how does the endocrine system act with the nervous system
acts with the nervous system to coordinate and integrate activity of body cells.
- influences metabolic activities via hormones transported in blood responses slower but longer lasting than nervous system responses
whats the 5 things the endocrine system controls and integrates
1- Reproduction
2- growth and development
3- maintence of electrolyre,water, and nutrient balance of blood
4- regulation of cellular metabolism and energy balance
5- Mobilization of body defenses
exocrine glands
produce nonhormonal substances (examples:sweat, saliva) have ducts to carry secretion to membrane surface
Endocrine glands function
produces hormones, lacks ducts
list some endocrine glands
pituitary, thyroid, parathyroid, adrenal, pineal glands
whats a neuroendocrine organ
hypothalamus
name the endocrine organs that have both endocrine and exocrine functions
pancreas, gonads, placenta
what are other tissues and organs that produce hormones
adipose cells, thymus, cells in walls of small intestine, stomach, kidneys, and hear
whats the three endocrine chemical messengers of endocrine system
hormones
autocrines
paracrines
hormones
long-distance chemical signals; tavel in blood or lyph
Autocrine
chemicals that exert effects on same cells that secret them
paracrines
locally acting chemicals that affect cells other than those that secrete them
what are autocrines and paracrines
are local chemical messenger; not considered part of the endocrine system
whats the two main classes of hormones
Amino acid-based hormones
steroids
Amino acid-based hormoes
amino acid derivatives, peptides and proteins
steroids
synthesized from cholesterol gonadal and adrenocortical hormones
whats a possible third class of hormones
eicosanoids, considered a hormone by some scientists but most classify it as a paracrine
what cells are affected by hormones
though hormones circulate systemically, only cells with receptors for that hormone are affected
target cells
tissues with receptors for a specific hormone
what do hormones do to target cell activity
hormones alter target cell activity
hormone action on target cells may do what
alter plasma membrane permability and/or membrane potential by opening or closing ion channels
what can hormones stimulate, activate, and induce
they stimulate synthesis of enzymes or other proteins
activate or deactivate enzymes
induce secretory activity
stimulate mitosis
whats the two ways, depending on their chemical nature and receptor location
Water soluble
lipid-soluble
describe water soluble receptor location
water soluble- all amino acid-based hormones except thyroid hormone)
- act on plasma membrane receptors
- act via G protein second messengers
- cant enter the cell
describe Lipid-soluble receptor location
(steroid and thyroid hormones)
- act on intracellular receptors that dircetly activate genes
- can enter the cell
whats cyclic AMP
a signaling mechanism
describe the cyclic AMP signaling mechanism
- hormone(first messenger) binds to receptor
- receptor activates a G protein
- G protein activates or inhibits effector enzyme adenylate cyclase
- Adenylate cyclase then converts ATP to cAMP (second messenger)
- cAMP activates protein kinases that phosphorylate (add a phosphate) other proteins
- phosphorylated proteins are then either activated or inactivated
- cAMP is rapidy degraded by enzyme phosphodiesterase, stopping cascade
- cascades have huge amplification effect
what can lipid soluble steroid hormones and thyroid hormone diffuse into
into target cells and bind with intracellular receptors
how do lipid-soluble steroid hormones and thyroid hormone can diffuse into target cells and bind with intracellular receptors
receptor-hormone complex enters nucleus and binds to specific region of DNA
- Helps initiate DNA transcription to produce mRNA
- mRNA is then translated into specific protein
- proteins synthesized have various functions
- ex: metabolic activites, structural purposes, or exported from the cell