Lesson 15 - Heart of the Heart - SAY WHAT??????????

 THIS IS ABOUT THE STUFF THAT MAKES THE HEART BEAT...

    Ok. The heart doesn't just beat magically (but that would be cool), it uses a complex system of nodes and fibers to keep the beat going. Let's get started

    All heart pulses start near the right atrium of the heart. Then the move diagonally to the left ventricle. They begin at the sinoatrial node (SA node). Then they move to the atrioventricular node (AV node) which causes the pulse to slow down. Then the AV node sends it down through the bundle of His which is located in the interventricular septum. The signal divides into the left and right bundle branches which spread to the left and right ventricles. The branches then lead to the Purkinje fibers which is wear the signal stops.

THIS IS VERY CONFUSING!!!!
IT WILL BECOME EASIER WHEN WE TALK ABOUT  THE   EKG

I hope this helped!

http://www.ceufast.com/courses/viewcourse.asp?id=239

Lesson 14 - The vessels of life - Arteries? Veins? Capillaries?

ARTERIES AND VEINS ARE BLOOD VESSELS... THEY ARE VERY IMPORTANT!!

    Ok. Let's talk about arteries first. Arteries carry blood away from the heart. People (A.K.A. YOU) often mistaken the arteries for always carrying oxygen. BUT THEY DO NOT. The pulmonary artery takes UNOXYGENATED blood to the lungs. HOPEFULLY, you won't make that mistake ever again. Also, arteries are high pressure.
    Now let's talk about structure of the blood vessel wall. All blood vessels have 3 layers. From in to out they are the tunica intima, tunica media, and tunica externa.
    The tunica intima is made of a layer of endothelial cells.
    The tunica media contains the muscle of the blood vessel. Arteries are generally high pressure so they have a larger tunica media. Veins are the opposite. They are low pressure so they don't have a thick tunica media.
    The tunica externa is the outmost layer. It is sometimes known as the tunica adventitia. The tunica externa is mainly composed of collagen. It is also supported by external elastic lamina.

    Ok. Arteries are high pressure. Veins are low pressure. So how do veins move blood around??? Veins use skeletal muscle movement to help move the blood. They also have valves that prevent the backflow of blood.


I HOPE THIS HELPED YOU. HERE IS A PICTURE OF VEIN AND ARTERY DIFFERENCE:

  

Lesson 13 - Resources

WHERE SHOULD I GO TO FIND MORE INFORMATION??????

HERE ARE SOME RESOURCES:
- http://www.mayoclinic.org/
- https://www.khanacademy.org/a/8yt7
- http://www.ncbi.nlm.nih.gov/pubmed/
- http://www.webmd.com/



I WILL CONTINUE TO ADD RESOURCES... DO NOT WORRY!

Lesson 12 - THE HEART - "BEAT IT! BEAT IT! BEAT IT!"

    THE HEART - A VERY ESSENTIAL PART OF OUR LIFE...

    The heart is a organ in our body that is the center of the cardiovascular system. It is located behind the sternum (breastbone) and slightly to the left. It is has four main compartments. It is has two atria which are located superior to the two ventricles below.
   

 

    This is a diagram of the heart. You are probably wondering what are all those arrows pointing to. I will explain. The arrows represent the flow of blood. We are going to start in the right atrium.

    -The blood flows into the right atrium from the Superior and Inferior vena cavas which are the largest veins in our body. The Superior vena cava takes blood from the upper part of our body. The Inferior vena cava takes blood from the lower part of our body.

    -The blood then travels through the tricuspid valve and into the right ventricle. The valves in the heart help stop the backflow of blood. The tricuspid valve is held by chordae tendineae.

    -The blood after that goes through the pulmonary valve and into the pulmonary artery (THE VALVE SHOULD BE PRETTY EASY TO REMEMBER). This takes the blood to the lungs to become oxygen rich.

    -The blood then comes back through the pulmonary vein and empties into the left atrium.

    -The blood then travels through the mitral valve and into the left ventricle.

    -The blood then travels through the Aortic valve and into the aortic trunk. Then it goes to the Aorta and to the rest to the body.

    The left ventricle is the most muscular of all the compartments because it has to pump to all of the body.

 

I HOPED YOU LEARNED A LOT ABOUT THE HEART. REMEMBER, "JUST BEAT IT!"

    -



 

Lesson 11 - WHAT IN DA WORLD IS THE LYMPHATIC SYSTEM?

