quiz laboratorio #5 Flashcards
OBJECTIVES
- Be able to distinguish between the structures and functions of the three types of blood vessels.
- Be able to explain the function of a circulatory system and blood.
- Be able to trace the pathway of blood through the circulatory system naming the major structures en route.
In humans the circulatory system is composed of the
heart and blood vessels.
The heart is a…
A typical heart weighs…, yet it may pump…
Abnormal heartbeats approximately…
At rest the heart pumps about:
If the body is submitted to strenuous exercise, the heart really gets workout, pumping as much as:
During the average lifetime the human heart will beat about
-muscular organ the size of a fist that pumps the blood through the body.
- less than twelve ounces, yet it may pump between four and five thousand gallons of blood a day.
- 72 times a minute, pumping the entire amount of blood in an adult (10-12 pints) in that minute.
-one gallon a minute
-nine gallons a minute
- 2.5 billion times.
The heart is located between:
Most of the heart is composed of strong muscle tissue called the:_________, which when it contracts, …
The outside of the myocardium is covered by a thin layer of tissue known as the:
A lubricating fluid helps prevent friction during contraction.
-the lungs in the middle of the chest.
-myocardium, forces blood into the arteries
-pericardium
The heart is divided into:
The upper and lower chambers are connected by ______ that allow…
Functionally, the heart is divided into:
The left side provides ________________, while the right side pumps ____________.
This separation, which occurs only in birds and mammals, is important because it prevents oxygen-poor blood from the body from mixing with oxygen-rich blood from the lungs.
This separation helps warm-blooded animals to maintain their high metabolic rates.
-four chambers, two upper atria and two lower ventricles.
-valves, that allow blood to flow in one direction only.
-left and right sides, separated by a septum.
-oxygenated blood to the body; blood only to the lungs
The heart is really a double pump:
One pathway:
Second pathway:
-blood is circulated from the heart to the lungs and back to the heart in one pathway
-blood is circulated from the heart to the body and back to the heart.
Blood pathway in the circulatory system
blood enters the right atrium via the superior and inferior venae cava.
The right atrium then forces the blood past a valve into the right ventricle.
The right ventricle contracts, sending the blood past a valve into the pulmonary arteries and to the lungs, where oxygen is picked up and carbon dioxide is released.
This oxygenated blood returns to the heart through the pulmonary veins and into the left atrium.
The next contraction forces the blood through the bicuspid valve and into the left ventricle.
The left ventricle is the largest chamber; when it contracts, it sends blood past a semilunar valve and through the aorta to all parts of the body.
most susceptible chamber to heart attacks:
The _____ is the largest artery in the body.
The blood nourishes our cells by distributing: throughout the body.
The blood picks up carbon dioxide and other wastes. It then travels to the right side of the heart again, where the cycle is renewed.
left ventricle
aorta
oxygen, food, hormones, and antibodies
The circulatory system is dependent on a vast network of tubes called blood vessels, which carry the blood throughout the body and the heart.
There are three types of blood vessels:
Arteries are… They are strong because blood is:
The pressure decreases as the blood travels further from the heart.
The arteries also become smaller and smaller until they open up into a network of microscopically thin vessels known as:
This is the point at which the blood actually comes into contact with the body’s cells.
After removing waste products, the blood enters a system of larger blood vessels known as ____, which transport the blood back to the heart. They are not as elastic as arteries. Instead, they have one-way valves that help in returning the blood to the heart.
- the arteries, veins, and capillaries.
-muscular, elastic blood vessels that carry blood away from the heart; under a great deal of pressure as it leaves the heart
-capillaries
-veins
In a single heartbeat, (what happens)
The heart is under control by a specialized type of tissue that functions as a _______. This tissue, which is located in the _______, …
Blood pressure is a measurement of:
The complete heartbeat consists of a period of:
Normal systolic pressure ranges from:
normal diastolic pressure ranges from:
-the two atria contract simultaneously followed by a similar simultaneous contraction of the two ventric1es and then a pause.
-pacemaker. located in the right atrium, keeps the heartbeat regular
-the force of blood on the walls of the arteries
-muscle contraction, known as systole, and a period of muscle relaxation, known as diastole
systolic: 100 to140
diastolic: 70 to 90
Blood pressure measurements are conducted with an instrument known as the:
Process of taking blood pressure:
-sphygmomanometer; , which consists of an inflatable cuff attached to a pressure meter that is wrapped around the arm.
-A stethoscope is placed over the artery and an air-compression bulb is squeezed to pump air into the cuff until circulation is momentarily cut off. The air is then slowly released.
As the pressure drops, a point is reached at which the systolic pressure is just able to overcome the pressure in the cuff and each heart beat is able to force blood past the point of compression. These “beats” are heard in the stethoscope, and the pressure at which they begin is recorded as the systolic pressure.
As the pressure continues to drop, the beats become louder, then stop as the pressure is reached at which blood can flow even between beats. This pressure is recorded as the diastolic pressure.
cardiovascular diseases
a. high blood pressure
b. atherosclerosis
c. heart attack
d. stroke
e. rheumatic fever
high blood pressure
the heart is::
risk factors:
also called hypertension. The heart is forced to work harder and may become enlarged. The artery walls become less elastic, harder, and narrowed. They are unable to deliver as much blood to the body. Eventually, high blood pressure can lead to heart attack, a stroke, or kidney failure. Risk factors: heredity, a high-fat diet, cigarette smoking, and stress.
The question the use of drugs to lower the risk of heart attack is still being studied.
Certainly, lowering the blood pressure will help reduce the risk of stroke and kidney failure.
atherosclerosis:
starts:
disease characterized by:
other name for blood clot
may begin very early in life. Its progressive development often leads to fatal heart.
The disease is characterized by deposits of fat, calcium, and other materials on the walls of the arteries. This deposition builds up and eventually clogs the artery, blocking the flow of blood. When blood flow is halted to vital organs such as the heart or brain, death may result.
-. A blood clot, or thrombus. If the artery to the heart is clogged, the resulting heart attack is called a coronary thrombosis. If the blockage occurs in the artery to the brain it is referred to as a cerebral thrombosis.
Heart attacks
symptoms:
can occur if:
If the heart fails to meet its oxygen needs,
what is collateral circulation?
characterized by a variety of symptoms including acute chest pains lasting more than two minutes and, frequently, nausea, sweating, dizziness, and shortness of breath.
Heart attacks can occur if atherosclerosis blocks off the coronary artery or if the artery is simply narrowed.
-severe chest pains known as angina pectoris will occur.
-Sometimes certain channels that are normally closed open up, allowing increased blood passage to the heart.
