Endocrine System Flashcards
Differences between Endocrine and Nervous System: Endocrine
slower, longer effect, long distance communication
Differences between Endocrine and Nervous System: Nervous
rapid, short term, short distance communication
Hormones
chemical messengers released into bloodstream that act on distant target cells
Pheromones
mark food trails and territory, predators, and mates
Target cells(what and location)
contain receptors for specific hormones can be located in the plasma membrane or inside cell
Secretin
hormone released by S cells of duodenum to go to the pancreas to signal release of bicarbonate
Polypeptides
Water Soluble (hydrophilic)
Steroids
Lipid soluble (hydrophobic)
Amines
Most are water soluble, but some are not
Water soluble hormones act on _____ because….
Water soluble hormones act on membrane proteins because they cannot pass through the lipid bilayer.
Lipid soluble hormones act on ____. They reach them by….
Lipid soluble hormones act on intracellular proteins. They cannot move well through the bloodstream without transport proteins, but they can easily pass through the phospholipid bilayer.
The function of a hormone depends on…
which receptor it binds to.
Epinephrine going to a Beta cell
dilation of blood vessels
Epinephrine going to an Alpha cell
constriction of blood vessels
Neurosecretory Cells
Release neurohormones from hypothalamus to bloodstream of the posterior section of the pituitary gland.
Hypothalamus
receives signals from neurons in brain and appropriates the correct endocrine response
Posterior Pituitary
direct extension of the hypothalamus
Peptide Hormones Produced and Sent to Posterior Pituitary
ADH, Oxytocin
ADH Phys/Behavioral
acts on kidneys to reduce water loss in urine. Helps in creation of pair bonds
Oxytocin Phys/Behavioral
acts on mammary glands and uterine muscles after receiving stimulus of suckling in order to release milk. Behaviorally stimulates maternal care.
Anterior Pituitary receives signals by…
Neurohormones (releasing hormones) from hypothalamus enter portal beings and trigger the release of AT hormones.
Tropic Hormones (& examples)
Indirect; regulates functions of other endocrine glands/cells. (FSH, LH, TSH, ACTH, GH)
Non-tropic hormones (& examples)
Directly acts on target cells. (Prolactin, MSH, GH)
The Story of the Thyroid Gland (1/3)
The hypothalamus releases thyrotropin (TRH) into the anterior pituitary gland.
The Story of the Thyroid Gland (2/3)
The anterior pituitary gland releases Thyroid Stimulating Hormone (TSH) to the thyroid gland.
The Story of the Thyroid Gland (3/3)
The thyroid gland itself releases T3 and T4 to body cells to increase metabolism and increase body heat.
Hyperthyroidism
Thyroid overreacts, and causes increased temperature, and decreased weight and decreased laziness.
Hypothyroidism
The thyroid does not function as much as it should, causing a lowering of body temperature, increased weight, and increased laziness.
Graves Disease
autoimmune disease that continually stimulates TSH, case of hyperthyroidism
Goiter
increased T3 and T4 production, thyroid may increase in size.
Melanocyte stimulating hormone (MSH)
controls pigment distribution in amphibians, and for mammals, both that and hunger/metabolism.
How does insulin lower blood glucose levels?
It activates GLUT 4 transporters in cells so glucose can enter cell.
The adrenal gland consists of 2 parts
the adrenal medulla and the adrenal cortex
The adrenal cortex produces: (kind of hormones and type of stress)
STEROID hormones glucocorticoids and mineral corticoids LONG term stress
The adrenal medulla produces: (Kind of hormones and type of stress)
AMINE hormones including epinephrine and norepinephrine SHORT term stress
Long Term Stress Pathway (1/3)
Hypothalamus releases corticotropin releasing hormone (CRH) through portal veins to anterior pituitary
Long Term Stress Pathway (2/3)
Anterior Pituitary releases adrenocorticotrophic hormone (ACTH) to adrenal cortex
Long Term Stress Pathway (3/3)
Adrenal Cortex releases mineralcorticoids and glucocorticoids
Effects of mineral corticoids: e.g: ____(2 functions)
aldosterone: retention of sodium ions and water by kidneys, increase in blood pressure and volume
Effects of glucocorticoids: e.g: ____(2 functions)
Cortisol: suppression of immune system and increase in blood glucose levels
Short term stress controlled by
adrenal medulla activated by the amines and nerve signals. Epinephrine and non epinephrine stimulate the sympathetic response.
3 Categories of sex hormones
Androgens (testosterone), Estrogens, Progestins (progesterone)
Synthesis of sex hormones controlled by:
FSH and LH from the anterior pituitary.
The Story of Sex Hormones (1/3)
Neurosecretory cells of hypothalamus receive signal to release Gonadotropin releasing hormone (GnRH)
The Story of Sex Hormones (2/3)
Anterior pituitary releases Lutenizing hormone and follicle stimulating hormone (LH and FSH)
The Story of Sex Hormones (3/3)
Gonads produce and release estradiol/progesterone from ovaries, or testes release testosterone
Arnold Adolph Berthold Experiment
Chicks’ secondary characteristics rely on which gonads they have, even if transplanted.
Alfred Jost Experiment
Embryonic gonad removal defaults to the female form.
Growth Hormone
plays important role in bone development
