Ch 6 Endocrine System

lipolysis

The breakdown and utilization of fat for energy.

enzyme

A substance in the body that causes a specific reaction or change.

glands

Organs that release substances into the bloodstream (such as hormones) or other surface of the body.

hormone

Chemical messenger released from a gland that travels to cells to activate a specific function.

target (receptor) cell

Cell that receives a message from a hormone or enzyme. Target cells exert an action after being stimulated or activated.

endocrine

Hormone secreting

The endocrine system

A body system that produces hormones to regulate many body functions.

main functions of the endocrine system

Controls mood, growth and development, tissue function, and metabolism

They help:

• Trigger muscle contraction

• Stimulate fat breakdown (lipolysis) and protein use

• Activate enzymes

• Regulate growth and metabolism

• Control the body's physical and emotional response to stress (like exercise or injury)

What do hormones from the endocrine system do?

how hormones affect exercise

They help the body respond to exercise by regulating muscle contraction, energy use, metabolism, and stress responses.

Hormone-Specific Receptors

Proteins on target cells that bind only to a specific hormone, allowing it to produce its intended effect.

hormone-binding (transport) proteins

Proteins in the bloodstream that bind to hormones, protecting them, transporting them, and controlling how much hormone is available to target cells.

hormone binding

The process by which a hormone binds to its specific receptor and carries out its intended action.

endocrine system

regulates multiple bodily functions to stabilize the body’s internal environment, much like a thermostat regulates the temperature in a room.

host organs

aka glands

hypothalamus

A gland located in the brain that communicates with the pituitary gland.

pineal gland

A small gland in the brain that secretes the hormone melatonin, which helps regulate sleep cycles.

pancreas

An organ with numerous functions, including the production of insulin, glucagon, and digestive juices.

thyroid gland

An endocrine gland, located in the anterior neck, responsible for the secretion of many hormones, including thyroxin and calcitonin.

pituitary gland

An endocrine gland that controls the secretion of many hormones, including growth hormone.

adrenal gland

A gland, located just above the kidneys, responsible for the secretion of catecholamines and cortisol.

reproductive glands

glands, such as the ovaries or testes, that serve sex-specific functions.

anterior, intermediate, and posterior

sections of the pituitary gland

liver and stomach

where hormones are secreted

hypothalamus and pituitary gland

Much of the control of hormonal activity ultimately rests with the (master glands)

endocrine and nervous system

which two systems are linked by hormones?

insulin

A hormone secreted by the pancreas that is responsible for glucose metabolism.

glucagon

A hormone secreted by the pancreas that regulates blood glucose and functions opposite to insulin.

substrates

Intermediate forms of nutrients used in metabolic reactions to create adenosine triphosphate.

glycogen

Glucose that is deposited and stored in bodily tissues, such as the liver and muscle cells; the storage form of carbohydrate.

carbs

make up the primary energy source during vigorous exercise and are human body’s key source of energy

inhibit performance

too little of blood glucose levels

potentially damage the vascular system

too much of blood glucose levels

substrates

fat, carbs, etc.

small intestine

After consuming a meal, glucose enters the blood at the

a rise in blood glucose levels

when glucose within the blood enters the small intestine, this causes

pancreas

The rise of glucose triggers this; releasing insulin into the bloodstream

insulin

binds to receptors on the surface of muscle, liver, and fat cells, facilitating the uptake of glucose from the bloodstream into these cells

drop of blood glucose levels

the net result of glycogen

insulin

causes cells in the liver, muscle, and fat tissue to take up glucose from the blood

glucagon

primarily works to raise blood glucose levels by triggering the release of glycogen stores from the liver

the body will begin to exhibit lower blood glucose levels.

