What are the two control systems in the body?
      Compare and contrast them.

Central Nervous System - uses electrical signals for FAST, short-lived, immediate results.
     Controls the body's immediate response to some condition in the environment. 
      Fast, in this instance, means the response lasts a few minutes to at most a half hour or,
      in extreme, situations perhaps a couple hours.  As soon as neural output ceases, the
      response also ceases.

Endocrine System - uses chemical messengers called hormones for SLOW, long-lasting
      control.  Controls the body's LONG-term activity - specifically growth, development and
      maintenance of the body.
      Slow, in this instance, means the response is initiated within a few minutes and lasts
      from a few hours, to days, and even to months.  Because the chemicals remain in the
      system long after being released, the effect lingers for long periods of time.

What are the two types of glands in the body (see integumentary system)?
     Compare and contrast them.

In general, the Function of the Endocrine System is to control growth, development, and maintenance of the body.
These are typically LONG LASTING controls - based on chemical messengers.

In general, each endocrine gland secretes one or more hormones. You must know the name of each gland and the major hormone(s) secreted.  Each gland is composed of cells that produce and secrete hormones.
  Which organelle(s) would you predict the endocrine cells to have in abundance? 
    What are the functions of the endomplasmic reticulum, golgi body, and secretory vessicles?

What is the functional unit of the endocrine system?
 The HORMONE.

A Hormone is a chemical messenger released in one tissue and transported by the bloodstream to reach target cells in other tissues.
How does a hormone know when it has found its 'target cells'?
   Remember the 6 types of proteins in the CM?
   List them - give the function for each type. 
   Now, Which of these tells the hormone it has found its target?
Each hormone has a receptor molecule in the target cell that is specific to that hormone.

Three main classes of hormones:

1. Amino acid derivatives – similar to Amino Acids (AA), relatively small, Epinephrine, norepinephrine.

2. Peptide hormones – chains of AAs. Short chains such as ADH & oxytocin to small proteins such as GH and Prolactin. Largest class and includes all the hormones secreted by the hypothalamus, pituitary gland, heart, kidneys, thymus, digestive tract, and pancreas.

These two are POLAR molecules, are hydrophilic and dissolve easily into water.

How does this affect their ability to pass through the CM?

3. Lipid derivatives – two subclasses

Derived from cholesterol – Steroid released by reproductive organs and adrenal glands

Derived from arachidonic acid – 20 carbon FA. Prostaglandins - AKA ‘local hormone’, these are chemicals that affect only adjacent cells. Coordinate local cellular activities and affect enzymatic processes, such as blood clotting, that occur in extracellular fluids. These chemicals initiate and regulate a local inflammatory response and the immune response. They regulate the body’s reaction to the presence of ‘invader/foreign’ organisms. Interleukins, cytokines, interferons, etc.

How does this affect their ability to pass through the CM?

Compare and contrast Hormone with Prostaglandin.

Define a Hormone. Define a prostaglandin.

In order to produce the response needed, the Hormone must be able to trigger a cell to respond. How does the hormone trigger the cell? A cell that can be triggered by a hormone has receptor proteins that are specific to THAT hormone. If a cell has no receptor sites, it cannot respond to the hormone. The receptor can be either on the external CM or in the cytoplasm.
Remember the 6 types of proteins in the CM?
List them.
Why is protein shape important?
How does protein shape affect the hormone function?

Protein based hormones (Amino Acid and Peptide derived) are POLAR molecules.
These use the 1st and 2nd messenger method.

Water-soluble, protein-derived hormones CANNOT easily diffuse through the CM. Therefore, they bind to receptor proteins on the external CM and activate G-protein, a chemical inside the CM. This is called the First and Second Messenger method. The hormone, outside the CM, is the First messenger. The G-protein inside the CM, is the Second messenger. The G-protein, the second messenger, activates the cell’s response to the hormone.

What are the electrical characteristics of these molecules? (hint: polar vs. nonpolar)
  Do they dissolve in water or lipids?
    What does this mean with respect to the CM?
   Review Chapter 3, Cells and the structure of the CM.
   Where are the receptors for these type hormones located?

Lipid derived hormones are NONpolar - i.e. they are hydrophobic and diffuse easily through the CM.

