Lesson 22 - The Nervous System...The ALL POWERFUL!!!!

Today, we will be talking about the...NERVOUS SYSTEM!!!!!!

Let's get started...

The Nervous System is defined as a network of nerve cells and fibers that transmit signals through out the body. The nervous system is what senses stuff, interprets it, and responds to it.

Now there are 2 main division of the nervous system: the Central Nervous System and the Peripheral Nervous System. The Central Nervous System is made up of the brain and spinal cord. The Peripheral Nervous System is made up of all the other nerve tissue in the body.

The Peripheral Nervous System can be divided up further into the Autonomic Nervous System and the Somatic Nervous System. The Somatic Nervous System helps in voluntary muscle movement or the muscles that we can control. The Autonomic Nervous System controls the involuntary functions of the nervous system.

Don't worry were almost done. The Autonomic Nervous System can be divided into the Sympathetic Nervous System and the Parasympathetic Nervous System. The Sympathetic Nervous System helps in our flight-or-fight response. The Parasympathetic Nervous System keep our body at rest and at homeostasis.

Now let's look at the basic component of the nervous system - the Neuron:

https://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Complete_neuron_cell_diagram_en.svg/1280px-Complete_neuron_cell_diagram_en.svg.png

Now the neuron has 3 main parts: the soma, dendrites, and axons. The soma or cell body houses the nucleus and the other organelles of the cell. The dendrites receives signals from other neurons. The axon sends signals from the neuron. 

I thinks that's good for starters... We'll continue this later...

Lesson 21 - Journey to the INJURY IN MY ARM!(21!)(Very significant number!)(Not actually related to the Lesson)

We are going to step back into the immune system. We will be talking about the INFLAMMATORY PROCESS and PHAGOCYTE MOBILIZATION

    Ok. We will start with the Inflammatory Process. First, a pathogen will be recognized by a macrophage. The macrophage will release chemical signals to activate other cells. The mast cells will release histamine. Histamine is a potent inflammatory agent.
    The injured tissue cells will release chemicals also. These chemicals will cause capillary dilation or capillary widening. This will result in hyperemia or increased blood flow. The chemicals will increase vascular permeability. This means that proteins and cells can easily diffuse across blood vessel membranes.
    The increased vascular permeability will allow edema to occur. Edema is the surge of fluid containing clotting factors and antibodies into tissue spaces of the injured tissue. Edema will provide nutrients to the tissue cells, antibodies for defense, and clotting proteins. The clotting proteins help stop the spread of bacteria with fibrin.
    Now we get to PHAGOCYTE (eating cell) MOBILIZATION. Phagocyte mobilization contains 4 main parts.
    1. Leukocytosis: Neutrophils are released from the bone marrow.
    2. Margination: Neutrophils cling to the capillary wall.
    3. Diapedesis: Neutrophils squeeze through the capillary wall near the tissue area.
    4. Chemotaxis: Neutrophils are attracted to the injured tissue by inflammatory chemicals.

http://legacy.owensboro.kctcs.edu/gcaplan/anat2/notes/APIINotes7%20Nonspepecific%20Defenses.htm
This diagram is a visual representation of Phagocyte Mobilization.

http://legacy.owensboro.kctcs.edu/gcaplan/anat2/notes/APIINotes7%20Nonspepecific%20Defenses.htm
This diagram summarizes tissue injury.

I hope this post helped!
 

Lesson 20 - Muscle Activation through a NEURON

In LESSON 19, we talked about myosin and actin. Now we will talk about the neuron activating the muscle cell.

