Exam 3 Flashcards
(47 cards)
Blood Vascular System consists of
Heart
Arteries
Capillaries
Veins
Lymphatic Vascular System
begins in the lymphatic capillaries, closed-ended tubules that form vessels of steadily increasing size
terminate in blood vascular system
return fluid from tissues spaces back to blood
What lines all blood and lymphatic vessels
simple squamous epithelium
endothelium
Capillaries
composed of a single layer of endothelial cells and a surrounding basal lamina
Diameter 7-9 micrometers
length 50 micrometers
Types of Capillaries: Continuous Capillaries
typically found in the muscle, lung, and CNS
consists of uninterrupted layer of endothelial cells connected by tight junctions (constantly take up substances from the blood and regulate)
surrounded by continuous basal lamina
Pericytes
often associated with continuous capillaries and venules
mesenchymal-derived cells that surround the endothelial cells
function in repair damaged capillaries (differentiation)
Fenestrated Capillaries
typically found at sites that require rapid exchange of substances between tissues and blood
fenstrations
characterization of fenestrated capillaries
essentially pores
Membrane Covering:
with diaphragms found in endocrine glands, intestines, and around kidney tubules
fenestrated capillaries without diaphragms found in RENAL GLOMERULI
Discontinous Capillaries
Also referred to as Sinusoidal Capillaries or Sinusoids: found in liver, spleen, and bone marrow
larger in diameter (30-40)
endothelial cells form a DISCONTINUOUS LAYER separated from one another by wide spaces
Basal Lamina is discontinous
cytoplasm of endothelial cells show multiple fenestrations without diaphragms
discontinous structure greatly facilitates interchange between blood and the tissues
Where are macrophages located on sinusoids?
either among or outside the cells of the endothelium
Immune System permanent structures
lymph nodes and spleen
Immune System free cells
lymphocytes
granulocytes
cells of the mononuclear phagocyte system
APC
Lymphoid Nodules
smaller collections of lymphoid tissue that form nodular aggregates
in mucosa of digestive system (tonsils, peyers patches, and appendix) , respiratory system, reproductive system, and urinary system
Lymphoid nodules constitute the mucosa associted lymphoid tissue (MALT)
Secondary Lymphoid Organs
Spleen
Lymph Nodes
Solitary nodules
Tonsils
Appendix
Peyers patches
sites where lymphocytes proliferate and complete their differentiation
Enlargement of lymph nodes is caused by
collection of lymph from infected region
mainly due to the proliferation of B cells and their differentiation into antibody-secreting plasma cells
Cells responsible in innate immunity
Phagocytes (macrophages and neutrophils)
and natural killer cells
bear receptors (TLR) that recognize PAMP that are not present in the host organism, including microbial DNA, lipids, polysaccharides and proteins
True or False: Adaptive immunity reactions are faster that innate immune reactions
False, due to the formation of antibodies but is more efficient beacuse of memory cells
Types of Adaptive Immune Reactions
Cellular Immunity
mediated by T lymphocytes
Humoral Immunity
involves antibodies that inactivate or destroy foreign substances
produced by plasma cells derived from B cells
Antigen
molecule that is able to provoke an immune response
Antigenic determinant (or epitope)
specific region of an antigenic molecule that binds to an antibody or T cell receptor
Another name for antibodies
immmunoglobulins
Composition of Antibody Molecule
Composed of four polypeptide chains
two identical antigen binding sites derived from heavy and light chains
Antibody-Antigen Interactions
Bc antibodies have two identical antigen-binding sites, they can cross link antigens
Antigens with 3 or more antigenic determinants can form large three-dimensional lattices that readily precipitate out of solution
True or False; IgG is the most abundant class of antibodies
True
