Ex Phys Chapter 4 Flashcards
_____ system used electrical communication
Nervous system
____system uses chemical communication
Endocrine system
Target cells are also known as
hormone receptors
This system:
- Controls substrate metabolism
- Regulates fluid, electrolyte balance
Endocrine system
This hormone is derived from cholesterol
steroid hormones
This hormone is lipid soluble, and diffuses through cell membranes
steroid hormones
Steroid hormones are secreted by four major glands
- Adrenal cortex (cortisol, aldosterone)
- Ovaries (estrogen, progesterone)
- Testes (testosterone)
- Placenta (estrogen, progesterone)
-Adrenal cortex creates the hormone:
(cortisol, aldosterone)
-Ovaries creates the hormone:
(estrogen, progesterone)
-Testes creates the hormone:
(testosterone)
-Placenta creates the hormone:
(estrogen, progesterone)
this type of hormone is Not lipid soluble & cannot cross membranes
Nonsteroid Hormones
What are the two groups of non-steroid hormones?
Protein/peptide hormones
&
Amino acid-derived hormones
Most nonsteroid hormones
From the pancreas, hypothalamus, pituitary gland are considered
Protein/peptide hormones
Thyroid hormones (T3, T4) Adrenal medulla hormones (epinephrine, norepinephrine)
Amino acid-derived hormones
The term describing that hormones are secreted in bursts
pulsatile
what triggers of regulates hormone bursts?
?
What is the process called when ↓ number of receptors during high plasma concentration = desensitization
Downregulation
What is the process called when ↑ number of receptors during high plasma concentration = sensitization
Upregulation:
Hormones limit scope of their effects by using:
hormone-specific receptors
Hormone only affects tissues with
specific receptor
Hormone exerts effects after:
binding with receptor
Typical cell has:
2,000 to 10,000 receptors
The Hormone binds to receptor:
hormone–receptor complex
Lipid soluble steroids can
cross cell membranes
Hormone–receptor complex enters nucleus and then…
Binds to DNA, direct gene activation
Regulates mRNA synthesis, protein synthesis
Not lipid soluble cannot:
cross cell membrane
for Nonsteroid Hormone messages are sent through:
Receptors on the cell membrane (second messengers)
Second messengers do what?
- Carry out hormone effects
- Intensify strength of hormone signal
some common second messengers consist of:
- Cyclic adenosine monophosphate (cAMP)
- Cyclic guanine monophosphate (cGMP)
- Inositol triphosphate (IP3), diacylglycerol (DAG)
The third class of Hormones is:
Prostaglandins
Prostaglandins is derived from
arachidonic acid
this hormone acts as a local hormone in the immediate area. it’s involved in:
- Inflammatory response (swelling, vasodilation)
- Sensitize nociceptor free nerve endings (pain)
Prostaglandins
________ regulate physiological variables during exercise
hormones
Important exercise-related functions of endocrine glands & their hormones consist of:
-Regulation of metabolism & body fluids during exercise
&
-Regulation of appetite and food intake
the Major endocrine glands responsible for metabolic regulation are:
- Anterior pituitary gland
- Thyroid gland
- Adrenal gland
- Pancreas
Hormones released by Anterior pituitary gland, Thyroid gland, Adrenal gland, Pancreasglands affect metabolism of _______ and ______ during exercise
Carbohydrates & fat
Pituitary gland attached to
inferior hypothalamus
The Pituitary gland is divided into what 3 parts?
anterior, intermediate, posterior
What are the tasks of the pituitary gland?
