humoral/antibody response:
B cells identify foreign antigens.
B cells are activated by helper T cells.

natural killer cells (NK cells) are white blood cells that destroy infected cells and cancer cells in your body. 

3. interferons...

a type of cytokine

 immune response cells

G proteins...how do they work?

Steroid Hormones
are hydrophobic so they can diffuse across the plasma membrane of a cell. Once inside, they bind to receptors in either the cytoplasm or nucleus, forming an activated receptor-hormone complex which moves into the nucleus and binds to the DNA. In this way it serves as a transcription factor, regulating gene expression. Examples of steroid hormones include estrogen, progesterone and testosterone.

phagocytes may be monocytes, macrophages and neutrophils - white blood cells that engulf pathogens,
foreign material, and dead cells.

                                         Immunity
​   and the Lymphatic System

interferons are a type of cytokine
that "interferes" with viruses' ability to infect and multiply. . 

         your immune response

1. phagocytes

Amine hormonesare synthesized from the amino acids tryptophan or tyrosine. Ex: melatonin is synthesized from tryptophan... when secreted by the pineal gland it helps regulate circadian rhythm. Tyrosine derivatives include thyroid hormones and
catecholamines such as epinephrine, norepinephrine, and dopamine. Epinephrine and norepinephrine are secreted by the adrenal medulla and play a role in the fight-or-flight response, whereas dopamine is secreted by the hypothalamus and inhibits the release of certain anterior pituitary hormones. Some amine hormones are polar while others are not. 

                                  chemical barriers:
1. lysozyme in tears/saliva/mucus
2. stomach acid kills pathogens in digestive system 
3. sweat is acidic - inhibits bacterial growth on the skin 

Diabetes: Type 1

 humoral/antibody immunity: B cells produce antibodies                                                                and memory cells

ooops...don't forget
synpatic signaling

internal innate defenses

    Acquired Immunity

compared to type 2

 innate vs adaptive
​immunity

  Lymph nodules (1 mm) are areas (no fibrous boundaries) where there are loads of lymphocytes. They are usually located in the loose connective tissue beneath membranes in the digestive system, respiratory system, and bladder. Nodes often form clusters such as your tonsils (pharyngeal, palatine, lingual) in the wall of your pharynx.  Another example is MALT = mucosa associated lymphoid tissue, lymphoid tissue that protects the epithelial lining of your gut, respiratory tract, urinary system and reproductive systems. Peyer's patches are nodule clusters in your gut.   

                    physical barriers:
1. cilia in respiratory tract
2. skin
3. mucous membranes line respiratory,             digestive, reproductive tracts

     coronavirus targets ACE=2 surface proteins found in lungs, kidneys, intestines and blood vessel endothelium.

2. natural killer cells
​NKs

  Hilum -->

review question:
describe the 6 categories of our internal innate defenses

Diabetes

now we'll explore acquired immunity 

Peptide/Protein Hormones are 
are hydrophylic so they cannot freely cross the plasma membrane requiring receptors on the surface of the cell which are typically coupled to internally anchored proteins such as G proteins. The hormone/receptor complex activates a series of intracellular molecules called second messengers which initiate cell activity, a process called signal transduction. Second messengers include cyclic AMP (cAMP), calcium ions (Ca2+), nitric oxide (NO) and protein kinases. Second messengers amplify the signal.
Peptide hormones consist of short chains of amino acids.
​Protein hormones are longer polypeptides. 
Peptide/Protein hormones include insulin, glucagon, leptin, ADH, oxytocin and GH.

        ​ Innate Immunity

review question:
describe the physical and chemical barriers of our external innate defense system

Feedback mechanisms:
a signal is sent from the hypothalamus to the pituitary gland in the form of a "releasing hormone," which stimulates the pituitary to secrete a "stimulating hormone" into circulation. The stimulating hormone then signals the target gland to secrete its hormone. As the level of this hormone rises in the circulation, the hypothalamus and the pituitary gland shut down secretion of the releasing hormone and the stimulating hormone, which in turn slows the secretion by the target gland.

Growth Hormone 

Why do we need Iodine?

Thyroid
​ Hormone 

                                                immune response cells
1. neutrophils: 65% of WBCs.  fight bacterial and fungal infections.
2. lymphocytes: 30% of WBCs. T cells protect against viruses and cancer
     B cells produce antibodies
3. monocytes: large, phagocytic cells
​4. macrophage: phagocytic cells that engulf pathogens/debris.
    derived from monocytes migrating from the bloodstream into tissues. 
5. eosinophils: allergic reactions and fight parasitic infections.
6. basophils: circulating cells release histamine and heparin 
7. mast cells: tissue resident cells release histamine and heparin

external innate defenses

1

2

3

4

5

​

6

  thoracic duct returns lymph from the majority of your body to the left subclavian vein and left internal jugular vein...
​the right lymphatic duct drains the right head and upper arm/torso into the right subclavian vein.

6. fever

 Endocrine
​System

competitive gut bacteria

we just explored
​innate immunity

  Your spleen is the largest (albeit secondary) organ of your lymphatic system. It's responsible for filtering your blood by removing old or damaged RBCs, storing iron from recycled RBCS, and triggering immune responses by B/T cells circulating in your blood. It exhibits a fibrous capsule attached to the stomach by the gastrosplenic ligament, numerous trabeculae, white pulp where the lymphocytes hang out and red pulp where macrophages  stand by the ready.

some hormones are lipid 
soluble...

review question:
list the immune response cells and provide a function for each

when an infection is detected, the        immune system triggers the      release of chemicals (pyrogens) which signal the hypothalamus    (the body's thermostat) to raise the        body temperature trying to       create an environment that is less            friendly to the pathogen:
1. inhibits bacterial growth
2. stimulates phagocytosis
3. speeds up tissue repair
4.liver stores more iron so bacteria cant replicate

Hypothalamus ->
Pituitary ->
Gonads

still working on this page...;)

 immune response
​participants

Blood Pressure Homeostasis:
ANP decreases blood pressure...