IN THE WORLD, the LYMPHATIC SYSTEM IS ...

   The lymphatic system is a series of nodes and vessels that support the cardiovascular and immune systems. It has 3 main functions.
    The first function of the lymphatic system is to collect lymph from the blood and then put it back into the blood. Ok. You are probably A LITTLE confused. WHAT THE HECK IS LYMPH???? Ok. Lymph is fluid that diffuses out of capillaries. Ok. Now you are NOT confused. Ok. So if this lymph just kept diffusing out of your blood in the capillaries, you would lose a lot of blood and that would be VERY VERY VERY VERY VERY VERY VERY (at this point its just dumb, but...) VERY VERY VERY VERY BAAAADDDDD! So basically your lymphatic system takes this lymph and filters it through lymph nodes and then places it back into the blood stream.
    So, how does the lymphatic system move this lymph? Lymph vessels don't actually have muscle to move them. They use our normal muscle movement to move this fluid.
    The second function of the lymphatic system is the movement of bacteria to lymph nodes to be killed. Ok. Let's say that you have an infection. And you need to get B-cells and T-cells there to help stop the infection. But you can't get it there. So the bacteria will actually diffuse into the lymph vessels kinda like lymph does. Then it will travel to a lymph node where B-cells, T-cells, and Macrophages are located in large numbers.
    The third function of the lymphatic system is to take proteins that are too large to diffuse into the blood vessels and transport them to the body. So, glucose molecules in the intestine can diffuse across the epithelial cells lining the intestine. Then they diffuse into blood vessels. But fats cannot diffuse into blood vessels because they are too big (THEY SO FAT!!! HAHAHAHA!!! THAT WAS SO FUNNY!!!) (Its also because they are packaged into vesicles called chylomicrons). But the fat can diffuse into the lymph vessels. So then the lymph vessels transport this fat to the body.

This is a diagram of the diffusion of fat into lymph and blood vessels. HOPE THIS POST HELPED!!

Lesson 10 - The bone marrow said ,"Plasma B-cell, I am your father..."

    This post is supposed to give you knowledge about the organs of the immune and lymphatic system. It may or MAY NOT give you knowledge. If not please let me know through the comments so I can give you knowledge.

    Ok so I will start with the bone marrow. The bone marrow is located inside many of your bones. The bone marrow is the site of Erythrocyte production or red blood cell production. The bone marrow is also the site of B-cell production (that is where the B in B-cell come from (**SHUT UP CAPTAIN OBVIOUS! :)**)). B-cell do not start out as memory and plasma cells. They only become either a plasma or a memory B-cell when they are activated by either an antigen or a Helper T-cell.

    The next organ is the thymus. The thymus is a organ which produces our body's T-cells. T-cells are VERY IMPORTANT in our immune system. If you want to know why they are important, check out Lesson 9. The thymus is located in the superior anterior portion of our chest, right behind the sternum.

    The next organ is part of the lymphatic system. They are lymph nodes. Lymph nodes are located all over the body in 3 main areas. The cervical, axillary, and groin areas. There are about 600 in our body and they can very from 1mm to 25mm in size. Lymph nodes filter out liquid that leaks out of capillaries.

    The next organ is also part of the lymphatic system. It is the spleen. The spleen is basically a big lymph node. It filters out lymph or liquid that leaks from the capillaries. It is made of the red and white pulp. The white pulp is more central. It's function is immune surveillance. The red pulp is rich in red blood cells and macrophages (The red blood cells have hemoglobin which is a red pigment. That makes the red pulp red) (I feel so SMART right now).

Here are some pictures of the organs that we went over:

 

Lesson 9 - STD's, 123, gotta know, about HIV!!!!!

WHAT THE HECK IS HIV? OR AIDS?

    HIV actually is a acronym which means human immunodefiency virus.
Let's go through the name:
    H- human: this means that it can only affect humans (PRETTY SELF-EXPLANTORY)
    I- immune: this means that it affects the immune system (PRETTY SELF-EXPLANATORY)
    V- virus: this means that it is a virus (PRETTY SELF-EXPLANATORY AGAIN)

As you can tell (hopefully) that was PRETTY SELF-EXPLANATORY!!!!

