February 28th

II. Cells
     B. Neurons
     3. Dendrites

III. The Nerve Impulse: how does a neuron initiate and propagate an electrical impulse?
      A. The Resting Potential: setting up the potential for a neuron to "fire".
          Cl - 10x
          Na+ 10x  (sodium can leak in, just as potassium can leak out)
  
(K+ 30x)  (large (-) polypeptides ) potassium can leak out~
- Resting Charge (-70mv) neutral/balance between negative and positive charges

Na+/K+ Pump:
      1.  K+ is at a 30 times greater concentration inside of the neuron. it can leak out and does.
      2. Large (-) polypeptides- made by neurons and they are highly concentrated inside the neuron. these want to hold K+ in so, K+ has two forces acting upon it.
        a. Diffusion- wants it out
        b. Electrical Attraction- wants it in.        }when these two forces are equal it makes the net flow of K+ zero and the inside or Resting Charge of the neuron will be at -70mv.
     3. Na+ - is at a 10x greater concentration. outside and it really wants to flow in because both forces want to move it in. (arrow) Na+ can leak in through gated channels and does, Na+/K+ pumps must constantly be at work to keep the resting charge and concentration of Na+ and K+ where they need to be
    4. Cl-is also at 10x concentration outside and the external environment is electrically neutral.

2/25/2013

2 Divisions of this:
        a. Somatic - "Voluntary". Control of Skeletal Muscle
        b. Antonomic - "involuntary".      "    Cardiac & Smooth Muscle
2 Divisions:
           i. Sympathetic - "waking" - involves neurons that increase activity & involve excitatory neurotransmitters.
           ii. Perasympathetic - "Sleeping" - involves neurons that decrease activity & involve inhibitory  neurotransmitters.
II. Cells
  A. Supporting Cells
      1. In the CNS. 2 types"
           a. Astrocytes - fat cells that invade arteries leading into the CNS. Sets up the Blood-Brain Barrier. Only fat-soluable substances should be able to pass through. protects us from viruses & other toxins that are water soluable. Reason why the CNS has its own immune system.
           b. Oligodendrocytes - fat cells that form the myelin sheeth of CNS neurons. Wrap around the axon of a neuron insulating it & making the impulse more efficient & faster. MS - these cells are being destroyed.
      2. In th PNS: Schwann Cells - form the myelin sheeth of PNS Neurons.
  B. Neurons - Cells that conduct electricity.

Nerve - Bundle of neurons. Are either motor or sensory. Ex. Funny Bone.
Ganglion - Cluster of neurons. are both motor and sensory.

Neuron:

1.  Cell Body - contains nucleus & other organelles. Performs all of the normal cell tasks
2. Axon - longest part. Where the initial electricity is generated.

February 21, 2013

The Nervous System

I. Organization
        A. Central Nervous System- Brain and Spinal Cord (CNS)
        B. Peripheral Nervous System (PNS)- Everything outside of theCNS.
                1.Sensory- Conveying messages to the CNS.
                2. Motor- Conveying messages from the CNS. (2 Divisions)
                                a.Somatic- "voluntary"- involves skeletal muscle response.
                                b.Autonomic-"involuntary"- involves cardiac and smooth muscle response and glands,   kidneys,pancreas etc. (2 Divisions)
                                         i. Sympathetic- "waking"-involved with increased activity.
                                        ii. Parasympathetic- "sleeping"- involved with decreased activity.

III...           

            ii. Precipitation-causes viruses to come out of solution and solidify. Some antibodies can act as a catalyst to precipitate the viruses. Viruses can't infect cells and they're easier to phagocytize.
           iii. Neutralization-of wastes of bacteria and fungi.
Note: The next 3 actions require another chemical called Compliment-a class of proteins that are produced by all cells and these act with antibodies to:
           iv. Inflammation-antibody bonds to a compliment on the surface of the mast cell.
           v. Flagging-infected cells will produce a compliment that bonds to a foreign protein and this complex is exocytized onto the surface of the cell and this flags it for destruction.
          vi. Lysis-antibody/compliment bonds to the surface of a foreign cell and lyses it.

Note- Antibodies are specifically designed to bond to a foreign chemical (usually a protein) called an antigen. Actions i-iii require antibody-antogen and actions iv-vi require antibody-compliment-antigen. This is called the Self/Nonself Complex.

B. The Cell Mediated Response- Involved T-Lymphocytes (T-Thymus T-Cells migrate and mature) These cells identify the antigen and kill infected cells.
                           1. Activation.
                                      a. A macrophage phagocytizes the pathogen, breaks it up, finds a Helper T-Cell, docks with it and "presents" the antigen to it. It is now an APC (Antigen Presenting Cell)
                                      b. The Helper T-Cell starts to secrete Interleukin I-carries the "recipe" for the antigen and it stimulates the growth of more Helper T-Cells.
                                      c. As these cells grow and multiply, they begin to send out a second protein called Interleukin II (IL II). IL II Does 2 things:
                                                      i. Activates the Humoral Response.
                                                     ii. Activates the Cell Mediated Response.
                          2. When IL II activates Effector T-Cells, they begin to divide into two types.
                                      a. Memory T-cells- Immuno Memory and Vaccines.
                                      b. Cytotoxic T-Cells-roam around the site of infection and dock with infected cells, release Perforin, which lyses the cell.

