Chapter 17 Flashcards
Maintenance of a stable internal environment by self-regulating physiological processes
Homeostasis
How is homeostasis maintained in the body?
endocrine and nervous systems
initial stimulus produces a response that opposes the original stimulus
negative feedback
initial stimulus that produces a response that reinforces the stimulus
positive feedback
what is the communication method of the endocrine system?
secrete hormones into blood
What is the target of stimulation for the endocrine system?
any cell with receptor for the hormone
what is the response time of the endocrine system?
slow; minutes to hours
what is the the effect of stimulation in the endocrine system?
change metabolic activity in cell
what is the range of effect in the endocrine system?
widespread effects throughout body
what is the duration of the response for the endocrine system?
long-lasting, may last after stimulus is gone
What are the general functions controlled by the endocrine system?
maintain homeostasis of blood composition and volume, control reproductive activity, regulate development, growth, metabolism, control digestive processes
How does the endocrine system maintain homeostasis of blood composition and volume?
Regulate amount of substances dissolved within the plasma
How does the endocrine system control reproductive activities?
Development, growth of reproductive system, expression, sexual behavior
How does the endocrine system regulate development, growth, and metabolism?
Regulate roles in cell differentiation and division, control metabolic processes during synthesis and degradation
How does the endocrine system regulate digestive processes?
influence secretory processes and movement of materials
hormones that circulate in blood throughout the body
circulating hormones
hormones that act locally
local hormones
what are the 2 types of local hormones?
paracrine, autocrine
act on neighboring cells?
paracrine
act on same cell that secreted them
autocrine
what type of solubility do steroid hormones have?
lipid soluble
enter cell membrane and bind to receptors inside target cell; may stimulate transcription of genes to make certain proteins (can alter structure or change metabolic activity when new protein is made)
Steroid hormone
Steroid hormone connected to a carrier molecule
bound hormone
steroid hormone not connected to a carrier molecule
unbound hormone
how fast is the response time for steroid hormones?
slower
what are some examples of steroid hormones?
testosterone, progesterone, estrogen, cortisol
Hormone and receptor bound together in the cell
hormone receptor complex (HRC)
HRC binds to DNA sequence in nucleus
Hormone response element
What does the hormone response element stimulate?
mRNA synthesis which interacts with ribosomes
What type of solubility do protein hormones have?
water soluble
Do protein hormones enter the cell directly?
no; hormone bind to receptor proteins in plasma membrane which creates signal transduction pathway
What is the response time for protein hormones?
fast
Modified amino acids
Biogenic amines
What are some examples of biogenic amines?
Adrenal gland and thyroid gland hormones
What is hormone synthesis and release controlled by?
reflexes
release one hormone in response to another hormone
Hormonal stimulation
Release one hormone in response to changing levels of nutrients
Humoral stimulation
release hormone in response from stimulation of the nervous system
Nervous system stimulation
What is target cell response dependent of?
Hormone concentration in blood and abundance of target cell receptors, influence exerted by other hormones
Increases number of receptors due to a low concentration of a hormone
up regulation
decreases number of receptors due to a high concentration of a hormone
down regulation
1 hormone reinforces the activity of another (work together)
synergistically
one hormone is dependent of another hormone (need each other)
Permissively
hormones have opposite effects on each other
Antagonistically
What are the 3 main steps in an interaction between protein hormone and target cell?
- ) 1st messenger binds to receptor
- ) G protein binds to activated receptor
- ) G protein is released