Endocrine System Flashcards
What is Hormones?
Hormones are chemical substance in the body that acts like a “messenger” to help other cells work. They secreted in bloodstreams.
What is the difference between Negative Feedback and Antagonistic Feedback Loop?
Negative Feedback: Accumulation of hormone turns off synthesis to maintain homeostasis.
Antagonistic Feedback Loop: Two hormones work against each other to maintain homeostasis.
What is Growth Hormone? Its origin? Target Cells? What happens to bones, muscles, liver?
Growth Hormone are cells that specializes in development of the body/ other cell. It can be found in pituitary gland and its target cells are bones , muscles, and liver. It causes bones and muscles to repair and grow. While in Liver, it helps to release glycogen and breaks down into glucose.
Draw the Growth Hormone Negative Feedback Loop
Hypothalamus
“ (+ turns on)
Pituitary Gland
“ (+ growth hormone)
Target Cells
- HT stimulates PIT.
- PIT releases G.H into bloodstream.
- G.H acts on targeted cells.
- G.H gives feedback to HT and PIT, to prevent overproduction and maintain homeostasis. It turns off HT and PIT.
Difference between Thyroid and Parathyroid
Thyroid is a gland in upper neck. It regulates metabolism and blood calcium levels.
Parathyroid is a four pea sized gland in the thyroid. It regulates blood calcium levels.
What does Thyroid releases and regulates? What does Thyroid contain? What happens where there is not enough iodine? What is goiter? Why does thyroid enlarges?
Thyroid releases Thyroxine (the hormone) and it regulates cellular respiration. Thyroid contains a mineral called iodine. When there’s not enough iodine in the body it causes Goiter. Thyroid enlarges when lack of iodine as it attempts to gather all the iodine it can get in order to produce thyroid.
Draw the Thyroxine Negative Feedback Loop
Hypothalamus
“ (+)
Pituitary Gland
“ ( + release TSH)
Thyroid Gland
“ (+ Thyroxine)
Target: All Cells
- HT stimulates PIT.
- PIT releases TSH.
3.TSH stimulates TG to produce and release Thyroxine. - As Thyroxine increases in bloodstream, they signal HT and PIT to turn off to prevent overproduction.
Difference between Hyperthyroidism and Hypothyroidism?
Hyperthyroidism is when there is too much thyroid. Some Symptoms: weight loss, hunger, heat intolerance, irritable and nervous.
Hypothyroidism is when there is too little thyroid.
Some Symptoms: low metabolic rate, sleepiness, weight gain, feel cold
What happens when:
a) Hypersecretion of thyroxine caused by pituitary disfunction?
b) Hypersecretion of thyroxine caused by thyroid disfunction?
c) Hyposecretion of thyroxine caused by pituitary disfunction?
d) Hyposecretion of thyroxine caused by thyroid disfunction?
a) TSH increases, Thyroxine increases ( brain/ PIT is broken.)
b) TSH decreases, Thyroxine increases
c) TSH decreases, Thyroxine decrease
d) TSH increases, Thyroxine decreases
Difference between Adrenal Cortex and Adrenal Medulla?
Adrenal Cortex: responds to long term stress, regulates water retention (aldosterone), activated by ACTH, Cortisol increases levels of amino acids.
Adrenal Medulla: gland that is connected in nervous system. They respond to short term stress. Produces two hormones: norepinephrine and epinephrine. Activated by Sympathetic Nervous System. These hormones prepares the body to fight, flight, or freeze.
Draw the Cortisol Negative Feedback Loop
Hypothalamus
“ (+)
Pituitary Gland
“ ( + ACTH)
Adrenal Cortex
“ ( + Cortisol)
Liver
Determine the effects of the following:
a) Hypersecretion of Cortisol
b) Hypersecretion of ACTH
c) Hyposecretion of Cortisol
d) Hyposecretion of ACTH
a) long term stress, high blood sugar, high cortisol, low ACTH
b) high blood sugar, high cortisol, high ACTH
c) no long term stress, low blood sugar, low cortisol, high ACTH
d) low blood sugar, low cortisol, low ACTH
What is Aldosterone?
Produced by Adrenal Cortex. Activated when dehydrate and by ACTH. Increases Na+ retention and fluid levels in the blood. It indirectly reabsorbs water in the kidney.
What is ADH ( antidiuretic hormone)?
Found in pituitary gland. It increases water reabsorption in kidney. It causes blood pressure to increase and causes urine output to decrease. Osmoreceptors sense water content in blood.
