Exam II: Cardiovascular System (Capillaries to Lymphatic Ducts) Flashcards
Blood flow into capillaries is controlled/influenced by:
- Metarterioles
- AVA’s (AV shunt- some locations only)
- Lumen size of terminal arteriole
- Pre-capillary sphincters
Form tiny pockets though the cytoplasm of capillaries
Pinocytotic Vesicles
Function of Pinocytotic vesicles
Movement of large molecules
Cell junction located in capillaries
Fasclae occludens (between endothelial cells)
Functions of cell junctions in capillaries
- Move macromolecules
- Allows cell movement
Most common capillary type and locations present
Continuous capillaries
-muscle, connective tissue, many organs
Cell often considered to be residual mesenchyme cells. They are numerous on capillaries and venules, can secrete basement membrane and matrix components.
Pericytes
Pericytes ___ divide and can change into:
Can divide
Change into: 1) Endothelial cells 2) Smooth muscle cells 3) Fibroblasts (all 3 cells are important for tissue repair and maintenance )
T/F Pericytes have contractile filaments
True
Functions of pericytes
- Important for healing
- May regulate blood flow (hypothesis only)
Modified continuous capillary in the CNS
- Zonula occludens instead of fasciae occludens
- Barrier regulation by endothelium, but influenced by astrocytes
Name and location of capillaries that have pores with a thin protein diaphragm containing 8 fibrils
Fenestrated capillaries
-Pancreas, intestines, endocrine organs, kidneys
Function of Fenestrated capillaries
To allow greater movement of molecules and cells
Name and location of capillaries with an enlarged diameter and many large fenestrae with no protein diaphragm
Sinusoidal capillaries (sinusoids)
Function of sinusoidal capillaries
Enhanced exchange between blood and tissues
T/F Arteries and veins both have 3 tunics
True
How are veins different from arteries?
Veins are:
- Not as uniform in structure
- Often larger
- Have higher numbers