Endo 1

Question 1

What is homeostasis?

Answer 1

The state of equilibrium (balance between opposing measures) in the body with respect to various functions and to the chemical compositions of the fluids and tissues”

Question 2

What does HYPER mean?

Answer 2

overproduction of a hormone and/or hypersensitivity to hormonal effects

Question 3

What does HYPO mean?

Answer 3

Underproduction of a hormone and/or insensitivity to hormonal effects

Question 4

Are endocrine changes qualitative or quantitative changes?

Answer 4

They are quantitative changes; hormones are always present but it’s about whether we’re tipping the balance one way or the other way

Question 5

How are endocrine pathologies characterized?

Answer 5

Characterized by hormone imbalance; quantitative (not qualitative) change from normal

Question 6

What is a congenital endocrine pathology?

Answer 6

This means the endocrine pathology is present at birth (doesn’t have to do with genetics; sometimes with maternal environment)

Question 7

What is a genetic endocrine pathology?

Answer 7

It tells you in the name … duh; sometimes you can see the etiology (cause of pathology) at birth but most of the time, it doesn’t show until later

Question 8

What are the possible causes of endocrine pathologies?

Answer 8

Malignant and benign tumors
Infections/Immunological problems
Environmental factors ("endocrine disruptors")
Trauma/Stress
Surgical 
Therapeutic

Question 9

What is the most common endocrine pathology?

Answer 9

DIABETES TYPE 2 BITCH

REMEMBER BMI/WEIGHT/OBESITY IS CORRELATED WITH TYPE 2 DIABETES; ITS NOT A CAUSE AND EFFECT RELATIONSHIP

Question 10

What are classical endocrine glands?

Answer 10

classical endocrine glands are ductless; release hormones straight into the blood (so they don’t need a ductal system)
the entire organ is dedicated primarily to endocrine function

Question 11

Which are the classical endocrine glands?

Answer 11

Pineal gland, hypothalamus, pituitary gland, thyroid gland, parathyroid glands. adrenal glands, pancreas, ovaries, and testes

Question 12

What are non-classical endocrine organs?

Answer 12

These are specialized cells within organs that can produce hormones

Question 13

What are the non-classical endocrine organs?

Answer 13

Brain (especially the hypothalamus), kidney (renin, vitamin D, erythropoietin (EPO)), heart (ANP/BNP), liver (IGF-1), GI (small intestine, stomach (serotonin, ghrelin)), adipose tissue (leptin)

Question 14

Endocrine hormone release

Answer 14

Hormones secreted into the blood acting on downstream target tissues

Question 15

Paracrine hormone release

Answer 15

Hormones secreted into the interstitial space acting at nearby cells

Question 16

Autocrine hormone release

Answer 16

hormones secreted into the interstitial space acting back on same cell

Question 17

What are the factors that affect hormone bioavailability?

Answer 17

Hormone transport
Target tissues
Hormone synthesis/release
Regulatory mechanisms

Question 18

How are hormones transported?

Answer 18

Certain hormones can be bound to proteins to help transport such as lipophilic hormones (steroid hormones)
Binding proteins extend half-life of the hormone –> going to last longer in the body

Question 19

Can hormones bind to the receptor when they are bound to binding protein(s)?

Answer 19

ABSOLUTELY NOT; it needs to be free, so usually enzymes needs to come along and cut those proteins off the hormones in order to bind to its receptor and do its biological effects

Question 20

Explain the main processes for metabolic clearance of hormones

Answer 20

Vast majority will be cleared by liver and go through phase 1 (reduced & hydroxylated) and/or phase 2 (conjugated) and will allow it to get excreted via biliary or urinary

Question 21

What are the two primary mechanisms for steroid hormones?

Answer 21

Scenario #1:

1. Steroid hormone (bound to binding protein) and is released at the membrane
2. Steroid hormone freely diffuses across lipid bilayer
3. Steroid hormone finds intracellular targets

Scenario #2:

1. Hormone/protein complex binds to megalin
2. Formation of endocytic vesicle
3. Hormone dissociates and is released from vesicle

Question 22

What happens if you have the hormone present but you have no receptor?

Answer 22

if there is no receptor = there is no action

The hormone can’t do anything without a receptor to work through

Question 23

How do receptors determine duration of hormone activity?

Answer 23

When the hormone binds to its receptor (cell surface vs intracellular receptors):
Cell surface receptors will get internalized and dissociated from its ligand and then you have to wait for more receptors to be made and moved back into the membrane for another response

Intracellular response: hormone binds and then the receptor will undergo ubiquitination and then gets degraded and then have to make more

Question 24

How are hormone receptors autoregulated?

Answer 24

Hormone receptors are autoregulated by their ligand; the body is good at determining the set number of receptors to be made to maintain homeostasis
There is up or down-regulation depending on the hormone levels

Question 25

What’s the difference between specificity and affinity in regards to hormone:receptor binding?

Answer 25

Specificity = receptor needs specificity to know which hormone it should look and bind for
Affinity = how much receptor is bound to a certain amount of ligand (known as Kd which is the ligand concentration that occupies 50% of the binding sites)
Less hormones you need to bind those receptors = higher affinity = lower Kd

Question 26

What are lipophobic hormones?

Answer 26

These hormones binds to cell surface receptors (since they don’t want to get into cell membrane)
Receptors coupled to second messenger signaling pathways including: cAMP, IP3/DAG
Response is usually fast and there’s rapid internalization or degradation and thus you get a fast response but when they get internalized, there’s no more response and you have to wait for the next response/receptors to get back up on the surface

Question 27

What are the types of the cell surface receptors?

Answer 27

GPCR (most protein hormones), RTK (insulin, ANP), and receptor-linked kinases (growth hormones, prolactin, EPO)

Question 28

what are lipophilic hormones?

Answer 28

lipophilic hormones = steroid hormones
bind mainly to intracellular receptors and are usually bound to chaperone proteins to keep receptor in cytoplasm
Once hormone is present, chaperone dissociates from receptors and allow hormone to bind to receptors and then repress or activate transcription (usually slow biological response)

Question 29

Which is the exception/special hormone?

Answer 29

The thyroid hormone; the thyroid hormones are amines and they bind to nuclear receptors
The nuclear receptor is already bound to DNA and thus repressing transcription
Once thyroid hormone binds to nuclear receptor, the nuclear receptor activates gene transcription