102.The answer is e.( Junqueira, p124. Ross & Pawlina, pp 239–241.)
Leptin is a protein hormone produced by adipocytes (shown in the pho-
tomicrograph). Leptin binds to receptors in the hypothalamus and has
multiple effects including increased release of norepinephrine (NE) from
sympathetic nerve terminals that innervate adipose tissue. Adipocyte
adrenergic receptors bind NE leading to increased metabolism of fatty acids
with dissipation of the energy as heat. As weight increases and adipocytes
accumulate triglycerides, the “obese” (ob) gene is up-regulated in
adipocytes and leptin synthesis and serum levels of leptin are increased
(answers b and c).Leptin-receptors in the hypothalamus are up-regulated as
Connective Tissue Answers 191B lymphocytes Bone marrow Humoral immunity
(bone marrow–
educated)
Plasma cell B lymphocyte Immunoglobulin secretion
Neutrophils Bone marrow First cells to enter an inflammation site,
(PMNs) secrete myeloperoxidase, phagocytose
bacteria, and die (forming pus)
Eosinophils Bone marrow Source of major basic protein,
histaminase (breakdown of histamine),
arylsulfatases (degradation of
leukotrienes), phagocytosis of antigen-
antibody complexes and parasites
Basophils Bone marrow Blood source of histamine
(different stem
cell from mast
cell)
Mast cells Bone marrow CTMC are T-lymphocyte independent,
connective tissue MMC are T-lymphocyte dependent,
mast cells secrete histamine and slow-reacting
(CTMC) and substance of anaphylaxis [(SRS-A)
mucosal mast increase vascular permeability],
cells (MMC) heparin (anticoagulant), eosinophil
chemoattractant factor of anaphylaxis
[(ECF-A), chemoattraction of
eosinophils], leukotrienes (smooth
muscle contraction)Cell Type Origin Function