BIOL 319: GH-IGF-1/Calcium Homeostasis

What does estrogen and testosterone stimulate?

epiphyseal growth plate

On average, why are males taller than females?

inhibition of the epiphyseal growth plate occurs later

stronger stimulation 

What are two examples of thyroid hormones?

thyroxine and triiodothyronine (T3)

How are these thyroid hormones made?

2 tyrosine are condensed and modified by the thyroid gland

What is needed to make thyroid hormone?

iodine and tyrosine

What are two gonadal sex hormones?

testosterone and estrogen (estradiol)

What is the arrangement of rings for the gonadal sex hormones called?

steroid nucleus

Where is testosterone/estrogen derived from?

cholesterol

How is cholesterol bad?

can cause heart attacks and strokes

How is cholesterol good?

necessary for holding the cell membrane together in the lipid bilayer

What are some other hormones derived from cholesterol?

cortisol

Vitamin D 

What kind of feedback is calcium homeostasis?

negative feedback

What levels should calcium be in the body?

9mg/dL

What happens if there is low calcium for your skeletal muscle?

elevates skeletal muscle excitability

fatal convulsions 

How many parathyroid glands does one have, and their size?

4: size of a green lentil

What hormone is secreted by the parathyroid gland?

PTH: secreted when calcium is too low

What is the variable and signal in calcium homeostasis?

variable: calcium

signal: depressed/elevated calcium levels

signal: depressed calcium levels

What do pTHC do?

bind calcium

When calcium is too low…?

binding is too low: stimulates a message to the parathyroid gland to produce PTH

How does low calcium affect the diaphragm?

can only contract but not relax