Unformatted text preview: +), or sodium bicarbonate by
combining with sodium ions. Negatively charged
proteins also associate with H+.
(g) Nutrient supply:
Blood component: Plasma
Mode of action: Glucose is carried in the
plasma and is taken up by cells (made available
throughout the body to all tissues).
(h) Tissue repair:
Blood components: Platelets and leukocytes
Mode of action: Platelets initiate the cascade of
reactions involved in clotting and wound repair.
Leukocytes (some types) engulf bacteria and
foreign material, preventing or halting infection.
(i) Hormone, lipid, and fat soluble vitamin transport:
Blood component: α-globulins
Mode of action: α-globulins bind these
substances and carry them in the plasma. This
prevents them being filtered in the kidneys and
lost in the urine. 2. 1. (a) They have the ability to self renew while
maintaining an undifferentiated state.
(b) A stem cell has the capacity to differentiate into
specialized cells types (potency). 2. (a) Myeloid progenitor cells: megakaryocyte (and
platelets), monocytes, macrophages, granulocytes
(neutrophils, basophils, eosinophils), and red
(b) Lymphoid progenitor cells: T lymphocytes, B
lymphocytes, and NK lymphocytes. 3. The main purpose of ASC are to maintain and repair
the tissue in which they are found. Examples are:
– Hematopoietic stem cells give rise to all the
types of blood cells, red blood cells, lymphocytes,
leukocytes and platelets.
– Bone marrow stromal cells (mesenchymal
stem cells) give rise to a variety of cell types
including bone cells (osteocytes), cartilage
cells (chondrocytes), fat cells (adipocytes) and
connective tissue cells such as tendons.
– Neural stem cells in the brain can produce
nerve cells (neurons) and the non-neuronal cells
astrocytes and oligodendrocytes.
– Epithelial stem cells that line the digestive tract
give rise to absorptive cells, globet cells, Paneth
cells and enteroendocrine cells.
– Skin stem cells in the basal layer of the epidermis
form keratinocytes which protect the skin.
Follicular stem cells at the base of...
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- Winter '13