Endocrine System Flashcards
What experiment did Arnold Berthold conduct in 1949?
He conducted the first experiment demonstrating that the testis contained a substance responsible for altering the behavior and phenotype of roosters.
Who was the first to coin the term “Hormone”?
Ernest Starling
What is hormone in Greek?
Ormao meaning stir up/excite.
What is the endocrine system?
A system that coordinates the biological functions underlying physiological and behavioral processes through chemical signals called hormones.
What are the effects of hormones? (2)
- Developmental (organizational)
- Functional (activational)
What is autocrine?
Effects of hormones on the gland of secretion.
What is paracrine?
Effects of hormones on nearby cells.
What is endocrine?
Effects of hormones secreted in the bloodstream.
What is ectocrine?
Effects of hormones secreted into the environment.
What are the Ultimate levels of analysis? (3)
- Evolutionary theory
- Sexual Selection
- Parental Investment
What are the Proximate levels of analysis? (3)
- Behaviors
- Systems Levels
- Cellular and Molecular
What is the hypothalamus?
Brain region controlling the pituitary gland.
What is the pituitary gland?
Gland that secretes many different hormones, some of which affect other glands.
What is the thyroid gland?
Gland that affects metabolism among other things.
What are the parathyroids?
Glands that help regulate the level of calcium in the blood.
What are ovaries?
Glands that secrete female sex hormones.
What is the pancreas?
Organ that helps regulate the level of sugar in the bloodstream.
What are the adrenal glands?
Glands that help trigger fight or flight response.
What are the testis?
Glands that secrete male sex hormones.
What does the hypothalamus secrete? (3)
Antidiuretic hormone (ADH), oxytocin and regulatory hormones.
What does the pineal gland secrete?
Melatonin.
What do the parathyroid glands secrete? (on the posterior surface of the thyroid)
Parathyroid hormone (PTH).
What does the heart secrete?
Natriuretic peptides: ANP and BNP.
What does the kidney secrete?
Renin Erythropoietin (EPO) Calcitriol.
What does the adipose (fatty) tissue secrete? (2)
Leptin and resistin.
What do the pancreatic islets release? (2)
Insulin and glucagon.
What do the gonads release?
Male: Androgens (testosterone primarily) and Inhibin
Female: Estrogen, progestins and inhibin.
What does the anterior lobe of the pituitary gland release? (7)
ACTH, TSH, GH, PRL, FSH, LH and MSH.
What does the posterior lobe of the pituitary gland release? (2)
Oxytocin and ADH.
What does the thyroid release? (3)
Thyroxine (T4)
Triiodothyronine (T3)
Calcitonin (CT)
What does the thymus release? (atrophy in adulthood)
Thymosins
What does the adrenal medulla secrete? (adrenal gland) (2)
Epinephrine (E)
Norepinephrine (NE)
What does the adrenal cortex secrete? (adrenal gland) (4)
Cortisol
Corticosterone
Aldosterone
Androgens
What hormones control food intake and where do they come from? (3)
- Adipose tissue = Leptin
- Pancreas = Insulin
- Stomach = Ghrelin
What are the four hormone classifications?
- Steroids
- Peptides
- Monoamines
- Lipid Based
What is the base of all steroids?
Cholesterol
How do you get estrogen?
Androgens (testosterones) + Aromatase
What makes steroids different if they all come from cholesterol?
The enzyme around them.
What happens when you combine testosterone and 5α-reductase?
You get a different androgen (dihydrotestosterone) which is stronger than testosterone.
What happens if a male has aromatase in male breast tissue?
Production of estrogen and growth of breasts.
How do peptide hormones form?
Peptides form as a result of ribosomes attaching to mRNA and producing the hormones from the genetic translation.
What are the two pre-pro peptides?
- Pro-Insulin
- Proopiomelanocortin (POMC)
Where is POMC found mostly? (2)
- Hypothalamus
- Pituitary gland
What are five monoamines?
- Serotonin
- Melatonin
- Dopamine
- Epinephrine
- Norepinephrine
What is a well-known neurotransmitter that acts as a lipid-based hormone?
Endocannabinoids
What do endocannabinoids do?
Slow things down synaptically.
What kind of loops do hormonal systems have?
- Positive Loop
- Negative Loop (most systems)
What happens in the negative loop?
You down regulate the system.
What happens in positive loops?
You activate the system.
What are the two gonadotropins?
- LH
- FSH
What is HPG axis?
Hypothalamic Pituitary Gonadal Axis (HPG)
What is ovulation?
Positive stimulation of the HPG axis.
What does ovulation cause?
Release of gonadotropins.
What does the release of gonadotropins cause?
Raises hormone levels and starts ovulation.
What does the hypothalamus act as?
The director. Everything starts at the hypothalamus.
Steps in HPG axis? (3)
- GnRH (peptide) acts on the anterior pituitary.
- The pituitary gland releases gonadotropins.
- The gonadotropins raise hormone levels through the gonads.
HPA Axis?
Review by self-notes.
