CH5 The Endocrine System Flashcards
Common Second Messengers
give 3 examples
CICa (ZIKA)
Cyclic adenosine monophosphate (cAMP)
Inositol Triphosphate (IP3)
Ca2+
Types of hormones:
Peptide Hormones ( end in -in or -ine)
Amino acid-derivative hormones ( end in -in or -ine)
Steroid Hormones (end in -one, -ol, -oid)
Give 1 hormone example for all
Peptide hormones: Come from previous larger polypeptides. They cant pass the cellular membrane and need a receptor because they are charged. i.e GPCR. They are fast-acting
i.e Insulin, epinephrine, norepinephrine
Steroid Hormones: Derived from cholesterol. Therefore, they are non-polar and can cross the membrane, They bind to receptor intracellularly, because of this they can cause dimerization and directly alter DNA and mRNA in cells influencing protein transcription. i.e Estrogen, Cortisol, Aldosterone
Amino acid-derivatives hormones: Derived from the addition or modification of one or two amino acids. i.e Thyroid hormones (Tyrosine + some I ions) and binds intracellularly
They can bind both intracellularly and to GPCR
Include catecholamines epinephrine and norepinephrine which bind to GPCRs
Hypothalamus and Anterior pituitary
- GnRH
- GHRH
- TRH
- CRF
what is the exception?
Hormones released by both on their reaction
how does the hypothalamus pass hormones to pituitary receptors?
Hypophyseal Portal System in a blood vessel that connects both and transmits the hormones to their AP receptor
- Gonadotropin-Releasing Hormone: Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH)
- Growth Hormone-Releasing Hormone: Growth Hormone (GH)
- Thyroid-Releasing Hormone (TRH): Thyroid Stimulating Hormone (TSH)
- Corticotropin-Releasing Factor (CRF): Adrenocorticotropic Hormone (ACTH)
Exception: Prolactin-Inhibition Factor (PIF) is Dopamine directly secreted from the hypothalamus and causes a decrease in prolactin
Mneumonic FLAT PEG
which ones are Tropic?
Tropic Hormones: act on organs to release another hormone
FSH
LH
ACTH
TSH
Direct Hormones:
Prolactin
Endorphins
GH
gigantism vs acromegaly
Excess GH
Gigantism: In childhood
Acromegaly: In Adults (happens in smaller bones)
Posterior Pituitary
What hormones are released and why are they s.
And where are they made?
Stores Antidiuretic Hormone (ADH) and Oxytocin (made in the hypothalamus)
ADH: released because of low blood pressure (sensed by baroreceptors) or increased blood osmolarity (sensed by osmoreceptors)
= Increase in reabsorption of h2o because permeability of renal collecting ducts
Oxytocin: promotes uterine contraction by positive feedback. It can also be released by nipple sucking
The Thyroid
two main functions?
what hormones involved, what do they do and how?
controlled by TSH
Controls basal metabolic rate because it releases triiodothyronine (T3) and Thyroxine (T4): produces by Tyrosine + Iodine from the follicular cells. (use negative feedback)
- Increase = Increase in cellular respiration
Calcium Homeostasis: by releasing calcitonin from the parafollicular cells. It decreases plasma Ca levels by increasing Ca excretion from kidney, and storage of calcium in the bone, and decreasing Ca absorption from the gut
Hypothyroidism and Hyperthyroidism
why does it happen? symptoms?
Hypothyroidism (cretinism): because of inflammation or iodine deficiency.
symptoms: decreased HR, respiration, and temperature. weight gain
Hyperthyroidism: because of Thyroid overstimulation or tumor.
Symptoms: opposite of hypothyroidism
Parathyroid Glands
hormone? what does it do? why?
whats polydipsia?
Parathyroid Hormone (PTH): opposite to calcitonin it increases the Ca level in blood
how: increases absorption of Ca in the gut via Vitamin D, increases osteoClast activity (break down bone) and Increases Ca reabsorption in the kidneys
polydipsia: increased thirst
Adrenal Cortex
what type of hormones? the 3s
- Glucocorticoids
- Mineralocorticoids
- Cortical sex hormones
Secrete corticosteroids divided into: Sugar, Salt, Sex
- Glucocorticoids (regulate glucose levels): Cortisol and Cortisone alertness hormones need to raise glucose blood levels
- Mineralocorticoids (Salt and water homeostasis): Aldosterone affects the kidneys because it increases sodium reabsorption in the distal convoluted tubule and collecting duct of the nephron. Increases blood pressure (water follows the Na ions)
- Cortical Sex Hormones: estrogen in males, testosterone in females
Renin-Angiotensin-Aldosterone complex
Blood Pressure causes Juxtaglomerular cells (baroreceptors) of the kidney to secrete renin and transform angiotensinogen into angiotensin 1. A1 is converted to A2 by antiotensin-converting enzyme (ACE) which stimulates Adrenal Cortex to secrete aldosterone and increase Na reabsorption to increase plasma volume
Adrenal Medulla Hormones
Catecholamines: Epinephrine and norepinephrine (amino-acid derivative)
Increases blood glucose, heart rate, dilate bronchi
Pancreas:
- Insulin
- Glucagon
- Somatostatin
secreted from what cell?
Insulin (beta): Lowers blood glucose, promote ANAbolic processes
Glucagon (alpha): (fasting) Increases blood glucose, glycogen breakdown.
Somatostatin (delta): supresses glucagon and insulin
Kidney Hormones
Erythropoietin: stimulate bone marrow to produce erythrocytes
Pineal Gland Hormones
Melatonin: controls circadian rhythms
