NPB101: Endocrine System Lec 1 Part 1

Endocrine System

Part of our control system

Primarily efferent (motor) pathway

Involves signal factors going into the blood stream

Works with the NS

Homeostasis

is the process by which living organisms maintain a stable internal environment despite changes in external conditions Which is NOT what our Hormones do!

Endocrine System Controls

• Growth, development

• Metabolism

• Stress response & adaptation

• Reproductive function

• Homeostatic responses

Endocrine Gland

1. Hypothalamus

2. Pituitary

3. Peripheral Endocrine gland axis (Thyroid,adrenal)

HPA

Endocrine Cell/Gland/Tissue

Produces & Secretes Hormones

Endocrine System requires the____ system

Transport

Transport System

transports hormones through blood

Hormone

signal factor that is released by endocrine tissue & it goes into blood & gets transported to target tissue

The ___ factor/hormone is released by ____ tissue

Signal, Endocrine

Classes of Hormones

• Water Soluble (hydrophilic) Hormones

Protein/Peptide hormones

often produced as precursors

• ex: precursor for insulin is proinsulin

Classes of Hormones

• Water Soluble (hydrophilic) Hormones

Amino Acid Derivatives

Classes of Hormones

• Lipid Soluble (lipophilic) Hormones

Steroid Hormones

made from cholesterol

Cholesterol is important for:

• Sex Hormones: Estrogen

• Aldosterone: Kidney Fxn

• Cortisol: stress

Cholesterol is not ___ soluble, it needs a transporter to push it into the ___, since ____ is ____ soluble

water, bloodstream, blood, water

There is a protein that ___ onto Cholesterol

holds

Classes of Hormones

• Water Soluble (hydrophilic) Hormone

  &

• Lipid Soluble (lipophilic) Hormone

Amino Acid Derivative

• made from a single a.a.

• Hydrophilic Hormone is epinephrine—→sympathetic—→fight-or-flight

• Lipophilic Hormone is Thyroid

Can’t store ____ Hormones in vesicles because it will ____ out since it’s ____

Steroid, leak, lipophilic

We have to ____ lipid-soluble hormones & then ____ them

synthesize, release

Exception of being released after synthesis

thyroid Hormone (TH)

____ soluble hormones are stored in ____ vesicles & then released

water, secretory

Bioavailability

• Hormone needs to be free

• Fully functional

• Fast activation rate

• Removal Rate: eliminate slowly

Activation rate

• Slow activation rate of precursor= no bioavailability

• Fast= availability

T/F: If you have slow activation of the hormone from the precursor it will affect with. no bioavailability

True, you need fast activation for hormone bioavailability because hormones need to apply their affects to regulate bodily functions

T/F: Albumin is in a bound state and will not affect hormone bioavailability

False, Albumin in bound state means its unavailable & will affect hormone bioavailability

T/F: If the removal rate is fast this will be good for hormone bioavailability

False, If you can remove a hormone fast with removal rate this will not be great for bioavailability, because we will have less time to absorb hormone

Bloodstream has to ___ hormones to particular ____ & the targets have to have the hormone ___

carry, targets, receptor

T/F: So if a patient has cardiovascular issues it will have problems with driving blood to tissues, the hormone will still get there

False, If a patient has cardiovascular issues where it has problems driving blood to tissues, the hormone will not still get to the blood because the bloodstream carries the hormone to the blood to a particular target and without the blood the hormone cant go anywhere

The Plasma Membrane bound receptors will bind to the ____ soluble hormones like peptide hormones

water

The Receptor will bind to the ___, inside the____

Hormone, cell

Hormone & Rector behave as a _____ factor

transcription —→ it can dec or inc transcription

Plasma-Membrane Associated Receptors

Receptor is stuck in the PM

Intracellular part of the Hormone binding

interacts with G-protein (a type of signal transduction protein)

G-Protein

has beta, alpha, gamma, subunits stuck together with a GDP

Alpha subunit

• turns on a signal process

• Left go of GDP and binds to GTP which activates it

• Transducing effect of hormone (1 hormone) —→ binding that allows activation of intracellular enzymes

T/F: In the presence of a hormone: The hormone doesn’t bind to G-protein, but bind to receptor

True, this occurence of a hormone binding to the receptor itself & not the G-Protein is because the hormone can be a steroid hormone, which initiates signaling with a recptor

Phospholipase C Beta (PLC-β)

Targets a phospholipid (PIP2) & chops it up —→ 2nd messenger

G-Protein _____ PLC-β which then ____ PIP2

activates, targets

When you ___ PIP2 it creates the molecule ___

target, IP3

T/F: IP3 is a secreting hormone

False, IP3 is a second messenger

So the alpha betta gamma subunit are together with GDP due to G protein, but then alpha subunit activates intracellular when bound to GTP which then activates PLC-B which then targets PIP2 and creates IP3, IP3 is a second messenger that then triggers release of Ca2+

Dimerization

Identical receptors w/intrinsic built inside

Why do Dimerization?

when dimerization occurs the protein kinase becomes active through cross phosphorylation and then the protein kinase will phosphorylate intracellular targets

T/F: There will be a delay in gene expression

True, There will be a delay because protein synthesis pathways take tons of minutes before you see a change in protein levels

Up-regulation

Increase in number of receptors

Down-Regulated

Decrease responsiveness

Permissiveness

To be responsive, it needs the exposure to another hormone before expose to the one hormone

The effect of Hormone _#_ requires the presence and action of Hormone _#_

1, 2 (adipose tissue needs to be (pre-treat) exposed to thyroid before responding to EPI

Syngerism

The combined effect of two hormones is greater than their individual effects

Antagonist

opposite effects (one rises & one falls)

Humoral (blood fluidity) Regulation

Altering liquid levels of hormones around our blood

Neural Regulation

Nueronal output that talks to glandular tissue & then alters levels of hormones (epinephrine)

Hormonal Regulation

variety of hormones being regulated

Neurons live in the _____ because its responsible for maintaining ____

hypothalamus, homeostasis

Oxytocin

mothering instinct

T/F: the Posterior Pituitary makes hormones

False the Posterior Pituitary stores the hormones, while the Anterior Pituitary is actually making the hormones

Tropic Hormones

• Induce hormone release by another endocrine gland—- TROPIC

• Can also cause growth —TROPHIC AFFECT

The ____ pituitary contains all trophic hormones that allow ____

Anterior, growth

Cortex

outside of something liek cerebral cortex —→ outside of cortex

Anterior Pituitary Hormones

• F: FSH

• A: ATCH

• T: TSH

• P: Prolactine

• I: LH

• G: GH

What is controlling/regulating these Anterior Pituitary Hormones?

The Hypothalamus

The Hypothalamic ___ and ____ hormones

releases and inhibits

__1__ comes out of hypothalamus and stimulates release of __2_ then __2__ talks to thyroid gland and causes release of __3__

TRH,TSH, TH

___ causes the release of ___

CRH, ACTH

Which hormone has the biological affect H1, 2, or 3?

Hormone 3 has the affect as Hypothalamus send hormone signal to anterior pituitary that then release/stimulates hormone to endo gland and the adrenal gland then porduces hormone 3 that carries that biological affect, H3 then goes bacjk to the brain and inhibits secretion from anterior pituitary

Negative Feedback

Hormone number 1 gets releases from hypothalamus to anterior pituitary and then the Anterior pituitary sends hormone 2 to endo gland and the endlo gland releases the biological affect in shape of Hormone 3 and then H3 gets send back to brain (anterior pituitary) and that inhibits release and then it inhibits release of hormone 1 from hypothalamus