Chapter 15 Flashcards
What layer of the blood vessel wall is responsible for vasoconstriction/dilation?
The tunica media
What layer of the blood vessel wall is responsible for preventing or allowing blood clotting?
Tunica Intima
What layer of the blood vessel wall is responsible for resistance to high blood pressure by providing structure?
Tunica Media
What layer of the blood vessel wall is responsible for formation of new blood vessels?
Tunica Intima
Which is more elastic, veins or arteries? WHY???
Arteries are because they need to withstand the high pressure of blood pumped directly from the heart. THEY ARE ALWAYS UNDER CONSTANT PRESSURE.
Veins are less elastic so they can hold a very high percentage of the blood in circulation
Explain elastic rebound in the large arteries
When the ventricle pushes the blood out the artery walls stretch because of the pressure (cushions the pressure during ventricular systole). Then when the ventricle relaxes (ventricular diastole) and there is no more pressure. Then it causes the artery walls to snap back (un stretch) and it sends a huge force in the artery to get the blood to the rest of the body.
How does elastic rebound affect systolic blood pressure?
It lowers systolic blood pressure
How does elastic rebound affect diastolic blood pressure?
It raises diastolic pressure
What type of vessel carries the highest percentage of blood at rest?
Veins and venules
What are the 2 things allow venous blood to return to the heart REAGARDLESS of low blood pressure?
- The skeletal muscle pump
- Respiratory pump
What causes varicose veins? (4) And what is it?
Sitting and standing in one place for long periods of time, pregnancy, obesity pressures or it is heredity
It is where blood pools in the leg veins stretching the walls and the valves no longer work
What are continuous capillaries and their functions?
They are endothelium complete lining capillaries connected by tight junctions
Functions: Prevent blood loss, keep plasma in the blood, allows passage of water, solutes, and lipid-soluble materials
What are fenestrated capillaries and their functions?
They help with quicker filtration (#2 fastest). They contain pores to do that and are located in the choroid plexus, endocrine organs, and kidneys
What are sinusoids capillaries and their functions?
They are capillaries that are larger and more permeable that allow blood cells and huge substances to go through by gaps between adjacent cells.
Where are continuous, fenestrated, and sinusoid capillaries located?
Continuous: in tissues EXCEPT cartilage and epithelia
Fenestrated: choroid plexus, endocrine organs, and kidneys
Sinusoids: Liver, bone marrow, spleen
How do you calculate pulse pressure?
systolic pressure MINUS the diastolic pressure
systolic pressure - diastolic pressure