Quiz

How does the immune system provide an immediate nonspecific immune response

The immune system does a number of things to provide an immediate nonspecific immune response. There are skin cells and mucus membranes that are able to prevent many pathogens from entering the body.
Skin has a low pH, fatty acids, and salts found on it that serve as chemical barriers to prevent infectious invaders from entering the body. The first thing the immune system does is to use mucus to sweep out the pathogens before even knowing what the bacterium is but there is a completely different process for when invaders
Inflammation

When skin is pierced and something punctures a body cell, it releases chemicals such as histamines that tell white blood cells, natural killer cells, and Phagocytes such as macrophages to surround and destroy foreign microbes. Then, fluid moves into the area which explain the swelling of the inflamed area, the local blood vessels are now leaky and blood vessels are dilated in order for a greater chance for infection fighting cells to enter the area. Phagocytes then consume bacteria and cell debris, healing the tissue. Phagocytes consume bacteria by finding the carbohydrates found in the bacteria, surrounding them and using lysosomes to kill and digest the bacteria. The kinds of chemicals that are released during tissue injury are histamine, prostaglandins, kinines, complement, and cytokines. These mediators work to increase blood flow by increasing the metabolic rate which explain the redness and heat. Then, they make local capillaries permeable which swell and make the area very sensitive to pressure. This brings oxygen and nutrients into and clotting proteins into the area. Also, mediators such as histamine help in phagocyte mobilization.


Here is an interesting picture to see what happens. Summary of what I explained.



T and B cells in infections

T and B cells are very different.
There are two types of T and B cells, there is a t helper cell that activate B cells and receive information from macrophages and cytoxic T cells that target and destroy infected cells. B cells are divided between memory cells that remember the shape of antigens and antibody b cells that create antibodies to attach to antigens that stop them in their tracks and tell killer cells to get rid of them. Memory B cells recognize these antigens by their shape and when they deal with them, they remember the shape of the antigens and are more prepared the second time the antigens appear again. Antibody B-cells are present to create Y shaped proteins called antibodies that stick to foreign invaders and that alert the body to the invader's presence. Basically, this is a watch guard that is yelling "HEY LOOK THERE IS A BAD GUY HERE KILL HIM". Phagocytes, natural killer cells, and cytoxic T cells then kill and destroy the intruders or infected covered with antibodies. T cells are activated when a phagocyte eats a foreign substance and takes it to the spleen to figure out what it is. The T cells kill the invader and the b cells create antigens that are able to bind to the invader. When it happens a second time, this is able to be done much faster because the b cells remember the shape of the invader now. This is why we have antibiotics and vaccinations so B cells can get the shape of the disease without actually getting the disease and be able to react to the infection much faster than it usually would

Notice this how a helper T cell receives information and activates other cells. .


The entire process. Notice how the Helper T cell is the first thing that receives the antigen and stimulates the B cells and memory T cells and Memory B cells.



T and B cells against themselves?

T and B cells can distinguish invader from self because the ones that distinguish molecules in our body have been destroyed while in the womb. The rest are memory cells that are trained to identify new invaders that enter the body rather than cells that already exist in the body.

T and B cells work together to remember invaders through shape and attack them when they recognize them.

Every cell also has a major histocompatibility complex(MBC) that is able to tell T and B cells if they are targeting themselves or not. This is why we cannot simply just accept someone else's liver because their liver's MBCs are different from ours and will be rejected by our body and attacked because our body will think the liver is a foreign invader.

Notice the MHC present that tells T and B cells it is self.

Lecture Overview

Glucose
Glucose is absorbed through the ileum and Jejunum and when blood Glucose is found to be too high, beta cells within the pancreas release insulin hormones that target Body Cells. They bind to receptors on top of these cells because they are not fat soluble. When Insulin binds to these receptors, it triggers the Cells to absorb Glucose which lowers the amount of glucose in our blood. Insulin also targets the liver to Produce Glycogen which are hundreds of Glucose molecules bound together and is stored in the liver and muscles. When blood glucose levels begin to lower below the optimum level, the body then breaks down the glycogen stored in the liver and muscles into glucose and releases it back into the bloodstream. The way Glycogen is created is through the process of Dehydration where substrate glucoses turn into product Glycogen through the use of enzymes. When Dehydration occurs, we are able to lower our Blood Glucose level. Opposingly, we can use Hydrolysis that uses an Enzyme, H20 and ATP to convert glycogen back into many Glucose molecules in order to raise our Blood Glucose levels.We also went over Protein synthesis and how many things could effect a strand of DNA to mutate it through Pt Base mutations, Frameshifts that involve deletions, insertions and duplications. During Protein Synthesis, we go from DNA to mRNA to Amino Acids and the first stage is Transcription where the DNA, a two stranded nucleotide is changed into mRNA, a one stranded nucleotide through the work of RNA Polymerase that reads the strand from 3' to 5' and lays down the mRNA from 5' to 3'. RNA Processing then occurs where Splisosomes cut out introns and a G cap and a poly A tail is placed on the mRNA strand to protect it from nucleases that constantly eat nucleotides in order to protect the body from foreign viruses. We then go to Translation where mRNA enters a ribosome that is found on the rough part of the endoplasmic reticulum and is read by codons and goes through a sequence of APE, A as accept, P as peptide bond and E as exit to go on to create proteins.

Muscular System and Calcium
There are 2 types of proteins, Actin and Myosin.. Actin is thin and Myosin is thick. Actin is a Globular Protiein that is helix shaped and Myosin is a Linear Protein. The way a muscle works is for the Myosin heads to be able to touch the actins but to do that we require ATP. With ATP, when it binds onto the myosin head, it hydrolyzes into ADP and a Phosphorous molecule and energy that essentially spring loads the myosin to move whatever it is attached to and eventually move the entire muscle when this process occurs repeatedly. How do we create ATP you ask? Well, it all starts with food entering the mouth where salivary amylase and the duodenum breaks down carbohydrates into disacharides through disacharidases called sucrase lactase and maltase that break down glucose, fructose and galactose. We then use glucose through glycolysis in the cytoslol to create 2 three carbon molecules called pyruvates that generate 2 ATP and 2 NADHs and going into the mitochondria we have the kreb's cycle that change the pyruvates from 2carbons to six carbons to four carbons to create 2 ATPs, Nadhs, and FADH2 s and this then goes through oxidative Phosphorylation where the electron transport chain accepts an electron and attracts protons and going through chemiosmosis where the Hydrogen proton goes through ATP Synthase to create 36 ATPs in optimum conditions. Now we use Calcium to move Tropomyosin to expose myosin binding sites on actin heads and causes the muscle to move. We have salt to polarize this process with sodium, potassium and chloride that create an electrical current to move the myosin binding sites. This entire process stimulates muscle movement.