Lipid-soluble lipid hormones DO pass through the CM. They bind to receptors in the nucleoplasm and therefore, directly activate the cell’s response to the hormone.

(See chapter 1.)

Negative feedback mechanisms are the primary control for both the nervous and endocrine systems.

What is homeostasis and the set point?
How is homeostasis related to the set point?

Negative Feedback: Directly homeostatic; it counteracts the trend, works to reverse the trend.

A change in a condition is noted (departure from homeostasis, i.e. away from the set point); a hormone is released which stimulates a return to ‘homeostasis’, i.e. it stimulates the reverse of the noted activity.

Why are Negative feedback mechanisms the primary control for the body?

Positive Feedback: supports the trend, pushing the condition farther away from the set point; NOT directly homeostatic.
Why are positive feedback mechanism rarely used to control the body?
What is stress?
How are positive feedback and stress similar?

Circulating serum Ca++ levels decline, release Parathyroid Hormone, Ca++ levels rise and exceed the set point for serum Ca++. Calcitonin is then released and target cells lower blood Ca++ levels.

Define hypocalcemia and hypercalcemia.

Calcitonin and PTH are antagonists.
What does this mean?

Insulin and Glucagon control blood sugar (glucose) level.
What is the normal blood sugar level?
What is the set point for blood sugar?
When blood sugar increases (when does this happen?) the pancreas releases insulin. Insulin binds to receptors on the CM of target cells and causes the CM to become more permeable to glucose and glucose enters the cell. This lowers the serum glucose level. As serum glucose declines, more glucose enters the blood from the digestive tract or the pancreas releases glucagon which triggers the liver to catabolize glycogen.

What is glycogen?

How does catabolizing glycogen affect blood sugar concentration?

Is this a positive or negative feedback mechanism?

Insulin and glucagon are antagonists.
What does this mean?

Hypothalamus – secretes Neurohormones that control the Pituitary gland. These neurohormones are called releasing or inhibiting hormones.The hypothalamus integrates the activities of the nervous and endocrine systems, the two control systems of the body.

Make a TABLE!

Pituitary gland (Hypophysis) – the master endocrine gland - rules and controls other endocrine glands. Has two lobes

Posterior pituitary lobe – 2 hormones

1. Oxytocin – Pitocin – stimulates contractions of the uterus during 
        labor and delivery of babies.

Anterior Pituitary - 7 hormones

1. GH – growth hormone; regulates metabolism
       Gigantism - too much GH as a child
       Cretinism - too little GH as a child
       Acromegaly - too much GH as an adult
   

2. TSH – thyroid stimulating hormone; stimulates the THYROID to release:

a. thyroxine (must have Iodine to function) sets the metabolic rate
  Goiter - a condition in which no Iodine is available and
    thryoxine builds up in the thyroid gland.

b. thyroCalcitonin – puts Ca++ into the bone, decreasing serum Ca++ levels. It is antagonistic to Parathyroid Hormone (PTH) which takes Ca++ out of the bone – increase serum Ca++ levels.

Describe the relationship between parathyroid hormone and calcitonin

Parathyroid glands – four small bodies close to the thyroid; make and release PTH –Parathyroid hormone.

What are the 2 main hormones responsible for regulating the amount of Ca++ in the blood? PTH and Calcitonin.

Why do we need to regulate Ca++ in the blood? Ca is used in:

Muscle contraction
Nerve signals
Clotting factor

Other endocrine glands:

Adrenal Glands- suprarenal glands, 2 parts:

Adrenal cortex – produces more than 2 dozen adrenocortical steroids (corticosteroids) which can be classified into 3 broad groups..

NOTE- these are all CHOLESTEROL based hormones – HYDROPHOBIC – How do NONPOLAR hormones cause the cell response?

Glucocorticoids - Cortisol – mobilizes energy reserves when blood sugar is low,
      it tells the liver to burn excess energy reserves: fat and muscle (protein)
      Cortisone - inhibits the immune system (it has other functions, too). 

Minerocorticoids – Aldosterone which concentrates urine;

Androgens or Sex hormones (steroid hormones) Testosterone, Estrogen,
      progesterone

What does cortisone do to the immune system?
   What is the effect when cortisone cream is used on an OPEN wound?

