BIO 108: Endocrine

Be sure to enable [answer with definition] and [multiple choice]

The endocrine system controls the body by releasing mediators called __.

hormones.

Hormones are specific molecules that bind to receptors on specific __.

target cells.

__ alters metabolic activities of many tissues and organs simultaneously.

Circulating hormone

__ uses chemical signals to transfer information from cell to cell within single tissue. Most common form of intercellular communication.

Paracrine

__ secretes hormones that act on itself.

Autocrine

What are these functions of:

• Stimulate synthesis of enzymes or structural proteins

• Increase or decrease rate of synthesis

• Turn existing enzyme or membrane channel “on” or “off”

Hormones

__ are specific cells that possess receptors needed to bind and “read” hormonal messages.

Target cells

__ is a protein molecule to which a particular molecule binds strongly, responds to several different hormones.

Hormone receptor

__ are different tissues have different combinations of receptors, presence or absence of specific receptor determines hormonal sensitivity.

Cells

__ system → reacts quicker → specific → short lived (Ex. phone call)

Nervous

__ system → reacts slower → wide ranging → lasts longer (Ex. mail)

Endocrine

__ = any perceived disturbance to homeostasis

Can be Physical, Chemical, or Emotional

Stress

Stress can lead to temporarily __ certain components of the __ system.

inhibiting, immune

Characteristics of __ Phase:

1. Increased mental alertness

2. Increased energy consumption

3. Mobilization of energy reserves (glycogen and lipids)

4. Circulation changes

5. Drastic reduction in digestion and urine production

6. Increased sweat gland secretion

7. Increases in blood pressure, heart rate, and respiratory rate

Alarm

Alarm Phase is an immediate response to __ and is directed by __.

stress, ANS.

The dominant hormone of the Alarm Phase is __.

epinephrine.

Effects of __ Phase:

1. Mobilize remaining lipid and protein reserves

2. Conserve glucose for neural tissues

3. Elevate and stabilize blood glucose concentrations

4. Conserve salts, water, and loss of K⁺, H⁺

Resistance

Resistance Phase is entered if stress lasts __ and glycogen reserves nearly exhausted after ____.

longer than few hours, several hours.

The dominant hormone of the Resistance Phase is __.

glucocorticoids.

Characteristics of __ Phase:

• Begins when homeostatic regulation breaks down

• Failure of 1 or more organ systems will prove fatal

• Mineral imbalance

Exhaustion

__ glands secrete their products through ducts to the body surface or body cavities.

Exocrine

__ glands are ductless glands that produce and release hormones secreted by their cells to the extracellular fluid and then to the blood through diffusion.

Endocrine

__ - when the number of open receptors increase, the target tissue becomes more sensitive to a hormone.

Up-regulation

__ - when a hormone is in surplus, there are less target receptors and responsiveness to the hormone decreases.

Down-regulation

__ (opposing) - when one hormone opposes the action of another hormone.

Antagonistic

__ (additive) - when the effect of two hormones acting together is greater than the sum of each hormone acting alone.

Synergistic

__ effects - 1 hormone is necessary for another to produce effect.

Permissive

__ effects - hormones produce different and complementary results.

Integrative

__ stimuli - arrival of neurotransmitters at neuroglandular junctions.

Neural

__ stimuli - changes in composition of extracellular fluid.

Humoral

__ stimuli - arrival or removal of specific hormone.

Hormonal

Actions of __:

• Synthesis of new molecules

• Changes plasma membrane permeability

• Stimulates transport in or out

• Alter rate of metabolic reactions

• Causes contraction of smooth or cardiac muscle

Hormone

Which classes of hormones:

• Small molecules structurally related to amino acids

• Synthesized from the amino acids: Tyrosine & Tryptophan

Amino Acid Derivatives

Synthesized from the amino acids:

__ - thyroid hormones & epinephrine, norepinephrine, dopamine

__ - Melatonin (produced by pineal gland)

Tyrosine, Tryptophan

Which classes of hormones:

• Chains of amino acids

• Synthesized as prohormones

  • inactive molecules converted to active hormones before or after secretion

Peptide Hormones

Which group of Peptide Hormones:

• More than 200 amino acids long, with carbohydrate side chains

Glycoproteins

Which group of Peptide Hormones is all hormones secreted by:

• hypothalamus, heart, thymus, digestive tract, pancreas, posterior lobe of pituitary gland, anterior lobe of pituitary gland

Short Polypeptides

Which classes of Lipid Derivatives:

• Derived from the fatty acid arachidonic acid

• Are small molecules with five-carbon ring at one end

• Are important paracrine factors

• Coordinate cellular activities

• Affect enzymatic processes in extracellular fluids

Eicosanoids

__ are released by activated white blood cells, or leukocytes. Important in coordinating tissue responses to injury or disease.

Leukotrienes

__ are produced in most tissues of body, are involved in coordinating local cellular activities.

Prostaglandins

Which classes of Lipid Derivatives:

__ hormones are derived from cholesterol.

Steroid

__ soluble hormones travels freely in blood, can not pass thru a plasma membrane, binds to target cell surface, uses a 2^nd messenger.

Water

__ soluble hormones bind receptors within target cells, effect DNA directly, travel in blood by transport proteins, can be taken orally.

Lipid

The hypothalamus is an important __ gland and controls the __ nervous system.

endocrine, autonomic

The __ is a major integrating link between nervous system and endocrine system, and secretes regulatory hormones.

hypothalamus

__ Hormones (RH) - Stimulate synthesis and secretion of 1 or more hormones at anterior lobe.

Releasing

__ Hormones (IH) - Prevent synthesis and secretion of hormones from anterior lobe.

Inhibiting

The Hypophyseal Portal System is located in __ pituitary gland and is a network of __ vessels.

anterior, blood

The Hypothalamohypophysial Tract is located in __ lobe of pituitary gland and contains axons of hypothalamic __.

posterior, neurons.

The __ gland lies within the sella turcica.

pituitary