Endocrine system Flashcards
Communication in the endocrine system is by way of ____
Chemical messages secreted by a collection of _____
hormones, glands
Hormones are grouped into three classes:
Steroids, Protein Hormones / Peptide Hormones, Biogenic Amines
_______:
They are secreted by the gonads, adrenal cortex, and placenta;
Only synthesized on ______;
These hormones can be taken orally;
Steroids, demand
Examples of steroids
estrogen, progesterone, testosterone, adrenal cortex hormones
Examples of protein hormones / peptide hormones
FSH, LH, ADH, oxytocin, insulin, glucagon, and growth hormone
Examples of biogenic amines
thyroxine, epinephrine, prostaglandin
_______:
these hormones are small molecules synthesized by
alteration of the structure of a specific amino acid
Biogenic amines
Functions of hormone
Regulate growth and development
Control the function of various tissues
Support reproductive functions
Regulate metabolism
Function of Hormone
Regulate salt & water balance
Hormone intercellular communication mechanisms is __________
through the bloodstream
Most hormones are _____ into the bloodstream and circulate in very ____
concentration;
Others require a ______ like protein molecule to act as a hormone reservoir for constant level and protection from chemical breakdown
directly released, low,
carrier substance
Examples of specific transport protein:
Cortisol binding globulin, thyroxine binding globulin, sex hormone binding globulin
General carrier proteins bind to hormones generally:
Albumin, Transthyretin (Pre-albumin)
_____ hormones action:
hormone binds onto the receptors generates an intracellular signal or
“___” which change the activity of the proteins that already exists in the cell;
second messenger was used due to insolubility in the lipid layer of plasma membrane
Amine and peptide, second messenger
_____ hormones action:
hormone entry into the cell and activate the genes; cause formation of intracellular proteins to initiate specific functions
Steroid
Negative feedback mechanism:
give response reverse a change of stimulus (slows down or
terminate the process)
Positive feedback mechanism:
involves the acceleration of the
original process
Example of negative feedback mechanism:
Secretion of thyroxin:
anterior pituitary secretes thyroid-stimulating hormone (TSH)
→ thyroid, when stimulated by TSH, secretes thyroxin →
increase level of thyroxin will inhibit the secretion of TSH from the anterior pituitary
Example of positive feedback mechanism:
Secretion of oxytocin:
head of baby pushes against cervix→ nerve impulse to the hypothalamus via spinal cord → release of oxytocin from the posterior pituitary → oxytocin causes
contraction of uterine contractions and pushes baby towards cervix
The hypothalamus serves as a ______ of the endocrine system that controls
the pituitary gland
regulator
______:
located in a loop of the small intestine just below the stomach;
consists of both exocrine and endocrine
functions;
contains exocrine cells (______) that secrete pancreatic enzymes into the small intestine
Pancreas, Islets of Langerhans
β-cells (secrete insulin and ____)
amylin
α-cells in the Islets of Langerhans secretes:
glucagon
β-cells in the Islets of Langerhans secretes:
insulin
Function of amylin:
Decrease blood glucose spikes by slowing down gastric emptying
Deficiency of insulin will lead to:
- Increased hepatic glucose output
- Reduce tissue uptake of glucose (Hyperglycemia and glycosuria)
- Increase lipolysis
(Formation of ketone bodies
Lead to Diabetic Ketoacidosis (DKA))
