The Endocrine System Flashcards
(108 cards)
The two systems that coordinate human body activities
Nervous and endocrine
Nervous system is quick in response and uses _________.
Neurotransmitters
Endocrine system is slow in response and uses _______ (chemical messengers in blood) – discipline is called ________.
- Hormones
- Endocrinology
Endocrine glands are _______ and unimpressive.
Small
The two kinds of glands in human body
Exocrine and endocrine
________ include pituitary, thyroid, parathyroid, adrenal, pineal and thymus; also gonads and pancreas.
Endocrine glands
Walls of stomach and small intestine, kidney, heart, hypothalamus are also in this category – also called ____________.
Neuroendocrine organs
_______ are chemical substances secreted by cells into extracellular fluid, are transported by blood and affect target organs and regulate metabolic activities.
Hormones
Example of _________ fits hormone actions
Airborne waves and appliances
Categories of hormones
- Amino acid based (water soluble)
- Steroid based (fat soluble)
Hormones cause changes in plasma membrane ________.
Permeability
Hormones cause synthesis of proteins or _______ molecules.
Regulatory
Hormones cause ______ activation or deactivation.
Enzyme
Hormones cause _______ of secretory activities of cells.
Induction
Hormones cause stimulation of ______.
Mitosis
For hormone action, _____ rather than speed is more important.
Duration
Amino acid based hormones cannot enter cell membrane because they are _________.
Water soluble
Amino acid based hormones work though a __________.
Second messenger
Most understood mechanism is the ______________.
Cyclic adenosine monophosphate (cAMP) mechanism
Three proteins involved:
- A ________ in the target cell plasma membrane
- A _________ (a G protein)
- An ________ (adenylate cyclase)
- Hormone receptor
- Signal transducer
- Effector enzyme
Endocrine cell –>
Hormone (________) in blood –>
Hormone binds to target cell membrane receptor –>
Receptor bound effector (_______) converts an ATP into cAMP (__________) –>
cAMP then alters preexisting intracellular enzyme activities and other properties of target cells
- First messenger
- Adenylate cyclase
- Second messenger
Examples of hormones using the ______ mechanism
ACTH, TSH, PTH, glucagon, calcitonin, FSH, LH, epinephrine, norepinephrine
cAMP
The Pituitary Gland (Hypophysis) is located at the _____ of the brain and weighs about _____.
- Base
- 0.5 g
Endocrine cells –>
Steroid hormones in blood –>
Hormone enters target cell membranes –>
Hormone binds to an ________ complex which in turn binds to an acceptor molecule on the __________
- Intracellular receptor-chaperon
- DNA in the nucleus