Chapter 4: Hormone Regulation Flashcards
What are the two communication systems?
- nervous system 2. endocrine system
What type of communication system is the nervous system?
electrical communication
What type of communication system is the endocrine system?
chemical communication
What system is slower responding, longer lasting than nervous system?
the endocrine system
how is homeostasis being maintained?
via hormones
What are the two things homeostasis is responsible for?
– that control and regulate cell/organ activity
– Act on target cells
What does the endocrine system coordinate?
integration of physiological systems during rest and exercise
What are the two things homeostasis is responsible for during EXERCISE?
- Controls substrate metabolism
– Regulates fluid, electrolyte balance
Does endocrine glands have ducts or no?
endocrine glands are DUCTLESS
In which space are products (hormones) secreted at?
extracellular space
Where does the hormones diffuse into when it is inside the endocrine glands?
it goes into the bloodstream and travel in the blood to their specific target organs
Why are receptors are only specific to hormones?
Receptors are specific to hormones such that only the correct hormone will fit in the correct receptor
How much specific receptors does each cell have?
Each cell has 2,000 to 10,000 specific receptors
Name the organs involved in the endocrine system.
- hypothalamus - pituitary gland - thyroid and parathyroid gland - thymus gland - adrenal glands - pancreas - ovaries - testes
Explain the two main way of hormone regulation.
- Secreted in bursts (pulsatile) - Secretion regulated by negative feedback
Explain more what it means when hormones are “secreted in bursts (pulsatile)”
- Plasma concentrations fluctuate over minutes/hours – Concentrations also fluctuate over days/weeks
Explain more what it means when hormones when “secretion is regulated by negative feedback
- Hormone release causes change in body – High levels DECREASE secretion – Low level INCREASE secretion – Example: home thermostat
True or False. Hormones limit scope of their effects by using hormone-specific receptors
TRUE
Hormones are classified into how many types and what are those types?
2; steroid and nonsteriod
From where are steroid hormones derived?
cholesterol
Are steroid hormones lipid soluble or not?
yes
True or false: Steroid hormones cannot diffuse through membranes
false
What are the major glands involved in steroid hormones?
Adrenal cortex ( cortisol, aldosterone) Ovaries (estrogen, progesterone) Testes (testosterone) Placenta (estrogen, progesterone) ATPO (acronym)
how does direct gene activation occur?
by diffusing through cell membrane and binding with receptors inside cell
Explain steps involved in the action of a steroid hormone
a). The steroid hormone enters a cell b). The hormone binds to a specific receptor in the cytoplasm or in the nucleus c). The hormone-receptor complex activates the cell’s DNA, which forms mRNA d). The mRNA leaves the nucleus e). The mRNA directs protein synthesis in the cytoplasm
How many groups is non-steroid hormones divided into and what are they?
2; protein/peptide hormones amino-acid derived hormones
Where is protein/peptide hormones secreted from?
pancreas, hypothalamus, pituitary gland
What are hormones secreted by amino acid derived hormones?
thyroid hormones (T3, T4) adrenal medulla hormones (epinephrine, norepinephrine)
what are the hormones secreted by protein/peptide hormones?
most nonsteriod hormones
true/false: Nonsteroid hormones are not lipid soluble and cannot cross cell membrane
true
Where are the receptors located in the non-steroid hormone?
cell membrane
binding triggers a series of reactions that lead to the formation of _______________
second messenger
What does the second messenger do?
carry out hormone effect intensify strength of hormone signal
What is the common second messengers?
cyclic adenosine monophosphate (cAMP) cyclic guanine monophosphate (cGMP) inositol triphosphate (IP3) diacylglycerol (DAG)
No receptors = what?
no hormone effect
when hormone binds to receptor it does what?
goes to hormone-receptor complex
Explain the action of a nonsteroid hormone
a. nonsteroid hormones can’t pass through the cell membrane.
b. the hormone binds to a specific receptor on the cell membrane.
c. the hormone- receptor complex activates adenylate cyclase within the cell
d. the adenylane cyclase forms cAMP.
e. the cAMP activates protein kinases (enzymes) that lead to cellular changes and hormonal effects.
during hormonal regulation, what happens to hormones in plasma levels?
hormones fluctuate
during hormonal regulation, secretion is regulated by what?
negative feedback system
during hormonal regulation, how does cells alter their number of hormone receptors?
via down- regulation or up- regulation
What is down-regulation?
- DECREASE in number of CELL RECEPTORS
- LESS hormone can bind to the cell and HIGHER concentrations of the hormone remain in the blood plasma
What is up-regulation?
- INCREASE in number of CELL RECEPTORS
- MORE hormone can bind to the cell and LOWER concentrations of the hormone remain in the blood plasma
What are the major endocrine glands responsible for metabolic regulation during exercise?
- anterior pituitary gland
- thyroid gland
- adrenal gland
- pancreas
During exercise, hormones released by anterior pituitary gland, thyroid gland, adrenal gland and pancreas affects metabolism of what two things?
carbohydrate and fat
What is the “master gland”?
hypothalamus
What is the part of the brain that is just above the pituitary gland?
hypothalamus
What is does the hypothalumus do regarding hormones?
it controls the release of PITUITARY hormones via various “releasing” hormones
What is the pituitary gland?
a marble size gland located at the base of the brain
What is the anterior lobe of the pituitary gland responsible for? (What hormones?)
growth hormone (GH)
prolactin (PRL)
What are the 4 “effector” hormones?
