Peripheral Circulation and Respiration Flashcards
What are the two main functions of the vascular system?
distribution and exchange
What makes up the middle layer of the arterial wall and determines the size of the artery?
smooth muscle
What makes up the inner layer of the material wall and functions to control flow, protection from clots, and regulation of permeability?
endothelial cells
Which layer of the arterial wall contains nerves that contribute to control of contraction?
sympathetic vasoconstrictor fiber
The majority of resistance to flow is contributed at the level of the _______.
arterioles
What kind of muscle is found in the vascular, bronchi, and gastric sections?
non-striated smooth muscle
What are a few differences between VSM cells and striated muscle cells?
VSM cells are smaller, only have one nucleus, and a smaller sarcoplasmic reticulum
In stead of “T” tubules what do VSM cells use?
Caveolae
In cardiac muscle what provides an electrical link between cells?
gap/intermediate junctions
What is the anchor in thin filaments which provides the mechanical connection between cells and contributes to elects recoil?
dense bodies
What is the supporting protein which links the dense bodies but does not contribute to the contractile process?
intermediate filaments
What is the difference in sarcomere of VSM?
fewer in number and not regularly organized as on cardiac and skeletal
What is surrounded by smooth muscle that regulates vascular time and thus resistance to flow?
arterioles
What is where exchange of material with surrounding tissues takes place?
capillaries
What collects blood flowing out of the capillary bed?
venules
What collects interstitial or extravascular fluid and returns it to venous circulation?
lymphatics
Why are capillaries good exchange vessels?
very thin capillary wall which contains holes/pores, blood also flows very slowly
Why is blood flow at the capillaries so low?
they represent the highest total cross sectional are in circulation
What functions to return fluid and plasma protein that have leaked out of the capillaries back to the circulating pool?
lymphatic system
What covers the surface of the lungs?
visceral pleura
What lines the walls of the thoracic cavity?
parietal pleura
What is between the visceral and parietal pleura?
pleural cavity
What dictates air flow in lungs?
changes in pressure in the intrapleural space governed by changes in volume of the thoracic cavity
What must be created in the lungs in order to drive the net movement of air from the atmosphere into the lungs?
a pressure gradient
