unit one endocrine system Flashcards
what does the endocrine system do?
it acts with the nervous system to coordinate and integrate activity of the body cells via hormones
endocrinology
study of hormones and endocrine organs
what does the endocrine system control and integrate?
- reproduction
- growth and development
- maintains electrolyte, water, and nutrient balance of blood
- regulation of cellular metabolism and energy balance
- mobilization of body defenses
what is the main difference between exocrine and endocrine glands?
endocrine glands lack ducts
what organs and glands are included in the endocrine system?
- pituitary
- hypothalamus
- thyroid
- parathyroid
- adrenal
- pineal gland
- pancreas
- gonads
- placenta
hormones
long-distance chemical signals
autocrines
same cells that secrete them
paracrines
cells other than those that secrete them
classes of hormones?
- amino acid-based hormones, water soluble
- steroids, lipid soluble
target cells
anything that has a receptor for that hormone
Characteristics of water-soluble hormones
- must have a receptor because that can’t pass the plasma membrane
- second messangers, cAMP and PIP2 calcium
Characteristics of lipid soluble hormones
- can act on receptors that directly activate the gene
steps for Cyclic AMP?
- bind to receptor
- activate a G protein
- G protein activates adenylate cyclase
- adenylate cyclase converts ATP to cAMP
- cAMP activates protein kinases
- phosphorylated proteins are activated or inactivated
- cAMP degenerates phosphodiesterase
steps for PIP2 calcium?
- protein G activates phospholipase C
- phospholipase splits PIP2 into diacylglycerol (DAG) or inositol triphosphate (IP3)
- calcium ions act as another messenger
lipid soluble steps?
- receptor hormone complex enters nucleus and binds to DNA
2. initiates DNA transcription
what the the three different endocrine gland stimuli and what are they associated with?
- humoral- blood
- neural- nervous system
- hormonal- 1 can release another
what three factors do target cell activation depend on?
- blood levels of hormone- up and down regulation
- relative number of receptors on or in the target cells
- affinity (strength) of binding
concentration of circulating hormone reflects?
- rate of release
2. speed at which it is inactivated and removed from body
what are the three different types of hormone interactions and how do they work?
- synergistic- together
- permissive- 1 sets of for the next hormone
- antagonistic- against each other
what does cell response depend on?
the amount of hormone and the combination of all hormones
when do tissues respond?
when hormone concentrations are at a certain normal level
anterior lobe
produces and secretes own hormones
regulated by hypothalamus and negative feedback
posterior lobe
stores and secretes hotness produced by the hypothalamus
what is sent from the anterior lobe
the anterior pituitary is controlled via releasing and inhibiting hormones transported through the?
hypothalamo-hypophyseal portal system
what does corticotropin- releasing hormone (CRH) stimulate?
adrenocorticotropic hormone (ACTH)
what does Thyrotropin-releasing hormone (TRH) stimulate?
thyroid stimulating hormone (TSH)