Blood and Lymphatic Systems PDF

26.3 The Blood and Lymphatic Systems The lymphatic system is a separate circulatory system that drains lymph fluid from extravascular tissues. (Figure 26.3) Blood is pumped through arteries and capillaries and returns from the body through veins. Lymph nodes contain high concentrat...

26.3 The Blood and Lymphatic Systems The lymphatic system is a separate circulatory system that drains lymph fluid from extravascular tissues. (Figure 26.3) Blood is pumped through arteries and capillaries and returns from the body through veins. Lymph nodes contain high concentrations of lymphocytes and phagocytes. (Figure 26.3d)  In capillary beds, leukocytes and solutes pass from blood into the lymphatic system. (Figure 26.3b, c)  Leukocytes – white blood cells 0.1 percent of blood cells are leukocytes – white ^ blood cells. (Table 26.2) – include phagocytes and lymphocytes Whole blood is composed of plasma and cells. – Plasma contains proteins and other solutes. Serum is the portion of blood that is not cells or clotting proteins. Key difference between serum and plasma: _^ Plasma still contains fibrinogen; serum is ^ obtained after the clotting of blood. ~  Adaptive immune Carrie oxygen response (T and B cells ^ Jaednoavetucd and CO2 and innate immune response (NK cells) - Antigen presenting for adaptive immunity. becomesmore wlth exficient pathogenexperience. Functlon wheh Innate immune materead. response 26.4 Leukocyte Production and Diversity Leukocytes are nucleated white blood cells. – Lymphocytes are specialized leukocytes involved exclusively in adaptive immune response. two types of lymphocytes – B cells: originate and mature in∞ bone marrow. – T cells: originate in bone marrow, but mature in ~ thymus. n Bone marrow and thymus are primary lymphoid organs. (Figure 26.4)  Cytokines influence the whole development white I process important blood cell types from the hematopoietic stem cells. of antibody ∅ Both impotant for ichentifying O anat ⑲ Igruamubes pathogen tlom clarp) Tcellveceptr Figure 26.4  Myeloid cells are derived from a myeloid precursor cell. – can be divided into two categories Antigen-presenting cells (APCs) engulf, process, antigensto lymphocytes. and present antibodies –monocytes including macrophages, and dendritic cells Granulocytes contain toxins or enzymes that are released to kill target cells. –neutrophils, basophils, eosinophils – Lymphoid stem cells produce T cells, B cells and NK cells. – Each lymphocyte produces a unique protein that interacts with a single antigen. d T cells: T cell receptors (TCRs) Abnestich,in the figure θ B cells: antibodies or immunoglobulins (Igs) →