Chapter 7- Endocrine System

hormones

secreted chemical messengers;
 travel in blood
 act on target tissues
 low concentrations

control enzymatic reactions, ion transport, and gene expression

what are the functions of hormones?

pancreas

what organ is both exocrine and enocrine?

pancreas, thyroid, adrenals, parathyroid, pituitary, gonads

what organs produce hormones?

varied

hormone binding elicits ________ cellular responses

half-life

the amount of time required to reduce the concentration/activity of a hormone by one-half

reduced secretion, endocytosis, enzymatic degradation into inactive metabolites

mechanisms for termination of hormone actions

synthesis or structure

what is hormone classification based on?

peptide/proteins

hormones formed from linked amino acids

steroid hormones

hormones derived from cholesterol

amine hormones

synthesized from single amino acids,
 tyrosine and tryptophan

storage, synthesis, and release

functions of peptide hormones

peptide

what type are the majority of hormones?

prephohormones

inactive precursor with signal sequence, directing to ER

prohormones

inactive precursor with signal sequence removed; packaged into vescles; stored until needed

binds to cell surface receptors to signal transduction pathways

mechanism of action for peptide hormones

adrenal cortex, gonads, skin, placenta

location of steroid hormone production in the body

yes

do lipophilic molecules move easily through membranes?

increase, extend

Carriers in the blood:
_________ solubility and _______ half lives

thyroid hormones

synthesized from tyrosine and iodine.
 Involved in metabolism, growth, development

Catecholamines

Dopamine, Norepinephrine, Epinephrine

melatonin

Regulates circadian rhythms and immune function

sensor, integrating/control center

what roles does the cell play in simple endocrine relex

hormone

what is the output signal in simple endocrine reflex?

parathyroid hormone

hormone that acts on bone, kidney, and intestines to increase blood Ca2+.

calcitonin

opposite of PTH, allows calcium to deposit in bone or be excreted

pancreatic beta cells

release insulin due to stimuli such as blood glucose levels

anterior pituitary

epithelial tissue, endocrine organ; “adenohypophysis”

posterior pituitary

extension of neural tissue; secretes hormones made in the hypothalamus; “neurohypophysis”

vasopressin

aka. Antidiuretic hormone (ADH); regulates water balance in the kidney by inserting aquaporin water channels

oxytocin

controls milk ejection during breastfeeding and uterine contractions during childbirth

vasopressin and oxytocin

2 primary hormones produced by the posterior pituitary

hypothalamic releasing hormones

secreted into portal system and to anterior pituitary where they act on target cells

prolaction

hormone that functions in milk production

thyrotropin

hormone that functions in increasing the production of T3 and T4 thyroid hormones

adrenocorticotropin

hormone that controls cortisol

growth hormone

hormone that promotes growth

gonadotrophins

Reproductive hormones including Follicle- Stimulating hormone (FSH) and Luteinizing hormone (LH)

prolactin, thyrotrophin, adrenocorticotrophin, growth hormone, gonadotropins

What type of hormones are secreted by the anterior pituitary?

short loop feedback

Pituitary hormones feedback back to hypothalamus to inhibit

long loop feedback

hormones of target endocrine gland feedback back to pituitary and/or hypothalamus