Porth's Chapter 31
What are hormones?
Highly specialized organic molecules produced by endocrine organs that exert their action on specific target cells
The easiest way to measure hormone levels during a specific period are by either blood samples or urine tests to measure ? or ?.
metabolites, hormone levels
What does hormone response element do?
Activate or suppress intracellular mechanisms such as gene activity.
In an adult with acromegaly, a growth hormone secreting tumor is suspected. What diagnostic test would be used for this client?
A GH suppression test
Hormones can be synthesized by both vesicle-mediated pathways and non-vesicle-mediated pathways. What hormones are synthesized by non-vesicle-mediated pathways?
Androgens and estrogens
When hormones act locally rather then being secreted into the bloodstream, their actions are termed what?
Autocrine and paracrine
The endocrine system is closely linked with the nervous system. What neurotransmitter can also act as a hormone?
Epinephrine
The hormone levels in the body need to be kept within an appropriate range. How is this accomplished for many of the hormones in the body?
Negative feedback loop
What is hypophysis?
The hypothalamus and the pituitary
What is paracrine?
A hormone that acts on cells that produced it
To prevent the accumulation of hormones in our bodies, the hormones are constantly being metabolized and excreted. Where are adrenal and gonadal steroid hormones excreted?
Bile and urine
The hypophysis is a unit formed by the pituitary and the hypothalamus. These two glands are connected by the blood flow in what system?
Hypophyseal portal system
What is second messenger?
Intracellular signal
? hormones attach to intracellular receptors and form a hormone-receptor complex that travels to the cell nucleus to initiate transcription.
Lipid-soluble
Many hormones are measured for diagnostic reasons by using the plasma levels of the hormones. What is used today to measure plasma hormone levels?
Radioimmunoassay methods
Imaging has proven useful in both the diagnosis and follow-up of endocrine disorders. Two types of imaging studies are useful when dealing with endocrine disorders, isotopic imaging and nonisotopic imaging. What is an example of isotopic imaging?
Thyroid sance
Sometimes the measurement of hormones is done through urine sample. What is an advantage of measuring hormone levels through a urine sample rather than a blood sample?
Urine samples are easily obtained
Hormones produce their effects through binding to ?, which in turn are linked to one or more effector systems within the cell.
high-affinity receptors
The endocrine system uses chemical substances called ? as a means of regulating and integrating body functions.
hormones
The synthesis and release or anterior pituitary hormones is regulated by the action of releasing or inhibiting hormones from the ?, which is the coordinating center of the brain for endocrine, behavioral, and autonomic nervous system function.
hypothalamus
The functions of the endocrine system are closely linked with those of the ? system, but the response time is much slower, but longer lasting.
nervous
When hormones act locally on cells other than those that produced the hormone, the action is called ?
paracrine
The structure of a hormone ? varies in a manner that allows target cells to respond to one hormone and not to others.
receptor
The pituitary gland has been called the ? because its hormones control the functions of many target glands and cells.
master gland
Hormones that are released into the bloodstream circulate either as ? molecules or as hormones ? to transport carriers.
free, bound
What is autocrine?
Hormone affecting neighboring cells
What the half-life of a hormone?
The time is takes for the body to reduce the concentration of the hormone by one half
Hormones also can exert an ? action on the cells from which they were produced.
autocrine
