Endocrine System

Function of endocrine system

an organ system that is responsible for the production of hormones

Function of hormone

a chemical that is going to be released by one group of cells

Endocrine gland

going to release hormones, those hormones go into blood and get transported over to another part of the body where they will activate those cells

Do endocrine glands have ducts?

No, they do not have ducts. These hormones are going to go straight into the blood

Describe the function of the hypothalamus

a structure of the brain that allows us to control a lot of autonomic functions

What are the ways in which the hypothalamus communicates?

via action potential and hormones

What structures does the hypothalamus communicate with?

anterior and posterior pituitary glands

What is the anterior pituitary gland known as?

adenohypophysis

What is the posterior pituitary gland known as?

neurohypophysis

What are the key characteristics of the hypothalamus?

• controls autonomic functions

• communicates via action potential and hormones

• communicates with anterior and posterior pituitary glands

• has blood vessels, hormones travel via circulatory system

Where are the hormones produced by the hypothalamus sent?

anterior pituitary gland

Where are the action potentials transmitted by neurons from the hypothalamus sent?

posterior pituitary gland

The ______ system is a network of capillary beds working with one another

hypothalamo-hypophyseal portal system

What is the function of the hypothalamo-hypophyseal portal vein?

allows blood to flow from the hypothalamus to the anterior pituitary gland

Explain the communication between the hypothalamus and the anterior pituitary gland?

• has blood vessels and releases hormones

• hormones sent to anterior pituitary gland

• HH portal system located here

• hormones sent out to the rest of the body

Explain the communication between the hypothalamus and the posterior pituitary gland?

• communication via action potential

• special neurons, their cell bodies are found in the hypothalamus

• axons go down and reach the posterior pituitary gland, cell bodies of neurons produce the hormones

• hormones travel down axon and reaches synaptic knobs

• synaptic knobs release hormones

This gland makes and releases its own hormones?

anterior pituitary gland

This gland is not its own gland and will not make hormones?

posterior pituitary gland

What hormone does the hypothalamus release?

• thyroid stimulating releasing hormone

• adrenocorticotropic releasing hormone

• growth hormone releasing hormone

What hormone does the adenohypophysis make and release?

• thyroid stimulating hormones

• adrenocorticotropic hormone

• growth hormone

What is the function of thyroid stimulating hormone?

can go to certain cells and cause metabolism to increase, energy used and given much greater

What issues arise if thyroid stimulating hormone is not produced and released?

if you didn't have this hormone, you would be low energy, weight gain quickly, among other negative side effects

What is the function of the adrenocorticotropic hormone?

goes to the anterior pituitary gland, stimulates it to make adrenocorticotropic hormone (AH), AH then goes over to the adrenal gland, specifically the cortex of the adrenal gland, and makes the hormone known as cortisol.

What does cortisol do?

hormone that helps you deal with stress and inhibits the immune system

What is a tropic hormone?

a hormone that causes the release of another hormone

What are some tropic hormones?

• thyroid stimulating hormone releasing hormone

• adrenocorticotropic releasing hormone

• growth hormone releasing hormone

What is the function of the growth hormone?

useful for growing children, we need growth hormone for osteoblasts to lay down more ECM

What issues can arise with a lack of growth hormone?

dwarfism (stunted growth)

What are the 2 reasons for dwarfism?

• First reason: is either not releasing growth hormone or not releasing growth hormone releasing hormone. 

• Second reason: if you don't have enough thyroid hormone you will not have enough material to make energy, growing is costly.

Explain the importance of hormone balancing

Balance of hormones is crucial, too much of one or lack of another will always cause an issue in the body. Hormones are complicated. They are constantly at play with one another. Everyone has a different physiological system.

What hormones can the thyroid gland produce?

thyroid hormone

What is the function of thyroid hormone?

allows us to regulate metabolism. In order to make it, you need a healthy amount of iodine

Explain the negative feedback system at play with our hormones

• thyroid hormone goes back to hypothalamus and inhibits it from producing thyroid stimulating hormone releasing hormone.  

