Endocrine Flashcards
What are the 2 types of Glands? How do they differ. What are some examples from the digestive system?
- Endocrine Gland
- Ductless Glands
- Hormones released into the extracellular fluid & diffuses into the blood
- Internal Environment
Examples: Secretin, CCK - Exocrine Gland
- Ducted glands
- Product relased into External enviroment
Examples: digestive enzymes
What are the 6 kinds of Endocrine Glands?
- Pituitary Gland
- Pineal Gland
- Thyroid Gland
- Parathyroid Glands (4)
- Thymus Gland
- Adrenal Glands (2)
What other organs are involved in the endocrine system?
Hypothalamus
- oxytocin, ADH,
regulatory hormones
Pancreas
- insulin, glucagon
Ovaries/ Testes
- estrogen,
progesterone,
testosterone
Kidneys
- renin
- erythropoieten
Stomach
- Gastrin
Liver
- Angiotensinogen
Small intestine
- Enteric Gastrin
- Secretin
- Cholecystokinin CCK
Where do hormone usually go?
hormones usually enter circulation to find its target organ
How are hormones cleared?
Liver
- break down
hormones
Kidney
- filter metabolites of
hormones into urine
to be excreted
Liver & Kidney Disease
- can have a buildup of hormones in the body
-> secondary endocrine conditions
What do hormones effect? In what ways do they have an effect? (6)
Effect: Target Cells which have the correct receptor w/in the cell or on the cell’s surface
6 effects:
1. Alter Cell’s Permeability
- open/close ion
channels
- ↑ or ↓ permeability to
H20
- Stimulate Protein Synthesis
- hormones, enzymes - Activate/ Deactivate another Hormone
- Secretion
- Mitosis
- Activate a Gene
- fat soluable hormones usual effect
What are the 2 types of hormones?
Fat Soluable Hormones
Water Soluable Hormones
Describe Fat Soluable Hormones and their mechanism of action.
Examples ?
Fat Soluable Hormones
- Cholesterol
- Steroids
Mechanism:
- no surface receptor
- diffuse through membrane
- attach to an intracellular receptor
- receptor binds to DNA
–> Gene Activation
Examples:
- Estrogen, Progesterone, Testosterone,
Cortisol
Describe Water Soluable Hormones and their mechanism of action. What are the 3 subtypes?
= Protein based
1) Amine Hormone
= modified amino acid
- epinephrine/
norepinephrine
2) Peptide Hormone
= short chain of a.a.
- Antiduiretic
Hormone (ADH)
3) Protein Hormone
= long folded chains
of a.a 3D protein
- insulin, GH
Mechanism:
- hormone attaches to a surface receptor
- that causes a chain reaction to activate the secondary messenger
=intracellular receptor
= ATP –> cAMP cyclic adenosine monophosphate
- that carries out the target response
Does the cell have any control to how suscepible it is to hormones?
Yes, can Up regulate and Down regulate
–> changing amt of surface receptors
Where does the pitutary gland attach and how?
The pituitary gland (posterior) attaches to the hypothalamus vis the infundibulum
What is the anterior pituitary gland’s other name?
How much of the pituitary gland does it make up?
What is it’s function?
Origins?
How does it communicate w/ hypothalamus?
How do hormones leave this gland?
Adenohypophysis
=75%
=> TRUE GLAND: makes hormones
Originates: @ base of the tongue as fetus & migrates up to brain & join w/ posterior pitutary gland
Communicate: Hypophyseal Portal System
- Primary capillary
PLEXUS
- Portal veins
- Secondary capillary
PLEXUS
=> regulatory hormones from the hypothalamus enter hypophyseal portal system and causes stimulation/ inhibition of hormones made in the adenohypophysis which then would enter hypophyseal veins to travel through the blood to the target cells
What is the Hypophyseal Portal System? What are it’s components?
Hypophyseal portal system transports regulatory hormones from the hypothalamus to the anterior pituitary hormone.
Regulatory hormones enter the primary capillary plexus in the hypothalamus and then enter the portal veins, and then the secondary capillary plexus in the anterior pituitary gland. Next the hormones secreted from the adenohypophysis enters the hypophyseal veins that then put the hormones in general circulation and then the hormones find it’s target cells/ tissues
What is the other name for the posterior pituitary gland?
How much of the pituitary gland does it make up?
Function?
What does it secrete & what synthesized this?
How does it communicate w/ Hypothalaus?
= Neurohypophysis
= 25%
Function:
- not a true gland
- stores hormones (in axon terminals) synthesized by the hypothalamus
-> Supra optic nucleus
= ADH
-> Paraventricular
nucleus
= Oxytocin
Communicate: Infundiubulum
Histology of anterior & posterior pituitary gland?
Anterior: cuboidal glandular cells
Posterior: nerve tract
=>bundles of axon terminals w/in CNS
(axon terminals of supraoptic & paraventricular nuclei where ADH & oxytocin stored)
