Cell Physiology"Cells are the basic structure and function of the human body."This statement is exactly true. Cells are the building blocks of the human body. Various cells work together to do a certain job, i.e binding together to make tissue--> Organ-->Organ System--> Organism.Cells do a variety of different tasks depending on their type. They are large in numbers, constantly rebuilding/multiplying themselves, and transporting essencial minerals, oxygen and signals to various parts of the body.

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Illustration of cell structure

PASSIVE & ACTIVE TRANSPORT
    • In passive transport, compounds move down the concentration gradiant and do NOT require ATP (energy).Types of passive transport include:
      • -Diffusion- movement of molecules from an area of higher concentration to an area of lower concentration.
        Ex: Gas Exchange in the lungs of CO2 and O2
        -Facilitated Diffusion- diffusion that is facilitated by transport proteins
        Ex: Transport of glucose into cells by the transport carrier (called GLUT).
        -Osmosis- diffusion of water across the membrane.

    • In active transport, compounds move against the concentration gradiant and require ATP. Active transport is used in two different ways:
      • Primary active transport directly uses ATP and uses protein as carriers that span across the membrane. Examples include:
        • Ca2+ pump- Found in the plasma membranes of all cells. Carrier proteins catalyze transport of Ca2+ away from the cytosol into the ER or out of the cell.
        • The Sodium-Potassium Pump- transports sodium out of and potassium into the cell against their concentration gradients.
      • Secondary Active Transport- In contrast to primary active transport, there is no direct coupling of ATP; instead, the electrochemical potential difference created by pumping ions out of the cell is used.


              • The video below is an animation of how the Na+/K+ pump works



CELL COMMUNICATION
      • Cellular communication is absolutely vital for multicellular organisms (humans) to survive and function. Most cells communicate by chemical signals that are released by the endocrine glands, neurons and other cells found in organs. Some cells can communicate directly, but only if their membranes are fused together. This way, the cytoplasm is shared and molecules and ions can be diffused between them.
        • Types of communication include synaptic trasmission (used by neurons), paracrine transmission (used by cells within an organ), and endocine signaling (used to produce hormones by the glands).
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Synaptic Transmission :)

        • As a nurse, I realize that cell dysfunction can be one of the first signs that there is an abnormality. We monitor WBC's when a person is ill or has an infection. A low RBC can show signs of a patient with anemia. An abnormal pap smear can show signs of cervical cancer or HPV.A biopsy is the removal of cells that can show signs of cancer/cell abnormality as well. We need to know how the cells function and what the normals are because we will be working with them when treating patients.