Lecture 8A: Neuroendocrine Adaptations To Exercise Flashcards
What are the 3 main categories of hormones?
- Amine Hormones
- Peptide Hormones
- Steroid Hormones
What 2 hormones make up the amine hormones?
- Epinephrine
2. Norepinephrine
What 2 hormones make up the peptide hormones?
- Insulin
2. Growth Hormone
What 2 hormones make up the steroid hormones?
- Testosterone
2. Estrogen
_______________ are special chemical messengers in the body that are created in the endocrine glands.
Cholesterol
Coverage of the cholesterol side chain between carbons 21 and 22 give rise to a 21-carbon _______________
Protesting
Removal of carbon 20 and 21 from cholesterol produces the 19 carbon chain series _______________
Androgens
Estrogen is how long of a carbon chain?
18-Carbon Chain: Estrogen
What is the general hormonal signaling pathway in the body?
Hypothalamus
- > Pituitary Endocrine Cells
- ->Circulatory System
- –>Kidney
- —>Hormone Cell reaches target cell with hormone binding to receptor
- —>
Hormones secreted from the _______________ glands travel in the blood stream to exert their influence on various tissues throughout the body.
Endocrine
Once a hormone reaches its target location, what must it do next in order to be activated?
Bind to its specific receptor
Circulating hormones are known as _______________
First Messengers
Circulating hormones bind to a specific receptor in the cell’s plasma membrane to trigger production of …
Cyclic AMP from ATP
Circulating hormones bind to a specific receptor in the cell’s plasma membrane to trigger production of cyclic AMP from ATP. What enzyme is responsible for this reaction?
Adenylate Cyclase
The Enzyme Adenylate Cyclase converts AMP from ATP. This is known as what kind of reaction?
Catabolic Reaction: Break down
Cyclic AMP is known as what kind of messenger in the hormonal signaling pathway?
Secondary Messenger
What is the role of Cyclic AMP?
Activate a protein kinase within the cell
Once a hormone is in the extracellular space of the target cell, what is the step-wise process that occurs next? (5)
- Hormone binds to specific receptor in the bilayer plasma membrane
- Adenylate cyclase converts ATP to Cyclic AMP
- Cyclic AMP + Protein Kinase = Active Protein Kinase
- Inactive Target enzyme becomes Active
- Cellular Response is elicited
How many different ways can the endocrine gland be stimulated?
3
What are the 3 ways the endocrine gland can be stimulated?
A. Adrenocorticotropic Hormone (ACTH)
B. High blood glucose concentrations
C. Neural Sympathetic Nervous System
Describe the process of ACTH Endocrine Gland Stimulation.
ACTH stimulates release of Glucocorticoid hormones by the Adrenal Cortex
Describe the process for endocrine gland stimulation via high blood glucose.
High blood glucose concentrations trigger insulin release, causing rapid cellular glucose uptake.
-The Subsequent decrease in blood glucose removes the stimulation for insulin release.
Decried the endocrine gland stimulation process for Neural Sympathetic Nervous System (SNS).
SNS fibers trigger catecholamine release to blood.
What is the 4 step process for ACTH Endocrine Gland Stimulation?
- ACTH Release into Blood from Anterior Pituitary
- Adrenal Cortex Secretes Glucocorticoids
- Glucocorticoids influence several target organs (ex Liver)
- Glucocorticoids exert negative feedback on ACTH release
What is the (5) step process for Endocrine Gland Stimulation via High Blood Glucose Concentrations?
- Capillary blood containing high concentrations of Glucose
- Insulin Secreted by Pancreas
- Target cells absorb more glucose from blood
- Capillary blood in which glucose levels have dropped
- Low Blood sugar levels inhibit insulin release
What is the (2) step process for SNS endocrine gland stimulation?
- Preganglionic SNS fibers stimulate adrenal Medullary Cells.
- Adrenal Medullary cells secrete Catecholamines
Insulin is release from the _______________
Pancreas
What are the 6 factors influencing Hormone Potency?
- Hormone Half-life
- Binding (Carrying) Proteins
- Receptor Concentration
- Receptor Affinity
- 1st Pass effect in the Liver
- Exposure (area under the curve)
What are the binding proteins associated with factors influencing hormone potency? (2)
- Sex Hormone Binding Globulin (SHBG)
2. Albumin
Hormones play a key role in exercise. What are 3 common Hormonal/endocrine effects that occur with exercise?
- Hormonal regulation of what fuel to be used during exercise
- Tissue Adaptation to exercise
- Regulation of body fluids during exercise
List the 6 hormones secreted by the Anterior Pituitary gland.
- Lactogen (Prolactin)
- Gonadotrophic Hormones (FSH, LH)
- ACTH (Corticotropin)
- Thyrotropin
- Growth Hormone (Somatotropin
- Endorphins
From the Anterior Pituitary, this hormones target tissue is the breast.
Lactogen (Prolactin)
From the Anterior Pituitary, this hormones target tissue is the Ovaries/Testicles
Gonadotrophic Hormones (FSH, LH)
From the Anterior Pituitary, this hormones target tissue is the Adrenal Cortex.
ACTH (Corticotropin)
From the Anterior Pituitary, this hormones target tissue is the Thyroid.
Thyrotropin
From the Anterior Pituitary, this hormones target tissue is the spread out amongst many organs.
Growth hormone (Somatotropin)
From the Anterior Pituitary, this hormones target tissue are diverse organs and tissues.
