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56 Cards in this Set
- Front
- Back
When the body is at rest, where is the blood? |
4% - Heart The rest in the blood vessels, 13% of that is in the brain. |
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The Vascular System |
An elaborate system of vessels in the body. |
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Arteries |
Carry blood away from the heart. |
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Veins |
Return blood to the heart. |
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Capillaries |
Connect the smallest arteries to the smallest veins. |
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Tunics |
The three layers of veins and arteries. |
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Tunica Intima |
The innermost layer of vessels. Consists of a simple squamous epithelium. |
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Tunica Media |
The middle layer of vessels. The thickest layer in arteries. |
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Tunica Externa |
The outer layer of vessels. The thickest layer in veins. |
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Aneurysm |
When a portion of the arterial wall weakens, and the blood pressure creates a bulge. |
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Conducting Arteries Elastic Arteries |
The body's largest arteries that expand as blood surges into them and recoil when the ventricles relax. |
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Distributing Arteries Muscular Arteries |
Arteries that carry blood to specific organs and areas of the body. |
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Arterioles Resistance Vessels |
The smallest arteries that can resist the flow of blood, helping regulate blood pressure as well as control how much blood enters an organ through the contraction of smooth muscle in their walls. |
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Metarterioles |
Short connecting vessels that connect arterioles to capillaries. |
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Which are thinner: arteries or veins? |
Veins |
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Capacitance Vessels |
Another name for veins, given because they have a great capacity for storing blood. |
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Medium-Sized Veins |
These veins have thicker, more elastic walls that contain one-way valves that prevent backflow. The most valves can be found in the legs, which must fight the forces of gravity. |
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Venules |
The smallest veins that collect blood from capillaries. The tunica media is poorly developed. Venules are porous and can exchange fluid with surrounding tissues. |
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Exchange Vessels |
Another name for capillaries, since nutrients, wastes, and hormones are transferred between blood and tissues. |
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Capillary Beds |
Networks that capillaries are organized into. |
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Microcirculation |
The connection between arterioles and venules, using capillaries. |
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Precapillary Sphincter |
Located at the beginning of each capillary bed. Regulates the flow of blood into the network. |
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Sinusoid |
A unique capillary that is more permeable, allowing for the passage of large substances such as proteins and blood cells. |
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Capillary Exchange |
Release chemicals like oxygen, glucose, hormones, and nutrients. Take up waste like CO2 and ammonia; take up substances that need to be transported. Water moves into and out of capillaries. |
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Diffusion Of Capillaries |
Oxygen diffuses out of capillaries and into surrounding fluid. CO2 diffuses into the capillaries. |
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Filtration |
Occurs close to the arterial side of the capillary bed. The higher pressure in the capillary pushes plasma and dissolved nutrients through the capillary wall and into the fluid in the surrounding tissues. |
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Colloid Osmotic Pressure |
Occurs toward the venous side of the capillary bed. Process whereby albumin in the blood pulls tissue fluid into capillaries. |
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Edema |
When fluid filters out of the capillaries faster than it's reabsorbed. Causes swelling in the ankles, fingers, abdomen, or face. |
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What causes Edema? |
1. Increased capillary filtration 2. Reduced capillary reabsorption 3. Obstructed Lymphatic Drainage |
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Where does the body's main portal system occur? |
The liver |
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Portal System |
A system in which blood flows through two networks of capillaries. |
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Anastomosis |
A natural connection between two vessels. |
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Arteriovenous Anastomosis |
When blood flows directly from on artery to a vein. |
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Venous Anastomosis |
When blood flows directly from a one vein to another vein. |
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Pulmonary Circulation |
Begins at the right ventricle and involves the circulation of blood through the lungs. |
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Systematic Circulation |
Begins at the left ventricle and involves the circulation of blood through the body. |
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Pulmonary Circulation Route |
1. Right Ventricle 2. Pulmonary Arteries 3. Lobar Arterties in the lungs 4. Arterioles 5. Lung Capillaries 6. Venules 7. Veins 8. Pulmonary Vein 9. Left Atrium |
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Circle of Willis |
Branches from the internal carotids and basilar artery form several anastomoses to create a circle of arteries at the base of the brain. |
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Pressure Gradient |
The differences in pressure. |
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Systolic Pressure |
As the left ventricle contracts, it ejects blood into the aorta, producing a normal pressure of 110 mm Hg. |
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Diastolic Pressure |
When the ventricle relaxes, the pressure drops to an average of 70 mm Hg. |
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Sphygmomanometer |
Measures BP |
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Normal BP |
Less than 120/80 mm Hg |
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Prehypertension |
120-139/80-89 mm Hg |
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Stage I Hypertension |
140-159/90-99 mm Hg |
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Stage II Hypertension |
160/100 mm Hg or greater |
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Hypertension |
When blood pressure is higher than normal. |
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Hypotension |
When blood pressure is lower than normal. |
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Vasomotion |
Adjusting the diameter of blood vessels. |
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Vasodilation |
An increase in vessel diameter caused by the relaxation of vascular muscles. |
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Vasoconstriction |
A reduction of the diameter of a vessel. |
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Atherosclerosis |
The hardening and narrowing of the arteries. |
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Vasomotor Center |
An area of the medulla in the brain that sends impulses via the autonomic nervous system to alter blood vessel diameter and blood pressure. |
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Baroreceptors |
In the carotid sinus and aortic arch. They detect changes in blood pressure and transmit signals along the glossopharyngeal and vagus nerves to the cardiac control center and the vasomotor center in the medulla. |
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Skeletal Muscle Pump |
When leg muscles contract, they massage the veins in the legs, propelling blood toward the heart. The valves in the veins ensure the blood flows upward. |
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Respiratory Pump |
During inhalation, the chest expands and the diaphragm moves downward, causing the pressure in the chest cavity to drop and the pressure in the abdominal cavity to rise. This forces blood upward toward the thorax. |