Exam 1 Review: Chapter 19: Capillaries
endothelium - The single layer of simple squamous cells which line the walls of the heart, blood vessels, and lymphatic vessels; this tissue arises from mesoderm.
continuous capillary - The category of ordinary capillaries which lack pores = fenestrations and in which adjacent endothelial cells are held together by tight junctions to limit fluid exchange between the plasma and the tissue fluid by controlling fluid transfer between endothelial cells.

fenestrated capillary - The category of capillaries, primarily the glomerular capillaries in the nephrons of the kidney, which have pores = fenestrations and in which adjacent endothelial cells have are held together by tight junctions to limit fluid exchange between the plasma and the tissue fluid by transfer between endothelial cells while permitting regulated fluid exchange through the pores = fenestrations.

sinusoid (capillary) - The category of capillaries, primarily the capillaries in the liver, bone marrow, some endocrine glands and in lymphoid tissue, which lack pores = fenestrations but in which adjacent endothelial cells exhibit some wider intercellular gaps which permit some fluid exchange between the plasma and the tissue fluid by transfer between adjoining endothelial cells; they often have an irregular and broad cross-section.

stellate reticuloendothelial cells - Fixed macrophages with branching cytoplasmic processes, derived from monocytes, which line the sinusoids of the capillary beds of the liver and the lymph nodes and serve to phagocytize microbial pathogens, worn-out RBCs, and some toxic substances; in the liver they are also called Kupffer's cells.
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vascular sinus - Any vein or sinus with an irregular, as opposed to round or oval, cross-section.
List:
2. the three mechanisms of capillary exchange and the type of materials exchanged by each.
| vesicular transport (generally less important) | water and most dissolved solutes in plasma and interstitial fluid |
| active transport | certain electrolytes |
| passive transport and simple diffusion | water and most dissolved solutes in plasma and interstitial fluid |
Sketch and Label:
2. the forces responsible for fluid flows between capillaries and the surrounding tissue spaces.
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Describe:
2. the three types of capillaries and where they are typically found.
| Capillary Type | Location |
|
continuous capillary |
ordinary capillaries found in most capillary beds of the body (exceptions below) |
|
fenestrated capillary |
the glomerulus (glomerular capillary tuft) in the capsule of the nephron of the kidney |
| sinusoid (capillary sinusoid) | capillaries in the liver, bone marrow, some endocrine glands and in lymphoid tissue |
3. the balance of forces that determine net filtration in the arterial versus venous side of capillaries.
| Forces Encouraging Flow From the Capillary Lumen to the Interstitial Space |
Forces Encouraging Flow From the Interstitial Space to the Capillary Lumen |
| Blood Hydrostatic Pressure (BHP) &
Interstitial Fluid Osmotic Pressure (IFOP) |
Blood Colloidal Osmotic Pressure (BCOP) &
Insterstitial Fluid Hydrostatic Pressure (IFHP) |
17. the three types of capillaries and the structural and functional differences between them.
| Capillary Type | Structural Differences | Functional Differences |
|
continuous capillary |
adjacent endothelial cells are held together by tight junctions; typically these capillaries have round to oval cross-sections | limits fluid exchange between the plasma and the tissue fluid by controlling transfer between endothelial cells |
|
fenestrated capillary |
adjacent endothelial cells have are held together by tight junctions but individual endothelial cells have pores = fenestrations; typically these capillaries have round to oval cross-sections | limits fluid exchange between the plasma and the tissue fluid by transfer between endothelial cells while permitting regulated fluid exchange through the pores = fenestrations |
| sinusoid (capillary sinusoid) | adjacent endothelial cells lack pores = fenestrations but exhibit some wider intercellular gaps; these sinusoids often have an irregular cross-section | permits some fluid exchange between the plasma and the tissue fluid by transfer between adjoining endothelial cells |