Feb 19th

III Specific Defense-Dual Response.  The Immune Response-Taylor make chemicals and cells for the particular pathogen infecting you. Dual Response: 2 cascades of evens that happen simultaneously
     A. The Humoral Response involves cells called B-Lymphocytes (B-Bone they emerge from bone marrow ready to do battle and produce antibodies-chemical warfare protiens) Lymph-fluid that flows through the lymphatic system-while blood kcells use it as a highway and lymph nodes are way stations for these cells. Lymph Nodes- storage for lymphocytes.
          1. Activation- 2 ways:
                a. The Capping Hypothesis- surface antibodies attach to the pathogen and endocytize it. (Minor)
               * b. Via the Cell Mediated Response and IL II. (Major)
          2. Action- B-cells that are activated begin to divide into 2 types:
                a. Memory B-Cells-stay in lymph nodes and wait for the same invader to infect you a second, third etc. time. Lifelong. Gives us our Immunological Memory.
Vaccines-when an attenuated(somehow rendered harmless) version of a pathogen is intorduced into the body in order to build Immunological memory.
               b.  Plasma B-Cells-produce antibodies. What do they do? They are Specifically design for the pathogen to:
                       i.  Agglutination-to glue together.  Attach a number of pathogens together.  Stops infection and helps phagocytosis.
                      ii. Precipitation-viruses dissolve in waternand some antibodies will cause them to precipitate-come out of solution and crystallize

02/14/13- Happy Valentine's Day! Here are some notes

B. Openings (continued)
3. Acidity- in digestive and reproductive tracts- kills cells
4. Normal Flora- in digestive tract. Outcompete potential pathogens

C. Cells
1. Platolets- blood celsl that produce clotting proteins
2. Phagocytes- white blood cells that "eat" anything foreign. Neutrophils (most common) and Macrophages (largest and most effective phagocyte)
3. Natural killer cells- White blood cell's- find foreign cells and lyse them. ID maligent cells and kill them.

D) The inflammatory response- 2 scenarios
1. Localized- (cut)
a. injured cells begin to release a chemical, HISTOMINE. (causes inflimation)
b. Histomine acts on surrounding blood vessels, dialating the, allowing a greater volume of blood to flow into them. (swelling, red color and possible heat)
c. Provides more oxygen, glucose, and clotting factors for healing
d. stretches the walls of the blood vessels an dit makes hte blood vessel more porous. This allows WBC's (phagocytes, NK cells) to enter the damaged area to do their job.
e. Pus- is hte remains of phagocytes that eaten themselves to death.

2. Systemic- system-wide
a. white blood cells produce antibodies that bond to Mast Cells- which release histomine
b. the area around the infection will have its blood vessels dilated, and this does what a LOCALIZED RESPONSE will do
c. this causes muscous membranes to increase production
d. it can also brain to increase body temp. The brain produces PYROGENS that cause fever

The Body's Defense System

I. Non-Specific Defense- General defense against any pathogen.
    A. Skin
         1. Almost Impenetrable
         2. Sweat and Oils are highly acidic- kills most bacteria & fungi.
         3. Normal flora- bacteria that live on the skin. They out compete pathogenic forms of bacteria.
     B. Openings
         1. Lysozymes- Enzymes that chemically destroy bacteria and fungi in tears and saliva.   
         2. Mucous Membranes- produce mucous in response to infection. 
        

II. Speciation
     B. "Peak Shift"
     When an environment drastically changes, this changes the "adaptive landscape" and promotes new adaptations for new niches (jobs) and this creates new species.
III. Adaptive Radiation- Darwin's Finches. When one species involves into many. Happens when the environment offers multiple unutilized resources and little or no competition.Happens on a global scale after mass extinctions.

 Blue-Black Graskwit----- Medium Ground Seeds

Reaches Carrying Capacity

The birds that were adapted to eat small and large seeds are good too.

The Graskwit also will eat Medium Tree Seeds, plus large and small tree seeds from adaptation, there is fruit in the trees they will eat too. Then that bird will eat insects if all the seeds run out and that is how the different species evolve from the starting species.

All the new species "radiate" around the first.

IV. Coevolution- when one species' evolution is significantly influenced by another species.

     A. Predator/Prey relationships. (antelope and cheetah, Red Queen Affect).

     B. Competitiors (Red Queen Affect)

     C. Mutuaism- Plants and Pollinators

     D. Parasitism

     E. Mimicry- When two species mimic the "look" of each other.

          1. Mullerian- when venomous or toxic organisms mimic each other. Black/yellow insect.

          2. Batesian- when a non-venomous or toxic species mimics a "harmful" one. Monarch and Viceroy butterflies.



Patterns of Evolution part 2

II. Speciation Patterns: 2 basic ways
    A. Speciation by Divergence : Step-
        1. The Founder Effect
        2. Genetic Drift: because of the small size
        3. Inbredding: Small populations = more Homozygotes
        4. Population Increses to Carrying capacity
       5. Competition for limited Resources
       6. Population begins to adapt to a new environment
       7. Repeat steps 4-6 to Speciation
       8. Add new mutations
   B. Speciation by "Peak-Shifts."

Patterns of Evolution

A. Anagenesis vs. Cladogenesis