Introduciton to the Endocrine System

Question 1

Autocrine
Paracrine
Endocrine
Neuroendocrine

Answer 1

Release H and it effects
Itself or neighboring same cell

Neighboring different cell

Different cell by flowing through the blood to that location

Different cell by flowing (H released by Neuron) though the blood to that location

Question 2

Peptide Hormone synthesis and secretion

Answer 2

Pre-pro-H—-> pro-H—->H in vesicle that is released

Question 3

Steroid H secretion and synthesis

Answer 3

Derivative of cholesterol
Hydroxylation or cyclication added

In gonads, corpus luteum, placenta, adrenal medulla

LIPID SOLUBLE so just pass cell membrane

Question 4

Amine Hormone synthesis and Secretion

Answer 4

Made from derivative Tyrosine
GROUP 1: Catecholamines (Dopamine NorEp., Epi)
In secretory granules
Bind on cell membrane receptors
GROUP2: Thyroid Hormones (TSH, T3, T4)
Synthesized by thyroid and put into follicles inside the thyroid gland
Can cross cell membrane to bind to NUCLEAR RECEPTORS

Question 5

Thyroid hormones

Answer 5

High protein binding
Long plasma half life
Low metabolic clearance

Question 6

Protein Hormones

Answer 6

Little protein binding
Short plasma half life
High metabolic clearance

Question 7

Steroid Hormones

Answer 7

In the middle for protein binding and plasma half life and metabolic clearance

Question 8

Positive feedback of overies

Answer 8

Overly secretes Estrodiol—-> stimulate AP to secrete H——> stimulates overly to secrete more Estrodiol

Question 9

Long loop vs Short loop feedback

Answer 9

LONG: Testosterone(from endocrine gland testis) inhibits AP and Hypothalamus

SHORT: AP inhibits Hypothalamus, or Testosterone inhibits Testis

Question 10

Supraorbital Nucleus and the Paraventricular Nucleus

Answer 10

Make ADH and Oxytocin in their neurons

Their axons travel to PP and release the O and A to the blood capillaries inside

Question 11

Oxytocin

Answer 11

Milk let down

Uterus contraction

Question 12

ADH

Answer 12

Reabsorb Solutes back into the kidneys

To regulate BP

Question 13

Releasing H

Answer 13

Are from the Hypothalamus that go to the AP

Question 14

TRH

Answer 14

Causes TSH—->thyroid to release TH

Question 15

ACTH

Answer 15

Causes cortisone from the AP

Question 16

Prolactin

Answer 16

Made in pituitary gland
Inhibited by dopamine from the hypothalamus

Milk production
And breast growth

Question 17

How is the hypothalamus regulated

Answer 17

By neural input

Most common is the SCN neurons

Question 18

SCN neurons pathways go

Answer 18

Light—> eyes—> Lateral Geniculate nucleus—> SCN
SCH——>
1. Pineal gland to secrete melatonin
2. Hypothalamus for sleep/wake cycles
3. Coordinate rhythms of metabolism and behavior and endocrine with help of melatonin

Question 19

How to regulate H. Receptors

Answer 19

They are very sensitive in the periphery since you don’t have that much hormone there

1. Change number of receptors
2. Change affinity of receptors to H. = like chemical modifications like phosphorylation

Question 20

Adenylyl cyclase mechanism and which H.s

Answer 20

ACTH, LH, FSH, TSH, Glucagon
Adenylase cyclase
cAMP —->5’AMP
PKA

Question 21

Phospholipase C mechanism and which H.s

Answer 21

GnRH, TRH, Oxytocin 
Activate PLC
IP3/DAG/Ca+2
DAG + Ca+2= protein kinase C
IP3= Ca+2 from ER

Question 22

Steroid mechanism and which H.s

Answer 22

Testosterone, Estrogen….?
Hydrophobic H.s (usually bound to a plasma protein)
Bind to cytoplasmic receptors
Go to bind nuclear receptors to activate or suppress genes

Some few bind to membrane receptors

Question 23

Guanylyl Cyclase Mechanism and H.s

Answer 23

GTP—-> cGMP

cGMP= activates cGMP Kinase (ANP) and also causes vasodilation due to NO

Question 24

Tyrosine Kinase Mechanism and H.s

Answer 24

Insulin and Nerve Growth
1. Receptor Tyrosine Kinase: intrinsic tyrosine kinase activity
Activated and phosphorylates downstream proteins

GH
2. Tyrosine Kinase-Associated Receptors: JAKSTAT
Non-covalent association to kinase proteins
Activated and phosphorylates downstream proteins