Phys II- Edocrine I

Question 1

What is a tropic hormone?

Answer 1

• regulates secretion of another endocrine gland

- stimulates and maintains target tissues

Question 2

What is a diurnal rhythm and what sets it?

Answer 2

• awake/sleep cycles

- CNS

Question 3

What is permissiveness?

Answer 3

one hormone must be present in enough amounts for full effect of another hormone

Question 4

Describe Synergism

Answer 4

• when actions of several hormones are complimentary

Question 5

What is the benefit of synergism?

Answer 5

• combined effect is greater than the sum of separate effects

Question 6

Describe Antagonism

Answer 6

• one hormone causes loss of another’s receptors

Question 7

Describe the three chemical classes of hormones

Answer 7

1. Peptides&Proteins
   
   • hydrophilic
   • synthesized, processed, packaged
2. Steroids
   
   • lipophilic
   • from cholesterol
   • sequential modification (enzymes)
   • cannot be stored
3. Amines
   
   • depends on hormone
   • catechacholamines
   • melatonin
   • thyroid hormones

Question 8

Posterior Pituitary

1. Synthesis
2. Stores/Releases
3. Partner in Crime

Answer 8

1. none
2. oxytocin, vasopressin
3. hypothalamus

Question 9

Function of Vasopressin

Answer 9

• conserves H2O in urine formation

Question 10

Function of Oxytocin

Answer 10

• uterine contraction

- milk ejection

Question 11

How do the posterior pituitary and hypothalamus work together?

Answer 11

• synthesis in hypo
• travel down axon to be stored in post pit
• excitation of hypo causes post pit to release

Question 12

How is the release of pituitary hormones regulated

Answer 12

1. hypothalamic hormones (release/inhibition of ant pit hormones)
2. Feedback by target gland hormones

Question 13

What is the Hypothalamic-Hypophyseal Portal System?

Answer 13

• vascular
• blood from one cap bed to another
• links brain and endocrine

Question 14

Describe GH levels across a lifespan

Answer 14

• fetal- none
• first two years- high
• puberty- high
• adulthood- low

Question 15

Describe Growth

Answer 15

1. Chondrocytes
2. Hyperplasia- cell division
3. Hypertophy- cell enlargement
4. Calcification
5. Osteoblasts deposit bone

Question 16

How does GH effect growth?

Answer 16

GH (tropic) –> IGF-1–> growth

Question 17

What does IGF-1 do?

Answer 17

• protein synthesis
• cell division
• lengthening/thickening of bones through osteoblast activity and proliferation of cartilage

Question 18

Describe growth plates

Answer 18

• where osteoblast proliferation occurs

- growth can only occur when plates are “open” (cartilaginous) not after they are ossified

Question 19

How does GH affect metabolism?

Answer 19

• increase blood glucose, decreases glucose uptake/stores in muscles
• increase blood fatty acid levels (breaks down triglyceride in adipose)

Question 20

GH abnormalities affect ___ more than ___.

Answer 20

growth, metabolism

Question 21

Hyposecretion of GH

Answer 21

• dwarfism in children
• adipose increase in adults but overall few symptoms
• less muscle

Question 22

Hypersectretion of GH

Answer 22

• gigantism in childhood
• acromegaly (tumor of GH cells) in adults
• caused by tumor in ant pit

Question 23

Pineal Gland

1. Anatomy
2. Secretion

Answer 23

1. tiny pinecone shaped in middle of brain

2. Melatonin

Question 24

Melatonin

Answer 24

• increases at night
• promotes sleep
• affects repro activity and puberty
• improves immune system
• triggered by photo receptors in retina

Question 25

Describe the path of Melatonin

Answer 25

1. photoreceptors
2. SCN
3. pineal
4. melatonin secretion