    Well HIV is a retrovirus (specifically a lentivirus) which affects the immune system.  A retrovirus is a virus that is enveloped and reproduces using reverse transcription in a host cell. It kills off CD4 cells or Helper T-cells. Helper T-cells are VERY VERY VERY important. They help activate B-cells, which help produce antibodies, and other T-cells.
    If they start killing off these Helper T-cells, that means that our body cannot produce antibodies. This causes the immune system to begin failing. When your immune system can barely function on its own, the viral infection is called AIDS.

    AIDS is also an acronym like HIV.
Let's go through the name:
    A-auto: this means that it affects yourself
    I- immune: this means that it affects your immune system
    D- defiency: this means that you have a defiency in your body (in this case being Helper T-cells)
    S- syndrome: a syndrome is a collection of signs and symptoms that are observed in, and characteristic of, a single condition

AIDS occurs after your body has been infected with HIV. It occurs when your body has already started having very severe symptoms.

Primary symptoms of an HIV infection: These symptoms are like flu symptoms.
    -fever
    -headaches
    -muscle aches
    -rash
    -chills
    -sore throat
    -mouth or genital ulcers
    -swollen lymph glands in the cervical (neck) area
    -joint pains
    -night sweats
    -diarrhea

Early symptoms of an HIV infection:
    -fever
    -fatigue
    -swollen lymph nodes
    -diarrhea
    -cough
    -weight loss
    -shortness of breath

Early AIDS symptoms:
    -soaking night sweats
    -shaking chills
    -fevers over 100 F
    -cough
    -shortness of breath
    -chronic diarrhea
    -persistent white spots or lesions on your tongue or in your mouth
    -fatigue
    -distorted or blurred vision
    -weight loss
    -skin rashes or bumps

    Since HIV is a virus, it cannot be cured. There are treatments to inhibit the transition into AIDS, but the best way is abstinence from sex. This is the 100% proved way (besides genetic cause) not to get HIV.

This is the HIV virus in the blood. I hope this post helped you know at least a little about HIV and AIDS.

Lesson 8 - Perforin and Granzyme both said , " We kill da viruses and da cancers in da cell!"

Humoral and Cellular Immunity:
    The humoral and cellular immune systems are the two main parts of the adaptive immune system. The humoral immune system is mainly controlled by the mass production of antibodies by B-cells. This part of the adaptive immune system is only effective against free floating pathogens. What viruses are replicating inside your own cells? This is where your cellular immunity comes into play. The cellular immune system is mainly controlled by Helper and Cytotoxic T-cells. It involves antigen-presentation by Class 1 and 2 MHC proteins. The class 1 proteins are located on all body cells (except for red blood cells). Class 2 proteins are located on immune cells only. When a cell is infected with a virus, it will display an antigen of the virus on a class 2 protein. Then a cytotoxic T-cell will come by and see the protein and will use perforins and granzymes to kill the cell.

Lesson 7 - IgG said ,"Here are the rest of my friends ..."

Immunoglobulins or Antibodies:
    IgA: They are found in mucosal areas such as the urogenital tract, gut, and respiratory tract. They are also found in tears, saliva, and breast milk. They attack microbes and prevent colonization by pathogens before they reach the blood stream.
    IgD: They are found on inactivated B-cells. They also activate basophils and mast cells which produce antimicrobial factors.
    IgG: They are the most common and make up about 75% of all antibodies. They are the only one to be able to cross the placenta to the fetus. They are the most versatile.
    IgE: They bind to allergens which causes the release of histamine from mast cells and basophils. They are mainly involved in allergies.
    IgM: They are first to eliminate the pathogen before IgG arrives. They are expressed on the surface of B-cells.

Major Organ:
    Thymus: It is the site of T-cell maturation. It is located in the upper area of the chest behind the sternum and between the lungs. It is pinkish-grey.
    There are other organs that you will learn about in the next couple of lessons.

Lesson 6 - ANTIBODY THREAT: I'm gonna AGGLUTINIZE you!

