Ch #8: Endocrine System (pt. 1)

What key hormone changes during exercise?

growth hormone

What are the 2 systems responsible for coordinating human functions?

nervous system and endocrine system

Hormones

a biological chemical that is secreted by an endocrine gland and found in blood plasma

What must a hormone do in order to exert its effect?

it must bind to its specific protein receptor

The liquid portion of blood that contains ions, proteins, and hormones is call what?

plasma

Where are hormones found?

plasma portion of blood

What happens to plasma during exercise?

the volume of plasma decreases

What are the 4 things that affect the concentration of hormones in plasma?

1. Rate of secretion increases

2. Rate of excretion decreases

3. Quantity of transport protein

   1. (Only applicable to some hormones)

4. Plasma volume increases

What happens to excretion during exercise?

exercise decreases blood flow to kidneys which decreases the rate of excreation

Hormones only impact what?

tissues with specific receptors

What 3 things help determine the strength of the effect a hormone has?

1. concentration of the hormone

2. number of receptors available

3. affinity (attraction) of the receptor for the appropriate hormone

   1. ie type 1 diabetes

How does insulin “work”?

by using membrane transport —> takes substrate and moves it into the cell

T1 diabetic works how?

insulin is no longer produced by the pancreas (auto immune disease)

T2 diabetics work how?

insulin no longer will bind to its receptor which means glucose can’t enter your cell

How does testosterone “work”?

is alters the activity of DNA in the nucleus

What does testosterone help make? Think broad goal and the two specific tasks.

Broad: building muscle (width only for adults no length)

Specific: make more actin and myosin

How does epinephrine “work”?

It uses a second messager

What does epinephrine have to do to activate its second messenger?

• Bind to the receptor on the membrane to activate a G protein, which then opens an ion channel

  • OR

• Activate an enzyme

What are the main 7 hormone regulators applicable to this course?

• Hypothalamus

• Pituitary glands

• Tyyroid gland

• Adrenal glands

• Pancreas

• Testes

• Ovaries

What controls secretions from the pituitary gland?

hypothalamus

The anterior pituitary gland secretes what 4 important hormones discussed in class?

• Adrenocorticotropic Hormone (ACTH)

• Luteinizing Hormone (LH)

• Thyroid-stimulating Hormone (TSH)

• Growth Hormone (GH)

Hormones that come 1st are what type of hormones?

upstream hormones

Growth hormone is released from where?

pituitary gland

What is the most important job of growth hormone in adults?

to spare plasma glucose by reducing the use of plasma glucose

Growth hormone does what 3 crucial things?

1. Gluconeogenesis of lactate, amino acids, and glycerides

2. Mobilization of FFA

3. Blocks glucose from entering the cell which spares blood plasma

What happens to GH during exercise?

Plasma GH increases as exercise intensity increases

What hormone stimulates the thyroid gland first?

TSH (upstream hormone)

What type of effect does testosterone have

androgenic effect = promotes male characteristics

Anabolic Steroids

• promotes tissue/muscle building

• is performance enhancing

What hormone comes “upstream” of testoserone?

Luteinizing Hormone (LH)

Resting values of testosterone are _____ in both endurance & resistance trained males.

lower

Why do you see small changes in levels of FSH, LH, progesterone, & estrogen?

Due to either:

1. changes in the plasma portion of the blood

2. decreased rate of excretion

What are the 3 components of the female triad?

1. Menstrual dysfunction (lack of, irregular, or delayed period)

2. Disordered eating (low energy availability)

3. Osteoporosis (low bone density)

Which hormone drops after intense exercise, explaining the female athlete triad?

LH (luteinizing hormone)