L27 Flashcards
Location thyroid gland?
-Just below larynx
-anterior and lateral surfaces of the trachea
What are the hormones secreted by thyroid gland? And functions
Thyroid Hormone- optimal metabolic activity
Calcitonin- Calcium homeostasis
follicles
Where are thyroid hormones made?
-Thyroid follicles
Where is calcitonin made?
-Clear cells
What is Thyroglobulin? TGB?
protein made in thyroid follicles and contrains tyrosine (Y)
purpose of iodine
Iodine enters follicle and iodises Tyrosine into T3 and T4
What does T3 do?
Active effects on target cells
what does T4 do?
Plentiful form, allows for steady supply of T3 hormones
What is the carrier protein which T3 and T4 is bound to?
Thyroid binding globulin TBG
What happens when Anterior Pituitary signals for release of thyroid hormone?
- Cuts Thyroid hormone out of TGB protein
How is thyroid hormone stored?
Attached to TGB as T3 and T4 until needed
What is the carrier protein allowing transport via blood of T3 and T4?
-thyroid binding globulin (TBG)
What is the carrier protein allowing transport via blood of T3 and T4?
-thyroid binding globulin (TBG)
What is basal metabolic rate? BMR
Bodies rate of energy expenditure under basal conditions
What is basal conditions
Resting, awake, lying down at comfortable temperature, fasted
What is thyroid hormone required for?
-growth
-alertness
-metabolism
What are the effects of metabolism from thyroid hormone?
-increase body heat production
-stimulates fatty acid oxidation (breakdown of fats)
-Proteolysis (breakdown of muscle)
-increases gluconeogenisis and glycoenolysis
Does thyroid hormone increase or decrease blood glucose levels
Neither as the productions and usage of glucose is balanced
How is the thyroid hormone stored?
Within follicles, TGB, tyrosine is iodised and stay attached to TGB until signalled otherwise
Where does calcium enter and exit?
Eat calcium in food
exits in poop and urine
Where does calcium come and go if we need more or less calcium
Resorption from bone (osteoclasts)
Deposition (osteoblasts)
What are features that calcium controls
-muscle contraction
-synapse and release of neurotransmitters
What three hormones can be involved in calcium regulations?
Parathyroid hormone (PTH)
Calcitriol
Calcitonin
Where does parathyroid hormone come from?
From parathyroid glands
Where is the parathyroid located?
Posterior, beans on thyroid
What does calcitriol do?
-Amplifies effects of Kidney calcium reabsorption and bone break down
-Once amplified, inhibits production of more calcitriol
What is the inner layer (red) and outer layer (yellow) of adrenal gland called?
inner - medulla
outer - cortex
Where are the adrenal glands located?
Superior to kidneys
There are three layers of the adrenal cortex what do they secrete
Outer: aldosterone
Middle: cortisol
inner: androgens
What does the adrenal medulla secrete?
Adrenaline
What effect does an increase of adrenaline have?
supplements the actions of sympathetic nervous system, in times of stress (fight or flight)
What method does adrenaline use for hormonal effects?
Second messenger system
Is adrenaline a lipid or water-soluble hormone? and is its response fast or slow?
Water soluble
Fast