    Ok. We will start off with a neuron. Neurons usually communicate with another neuron, but in this scenario, we will be talking about a motor neuron. A motor neuron activates muscle cells and causes muscle contraction.

http://bcrc.bio.umass.edu/courses/spring2009/biol/biol101section2/review/20090306/TTubeSarcoRetic.GIF

    Ok. Let's continue.
    1. The first step in this occurs when a action potential (signal) travels down the motor neuron and to the synapse.
    2. Then sodium is released near the synapse. The sodium binds to the neurotransmitters (chemical signals that are used in communication) which then cross the synaptic cleft.
    3. The sodium then triggers another action potential in the muscle cell.
    4. The sodium goes through voltage channels (channels that allow ions to pass through based on the state of voltage) and then they enter also through the T-tubules.
    5. Then a protein complex which is made up of proteins like triadin and calsequestrin is activated by the sodium entering the cell and then activates the sarcoplasmic reticulum.
    6. Inside the sarcoplasmic reticulum in a resting muscle cell, there is a lot of calcium on the inside of the cell. But during muscle contraction calcium is diffuses out of the sarcoplasmic reticulum. So this protein complex activates the calcium ions and causes them to diffuse out.
    7. This calcium goes to bind with the troponin protein which we talked about in Lesson 19.

I HOPE YOU NOW KNOW MORE ABOUT
YOUR MUSCLES THAN BEFORE.

Thanks for reading this post!

Lesson 19 - Myosin and Actin Physiology - WORK THOSE MUSCLES!!!!

MYOSIN AND ACTIN

    In this post, I will try to make you understand muscle contractions and how they work. Now, the 2 major proteins that you may have heard of are myosin and actin. First, what do these structures actually look like? And how do they work?

    This is diagram of myosin and actin. So basically, actin is a helical protein. Myosin is like a protein that has a head that climbs up the actin and this causes muscle contraction.

http://pixgood.com/myosin-and-actin.html

    Now let's get deeper into all the physiology behind this. There are two other proteins that work also. These proteins are tropomyosin and troponin. Tropomyosin is a protein that wraps around the actin and the troponin helps keep the tropomyosin bound to the actin. The function of tropomyosin in rest, is to keep the myosin head from being able to bind or move along the actin.
    Now if there is a high calcium concentration in the muscle cell, troponin (since it is bound to the tropomyosin) is used to move tropomyosin out of the way.
    1. This allows the ATP to be hydrolyzed.
    2. This causes the ADP + Phosphate group to form and the myosin head can attach to the that actin.
    3. This also causes the release of energy which causes the movement of the myosin head up the actin filament.
    4. These steps end in muscle movement.
    5. Then the myosin returns to its resting position.

So let's summarize:
    Actin: A helical filament which helps cause muscle contraction.
    Myosin: A motor protein that climbs along the actin filament to create muscle movement.
    ATP: Adenosine Triphosphate - sometimes called the biological currency of all living organisms.
    Tropomyosin: A protein which wraps around the actin filament and when there is a low calcium concentration it will block and prevent the movement of myosin up the actin filament. But in a high concentration, it will let the myosin head move up the actin filament.
    Troponin: A protein which binds the tropomyosin to the actin filament. It helps the tropomyosin block the myosin movement.
    Calcium: A very important ion that is important in muscle movement.

I hope this helped you understand muscle movement! Muscle movement is VERY VERY VERY important because then you wouldn't be able to move.

Lesson 18 - RAAS - Renin Angiotensin Aldosterone System - REGULATING THEM VESSELS

RAAS - RENIN ANGIOTENSIN ALDOSTERONE SYSTEM

The renin angiotensin aldosterone system is a hormone system that is used for the regulation of blood pressure and fluid balance in the blood vessels. This is IMPORTANT BECAUSE YOU COULD DIE (DRAMA!!!!!) IF THE RAAS DID NOT EXIST.

1. First renal blood flow is reduced. This causes the juxtaglomerular cells in the kidneys to secrete renin into the bloodstream.
2. Renin, now in the bloodstream, is used to convert angiotensinogen, which is released by the liver, into angiotensin 1.
3. Angiotensin 1 is then produced into angiotensin 2 by the ACE (angiotensin converting enzyme - PRETTY SELF EXPLANATORY OF WHAT THAT MEANS) which is found in the lungs.
4. Angiotensin 2 is a peptide which causes the blood vessels to constrict. This causes an increase in blood pressure.
5. Angiotensin 2 also causes the release of aldosterone from the adrenal cortex.
6. Aldosterone is a hormone that causes the tubules of the kidneys to increase the reabsorption of water and sodium into the blood. This causes the increase in blood pressure.