ATTACK OF THE ANTIBODIES

Adaptive Immunity:
    The adaptive immune system is the part of the immune system that can specifically target pathogens. It also stores immunological memory. This memory means that when a pathogen is encountered a second time, the response will be quicker and more effective. This memory can be stored in different types of B-cells and T-cells. There are two types of adaptive immunity: cellular and humoral.
    B-cells: They are immune cells that mature in the bone marrow. They are involved in humoral immunity. When they encounter an antigen (substances that can cause a adaptive immune response), the cells divide into plasma cells, which produce antibodies and into memory cells which store memory in case of a second exposure.
    T-cells: They are immune cells that mature in the thymus. They are involved in cellular immunity. There are four types. The helper T-cells help activate other T-cells and B-cells. Cytotoxic T-cells kill virally infected cells or cancerous cells. They act like natural killer cells. They also use perforins and granzymes. Memory T-cells have the same function as memory B-cells. They store immunological memory in case of a second exposure. Regulatory or Suppressor T-cells are the cells that stop the immune response. This prevents the immune system from going crazy.
    You may have heard me mention the word antibody. Antibodies are Y-shaped proteins that bind to a specific antigen. They all have a variable portion that is different among every plasma B-cell. This helps the immune system to be more versatile and a more variety of pathogens that they can kill. Antibodies fight infection in four ways: Complement fixation and activation, Agglutination, Neutralization, and Precipitation. Complement fixation and activation helps activate the complement (self explanatory). This means that they help with phagocytosis (adherence specifically). Neutralization occurs when antibodies block specific site on bacteria or viruses which cause them to be inactive. Agglutination occurs when antigens clump together which also makes adherence easier for phagocytes. Precipitation is the same as agglutination, but with free-floating antigens not with cells.

Lesson 5 - The Macrophage said ,"I DON"T KNOW YOU, SO I WILL EAT YOU!!!!!!"

DEATH SENTENCE: PHAGOCYTOSIS

Innate Immunity:
    The immune system is the body system that fights infection and keeps our body from pathogens. There are types of immunity: Innate and Adaptive Immunities.
   Innate Immunity: The innate immune system is the cells and physical barriers that you are born with. They target all types of pathogens; not specific pathogens.  The innate immune system consists of two lines.
    The 1st line consists of physical barriers including skin, nose, stomach, and other mucosae. Keratin on the skin makes the skin resistant to bacteria. Secretions such as sebum and sweat make the skin slightly acidic. The stomach contains gastric juice which destroy pathogens in the stomach. Tears and saliva contain lysozymes which kill pathogens in the oral cavity (mouth) and eyes.
    The 2nd line consists of phagocytes (cells that engulf pathogens), natural killer cells (cells that kill our own body cells that are cancerous or virally infected), antimicrobial proteins, and causes fever and inflammation. Phagocytes engulf pathogens through phagocytosis. Phagocytosis has 5 steps: Adherence-occurs when the phagocyte binds to the pathogen. Endocytosis-the cell membrane reaches around pathogen to enclose which forms a phagosome or food vacuole. Fusion-lysosome fuses with the phagosome. Digestion-the lysozymes from the lysosomes digest and breakdown the pathogen. Exocytosis-the unneeded material is ejected from the cell. Opsonization occurs when complement proteins or antibodies bind to the pathogen and makes adherence easier. Respiratory Bursts occurs when the lysosome is not enough so the T-cells release free radicals.

Natural Killer cells kill out own human cells that have already been infected or have become cancerous. They function using perforins and granzymes. The perforins create a hole in cell membrane and the granzymes enter and breakdown cell material.

Lesson 4 - Skin Diseases

You DO NOT want to get these in your body!!!!!

Diseases of the Integumentary:
    Cancers:
        Malignant Melanoma: It is a cancer that develops in the melanocytes (from lesson 2). It is can be caused by tanning beds and ultraviolet light overexposure. It is the most dangerous of skin cancers. It easily metastasizes through dermal blood vessels. They are normally black or dark brown in color.
        Basal Cell Carcinoma: It is a cancer that develops in the stratum basale. It is the least dangerous of all cancers. It rarely metastasizes. It is generally raised off the skin in bumps. It is the most common skin cancer.
        Squamous Cell Carcinoma: It is a cancer that develops in the squamous cell. It mainly affects the epidermis. It causes scars and bumps with a central depression.

    Other Diseases:
        Psoriasis: It is a chronic skin disease that is characterized by silvery, white inflamed lesions. It is caused by overactive T-cells collecting in the skin. It can be treated with small doses of sunlight, salicylic acid, and prescription retinoids.
        Vitiligo: It is a disease that causes the depigmentation of the skin. It occurs when pigment cells die or malfunction.
        Ringworm: It is a fungal infection caused by dermophytes that feed on keratin. These dermophytes thrive in warm and moist conditions. They can be treated with gold bond, different prescription creams, and drier feet.