Hours after a meal, or as a result of a combination of normal metabolic processes and physical activity, this happens:

the drops in circulating blood glucose levels triggers the release of

glucagon from the pancreas

glucose uptake by the body’s cells will also increase

As activity levels increase

insulin to transport glucose into the cells, essentially lowering insulin resistance

Evidence suggests that exercise helps muscle cells increase their ability to use

noninsulin-mediated mechanisms

The body's ability to take glucose into cells without insulin, such as during exercise when muscles can absorb glucose on their own.

growth hormone

An anabolic hormone produced by the pituitary gland that is responsible for growth and development.

catecholamines

Hormones produced by the adrenal glands that are part of the stress response known as the fight-or-flight response.

adrenal gland medulla

Inner portion of the adrenal gland that releases epinephrine (adrenaline) and norepinephrine (noradrenaline) to activate the fight-or-flight response. Increases heart rate, blood glucose, blood flow to muscles, airway opening, and fat breakdown.

adrenal gland cortex

Outer portion of the adrenal gland that releases cortisol, aldosterone, and small amounts of androgens. Helps regulate metabolism, blood pressure, electrolyte balance, and the body's long-term response to stress.

medulla

immediate stress

cortex

chronic stress

immediately

how long does it take for the adrenal glands to produce epinephrine for exercise?

catabolic

Metabolic process that breaks down molecules into smaller units used for energy.

gluconeogenesis

The formation of glucose from noncarbohydrate sources (proteins and fats).

overtraining

Excessive frequency, volume, or intensity of training, resulting in reduction of performance, which is also caused by a lack of proper rest and recovery.

testosterone

A hormone producing secondary male sex characteristics.

anabolic

Metabolic process that synthesizes smaller molecules into larger units used for building and repairing tissues.

cortisol

typically referred to as a catabolic hormone; Under times of stress, such as exercise, this is secreted by the adrenal cortex and serves to maintain energy supply through the breakdown of fats and protein.

cortisol

Evidence suggests that low blood glucose and poor sleep may stimulate an increase in; normally elevated early in the morning with declining levels throughout the day and into early hours of sleep.

When sleep time is reduced

cortisol levels are elevated in early evening

testosterone

can increase in response to high-intensity interval training or strength training with sufficient overload, whereby large muscle masses are trained, and shorter rest periods are incorporated; 10x more in men than women

estrogen

produced primarily in the ovaries in the female, with small amounts produced in the adrenal glands in males. responsible for breast development and regulation of the menstrual cycle

estrogen

has an influence on fat deposition around the hips, buttocks, and thighs

training larger muscles

Acute hormone secretions also seem to be influenced to a greater degree when

higher

the healthiest the male, the levels of testosterone are

hypothalamus

The pathway for testosterone-stimulating muscle growth and recovery begins at the

thyroid gland

located in the anterior neck region and releases hormones into the bloodstream that control numerous functions in almost every organ in the body

insulin-like growth factors (IGF)

Anabolic hormone produced by the liver, which is responsible for growth and development.

mechano-growth factor

A unique characteristic of IGF is that is it also synthesized (made) and stored in muscles and tendons; released in response to the overload of a muscle or tendon, which, in part, plays a role in growth, repair, and recover

increase local IGF secretion of the muscles being overloaded

Evidence suggests that an emphasis on the eccentric (lowering or decelerating) phase of an exercise in which a weight is slowly returned back to the starting position will

bmr

The amount of energy required to maintain the body at rest; thyroid hormones are responsible for this

calcitonin

Thyroid hormone that helps the body use calcium properly to aid with maintaining bone mineral density.

Effects of Increased Time Under Tension (TUT)

Slower resistance training repetitions (more time under tension) increase growth hormone, testosterone, and epinephrine compared to faster repetitions.

glucose intolerance

A condition that results in elevated blood glucose levels; can be a result of inadequate sleep

posterior lobe

dark green

anterior lobe

red

pineal gland

blue

hypothalamus

pink

pituitary

light purple

thyroid

orange

parathyroid

yellow

liver

light blue

adrenal

light green

cortex

gray

medulla

yellow orange

stomach

yellow

pancreas

red

follicle

dark green

ovary

light green

corpus luteum

blue

sperm-producing cells

orange

endocrine cells

purple

testis

gray

meal is consumed

Insulin response to elevated blood sugar step 1

glucose enters the blood, raising blood glucose levels

Insulin response to elevated blood sugar step 2

pancreas releases insulin in response to elevated glucode levels

Insulin response to elevated blood sugar step 3

insulin binds to glucose in the blood

Insulin response to elevated blood sugar step 4

insulin escorts glucose to muscle fat and liver cells to be be used as energy

Insulin response to elevated blood sugar step 5

blood glucose levels drop

Insulin response to elevated blood sugar step 6