- Secretes hormones in response to hypothalamic hormone factors
- Releases growth hormone (GH)
-GH release is proportional to
exercise intensity
Releasing growth hormone (GH) involves
- Potent anabolic hormone
- Builds tissues, organs
- Promotes muscle growth (hypertrophy)
- Stimulates fat metabolism
The Thyroid gland secretes
triiodothyronine (T3), thyroxine (T4)
T3 and T4 lead to increases in
Metabolic rate of all tissues -Protein synthesis -Number and size of mitochondria -Glucose uptake by cells -Rate of glycolysis, gluconeogenesis -FFA mobilization (continued)
Anterior pituitary releases
thyrotropin
thyrotropin is also known as
thyroid-stimulating hormone (TSH)
Thyrotropin (TSH) Travels to thyroid, stimulates _____and ______
T3 & T4
TSH levels are increased by______
Short term: T4 ↑ (delayed release)
Prolonged exercise: T4 constant, T3 ↓
exercise
catecholamines is released by the
adrenal medulla
catecholamines during fight or flight consist of
Epinephrine 80%, norepinephrine 20%
Catecholamine release increases
-Heart rate, contractile force, blood pressure
– Glycogenolysis, FFA
-Blood flow to skeletal muscle
(– ↑ Exercise → ↑ sympathetic nervous system →
↑ epinephrine and norepinephrine)
The adrenal cortex releases
corticosteroids
The corticosteroids released form the adrenal cortex consist of
- Glucocorticoids
- Also, mineralocorticoids, gonadocorticoids
A Major glucocorticoid is:
cortisol
Cortisol is responsible for
– ↑ Gluconeogenesis
– ↑ FFA mobilization, protein catabolism
-Anti-inflammatory, anti-immune
The pancreas is responsible for
raising and lowering blood glucose
insulin is responsible for
lowering blood glucose level
\_\_\_\_\_\_\_ lowers blood glucose Counters hyperglycemia, opposes glucagon – ↑ Glucose transport into cells – ↑ Synthesis of glycogen, protein, fat – Inhibits gluconeogenesis
Insulin
______ raises blood glucose
glucagon
glucagon is responsible for
-Counters hypoglycemia, opposes insulin
– ↑ Glycogenolysis, gluconeogenesis
Glycogenolysis involves converting ____ to _____
(glycogen → glucose)
Gluconeogenesis involves converting ___ and ___ to ____
(FFAs, protein → glucose)
during Regulation of Carbohydrate Metabolism During Exercise glucose must
be available to tissues
Adequate glucose during exercise requires:
Glucose release by liver
Glucose uptake by muscles
Hormones that ↑ circulating glucose
Glucagon
Epinephrine
Norepinephrine
Cortisol
Amount of glucose released from liver depends on:
exercise intensity, duration
Circulating glucose during exercise also affected by
GH: ↑ FFA mobilization, ↓ cellular glucose uptake
T3, T4: ↑ glucose catabolism and fat metabolism
regarding the regulation of carbohydrate metabolism: As exercise intensity increases
– Catecholamine release ↑
– Glycogenolysis rate ↑ (liver, muscles)
-Muscle glycogen used before liver glycogen
regarding the regulation of carbohydrate metabolism: As exercise duration increases
–More liver glycogen utilized
– ↑ Muscle glucose uptake → ↑ liver glucose release
–As glycogen stores ↓, glucagon levels ↑
FFA mobilization and fat metabolism critical to:
endurance exercise performance
during endurance exercise performance:
- when glycogen is depleted, need ______ ______ ______
- In response, hormones accelerate fat breakdown (______)
fat energy substrates, lipolysis
FFA mobilization and fat metabolism critical to
endurance exercise performance
when glycogen is depleted the body utilizes
-In response, hormones accelerate fat breakdown (lipolysis)
fat energy substrates
Triglycerides → ______ + _____
FFAs + glycerol
Fat is stored as triglycerides in
adipose tissue
____ is Broken down into FFAs and transported to muscle
triglycerides
Rate of triglyceride breakdown into FFAs may determine rate of ____ _____ ____
cellular fat metabolism
Lipolysis stimulated by what hormones?
