False. The right side of the heart pumps oxygen-poor blood to the lungs to be re-oxygenated. For this reason, the right side of the heart is considered the pulmonary circuit pump. The left side of the heart pumps blood to the body, and is therefore considered the systemic circuit pump. ;)
In animal cells centrioles are located in, and form part of, the centrosome where they are paired structures lying at right angles to one another. In this context they are possibly involved in spindle assembly during mitosis. The centrosome is positioned in the cytoplasm outside the nucleus but often near to it.
<span>sotonic Solution. Isotonic-no water movement across the cell membrane since the concentration of ions are farily equal in and out of the cell. Hypertonic-a condition where cell loose it water content and ultimately plasmolyze due to the higher ionic concentration outside the cell than inside.
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Answer:
Macrophages are part of your innate immune system, which is antigen-independent and does not require activation.
Explanation:
Macrophages phagocytize (internalize) all non-self pathogens it encounters. These do their job without activation. Other cells in the innate immune system include basophils, neutrophils, eosinophils (these cells are polymorphonuclear leukocytes), mast cells, and dendritic cells, which act as the bridge between your innate and adaptive immune system.
All of the other entities listed above are part of your adaptive immune system. The adaptive immune system is antigen-dependent and requires activation. This section of your immune system responds differently to different pathogens, and has the bonus of having immunologic memory, the ability to remember pathogens after infection and respond much quicker upon secondary and tertiary encounters.
Note: All lymphocyte types begin as naïve cells, which then differentiate into their fully matured form upon activation.
Helper T cells are a type of CD4+ T cell that has the job of activating B and T lymphocytes. There are two different types of T helper cells: Th1 and Th2. Th1 cells secrete the cytokine interferon-gamma (IFNγ), and is primarily involved with the stimulation and activation of cytotoxic T cells, while Th2 cells secrete a variety of cytokines and are responsible for activating and assisting with B cells to make antibodies. To make a long story short, Th cells interact with APC (Antigen Presenting Cells), specifically their Class II MHC (a group of genes that present exogenous proteins). The Th cells then proliferate and gain the ability to activate these APC cells and provide the necessary signals to activate B and T cells and make them proliferate and do their specific function.