- thyroid stimulating hormone (TSH)
- adrenocorticotropin (ACTH)
- follicle stimulating hormone (FSH)
- leutinizing hormone
What cells are growth hormones responsible for?
ALL cells
What is prolactin responsible for?
breasts
What is TSH responsible for?
thyroid (t3 and t4)
What is ACTH responsible for?
adrenal cortex (mineralocorticoids, gluoocorticoids, gonadocorticoids)
What are FSH and LH responsible for?
ovaries and testes (testosterone, estrogen, progesterone)
What is anterior pituitary?
growth hormone
What does the potenet anabolic hormone do?
- builds tissues, organs
- promotes muscle growth (hypertrophy)
- stimulates fat metabolism
during the regulation of anterior pituitary, what happens?
- hypothalamus releases growth hormone- releasing hormone (controls GH release)
- stimulates release of GH from the anterior pituitary
is GH release proportional to exercise intensity?
yes
what happens to the levels of GH during aerobic exercise?
levels are ELEVATED during AEROBIC exercise in proportion to exercise INTENSITY
what happens to the levels of GH during strength training?
levels ELEVATED SOMEWHAT during strength training, BUT HIGHER 8-24 hours post workout
T3 and T4 lead to increase in?
Metabolic rate of all tissues
Protein synthesis
Number and size of mitochondria
Glucose uptake by cells
Rate of glycolysis, gluconeogenesis
lipolysis (FFA mobilization)
How is thyroid gland regulated?
Hypothlamus produces thyrotropin-releasing hormone which stimulates the anterior pituitary to release thyrotropin also called thyroid-stimulating hormone (TSH) whcih travels to thyroid and stimulates release of t3 and t4
What happens to TSH during exercise?
Increases
Where are adrenal glands located?
top of each kidney
What are the parts of adrenal glands?
adrenal cortex; the outer part
adrenal edulla; the inner part
Which hormones are necessary for life out of these two: adrenal cortex or adrenal medulla?
adrenal cortex
From where does the adrenal medulla recieves input from?
SNS
What hormones are released by adrenal medulla?
catecholamines (fight or flight)
epinephrine 80%
norepinephrine 20%
What triggers the release of catecholamines?
increase exercise leads to increase SNS stimulation which leads to increase release of epinephrine and norepinephrine
What increases with release of catecholamine?
heart rate, contractility, blood pressure
metabolic rate, respiration
Glycogenolysis, lipolysis
vasodilation to skeletal muscle
What does adrenal cortex release?
corticosteroids
Give the types of corticosteroids?
glucocorticoids
mineralocorticoids
sex hormones
What are the subtypes of glucocorticoids and what are its function?
- Hydrocortisone: it is the cortisol that helps to regulate metabolism of fat, protein, and CHO. Also hels regulate BP and CV function
- Corticosterone: works with hydrocortisone to regulate immune response and suppress inflammatory reactions
What is the subtype of mineralocorticoids and its function?
aldosterone: maintains balance of salt and water & helps control blood prssure
What is the major form of glucocorticoid?
cortisol
true/flase: cortisol helps to increase glucose utilization
false: it decreases
true/false: cortisol helps to increase protein catabolism, gluconeogenesis and FFA mobilization
true
true/false: cortisol is anti-inflammatory and immunosupressant
true
What produces corticotrophin relesing hormone (CRH)?
hypothalamus
What provides major control over plasma glucose concentrations?
insulin and glucagon
What lowers blood glucose level?
insulin
What raises blood glucose level?
glucagon
true/false: insulin counters hyperglycemia and opposes glucagon
true
How does insulin lower blood glucose?
- increase transport into cells
- increase synthesis of glycogen, protein, fat
- inhibits gluconeogenesis
Does glucagon counter hypoglycemia and oppose insulin?
yes
How does glucagon raise blood glucose level?
by increasing glycogenolysis and gluconeogenesis
What is this process called?
glycogen ——–> glucose
glycogenolysis
What is this process called?
protein ——> glucose
gluconeogenesis
What happens during regulation of carbohydrate metabolism during exercise?
- glucose must be available to tissues
- glycogenolysis
- gluconeogenesis
What are the hormones that increases circulating glucose via glycogenolysis and gluconeogenesis?
- glucagon
- epinephrine
- norepinephrine
- cortisol
What increases protein catabolism and makes amino acids available for gluconeogenesis?
cortisol
What enables glucose uptake in muscle?
insulin
What is uptaken by the muscls during exercise?
glucose
What happens to level of glucose during execise?
stays the same
What happens to the level of insulin concentration during exercise?
decreases
What happens to CELLULAR insulin sensitivity?
increases
Lipolysis is stimulated by?
- decreased insulin
- epinephrine/norepinephrine
- cortisol
- GH
lipolysis is stimulated via?
lipase
