The Systematic Circulation, Blood Vessels, and Capillary Networks Flashcards
Open systems are systems in which…
the heart pumps blood to the tissues in closed arteries, without a venous return.
Closed systems are systems in which…
blood never leaves the vessels.
What are the five fluid systems in the body?
- Blood Vascular System;
- Lymphatic System;
- Cerebrospinal Fluid;
- Coelomic / Peritoneal Fluid
- Interstitial Fluid.
The two main functions of the blood system is to:
- Transport to the cells the materials necessary for their metabolism and synthesis
- The transportation away of the waste products of cell activity
____________ and _____________ must be supplied to the cells and _____________ and _______________ removed.
Oxygen and nutrients; carbon dioxide and nitrogenous wastes
Blood vessels are the structures that ____________; in mammals these are divided into _________________ (Hint: 3 things)
carry out transport; arteries, capillaries, and veins
How would you list the direction of transport in the blood vascular system?
Aorta –> arteries –> arterioles –> metarterioles –> arterial capillaries –> venous capillaries –> venules –> veins –> Vena Cava
The walls of arteries and veins have three layer, what are they?
Tunica Intima; Tunica Media; Tunica Adventitia/ Externa
In large arteries such as the aorta there is little…
muscle in the media and it mostly consists of sheets of elastic tissue.
Medium sized arteries have lots of…
smooth muscle in the media.
Nerve supply from the sympathetic nervous system enabling…
the control of blood flow.
Veins are similar to arteries in structure, but the walls are…
thinner and have less smooth muscle and elastic tissue.
Medium sized veins have ______ in the ________.
Valves, lumen
Both large arteries and veins have their own blood supply called the…
Vasa vasorum
Capillaries, the smallest vessels, are formed of…
a single layer of endothelial cells, 8-10m thick, without any smooth muscle.
It is rare for any cell to be more than _________ from a capillary.
20-30 micrometers
Capillaries tend to be arranged in…
capillary beds
Only about ____ of blood volume is in the capillaries at a time.
5%
The arteriole divides into a number of…
met-arterioles which do not have a continuous smooth muscle coat.
Blood passes through the met-arterioles and enterers the capillary bed via the
precapillary sphincters
What can precapillary sphincters do?
These can close off the circulation to the capillary bed.
Blood does not flow continuously through the capillary beds because…
in most organs only a small number of capillaries are filled.
Besides the capillary beds, direct connections called _____________________ shunt blood rapidly from the arterial to venous side.
preferential channels or arteriovenous anastomoses
Most cells obtain their nutrient and oxygen requirements via the…
Interstitial fluid