• It will also go back and inhibit the adenohypophysis from making and releasing thyroid stimulating hormone 

• We have essentially shut off the system and as a result will also not be making and releasing thyroid hormone. We will keep it off until we need more thyroid hormone.

What is the issue that arises due to the enlargement of the thyroid gland?

goiter

Is the thyroid gland a tropic gland?

yes, the thyroid gland is a tropic gland

Why is the thyroid gland a tropic gland?

it is a gland that is going to be stimulated in order to make another hormone

What condition of the thyroid does a goiter lead to?

hypothyroidism, the overstimulation of the thyroid gland. Does not make enough energy or cannot use the energy

Difference between hypothyroidism and hyperthyroidism?

hypo - overstimulated, not making enough or not being able to use energy

hyper - making too much energy or using too much energy

Cause of graves disease?

autoimmune disorder that will have the immune system make a protein that looks exactly like a thyroid stimulating hormone

What are people with graves disease at risk of getting?

a goiter (hypothyroidism)

Does hypothyroidism from graves disease stop us from making thyroid hormone?

No, because the issue is not within the endocrine gland pathway, ‘fake’ hormone is coming in from the immune system.

True or False: all hormones are controlled by the hypothalamus

False, not all hormones are controlled by the hypothalamus. We have hormones that are produced by the pancreas, for example.

Where is the parathyroid gland located in relation to the thyroid gland?

backside of the thyroid gland

What is the function of the parathyroid gland?

make a hormone called parathyroid hormone, which are antagonistic to calcitonin.

Does parathyroid hormone increase or decrease calcium levels in the blood?

increases calcium levels in the blood

Parathyroid hormones will activate ____ to break down the extracellular matrix of bones

osteaclasts

How do parathyroid hormones activate calcium levels?

they activate osteoclast activity to break down the ECM and release Ca into the blood

What effect does calcitonin have on calcium levels?

it will activate osteoblast activity, taking Ca from the blood and putting it into the bone so that we can release it later on if we ever need it

Where is the adrenal cortex located?

on top of the kidneys

What is the function of the adrenal glands?

makes many types of hormones; steroid, sex, testosterone and estrogen (to name a few)

What is the hormone that allows us to deal with stress?

cortisol

Which hormone supresses our immune system?

cortisol

What are the two regions of our adrenal glands?

adrenal cortex and adrenal medulla

What hormone does the adrenal medulla make?

Epinephrine

What is the function of epinephrine?

also known as adrenaline. It is going to activate the sympathetic nervous system which effectively increases heart rate, blood pressure, and also vaso dilation.

A person with a peanut allergy will undergo shock, affecting their nervous system, what happens to their blood pressure? What would we do to help?

their BP will drop, we will use an epipen to then increase their BP

What hormones does the posterior pituitary gland make?

Antidiuretic hormone and oxytocin

What is the function of antidiuretic hormone?

helps the fluid, or water, reabsorb back into the cardiovascular system

What is the condition known as diabetes insipidus and why is it dangerous?

a deficiency of antidiuretic hormone. Your kidneys are not able to reabsorb enough water. Dangerous because it enhances the dangers of dehydration within these patients

What is the function of oxytocin and where does it show up with people?

the pair bonding hormone, it shows up between people like mothers and baby and with mammary glands to stimulate milk production

Which type of gland is the pancreas?

mix or both an exocrine and endocrine gland

List the structures of the pancreas

• pancreatic duct

• pancreatic acini

• islets of langerhans

What are the cells related to Islets of langerhans?

beta and alpha cells

What do beta cells make and release?

insulin

What do alpha cells make and release?

glucagon

What does insulin do?

• Decrease blood glucose levels 

• We are able to send glucose into the cell, that’s why blood glucose levels fall

What does glucagon do?

Increase blood glucose levels

What are the two types of diabetes?

• Type 1: people who lose ability to make and release insulin 

• Type 2: people who lose the ability to respond to insulin

What is the function and issue with leptin?

• Function: When you release leptin, it sends signals to the brain to stop eating, deals with satiation when eating 

• Issue: when no leptin is released, deficiency will lead to no signal → overconsumption

What tissue is leptin made by?

made by the adipose connective tissue of the body