Hormones Flashcards
What hormones are released from the pituitary gland? (9)
- Growth Hormone
- Antidiuretic Hormone (vasopressin)
- Oxytocin
- Follicle stimulating hormone
- Luteinizing hormone
- Thyroid stimulating hormone
- Adrenocorticotropin hormone
- Prolactin
What hormones are released from the adrenal glands? (3)
- Catecholamines- Epinephrine/Norepinephrine
- Mineralocorticoids - Aldosterone
- Glucocorticoids - Cortisol
What hormones are released from the pancreas?
Insulin and Glucagon.
What hormone is released from the testes?
Testosterone.
What hormone is released from the ovaries?
Estrogen.
What does the growth hormone do?
stimulates general growth and skeletal growth and promotes metabolic functions
What does vasopressin / antidiuretic hormone do?
Helps to reduce urinary secretion of water during dehydration (from sweating)
What do the catecholamines do?
Increase cardiac output and help the liver break down glucose for release in to the bloodstream and for use by active muscles.
What does aldosterone do?
Limits sodium excretion to aid electrolyte balance during exercise.
What does cortisol do?
Maintains blood glucose levels during prolonged exercise by promoting protein and triglyceride breakdown.
When is insulin released and what does it faciliate?
Insulin is released when blood glucose levels are too high and so it facilitates glucose removal from the blood and other tissues so that the levels can return to normal.
What does glucagon do?
Glucagon does the opposite than insulin, it releases glucose back into the bloodstream when blood glucose levels are too low.
What does testosterone do?
It is the primary male sex hormone and has muscle building effects.
What does estrogen do?
It is the primary female sex hormone and help bone formation and maintenance.
What are the 5 responses to a release of epinephrine and nonepinephrine?
- Increase in cardiac output/contractions
- Generalized vasoconstriction in non-active muscles
- Stimulates mobilization of carbs/fats for fuel and increase of liver glycogen production
- Dilation of respiratory passages to aid ventilation and reduce digestive/urinary activity
- Vasodilation of blood vessels in heart and active skeletal muscle
What happens to insulin/glucagon levels during the first few weeks of exercise?
Levels are maintained/stay the same in aerobically trained individuals.
What happens to cortisol levels during the first few weeks of exercise?
Levels increase slightly as body become better at preserving glucose.
What happens to growth hormone levels during the first few weeks of exercise?
Levels decrease in endurance trained individuals.
What happens to catecholamines during the first few weeks of exercise?
Levels reduce significantly during first few weeks.
Do catecholamines increase linerally or non-linerally with duration of exercise?
Linerally.
At what point does nonepinephrine stop increasing with exercise?
Nonepinephrine stops increasing when exercise intensity reaches 50% VO2 Max.
When does epinephrine start to increase?
When exercise levels reach 60% VO2 Max.
What happens to insulin during exercise?
Insulin is suppressed and glucose uptake by skeletal muscle is increased 7-20% above resting rate.
What does insulin promote?
The uptake of glucose, fats and amino acids into cells for storage.
How does acute bouts of exercise alter the need for more insulin?
Acute bouts of exercise increases the muscles sensitivity to insulin therefore less insulin is needed to bring about the same effect on glucose uptake in to muscles.
Is insulin a fast-acting or a slow-acting hormone?
Fast
What hormone is glucagon the opposite effect of?
Insulin
What is the primary role of glucagon during exercise?
To contribute to blood glucose control as exercise progresses and glycogen levels decrease.
What does cortisol mobilize in the liver?
Glucose synthesis
What are 3 things that cortisol decreases?
- Rate of glucose utilization by the cells.
- Amino Acid uptake by muscles.
- Bone Formation.
What are 2 things that cortisol promotes/stimulates?
- Breakdown of adipose tissue.
2. Free-Fatty-Acid mobilization from adipose tissue.
What will prolonged high levels of cortisol lead to? (4)
Excessive protein breakdown, tissue wasting, negative nitrogen balance and abdominal obesity.
How does the growth hormone support the actions of cortisol?
It helps by decreasing glucose uptake by tissues, increasing FFA Mobilization and enhancing gluconeogenesis.
Is insulin a slow or fast acting hormone?
Fast.
What form of training and conditioning works together to improve a muscle’s insulin’s sensitivity over a couple weeks?
Resistance training and aerobic conditioning.
What hormone helps the regulation of carbohydrates, fat or protein metabolism?
Cortisol
What are two components broken down by glucagon to aid the body during an endurance run?
Protein and triglycerides.
How does the growth hormone support the actions of cortisol?
By decreasing glucose uptake by tissues, increasing free-fatty acids mobilization and enhancing gluconeogensis.
What hormones are released from the Thyroid? (3)
- Thyroxine
- Triiodothyronine
- Calcitonin
What hormone is released from the Parathyroids and what does it do?
