What body system(s) malfunctioned to cause these differences? Skeletal, Muscular and other systems...

What body system(s) malfunctioned to cause these differences?

Skeletal, Muscular and other systems involved but caused by problems with the __________ system!

BIOL 2030 Human Anatomy & Physiology IIBIOL 2030 Human Anatomy & Physiology II

What is the main function of the endocrine system?

Regulate tissues/cells• *

• *

• *

• *

• *

Nervous System

How did the nervous system regulate other tissues?

What was the medium for transmitting the control signal?

Intercellular communication via the ______________ can be likened to using the telephone and an FM signal…

The message goes …

Pulses (___________) regulate response.

Any other system(s) that regulate other tissues?

The Endocrine system on the other hand is more like a radio broadcast and AM signals…

The message is sent …

Concentration (________) regulates response.

Historically these two systems thought to be very independent. Now their interdependence is recognized

Which is frequency modulated?

Which is amplitude modulated?

One aspect shared between 2 systems is use of intercellular chemical signals

Type Function Example

* similar, adjacent tissue Prostaglandins

* different, nearby tissue histamine

* regulate other distant tissue Thyroxine

* produced by neuron Oxytocin

* secreted by neuron Acetylcholine

* secreted into environment sex pheromone

Where do hormones come from?

The Endocrine system is comprised of what organs (glands)?

Actually other organs are also capable of secreting hormones… Example the heart and the placenta

What are the characteristics of hormones?

3 general characteristics…

1) ___________…

2) ___________…

3) ___________…

Do hormones persist once formed?_______________! They are “decommissioned” at various rates depending on the nature of the hormone (some hormones are removed from circulation

within 2 min. of secretion).

Hormones are only active if “______” and are usually only acted upon if “______”

Amount of time to remove 1/2 the initial dose is the ______________.

________ based hormones have short 1/2 lives

________ based (steroids) have long 1/2 lives

How are hormones distributed?

All hormones by definition travel via _________!

They can travel either:

1) _______, in an unbound state

2) _______ with plasma proteins

When hormones are bound to their protein (usually specific protein for each hormone) they exist in an ___________ of bound and free hormones.

Response?

Take 5!!!

How is the half-life of a hormone affected by a decrease in the concentration of the specific plasma protein to which that hormone binds?

Discuss with your neighbor and predict an answer

What are the chemical categories of hormones?

Hormones fall into 2 basic categories:

1) _________________Biogenic amines (amino acid derivatives) ~ T4 Polypeptides ~ TRHGlycoproteins ~ TSHProteins ~ GH

2) ______________Steroids (made of cholesterol) ~ Testosterone

Would you expect these to be

hydrophylic or hydrophobic?

How are hormones distributed?

What are the patterns of hormone secretion?

3 characteristics…

1) _________… stable levels.

2) _________… levels change dramatically.

3) _________… levels change, but at regular intervals.

Which is which?

How do hormones work?

Hormones bind to _________ receptors on ___________.

This binding results in ________ of _____________.

3 patterns of regulation…

1)

The level of a monitored substance initiates response and secretion of hormones. Ex. elevated blood glucose results in increased insulin levels, which in turn reduce blood glucose levels.

How is hormone secretion stimulated?



1) Other substance acting on gland (humoral)

2)Nervous stimulation results in the release or inhibition of hormones. Ex. epinephrine released as a result of sympathetic stimulation.




2) Neural control glandsNervous stimulation results in the release or inhibition of hormones.




2) Neural control glands

3)

The secretion of one hormone influences thesecretion (+ or -) of another hormone.

Ex. TRH causes release of TSH

How is hormone secretion inhibited?



2) Neural control glands

3) Hormonal control of other endocrine glandsThe secretion of one hormone influences the

secretion (+ or -) of another hormone.

The activity of endocrine glands depends on Feedback mechanisms (see pgs. 9-12).

These regulate one or more variables and often consist of 3 components:

1) ___________What are their function?

2) ____________________What function?

3) ___________ How about their function?

How is hormone secretion controlled?

2 main situations…

1) Variable is maintained within “+” & “-” limits

thresholdsSet point

Normal range• Where are the receptors

working?

• Where does the receiver respond?

• Where is the effector(s) active?

2 main situations…

2) The variable moves away from a “normal” value

Set point

Normal range

thresholds

• Where are the receptors working?

• Where does the receiver respond?

• Where is the effector(s) active?

Comparing the status of the variable prior to and after the response... which one would you classify as positive feedback and which one is negative feedback???

