissive for GH actions

Question 29

what do glucocorticoids do?

Answer 29

inhibit growth

Question 30

what controls thyroid gland?

Answer 30

hypothalamus (TRH)–> pituitary (TSH) –> thyroid (T4/T3)

Question 31

what is the active form of TH?

Answer 31

T3

Question 32

how is T4 turned into T3?

Answer 32

deiodination

Question 33

how is T3 used?

Answer 33

• T3 binds to receptor in nucleus
• inc/dec transcription of genes

-inc mitochondria activity

Question 34

what does T3 regulate?

Answer 34

• GH
• K/Na ATPase
• lipogenic genes
• uncoupling proteins
• inc breakdown of carbs, lipids
• determines metabolic rate and heat production

Question 35

T3 effects on other organs

Answer 35

• heart: inc rate, dec force
• vascular: dilation
• GI: inc motility and absorption
• skeletal: inc bone turnover
• neuromusc: hyperactive, inc muscle contraction

Question 36

endemic cretinism

Answer 36

• lack of I
• low TH level

-little/no growth

Question 37

goiter

Answer 37

-enlarged thyroid gland

• inc TSH
• inc uptake of I

-gland overgrowth

Question 38

hasimoto’s

Answer 38

• most common cause of hypothyroidism
• inc TSH
• low TH
• treat with T4

Question 39

grave’s disease

Answer 39

• auto-antibodies bind to TSH receptor and stim thyroid
• hyperactive thyroid
• low TSH
• inc TH
• inc heart rate and BMR
• inc glycoamino glycan production in the eyes

Question 40

cortisol secretion

Answer 40

• inc at night
• stress –> hypothal CRH –> pituitary ACTH –> adrenal cortisol

-negative feedback loop to CRH and ACTH

Question 41

effects of cortisol

Answer 41

• supress immune fxn
• inc gluconeogenesis on liver
• inc protein catabolism
• inc bone breakdown
• inc lipolysis of adipose

Question 42

why is cortisol high with stress?

Answer 42

• mobilize energy stores
• inc binding of epinephrine to receptors

-allows for cardio health during blood loss

Question 43

cushing’s syndrome

Answer 43

• inc cortisol secretion
• hyperglycemia
• diabetes
• hypertension
• protein depletion
• altered cognition
• hyperphagia (fat to stomach and shoulders)
• inc ACTH (bronze skin)

Question 44

addison’s disease

Answer 44

• dec cortisol secretion
• hypoglycemia
• poor stress tolerance
• dec appetite
• bronzing skin
• inc ACTH