Endocrine Flashcards
1
Q
Characteristics of a Hormone
A
- Made in glands or cells
- Transported by blood
- Distant targets
- Activates a physiological response
2
Q
Tropic Hormone
A
- Acts on other endocrine glands to produce more hormones
- Ex. hypothalamus and ant. pituitary
3
Q
Non-Tropic Hormone
A
- Acts directly on effector organs
- Ex. thyroid, adrenals, pancreas
4
Q
Where do Endocrine Glands Secrete Hormones
A
- Directly into the blood
- No ducts
5
Q
Neuro-secretory Cell
A
- Secrete neuro-hormones or neuro-peptides
6
Q
Peptide Hormone
A
- Made of proteins
- Cannot cross the lipid membrane bc it is water soluble
- Bind to surface receptors and activates second messenger response
- Creates a response within the receiving cell
- Quick acting, short half life
7
Q
Life Cycle of a Peptide Hormone
A
- Preprohormone: large, inactive
- Prohormone: Post-translational modification, still inactive
- Hormone: Final cuts have been made before it leaves the cell and enters the blood
8
Q
Steroid Hormone
A
- Cholesterol base
- Can enter the target cell because it is lipophilic
- Attach to nuclear receptors
- Activate DNA for protein synthesis
- Slower acting, longer half-life
9
Q
Amine Hormone
A
- Tryptophan or Tyrosine amino acid base
- Ring structure
- Thyroid hormones behave similar to steroids, catecholamines behave similar to peptides
10
Q
Synergism
A
- Multiple stimuli trigger release
- The stimuli act together and are more than additive
- One- sided, so TH will increase epi effects, but epi won’t increase TH effects
- This stops the positive feedback loop from running away
11
Q
Permissiveness
A
- Needs a second hormone to create a full response
12
Q
Antagonism
A
- Other hormones oppose it with opposite effects
- Ex. glucagon and insulin
13
Q
Three Levels of Endocrine Control
A
- Hypothalamic from CNS
- Pituitary from hypothalamic trophic hormones
- Endocrine gland from pituitary trophic hormones
14
Q
Factors Affecting Hormone Secretion
A
- Emotional state
- Disease state
- Stress
- Diet
- Sleep
- Body cycles
15
Q
Hyposecretion
A
- Too little of a hormone is being secreted
- Abnormal hormone concentration in blood plasma
- Primary: Gland is abnormal and not secreting properly
- Secondary: Not enough trophic hormones are reaching the gland for normal secretion
16
Q
Hypersecretion
A
- Too much hormone is being secreted
- Abnormal hormone concentrations in blood plasma
- Primary: gland is abnormal and secreting too much
- Secondary: Excessive trophic hormones stimulate too much gland secretion
17
Q
Hypothalamus
A
- Maintains hormone homeostasis
- Controls ant. pituitary
18
Q
Posterior Pituitary
A
- Stores hormones made in the hypothalamus
- Releases hormones when neuron is excited
19
Q
Anterior Pituitary
A
- When a hypothalamus neuron is stimulated, hypophysiotropic hormones are released into systemic arteries going to the ant. pituitary
- These cause the release of pituitary hormones
20
Q
Thyroid Gland
A
- Largest pure endocrine gland
- Produces TH and calcitonin
- Requiresiodine
21
Q
Parathyroid Glands
A
- Small glands attached to the thyroid
- Secrete PTH and vit. D
22
Q
Adrenal Glands
A
- Separated into cortex and medulla
- Cortex produces steroids, corticoids, and androgens
- Medulla produces epinephrine
23
Q
Pancreas
A
- Exocrine acinar cells secrete digestive enzymes
- Endocrine cells for islets of Langerhans with alpha and beta cells
- Alpha cells (15%) produce glucagon
- Beta cells (80%) produce insulin
- Delta cells (5%) secrete somatostatin, which blocks secretion of insulin and glucagon
24
Q
Absorptive Feeding State
A
- 3-4 hours after eating
- Insulin is in control
- Nutrients are moved into cells and storage
25
Q
Post-Absorptive Feeding State
A
- 4+ hours after eating
- Glucagon is the main controller
- Nutrients are moved out of cells and storage