Set point

Set point

An example from your body…

Case Study pg. 580

Josie owns a business and works hard to manage her employees and make time for her family. Over several months, she frequently felt weak, was often unable to concentrate, and felt cold when others did not. In addition, she began to gain weight, even though she had a small appetite. Finally, after noticing a large lump in her neck inferior and lateral to her larynx, Josie decided to see her physician. A blood sample was taken, and the results indicated low levels of thyroid hormones (hypothyroidism; see chapter 18), high levels of TSH, and low levels of iodine. The doctor concluded that Josie had developed a goiter, or an enlarged thyroid gland. He explained that the goiter had probably formed because her dietary intake of iodine was too low over a prolonged time. Without iodine, Josie's thyroid gland was unable to synthesize thyroid hormones. Thus, in response to low thyroid hormone levels, the anterior pituitary gland continued to secrete the tropic hormone TSH, which caused the thyroid gland to keep getting bigger and bigger. In addition, the hypothalamus continued to stimulate the anterior pituitary in the absence of thyroid hormones. Josie was treated with radioactive iodine (131I) atoms, which were actively transported into her thyroid cells, where the radiation helped shrink her thyroid gland back to normal size. Subsequently, Josie had to take dietary iodine supplements and thyroid hormone supplements until her thyroid gland was able to produce thyroid hormones on its own again.

Case Study pg. 580

http://www.ijem.in/articles/2013/17/2/images/IndianJEndocrMetab_2013_17_2_228_109671_f2.jpg

HormoneMembrane-Bound

ReceptorIntracellular

Receptor

Receptor/ion channels

Cell Response

Receptor/G proteins

Opens/closes channels

Activates existing enzymes

Synthesizes new enzymes

Activates genes

Receptor/intracellular enzymes

Target tissues can modify their response to a hormone by Down- and Up- regulation.

Why do tissue responses vary over time?

_____________ is the decrease in the number of hormone receptors. Caused by:1) Decrease in receptor _____________2) Hormone/receptor binding can lead …

Is this pattern effective for Long-term constant levels or short-term changing concentrations?

____________ is an increasein hormone receptors

Why do tissue responses vary over time?

For example, Follicle-stimulating Hormone (FSH) causes and increase in the number of Luteinizing Hormone (LH) receptors

Is this pattern effective for Long-term constant levels or short-term changing concentrations?

Take 5!!!Estrogen is a hormone secreted by the ovary. It is secreted in > amounts after menstruation and a few days before ovulation. Among its many effects is causing up-regulation of receptors for another hormone secreted by the ovaries, progesterone. Progesterone is secreted after ovulation and a major effect is to cause the uterus to become ready for the embryo to attach. Predict the result if the ovary secretes too little estrogen?Discuss with your neighbor and predict an answer

How are hormones removed from circulation?4 mechanisms used:

1) ______________ -- enzymatically broken down by liver, kidneys, lungs etc.

2) ______________ -- hormones that can’t be broken by themselves are combined with another compound and then they can be excreted.

3) _____________ -- some hormones can be excreted by the kidneys in urine and by the liver in bile.

4) _________________________-- some hormones are pumped back into cells that can re-use them later.

How do hormones and their receptors vary?

Receptors also fall into 2 major categories:

1) Receptors embedded in the plasma membrane with a receptor site on the outside and an “affector” component inside.

2) Receptors are in the cytoplasm or in the nucleus of the cell.

Intracellular receptors

These receptors are in the cytoplasm or nucleus of the host/target cell. Hormones that bind to these receptors must be able to…

These hormones influence the manufacture rate of cellular products or activate enzymes


Ex. Aldosterone

1)

2) ___________ with receptor in cytoplasm

3) Hormone/receptor complex …

4) Complex activates…

5) mRNA is …

6) ____________produce response


Membrane-bound receptors regulate/influence cells via 2 basic mechanisms:

1)

2)


What type of scenario is this?!?



1) Receptors that activate G Proteins

2) Hormones that influence intracellular enzymes

Some receptors have internal portions that function as enzymes, or they are closely associated with enzymes.

Ex. Atrial natriuretic hormone and receptor cause enzyme portion (GCase) to make cyclic GMP


How can < conc. of hormone result in > effects?A _____ number of hormones bind with receptors activating several existing components, all of which activate more components individually, causing a large number of final product. This is the _______________.

Is this more likely with proteinaceous or lipid-based hormones?

Take 5!!!Which hormone would have the quickest effect… estradiol (sex hormone) or insulin ? Why?

Discuss with your neighbor and predict an answer

What body system(s) malfunctioned to cause these differences? Skeletal, Muscular and other systems...

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