CC2 LAB: Endocrinology (Quiz 3) Flashcards
Study of Hormones
ENDOCRINOLOGY
GENERAL FUNCTIONS OF ENDOCRINOLOGY:
- Regulatory: constancy of chemicals
- Morphogenesis: Growth/Development
- Integrative
Released because of critical levels of ions/Nutrients
Humoral Stimulus
Released caused by neural input
Neural Stimulus
Released caused by another hormone
Hormonal Stimulus
Release hormones to blood (by diffusion)
Endocrine glands
Could be Strictly endocrine or organs that have hormone production as one of its function
Endocrine glands
From the Greek word “Hormon” meaning
“to set in motion”
Secreted by cells to extracellular fluid
Hormones
Long distance chemical signals
Hormones
Hormones regulate metabolic functions which provide changes in:
- membrane permeability 2. stimulate protein
- synthesis regulatory molecules
- activate or deactivate enzyme
- induce secretory activity 6. stimulate mitosis
Action Categories: synthesize in one location
Endocrine
Action Categories: synthesized in the endocrine cells
Paracrine, Autocrine & Juxtacrine
Action Categories: released to lumen of gut, binds to cells of gut
Exocrine
Action Categories: synthesized in neurons
Neurocrine
Action Categories: synthesized in nerve endings
Neuroendocrine & Neurotransmission
Action Categories:
Enters circulation and binds specific cells at distant site to elicit response
Endocrine
Action Categories: Enters interstitial spaces and binds specific receptor in adjacent gland for its effect
Paracrine
Action Categories: Enters interstitial space and binds specific receptor cell of the origin to autoregulate its function
Autocrine
Action Categories: Remains associated with plasma membrane and acts on adjacent receptor by direct cell to cell
Juxtacrine
Action Categories: moves to extracellular space, binds to receptors in nearby cells for its action
Neurocrine
Action Categories: enters the circulation, interacts with receptor of cells of distant sites
Neuroendocrine
Action Categories: crosses synapse and binds to receptors in another neuron affecting its action
Neurotransmission
cyclal patterns of hormone release
Biorhythms
Biorhythms types
- Circadian/Diurnal
- Infradian – occur over a period of time greater than 24hours
- Ultradian – less than 1 day
Hormone concentration is controlled by:
- Rate of production/Synthesis
- Efficiency of delivery
- Metabolism
Chemical Categories: Hydrophobic (non-water soluble)
Steroids
Chemical Categories: Water soluble
Polypeptides
Chemical Categories: Freely circulating
Amino Acid derived
Example of Steroids
Cortisol
Progesterone
Estrogen
Testosterone
Aldosterone
Example of Polypeptides
PTH
Insulin
LH
FSH
TSH
TRH
ACTH
Prolactin
GH
Calcitonin
Example of Amino Acid Derived
Epinephrine
Norepinephrine
T3
T4
Chemical Categories: Bound to proteins
Amino Acid derived
Chemical Categories: Circulate freely & Only when needed
Polypeptides
Mechanism of Hormone Action
- Cell Surface Receptors
- Nuclear Receptors
Interaction of hormones to target cells:
- Permissiveness
- Synergism
- Antagonism
hydrophobic, from cholesterol and needs a carrier protein
Steroids
hydrophilic, no need of carrier and usually in low concentrations
Proteins
when 1 hormone cannot exert its full effect without another hormone being present
Permissiveness
more than one hormone produce same effects on target cells
Synergism
one hormone opposes the action of another hormone
Antagonism
Target Cell Specificity response depends on
- Blood levels of hormones
- number of receptors
- Affinity of receptors to
hormones