 

Adrenal Medulla - secretes the STRESS hormones that prepare the body for fight or flight.

Adrenaline (AKA Epinephrine) – Sympathetic NS.

Noradrenaline (AKA Norepinephrine and/or NorEpi) – Sympathetic NS

Both cause the stress response.

What is the other name for the Sympathetic NS?
   Describe the Stress Response.

What two hormones are released by the adrenal medulla?
    What is another name for epinephrine?
    What is another name for norepinephrine?

Hyperglycemia – too high blood sugar – and Beta cells make insulin which binds to cell receptors and speeds up (facilitates) cellular uptake of glucose, lowering blood sugar level.

Insulin is the ONLY hormone that decreases blood sugar level. Cannot depend solely on diffusion of glucose and steady state of glucose in blood. Requires facilitated diffusion, which requires insulin.

Hypoglycemia – alpha cells release glucagon which allows fine control – goes to the liver and triggers glycogenolysis which makes glucose which is then released into the blood.

How does exercise lower blood sugar levels?

Diabetes is a condition in which the body fluctuates between hypoglycemia and hyperglycemia. 
  Two dominant types of diabetes
     Type 1 - AKA Insulin DEPENDENT and Juvenile Diabetes
          Insulin producing cells in the pancreas are destroyed by the immune system
     Type 2 - AKA Insulin RESISTANT and Adult onset Diabetes
         By far the most common type. 

While these are the two most common types, some diabetics have symptoms and characteristics of both (sometimes called Type 3, Hybrid, or double Diabetes), and/or other symptoms and characteristics.  This is a complex disease with many variations.  Appropriate treatment depends on understanding completely the disease process in each person - there is no 'one-size-fits-all' in treating diabetes.

Define Hyperglycemia, hypoglycemia.
What does the prefix 'hyper-' and 'hypo-' indicate?
What does the suffix '-emia' indicate?

 

What are the two feedback mechanisms that control hormone secretion?
  What is the 'set point' in homeostasis?  Review Chapter 1, homeostasis
     What is the set point for blood sugar concentration?
        What does glucagon do to blood sugar concentration?
              How?
        What does insulin do to blood sugar concentration?
              How?

What is the simple formula for aerobic cellular respiration?

                         What is ATP?
  What is the role of Glucose in cellular respiration?
       Glucose is the source of STORED energy that is transferred to ATP.
  What is the function of insulin and glucagon in cellular respiration?
       Insulin causes cells to UPTAKE glucose, which puts glucose inside the cell and
          available to cellular respiration.
       Glucagon tells the liver to lyse glucose molecules from glycogen and put the glucose
           into the blood, which increases blood glucose levels, where it can be moved into
           cells.  Once inside the cell, the glucose is available for cellular respiration.
             What is glycogen?

Testes – testosterone

Ovaries – FSH, from the anterior pituitary, promotes ova development in follicles.

Follicle Cells – produce estrogen

Corpus luteum release a mixture of estrogens and progestins.

Placenta – through synergistic endocrine activity with the ovaries and pituitary gland, promotes normal fetal development and delivery.

 

Pineal gland – Synthesizes melatonin. Regulates sleep/wake cycles.

Thymus – thymosins play a key role in development and maintenance of normal immunological defenses.

Adipose tissues – insulin initiates a chain reaction of hormonal responses in adipose tissues which coordinate energy release and storage in the body. This cascade of chemical reactions influences many body systems metabolic rate, enzymatic activity, growth and development, health, and immune system responses, etc.

Adiponectin - counters Resistin - reduces inflammation, increases insulin sensitivity, improves HDL to LDL ratios.
Leptin - plays a role in weight mainenance, speeds metabolism which burns calories, ,
Resistin - may interfere with insulin; may promote conversion of fat to glucose.
 

The location of adipose tissues affects the type and quantity of hormones produced/secreted, as well as the effects of those hormones.  Abdominal fat - that located within the mesentaries and omenta of the abdomen- promotes problems such as diabetes and high blood pressure.

 

What are the hormones that control urine output, blood calcium concentration, & blood sugar concentration?
Know what each hormone does.

 

Remember – all the systems have to work together to maintain homeostasis.
 

Know which hormones are produced by which organ. These are also described in the Class Notes.