- (Decreased) insulin
- Epinephrine
- Norepinephrine
- Cortisol
- GH
During exercise, plasma volume ↓, causing
– ↑ Hydrostatic pressure, tissue osmotic pressure
– ↓ Plasma water content via sweating
– ↓ blood pressure, ↑ Heart strain
Hormones from the following areas correct fluid imbalances
- Posterior pituitary gland
- Adrenal cortex
- Kidneys
Posterior pituitary’s duties include
Secretes antidiuretic hormone (ADH), oxytocin
Produced in hypothalamus, travels to posterior pituitary
Secreted upon neural signal from hypothalamus
ADH is only involved with
exercise
ADH involved in exercise
– ↑ Water reabsorption at kidneys
-Less water in urine, antidiuresis
what is the Stimuli for ADH release
– ↓ Plasma volume = hemoconcentration = ↑ osmolality
– ↑ Osmolality stimulates osmoreceptors in hypothalamus
when ADH released, it increases
water retention by kidneys
ADH Minimizes water loss, therefore avoiding
severe dehydration
Adrenal cortex
Secretes:______
Major mineralocorticoid: _______
- mineralocorticoids
- aldosterone
Aldosterone effects – ↑ \_\_\_ retention by kidneys – ↑ \_\_\_ retention → ↑ water retention via osmosis – ↑ \_\_\_ retention → ↑ K+ excretion (continued)
Na+
Stimuli for aldosterone release
– ↓ ____
– ↓ Blood ____, blood _____
– ↑ ______ k+
- Plasma Na+
- blood volume & blood pressure
- Plasma K+
Aldosterone release is indirectly stimulated by ↓ ________ & ↓________ in kidneys
- blood volume
- blood pressure
during Hormonal Regulation of Fluid and Electrolytes: Kidneys
- Target tissue for____ & _____
- Secrete _____, & ________
ADH, aldosterone
erythropoietin (EPO), renin
during Hormonal Regulation of Fluid and Electrolytes: Kidneys
Stimulus for RENIN (enzyme) release
- ↓ Blood volume, ↓ blood pressure
- Sympathetic nervous system impulses
during Hormonal Regulation of Fluid and Electrolytes: Kidneys
Renin-angiotensin-aldosterone mechanism
- Renin: converts angiotensinogen → angiotensin I
- ACE: converts angiotensin I → angiotensin II
- Angiotensin II stimulates aldosterone release
_____ is the:
- Ionic concentration of dissolved particles (proteins, ions, etc.) in body fluid compartments
- Normal value: ~300 mOsm/kg
osmolality
Osmolality and osmosis:
-If compartment osmolality ↑, water drawn ____
-If compartment osmolality ↓, water drawn ____
(continued)
- In
- Out
when considering aldosterone and osmosis:
increase in Na+ retention would increase
osmolality
an increase in osmolality would cause an increase in
water retention
when considering Aldosterone and osmosis:
-where Na+ moves, ____ flows
water
Osmotic water movement minimizes loss of ____ volume, maintains _____ pressure
plasma, blood
ADH, aldosterone effects persist for ___ to
___ hours after exercise
12-48
Prolonged Na+ retention → abnormally high [Na+] after exercise
- Water follows ___
- Prolonged rehydration effects
Na+
______ is appetite control center of brain
Hypothalamus
Hypothalamus:
Satiety center is located in:
ventromedial nucleus
Hunger center is in the lateral
hypothalamus
GI tract releases hormones that affect:
hunger signals
______(CCK): stimulated when stomach is full; decreases appetite
Cholecyctokinin
________: released in small intestine; decreases appetite
Glucagon-like peptide 1 (GLP-1)
______released in small intestine; decreases appetite
Peptide YY (PYY):
_____increases appetite
Ghrelin
Adipose is an _____ organ
endocrine
Leptin released from adipose stores reduces
hunger
Leptin and ghrelin act in _____ ways
opposing
Obese people have higher but resistant to effects
leptin
Exercise affects ____ and _____ hormones
Hunger & Satiety
Acute, vigorous exercise (aerobic) increases ____ and ___, reducing hunger
PPY & GLP-1
Appetite and satiety hormones are sensitive to the total energy balance that is modulated by ________
regular exercise
