Lecture 1-Endocrine System Flashcards
1
Q
Endocrine System
A
- Consists of endocrine glands, organs, and tissues containing hormone secreting cells
- EX of glands- pituitary, thyroid, adrenal, parathyroid, and pineal glands
- EX of organs and tissues- hypothalamus, thymus, pancreas, ovaries, testes, kidneys, stomach, liver, small intestine, skin, heart, adipose tissue, and placenta
2
Q
Hormones
A
- Bodys chemical messengers
- secreted by cells into the interstitial fluid (tissue fluid) and diffuse in blood
- Act on target tissues, then bind to specific proteins (Receptors)
3
Q
Hormone Concentrations (3)
A
- Physiological Concentrations
- Pathological Concentrations
- Pharmacological Concentration
4
Q
Hormone types (2)
A
- Circulating Hormones (most common)
2. Local Hormones–> paracrine and autocrine
5
Q
Circulating Hormones
A
- Secreted into the blood
- Carried to distant TARGET TISSUES
- bind to receptors in target cells
- EX-Thyroid hormones. they are produced and secreted by the thyroid gland and act on bones (growth)
6
Q
Local Hormones-Autocrines
A
- Secreted into the extracellular fluid- do not enter blood
- Hormones act on the same cell that secretes them because they can not travel long distances
- EX- cytokine interleukin-1 (released by monocytes and act on monocytes)
7
Q
Local Hormones-Paracrines
A
- Secreted into extracellular fluid-do NOT enter the blood
- Act on neighboring cells–>diffuse short distance
- EX- Testosterone- (released from the testes)
8
Q
Chemical Classes of Hormones (2)
A
- Water-soluble Hormones
2. Lipid-soluble Hormones
9
Q
Water-Soluble Hormones
A
- want to be in Aqueous environment
- stored in secretory vesicles (granules) inside the cells
- Stimulus of the cells cause their release
- bind to receptors on the surface of target cells
- AMINE HORMONES=synthesized by modification of certain amino acids (Norepinephrine/epinephrine/dopamine from tyrosine
- PEPTIDE/PROTEIN HORMONES= amino acid polymers. peptide>100, protein
10
Q
Eicosanoid Hormones
A
- Water-soluble hormone
- derived from fatty acid (arachidonic acid)
- local hormones (paracrine)
- Not stored in vesicles
- Inactivate quickly near site of synthesis, very short responses
11
Q
Water-Soluble Hormones: Transport and Excretion
A
- Do not have a problem with blood, diffuse easily
- Transport- free in plasma. Quickly broken down by enzymes, regulate activities
- Metabolism/Excretion: metabolized in liver and excreted by the kidneys
- NSAIDS= EXAMPLE
12
Q
Lipid Soluble Hormones
A
- Not stored. stimulus causes synthesis and secretion into the blood
- Bind to receptors in the cytoplasm or nucleus
13
Q
Steroid Hormones
A
- Lipid Soluble Hormone
- Synthesized from cholesterol
- EX- testosteron, aldosterone, cortisol, estrogen
14
Q
Thyroid Hormones
A
- Lipid-soluble hormone
- Synthesized by attaching iodine to tyrosine
- EX: T3/T4
15
Q
Lipid Soluble- Transport and Excretion
A
-Transport: they circulate bound to transport protein (TP).
TP makes them water soluble, Not quickly removed from the blood, produce a prolonged effect
-Excretion: Kidneys or Liver
