binds only to thyroid cells

target cell receptors decrease due to excess of the hormone ( they become less sensitive)

– bound to transport proteins that are synthesized in the liver. They can be digested and taken orally.

·       steroid hormones- large diverse group

·      thyroid hormones- t3 and t4

·      nitric oxide- gas ex viagra

– circulate freely in our water plasma and are destroyed by digestion.

·       amine hormones- ex epinephrine, norepinephrine, dopamine

·       peptide & protein hormones- ex hgh, insulin, oxytoxin

·       eicosanoid hormones- ex prostaglandins leuctrines

Response to a hormone depends both on the hormone and the target cells. Ex many target cells react differently to the same hormone.

A single hormone can cause several different cellular responses. Ex the hormone can cause contraction at the same time it can change permeability of something

Hormones must bind to receptors to function.

1.   lipid soluble hormone molecule diffuses from the blood through the intersticial fluid and lipid bilayer into the plasma membrane of the cell

2.   if that cell is a target cell the hormone will bind to the receptor in the cytosol or nucleus and alter the gene expression: turns specific genes of dna on and off.

3.    New messenger rna forms, leaves the

4.   new proteins alter the cells activity and cause the typical hormone response

                               1.     The water soluble hormone is known as the first messenger it diffuses from the blood and binds to its receptor on the surface of the target cell. The hormone receptor complex activate membrane proteins. Which activates the enzyme adenylate cyclase.

                               2.     Adenylate cylase converts atp to cAMP it takes place inside the cytosol

                               3.     cAMP is know as the 2^nd messenger and it activates enzymes inside the cell.

                               4.     Cellular proteins are phosphorolated by the enzymes by the enzymes causing the proteins to become active or inactive

                               5.     These active proteins produce our physiological response desired by the hormone

                               6.     Enzymes inactivate cAMP turning off the cells response to the hormone. Hormones that bind to plasma membrane receptors can induce effectes a low concentrations because a chain reaction occurs inside a cell.

Hormone Interactions (3 variables)- the responsiveness of the target cell depends on:

1.     the hormone concentration

2.     the abundance of the target cells hormone response related to the # of receptors

3.     influence exerted by other hormones

1. permissive effect
2. synergistic effect
3. antagonistic effect

                              1.     signals from the nervous system

                              2.     chemical changes in the blood

                              3.     other hormones

·      types of cells in anterior pituitary gland (5)

1. somatotrophs
2. thyrotrophs
3. gonadotrophs
4. lactotrophs
5. corticotrophs

Thyroid-stimulating hormone (TSH)

1.   prolactin (PRL) initiates milk production in the mammary glands

1.   Adenocorticoropic hormone (ACTH)- and Melanocyte-stimulating hormone (MSH)- ACTH stimulates adrenal cortex to secrete glucocorticoids.

1.   with other hormones, initiates and regulates milk production of the mammary glands.

·      effect 2 target tissues, the uterus and breast and during delivery it enhances contraction of the uterus. After delivery it stimulates milk ejection from the mammary glands.

located inferior to the larynx

Made up of

• thyroid follicles
• follicular cells
• thyroid homrones
• parafollicular cells

o   simple cells that form the walls of the follicle and they range from cuboidal to the columnar. When influenced by thyroid stimulating hormone touches the cell it tells the cell to produce 2 hormones, t3 and t4.

·      iodine ions are taken from the blood and put into the follicular cells.

·      is a glycoprotein that helps form T3 and T4.

·      Iodine is attached to tirozine and forms a colloid.

·      breaks the colloid forming t3 and t4.

·      Then they are sent out into the blood

1.   Increase basil metabolic rate (BMR)

2.   Stimulate the synthesis of sodium and potassium pumps

3.   Stimulates protein sythesis and increase use of glucose and fatty acids for ATP

4.   Increase body temperature

5.   Enhances actions of epinephrine, hgh, and insulin

secreted by parafolliular cells,decreases blood calcium levels by inhibiting osteoclast activity.

embedded in the posterior lobes of the thyroid. Made of 2 different types of cells

·      Chief cell- most abundant and produces the hormone

·      Oxyfil cells- function is unknown

of them located on the superior portion of the kidney and it is triangular/pyramid shaped. 2 parts that function differently: cortex and medulla. Cortext makes up the majority. Medulla is the smaller inner most region. Complete lost of adrenal cortex hormones will lead to death from dehydration with in a couple days.

o   zona glomerulosa- secretes hormones called mineralcorticoids- involved in mineral metabolism

o   zona fasciculate- glucosecortacoids - cortisol

o   zona reticularis- androgens -CHEA

found in zona glomerulosa

secretes aldosterone

secreted by mineralcortocoids

 regulates sodium and potassium and helps adjust to low blood pressure and low blood volume. Also causes excretion of hydrogen ions to help raise your bodies PH

main glucocorticoid

o   roughly 95 % of what is secreted by that cortex.

§  effects of cortisol-

ú  protein break down,

ú  glucose formation,

ú  lypolysis

ú  resistence to stress

ú  anti-inflammatory (inhibits WBC from getting to a wound)

ú  depression of the immune system

secrted in the zona reticulars

steroid hormones

main one is DHEA

is an adrogen

promotes an increased sex drive and is convereted to estrogen for women after menopause. Stimulates growth spirts during adolescence.

made in the adrenal medulla

to intensify the fight or flight response. No essential for life

1. alpha
2. beta
3. delta
4. F cells

located in the roof of the 3^rd ventrical. Secretes melatonin.

located behind the lungs. Secretes hormones that promote the maturation of T cells( a white blood cell that destroys microbes and foreign substances.

1. fight or flight response
2. resistance reaction
3. exhaustion

1.   hypothalamus tells the adrenal medulla to secrete epinephrine.

1.   if the stressor stays long enough, this goes into play and it helps the body keep fighting the stressor when the fight of flight response dissipates. done by the hormones cortisol, HGH, and thyroid stimulating hormone