The Endocrine Syste,

Question 1

Glands

Answer 1

organs of the endocrine system that secrete hormones

Question 2

Hormones

Answer 2

signaling molecules that are secreted directly into the bloodstream to travel to target tissue

they bind to receptors and induce a change in gene expression or cellular function

Question 3

Hormones can be classified into the following:

Answer 3

Peptides

Steroids

Amino Acid Derivatives

Question 4

Peptide hormones

Answer 4

made up of amino acids and can be small to large

derived from larger precursor polypeptide cleaved during posttranslational modification; small units go to golgi apparatus for modifications to activate hormone and released by exocytosis

rapid but short lived effects as they act through transient second messenger system meaning easier to turn on and off

water soluble and do not require carriers, travel through blood stream

Question 5

Because peptide hormones are ____, they cannot pass through the plasma membrane and must bind to _____

Answer 5

charged

extracellular receptor

Question 6

First messenger

Answer 6

ie. peptide hormones

bind to receptor and trigger transmission of second signal/second messenger

Question 7

Signaling Cascade

Answer 7

connection between hormone and the effect caused by the secon messengers

Question 8

Amplification

Answer 8

one hormone may bind to multiple receptors before degradation

each receptor will activate multiple enzymes and trigger production of large quantities of second messengers

each step increases intensity of signal

Question 9

Common Secondary Messnegers

Answer 9

cyclic adenosine monophosphate (cAMP)

inositol triphosphate (IP3)

Calcium

Question 10

G Protein Coupled Receptor

Answer 10

1) Peptide hormone binds and triggers receptor to EITHER ACTIVATE OR INHIBIT adenylate cyclase
2) this raises or lowers levels of cAMP
3) cAMP binds to protein kinase A and phosphorylates transcription factors such as cAMP and then exert hormones true effect

Question 11

Steroid Hormones

Answer 11

derived from cholesterol and produced in gonads/adrenal cortex

non polar molecules that easily cross the cell membrane

slower but longer lived than peptide hormones as they alter mRNA and protein present by affecting DNA

non water soluble and carried by protein

Question 12

Receptors of steroid hormones are usually _____ or ______.

The hormone-receptor complex undergoes ______ which can the bind directly to ______ resulting in increased or decreased _________

Answer 12

intracellular (cytosol) or intranuclear (nucleus)

conformational change

DNA

transcription of genes

Question 13

Dimerization

Answer 13

pairing of two receptor-hormone complezes

Question 14

Steroid Carrying Proteins

Answer 14

specific and cary only one specific hormone

non specific

Note, homrones are inactive while in carrier protein

LEVELS OF CARRIER PROTEIN CAN IMPACT LEVELS OF ACTIVE HORMONE (more carrier protein, less hormone as it is bound to protei)

Question 15

Amino Acid Derivative Hormones

Answer 15

less common than peptide and steroid hormones

derived from one or two amino acids with a few modifications

Question 16

Catecholamines

Answer 16

epinephrine and norepinephrine

bind to g protein couple receptors while thyroid hormones bind intracellularly

Question 17

Direct Hormones

Answer 17

secreted and act directly on a target tissue

ie insulin causing increased uptake of glucose by msucles

Question 18

Tropic Hormones

Answer 18

require and intermediary to act , stimulate preoduction of another hormone to induce an action

ie: originate from the brain or anterior pityitary gland

Question 19

Endocrine Glands

Answer 19

Hypothalamus
Pituitary
Thyroid
Parathryoid 
Adrenal
Pancreas
Gonads
Pineal

Question 20

Kidney, gastroinsstial glands, heart and thymus secret hormones but are not endocrine organs because…

Answer 20

hormone production is not main function

Question 21

Hypothalamus

Answer 21

bridge between nercous and endocrine systems

regulates pituitary gland hrough tropic hormones

Location: forebrain between thalamus and pituitary

release of hormones is regulated by negative feedback where hormone produced inhibits homrones earlier in pathway

Question 22

Suprachiasmatic Nucleus

Answer 22

receives light input from retinae to control sleep wake cycle

Question 23

Hypothalamus and Anterior Pituitary

Answer 23

hypothalmus secretes into HYPOPHYSEAL PORTAL SYSTEM and bind to receptors in anterior pituitary to stimulate release of hormones

Question 24

Hypophyseal Portal System

Answer 24

blood vessel system connecting hypothalamus and anterior pituitary

hence hormones secreted by the hypothalamus cannot be in appreciable concentrations in systemic circulation

Question 25

Hypophysis

Answer 25

alternative term for pituitary

Question 26

Hypothalamus Tropic Hormones Affectiong Anterior Pituitary Hormones

Answer 26

GnRH -> LH and FSH GHRH -> GH TRH -> TSH CRF -> ACTH

Question 27

Exception in Hypothalamus and Pituitary Relation

Answer 27

Prolactin-inhibiting factor (dopamine) decreases prolactin secretion!

Question 28

Three Organ Systems Axes

Answer 28

Hypothalamic-Pituitary-Adrenal (HPA) Hypothalamic-Pituitary-Ovarian (HPO) etc

Question 29

Hypothalamus and Posterior Pituitary

Answer 29

axons of hypothalamus to pituitary - Oxytocin Released: stimulates contractions during labor and milk - ADH/Vasppressin: increases reabsorption of water in collecting ducts of kidney s

Question 30

ADH is released from ______ and secreted in response to _____ or _______. It ______ the duct towards water and results in ______ of water leading to ____ blood pressure and volume.

Answer 30

posterior pituitary increased plasma osmalarity increased concentration of solutes within the blood increases permeability retention of increase

Question 31

Anterior pituitary secretes ____ tropic hormones and ____ direct hormones.

Answer 31

4 3

Question 32

Tropic Hormones

Answer 32

cause he release of another hormone at the organ level ex: GnRH stimulates release of FSH and LH from the anterior pituitary

Question 33

Direct Hormones

Answer 33

Prolactin stimulates milk production Endorphins decrease perception of pain Growth Hormone promotoes growth of bone and muscle and is energetically expensive by preventing glucose uptake and stimulate the breakdown of fatty acids by some tissues so gucose is available for muscle and bone

Question 34

Prolactin _____ from the release of dopamine from the hypothalamus

Answer 34

decreases

Question 35

Gigantism vs Dwarfism

Answer 35

excess growth hormone vs less growth hormone in childhood

Question 36

Acromegaly

Answer 36

GH impacts the smaller bones such as those in hands and feet

Question 37

Posterior Pituitary contains ______ in the hypothalamus. ITs two hormones are _______. THey are produced in _____ and stored in _____

Answer 37

nerve terminals of neurons with cell bodies in hypothalamus ADH and Oxytocin hypothalamus posterior pituitary