Endocrine Control of TH

Question 1

follicular cells

Answer 1

• serve as extracellular storage site for thyroid hormones
• produce:
  
  • Tetraiodothyonine (T4 or thyroxine)
    - Tri-iodothyronine (T3)

Question 2

T3 and T4 are derived from

Answer 2

amimo acid tyrosine

Question 3

T3 and T4 contain

Answer 3

iodine

Question 4

C cells function

Answer 4

secrete calcitonin

Question 5

how do you make thyroid hormones

Answer 5

tyrosine and idodine

Question 6

where do the steps of synthesis of thyroid hormones occur

Answer 6

thyroglobin molecules within the colloid

Question 7

tyrosine containing thyroglobin is exported from the follicular cells into the colloid by

Answer 7

exocytosis

Question 8

how does the capture idondine from the blood

Answer 8

iodine pump

Question 9

where are thyroid hormones stored

Answer 9

colloid
- usually stores enough to supply the bodies neeeds fro several months

Question 10

how are thyroid hormones secreted

Answer 10

phagocytize thryroglobin laden colloid
- frees T3 and T4 and therefore can diffuse across the plasma membrane into the blood

Question 11

what is the main function of TH

Answer 11

determinate of basal metabolic rate

Question 12

other functions of TH

Answer 12

• influences synthesis and degration of carbohydrates, fats, and proteins
• increases target cell responsiveness to catecholamines
• increases heart rate and force of contractions
• essential of normal growth
• critical role in normal development of the nervous system

Question 13

thyroid hormone _______ body metabolic rate

Answer 13

increases

Question 14

thyroid hormones are an important regulator of

Answer 14

oxygen, energy consumption, energy expendatures

Question 15

Th influences both the_________ of CHO, fats and proteins

Answer 15

synthesis and degration

Question 16

small amoutn of Th effect on glucose

Answer 16

converts glucose to glycogen

Question 17

(hypersecretion) large amount of TH effect on glucose

Answer 17

converts glycogen to glucose

Question 18

TH produces action similar to sympathetic NS called the

Answer 18

sympathomimetic effect

Question 19

sympathomimetic effect

Answer 19

• increases target cells responsiveness to catecholamines
• “permissive actions” by causing both the proliferation of specific cathecolamines target receptos on target tissues such as the heart

Question 20

thyroid hormones effects on the cardivascular system

Answer 20

• increases hearts responsiveness to cathecholamines
• increases heart rate and force (increases cardiac output)
• peripheral vasodilator (dissipates extra heat generated during calorigenic effects
• increases blood flow and volume

Question 21

Th effect on Growth and NS

Answer 21

• increased GH secretion (stimulates GH and promotes IGF-1’s action in protein synthesis and skeletal growth)
• regulates normal development of the NS

Question 22

TH deficency in children effect

Answer 22

stunted growth and CNS disorders

Question 23

Negative Feedback

Answer 23

(-) stress. (+) cold in infants
hypothalamus
thyrotropin-releasing hormone (TRH)
anterior pituitary
TSH
thyroid gland
Thyroid hormone (T3+T4)

Question 24

hypothyroidism causes

Answer 24

• fails to produce TH
• deficency in TRH or TSH
• inadequate dietary supply of iodine

Question 25

symptoms of hypothyroidism

Answer 25

• edenatous condition (infiltration of skin with water retaining CHO molecules)
• develop myxoedema (puffy)
• develop cretinsim (dwarfism and mental retardation

Question 26

huperthyroidism is also called

Answer 26

graves disease

Question 27

graves disease

Answer 27

• automimmune disease ( produces long acting thyroid stimulator (LATS) –> targets TSH receptors on thyroid)
• characterized by exophthalmos (eyes)

Question 28

graves disease treatment

Answer 28

• surgical removal of thyroid
• administration of radioactive iodine
• use of antithyroid drug

Question 29

calcitonin

Answer 29

decreases calcium levels in the blood