Parathyroid Hormone raises plasma calcium levels and lowers plasma phosphate levels
what does Oxytocin do?
stimulates the contraction of the smooth muscle of the uterus and intestines
What do the Follicle Stimulating Hormone and Luteinizing Hormones do?
Stimulates gonads to secrete sex hormones
what does the thyroid stimulating hormone do?
stimulates the thyroid gland to secrete thyroid hormones
what does the adrenocorticotropin hormone do?
stimulates adrenal glands to secrete glucocotricoids
what does prolactin do?
initiates and maintains breast milk secretion in females
what do thyroxine and triiodothyronine do?
increase oxygen consumption and heat production and affects many metabolic functions
what does calcitonin do?
decreases blood calcium and phosphate levels
what does epinephrine do?
affects carbohydrate metabolism (generally promotes hyperglycemia) and constricts vessels in the skin, mucous membranes and kidneys but dilates vessels in skeletal muscle
what does norepinephrine do?
increases HR and force of contraction of the myocardium and constricts blood vessels in most areas of the body
What do mineralocorticoids do?
promote reabsorption of sodium and excretion of potassium in the kidneys
what do glucocorticoids do?
promote protein and triglyceride breakdown
what does insulin do?
it causes liver and muscles to take up glucose and store it in the form of glycogen whilst encouraging fat cells to take on blood lipids and turn them into triglycerides.
It also has anabolic effects throughout the body
What does glucagon do?
causes the liver to convert stored glycogen into glucose and release it into the bloodstream
What are the 2 general categories of hormones?
hormones that are steroid-derived and hormones synthesized from amino acids
Follicule-Stimulating + Luteinizing hormones are Gonadotropins because of their effects on the gonads, what do these substances control?
They control the secretion of estrogen and progesterone in the ovaries and the production of testosterone in the testicles.
What does calcitonin do?
lowers blood calcium and phosphate levels by accelerating the absorption of calcium by the bones
what does epinephrine do?
- elevates blood glucose levels
- increases the rate, force and amplitude of the heartbeat
- dilates blood vessels that feed the heart, lungs and skeletal muscles
what does norepinephrine do?
it causes an increase in heart rate and in the force of contraction of the cardiac muscle, it also contributes to the constriction of blood vessels in the body
What does testosterone do?
acts to initiate sperm production, stimulate the development of male secondary sex characteristics and promotes tissue building
What does estrogen do?
regulates ovulation, menstruation, the physiological adjustments during pregnancy and the appearance of secondary female sex characteristics.
What is affected by estrogen?
blood vessels, bones, lungs, liver, intestine, prostate and testes
Growth hormone is secreted by the anterior pituitary gland, what does it facilitate?
It facilitates protein synthesis in the body, mostly by helping the cell transport nutrients from outside the cell to the interior where they may be incorporated into cell proteins.
Many of growth hormone’s effects are mediated by _____ _____ ______ _______.
insulin-like growth factors
Where are insulin-like growth factors synthesized?
they are synthesized in the liver as a result of growth hormone release during exercise
Antidiuretic hormone / vasopressin is released by the posterior pituitary gland during exercise, why does it reduce urinary excretion?
it reduces urinary excretion in response to the dehydrating effects of sweating and helps preserve the plasma volume and osmolality of the blood.
Epinephrine and norepinephrine are catecholamines released by the adrenal medulla as part of the sympathetic response to exercise, what is their role during this?
to increase cardiac output but increasing HR and contractility during exercise and to cause glycogenolysis in the liver so that more glucose can be released to active muscles.
Aldosterone and cortisol are two of the main hormones released by the adrenal cortex, what do they each do during exercise?
- aldosterone limits sodium excretion in the urine to maintain electrolyte balance
- cortisol maintains blood glucose during prolonged exercise by promoting protein and triglyceride breakdown
Insulin and glucagon are both secreted by the cells of the islets of Langerhans in the pancreas yet have opposing effects, what are they?
- insulin facilitates glucose removal from the blood to facilitate glucose entry into the tissues and decreases blood glucose
- glucagon stimulates glucose release from the liver to increase blood glucose
Insulin and Glucagon are both secreted by the islets of Langerhans, what cells release each of them?
Insulin is released via beta cells whereas glucagon is released via alpha cells
Whilst increasing blood glucose levels, what other effect does glucagon have?
it also causes the release of free fatty acids from adipose tissue to be used as fuel
Testosterone has both androgenic effects and anabolic effects, what are these?
androgenic effects are masculine characteristics
anabolic effects are muscle building effects
Why is testosterone often abused in attempts to enhance athletic performance?
because of its anabolic effects
what type of exercise pattern can cause amenorrhea?
high levels of chronic exercise training and low body weight
The thyroid is a small gland in the neck that secretes 2 hormones, what are they and what do they do?
Thyroxine and triiodothyronine both increase oxygen uptake and heat production and affect metabolic functions.
What are 2 key hormones of behaviour?
- Corticotropin Releasing Hormone CRH
2. Adrenocorticotropin Hormone ACTH