ABCDE: A rule to determine a skin cancer. A-Asymmetry, B-Border, C-Color, D-Diameter, E-Evolution


There are still other diseases that you need to learn.

Lesson 3 - OMG! I need to brush my hair!

STUFF ABOUT YOUR HAIR!!

Hair Information:
   
    Hair Cross-sectional Anatomy:
        The 3 main layers of the include: medulla to the cortex to the cuticle. They are all made from hard keratin
    Medulla: It is the innermost layer. It is present in different amounts in different hairs (not consistent).
    Cortex: It is the middle layer. It contains pigment and gives the hair its color. It may  contain ovoid bodies and cortical fusi.
    Cuticle: It is the outermost layer. It is made from overlapping scales. It is very resistant to chemical decomposition.
   
    Hair General Anatomy:
        The hair above the surface of the skin is known as the hair shaft. The hair below the surface of the skin is known as the hair root. The hair under the skin is located in a hair follicle which houses the hair root. The arrector pili muscle is attached to the hair follicle. It contracts when you are in fear or when you are cold.

    Hair Phases:
        Anagen: Anagen is the growth phase for the hair. Hair can last in Anagen for 2-7 years.
        Catagen: Catagen is the transitional phase for the hair. It is a 2-3 week phase. It lasts until the hair becomes a club hair. A club is formed when the hair is pushed toward the surface of the skin until it is cut off from the blood supply and hair matrix (site of hair growth).
        Telogen: Telogen is the resting phase for the hair (which is a club hair just in case you forgot from about 3 lines ago). 50-100 club hairs are shed from a normal scalp.

    Affect of Age on the Hair:
        When hair turns white, it is because of decreased melanin production and air bubbles produced in the medulla of the hair.

Lesson 2 - SWEATING? TOUCHING?

HOW DO WE SWEAT??? WHAT DO WE DO TO SWEAT??   


Mechanoreceptors and Glands:

The four mechanoreceptors of the Integumentary System include: Merkel cells, Pacinian corpuscles, Meissner's corpuscles, and Ruffini corpuscles.
   Merkel cells: They are sensory receptors for touch. It lies on the Merkel disc. It lies at the epithelial-dermal junction.
    Pacinian Corpuscles: They are nerve endings that are sense vibration and pressure. It is very few in number and is 1mm in length. They can sense up to 250Hz.
    Meissner's Corpuscles: They are nerve endings that sense light touch. They can sense well between 10Hz and 50Hz.
    Ruffini corpuscles: It is found in the subcutaneous layer. It helps sense warmth. It is also known as Bulbous corpuscle.

Exocrine glands are glands that secrete out onto the environment directly.
Sudoriferous glands are sweat glands. There are two types: Apocrine and Eccrine glands.
    Apocrine glands: They are a type of sudoriferous gland. They are located at the junction between the subcutaneous layer and dermis. They are only located at the armpits, areola and nipples of breasts, and genital area. Their secretions have a odor.
    Eccrine glands: They are a type of sudoriferous gland. They secrete directly onto the skin. Their secretions are odorless.
Sebaceous glands are glands that secrete sebum. The secrete directly on the hair. Sebum inhibits bacterial growth on the skin.

Lesson 1 - WHAT IN THE WORLD IS THE SKIN?????

    WHAT IS THE SKIN??????????????
    The Integumentary System consists of the skin and its accessories. It is the largest organ system in the human body. Its main function is to act like a barrier to protect the body from the outside world. It also retains body fluids, eliminate waste, protect against disease, and regulate body temperature.
    The Integumentary System has two layers: epidermis and dermis. The epidermis is the most superficial. It consists of 5 layers: stratum corneum, stratum lucidum, stratum granulosum, stratum, spinosum, and stratum basale. This is only in thick skin which is found only on palms and the soles of your feet. In thin skin, the stratum lucidum is not present. The stratum basale is the site of mitosis. The blood supply to the epidermis is the subpapillary plexus.
    The dermis is located right under the epidermis. It has two layers: papillary and reticular. The papillary layer is more superficial. It contains areolar tissue. The reticular layer contains connective tissue. The blood supply to the dermis is the cutaneous plexus (cutaneous meaning skin).
    The hypodermis is not considered part of the skin. It is made up of areolar tissue and adipose (fat) tissue. It is known as the subcutaneous layer (below the skin). It acts as a energy reserve for the skin.





This diagram is very important to learn. It can help to memorize it.
Lesson 1 End