Endorphins
Thyrotropin is released from the Anterior pituitary to the thyroid, where it than creates… (2)
- Thyroxine (T4)
2. Triiodothyronine (T3)
ACTH (Corticotropin) is released from the Anterior Pituitary to the adrenal cortex (Kidney) to release … (2)
- Cortisol
2. Aldosterone
Gonadotrophic Hormones (FSH, LH) are released from the Anterior Pituitary to the Ovaries/Testes to release … (2)
- Estrogen
2. Testosterone
Growth hormone stimulates the breakdown and release of _____________ from adipose tissue.
Triglycerides
What are the 2 functions of Growth hormone?
- Release of triglycerides from Adipose Tissue
2. Hinder Glucose uptake by the cell (Anti-Insulin effect)to maintain relatively high blood glucose
_____________ mediate the indirect anabolic effects of GH.
Somatomedins
Elevated GH levels and somatomedins provide feedback to promote _____________ release
Growth Hormone Inhibiting Hormone
With respect to Growth hormone, what 2 hormones does the hypothalamus release?
- Growth Hormone-Releasing Hormone (GHRH)
2. Growth Hormone-Inhibiting Hormone (GHIH)
What are the direct actions of Growth Hormone (2)?
- Target adipose tissue to release Triglycerides
2. Hinder Glucose uptake to maintain blood sugar levels
What is the indirect action of Growth Hormone?
- Promote Anabolism
2. Target Liver and other organs to release Somatomedins
What is the non-skeletal effects of Somatomedins?
Increases Synthesis of protein and new cell growth
What is the skeletal effect of Somatomedins? (2)
- > Increased formation of cartilage
- ->Promotes Skeletal Growth
What is the relationship between growth hormone and exercise?
Pre-training: GH levels will spike and linger post exercise
Post-Training: GH levels levels will have little to no change.
What is true about GH, Epinephrine, Norepinephrine, and Blood Lactate levels pre and post training periods?
Pre-training: All levels will be elevated post exercises
Post-training: Significantly less elevation than pre training individuals
GH stimulates lipolysis and inhibits glycolysis, therefore, one might hypothesis that endurance training enhances GH secretion and conserves glycogen stores. This is a false statement, why?
Endurance trained individuals show less rise in GH levels at a given exercise intensity. A response attributed to a reduction in the stress of exercise as training progresses and fitness improves.
_____________ training in men increases the frequency and amplitude of GH Secretion. Creating a favorable hormonal environment for muscular hypertrophy.
Resistance Training
What are the two inner regions of the Adrenal Gland?
- Cortex
2. Medulla
What hormones are released from the Adrenal Medulla? (2)
Catecholamines
- Epinephrine
- Norepinephrine
What hormones are released from the Adrenal Cortex?
- Mineralocorticoids: Aldosterone, corticosterone, Deoxycortocosterone
- Glucocorticoids: cortisol
- Androgens
What are the functions of Norepinephrine and Epinephrine?
- Releasing Glucose from the liver
- Releasing FFA from adipose tissue
- Blunting Glucose uptake by Skeletal Muscles
_____________ Serves both as a hormone and precursor to epinephrine. It also functions as a neurotransmitter when released by the sympathetic nerve endings
Norepinephrine
Who has higher levels of Epinephrine and Norepinephrine, trained or untrained athletes?
Untrained athletes have a higher level
At rest, which is higher in the body, concentration of norepinephrine or epinephrine?
Norepinephrine, it acts as a precursor to epinephrine.
Cortisol is released from the _____________
Adrenal Cortex of the kidney
Cortisol is a catabolic or anabolic hormone?
Catabolic
List how cortisol effects these 4 major systems in the body.
- Muscle
- Liver
- General Tissue
- Adipose Tissue
- Muscle: Protein breakdown to amino Acids
- Liver: Amino acids + Glycerol to create Glucose via Gluconeogenesis
- General Tissue: Increase FFA Oxidation
- Adipose Tissue: Breakdown Triglycerides to Glycerol and Fatty Acids
Cortisol acts to break down protein to amino acids and triglycerides to Glycerol and FFA. What happens to the amino acid and Glycerol back bone?
Gluconeogenesis: Converted to Glucose
When do cortisol levels increase?
During Acute Exercise
Cortisol levels tend to increase less in _____________ individuals
Trained
A single session of RT can elicit a shot-term _____________ in cortisol
Decrease
Male endurance athletes maintain resting Testosterone levels between _____________% of values for sedentary men.
60-85%
_____________ Training appears to increase resting testosterone in men and possibly women..
Resistance Training
Resistance training in men increases the _____________ and _____________ of Testosterone segregating, creating a favorable hormonal environment for muscular hypoertrophy.
Frequency and Amplitude
What is true about exercise and Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH)
There will be no significant difference between trained and untrained individuals
What effect does acute exercise have on Estrogen
Acute exercise Increases Estrogen Levels in women
__________________________ in women often causes altered FSH and LH levels during different times of the menstrual cycle and decreased Estrogen.
Chronic Exercise
Variations in the menstrual cycle do not significantly affect _____________ and _____________ responses to acute bouts of exercises
Metabolic
Hormonal
What is true of Resistance training in women and testosterone levels?
No acute changes in T with RT in women
What is true of acute training in women’s and GH?
GH increases with training in women
What are the 3 favorable conditions to increase Testosterone?
- Activation of Large Muscle Groups
- Heavy Resistance Training
- High Volume Training with <1 min rest intervals
What is true of endurance training on the endocrine system and trained/untrained individuals?
Hormonal responses remain lower in athletes compared to sedentary controls when performing at the same absolute intensity
