Physiology wk2 Flashcards
(61 cards)
what is neuroendocrinology
the combination of the nervous system + endocrine system
what does the nervous system do
uses neurotransmitters to relay messages from one nerve tissue to another, or nerve to a tissue
how do hormones act
they are released into the blood by endocrine glands, they then bind to specific receptors to exert effect
what affects the effect of hormones on a tissue
plasma concentration, it alters their access to target tissue by either allowing greater access or restricts it
what is plasma concentration determined by
Rate of secretion of hormones from endocrine gland
Rate of metabolism/excretion of hormone
Quantity of the transport protein
Changes in plasma volume
what two types of influence do endocrine glands cause
they can either interfere or reinforce
what does the magnitude of effect depend upon
Concentration of hormones
Number of target receptors
Affinity of receptor to hormone
plasma concentration/volume
what is down-regulation
decrease in receptors in response to high concentration of hormone
what is up-regulation
increase in receptor number in response to low concentration of hormone
what is the mechanism of steroid hormone action
- Hormone passes through membrane
- Hormone binds to receptor protein in cytoplasm/nucleus
- Hormone-receptor complex binds to hormone response element on DNA regulating gene transcription
- Protein synthesis
- Change in protein synthesis is cellular response
what are the steps of glucose membrane transport mechanism
1.Insulin binds to the extracellular domain of the alpha-subunit of insulin receptor
2.The beta-subunit of one insulin receptor phosphorylates the other, allowing insulin response proteins to be activated
3.Phosphorylated insulin response proteins activate glycogen synthase
4.Glycogen synthase converts glucose into glycogen
what is the hypothalamus
this is the sector of the brain that controls secretion of the pituitary glands
what hormones does the anterior pituitary gland secret
- Adrenocorticotropic hormone (ACTH)
- Follicle-stimulating hormone (FSH)
- Luteinizing hormone (LH)
- Melanocyte-stimulating hormone (MSH)
- Thyroid-stimulating hormone (TSH)
- Growth hormone
what hormones does the posterior pituitary gland secret
*Oxytocin
*Antidiuretic hormone (ADH) – reduces water loss from the body, release is caused by high plasma osmolality and low plasma volume
what does aldosterone do
helps to regulate your blood volume/pressure by managing levels of Na and K in blood
how is aldosterone activated
- low plasma volume and blood pressure
- secretes renin at the kidney
- activates ANGIOTENSIN 1
- acted on by ACE (angiotensin converting enzyme)
- activates ANGIOTENSIN 2
- triggers aldosterone
what is the definition of bioenergentics
the flow and exchange of energy within a living system, conversion of substance into useable energy
what is the definition of metabolism
the sum of all chemical reactions within the body
what are the two types of metabolism
anabolic - synthesis of molecules
catabolic - breakdown of molecules
what does endergonic mean
requires energy to be added to the reactants (pushing a ball up a hill)
what does exergonic mean
this releases energy (pushing a ball down a hill)
what is special about coupled reactions
they use the liberation of energy from an exergonic reaction to drive and endergonic reaction
oxidation-reduction reactions are always coupled
what is oxidation
the removal of an electron
what is a reduction reaction
the gaining of an electron