An Endocrine Disease
occurs when a gland produces too much or too little of an endocrine hormone leading to a hormone imbalance. Causes may be the development of nodules or tumors which may affect hormone levels.

Hypothalamus ->
Pituitary ->
Adrenal glands

                             Pathogenic bacteria make us sick by:
1. Invading host cells. Cells  rupture and intercellular bacteria are released. E. coli, Shigella, Salmonella, and   Neisseria gonorrhoeae induce host epithelial cells to engulf them in a process resembling phagocytosis. 

​2. Producing toxins. Toxins are poisons. Endotoxins are part of the cell wall of some bacteria and are released   when the bacteria lyses. Exotoxins are proteins produced inside pathogenic bacteria as part of their growth and   metabolism. Exotoxins are released when bacteria die and inhibit cellular metabolism. Exotoxins are VERY   lethal...1 mg of the botulinum exotoxin is enough to kill one million guinea pigs. Disease is caused by the toxins. 

with subsequent infections to the same pathogen, antibodies are produced much more quickly

Hypothalamus/ Pituitary
​Relay

                                 Sequence of Hormone Action:
   1.hormone is synthesized, stored then secreted when release is triggered 
   2.hormone is transported via circulation to target cells
   3.hormone is recognized by specific cells membrane receptors of target cells
   4.hormone signal is relayed and amplified to the cell interior causing cell response
   5.reactions of target cells are recognized by the original hormone-producing
       cells leading to a reduction of hormone production in a negative feedback loop.
   6. hormone is degraded

                                                              ​inflammation:
1. damaged cells and immune cells release  chemicals like histamine and cytokines. 
2. these chemicals cause blood vessels to dilate (vasodilation), leading to increased blood flow to the area and increased permeability of the vessels, allowing fluids and white blood cells to leak into the tissues. 
3. this increased blood flow, fluid leakage, and the activity of immune cells results in the the signs of inflammation we know: redness, swelling, heat and pain
4. immune cells try to eliminate the
pathogens/damaged cells and start repairing the tissue.
5. acute inflammation: tissue is repaired.
chronic inflammation: tissue damage and long-term health issues.
more on this later...

Classes of Hormones

btw...
TNF-alpha = Tumor Necrosis Factor alpha = a cytokine 

 cell mediated immunity: cytotoxic T cells destroy pathogen

​Cushing's Disease: excess Cortisol

4. complement

​proteins

Catecholamines are adrenal hormones. Dopamine, norepinephrine; and epinephrine (adrenalin) are examples. Adrenal glands release catecholamines during physical/emotional stress. 

Hypothalamus ->
Pituitary ->
Thyroid

cytokines are produced by macrophages, B lymphocytes,
​ T lymphocytes and mast cells

Interleukin released by monocytes is a  cytokine
that can reset the 
​thermostat in the hypothalamus causing fever

Hypothalamus ->
Pituitary ->
Growth Hormone

Thyroid/
​Parathyroid
Connection

Blood Glucose controlled by alpha/beta cells of Pancreas

5. inflammation

complement proteins are released when the complement system is activated.
this occurs in response to infection or tissue damage. inactive proteins are activated via through a cascade of enzymatic reactions which trigger a chain reaction where one protein activates the next.,

...while others are water soluble

exogenous pyrogens (from pathogens)
 trigger the release of endogenous pyrogens which cause fever.
ex: lipopolysaccharide
(LPS of Gram-negative bacteria)
is an endotoxin and an exogenous pyrogen

...while the
RAA system increases blood pressure

  Lymph nodes exhibit a fibrous capsule which extends inward to divide the node into trabelculae Blood vessels enter and exit the node at the hilum as does the efferent lymphatic vessel. Afferent lymphatics enter the node along the opposite margin. Between the two are mesh like areas including the outer cortex which exposes the lymph to B cells, the paracortex which contains T cells, and the medulla also with B cells and macrophages. As lymph travels through these areas and and dense tissue called medullary cords (think a strainer), 99% of antigens are removed and the immune system has a watchful guard dog. The largest nodes are found at the intersections of peripheral areas and the trunk and can swell in response to infection (inflammation of tissue).

    Hormone levels are controlled by one of three homeostatic mechanisms:
   
1. Negative feedback by stimulated hormone:    When one hormone stimulates the
    production of a second, the second suppresses the production of the first.

    Ex.: Follicle stimulating hormone FSH stimulates the release of estrogens from the ovary.
             A high level of estrogen, in turn, suppresses the further production of FSH.

2. Antagonistic pair of hormones:
    Ex. Insulin causes the level of blood sugar (glucose) to drop when it is too high.   
           Glucagon causes it to rise when it is too low.

3. Negative Feedback by controlled molecule:
    Hormone secretion is increased (or decreased) by the concentration of the controlled molecule.
     Ex.: As Ca2+ in the blood rises, it suppresses the production of the Parathyroid hormone (PTH).               
             Low levels of Ca2+ stimulate PTH release.

Chemical Signaling