Those are the steps to RAAS raising blood pressure. Now, what would happen if this system overreacted?
    - hypertension (high blood pressure)
    - heart failure (NOT GOOD)
    - kidney failure

Treatments for these include ACE inhibitors (hopefully you know what ACE stands for), Tekturna, Aliskiren, and other Renin inhibitors.

I hope this helped! Here is a diagram to help explain the RAAS.

http://www.cvpharmacology.com/vasodilator/renin.htm

Lesson 17 - Coronary Heart Disease - Do you have clogged arteries????????

IN THIS LESSON, WE WILL BE LEARNING ABOUT HOW YOUR HEART CLOGS AND HOW THIS MIGHT KILL YOU...

    Ok. Coronary Heart Disease occurs when your coronary arteries become blocked which causes a lack of oxygen to your myocardium. OK. WHAT THE HECK ARE CORONARY ARTERIES? They are arteries that give blood to your heart muscle or myocardium (myo: muscle, cardium: heart).
Why is clogging your coronary arteries bad? **Maybe because your heart is A LITTLE important to the function of your body** Well yeah that is true, but let's talk about how this happens.
    Heart clogs generally start up with cholesterol buildup in a specific coronary artery.
        -What happens is that the cholesterol clumps on the artery wall.
        -Then white blood cells and other proteins in the blood try to fix it but end up just making it bigger which causes Atherosclerosis (the hardening of the blood vessels).

http://www.bupa.co.uk/health-information/directory/c/coronary-heart-disease

        - After that, the little 'bump' turns into plaque. Then the plaque ruptures. This either happens spontaneously or because of high blood pressure or sudden heart rate increases. And also this is BAD!!!!! It causes all that plaque material to be exposed to the blood. Suddenly, red blood cells and clotting factors began to add to the plaque turning it into a thrombus or a blood clot.

http://www.bloodjournal.org/content/bloodjournal/123/21/3354/F7.large.jpg?sso-checked=true

 

    This plaque is so large that at rest, the person will feel chest pain. If the person does a workout it causes there heart muscle to need more oxygen. But blood can't get there. This causes the piece of heart tissue to lose its ability to function. A person will experience this through a myocardial infarction or a heart attack. If the person is not treated within 20 minutes, then the person's heart will have suffered severe and IRREVERSIBLE damage to the heart. WHICH IS REALLY BAD!!!!!

 

 

I hoped you learned a lot!!!!!

Lesson 16 - ECG - WHAT IS THAT??????

ECG READINGS

    An ECG is a way of reading the way a heart is beating. Let's break it down:
        E: electro - means that it uses electricity
        C: cardio - means that it involves the heart
        G: gram - means that it records something

    An ECG is a way to check if a persons heart is beating correctly.
Ok. A normal heart beat on a ECG shows up like this:

    If anything changes about this diagram, significantly, then it will not be a normal heart beat.
Now let us see a more scientific heart beat that labels the heart beat.

http://noodle.med.yale.edu/staib/bme355/ecg/prep.htm

    Ok. The basic parts of an ECG consists of a P, Q, R, S, T, and U. 
The P: refers to atrial depolarization
The QRS: refers to ventricular depolarization and atrial repolarization
The T: refers to ventricular repolarization
The U: occurs in people with heart problems - it is not always seen

http://hyperphysics.phy-astr.gsu.edu/hbase/biology/ecg.html

    In Lesson 16, we learned about the heart conduction system. There is definitely a connection between them.
    SA node to AV node: atrial depolarization
    AV node to Purkinje Fibers: ventricular depolarization
    Now these are only basic groupings. I encourage you to learn more about the heart conduction system and ECG diagrams.

I hope this helped!!