Thyroid cancer can develop slowly over many months or even years. Because the symptoms are frequently overlooked, diagnosis is often delayed. However, thyroid cancer is usually treated successfully with a combination of surgery, radioactive iodine, and thyroid medication. Surgical removal of the thyroid gland results in A. a decrease in thyroxine levels and TSH levels B. an increase in thyroxine levels and TSH levels C. an increase in thyroxine levels and a decrease in TSH levels D. a decrease in thyroxine levels and an increase in TSH levels

 Following the removal of the thyroid gland, thyroid medication is prescribed in order to A. increase sodium reabsorption and water retention B. decrease sodium reabsorption and water retention C. increase the rate of metabolism and the rate of heat production D. decrease the rate of metabolism and the rate of heat production

 The release of thyroxine from the thyroid is directly regulated by  A. TSH  B. TRH  C. iodine  D. thyroxine

 A characteristic symptom of hyperthyroidism is  A. lethargy  B. weight loss  C. intolerance to cold  D. slowed mental processes

Hormones: Blood Pressure and Long- Term Hormonal Problems Chapter 15.4

Blood Pressure  There are two hormones that affect blood pressure in the body: 1.ADH (antidiuretic hormone) 2.Aldosterone

ADH  The process of producing urine is known as diuresis.  Thus, antidiuretic hormone works to counter urine production, mainly through reabsorption in the kidney.  ADH tells the kidneys to reabsorb more water.

Detecting Water Loss  The hypothalamus contains osmoreceptors which detect the blood’s osmotic pressure.  When it finds the pressure is too high it will counter this by releasing some of it’s water into the bloodstream.  This causes the hypothalamus to shrink.

 When the hypothalamus shrinks, it triggers two nerve impulses: 1.The thirst response, which will lead to fluid intake, increasing water. 2.The pituitary will release stored ADH, which will increase reabsoprtion, increasing water.

 When the blood receives enough water, some will move back into the hypothalamus.  This stops the above nerve impulses and acts as a negative feedback loop.

Aldosterone  When blood pressure is low, a structure in the kidneys called the juxtaglomerular apparatus (JGA) releases renin.  Renin, through a series of steps, eventually activates aldosterone production from the adrenal cortex.  It also initiates vasodilation.

 Aldosterone makes the nephrons more permeable to sodium, increasing sodium reabsorption.  As this happens, water is also reabsorbed to maintain the osmotic pressure.  It, like ADH, works to maintain the water balance, but in different means.

Stress  Through experiments, scientists have found the following hormonal responses to long-term stress: 1.Increased epinephrine 2.Increased cortisol 3.Increased glucagon 4.Decreased insulin

 All four of these responses lead to an increase in blood glucose, which directly leads to an increase in blood pressure.  This activates ADH production, which will greatly increase blood volume.  With this increased volume, pressure and heart rate from epinephrine you have some serious long-term effects on the vascular system.

Steroids  Anabolic steroid use first began back in the 1950’s primarily by competitive weight lifters.  These replicate the effects of testosterone, which you will learn in Unit B.  Studies have found they increase fast twitch muscles, but slow twitch are relatively unaffected.

 Steroids have quite a few negative side effects that have been documented.  In teens it fuses growth plates along bones, leading to stunted height.  It has also been linked to mood swings and unprovoked rage.  The next diagram also outlines effects steroids would have on both genders.

Prostoglandins  Prostoglandins are a hormone produced by every cell in the body.  Specifically, the prostoglandin produced by a cell is designed to target itself.  It is released in response to damage in a tissue, and acts inflame the area with extra blood and thus platelets.  Aspirin acts as a prostoglandin inhibitor.

Homework  Pg  Pg