Chapter 26: The Heart and Blood Vessels Flashcards
what is the purpose of the circulatory system?
carries digested food carries oxygen aids in the disposal of waste products distributes heat fights disease
what are the two types of circulatory systems?
open circulatory system
closed circulatory system
whats the difference between the two circulatory systems?
open circulatory system consists of open ended blood vessels, this means that the blood exits the vessels and enters the body cells and then returns to the vessels.
closed circulatory system consisted of closed vessels, the blood enters cells through thin walls in the small blood vessels
why is the closed circulatory system more efficient?
blood can be pumped faster around the body - organism is more active
blood flow can be altered
composed of blood, blood vessels and heart
what are the 3 types of blood vessels?
arteries, capilleries, veins
arteries divide into smaller blood vessels, what are they called?
arterioles
veins divide into smaller blood vessels, what are they called?
venules
what is the difference between arteries and veins?
arteries carry blood away from the heart, vein carry blood to the heart.
arteries have thick, muscular walls (high blood pressure here), veins have thin walls (low blood pressure here).
arteries have a pulse, veins do not.
arteries are deep under the skin, veins are near the surface of the skin.
arteries have no valves, veins have valves.
blood in arteries are high in oxygen - except for the pulmonary artery, blood in veins is low in oxygen.
why do arteries have a pulse?
the high blood pressure means the force of blood exerts against the walls of the blood vessels due to the heart contracting, this causes the arteries to expand
why do veins have low blood pressure?
skeletal muscles aid blood circulation, valves control the direction of blood preventing backflow
what are capilleries?
small blood vessels acting as veins and arteries
where are capilleries?
they surround the body cells at the ends of arteries and at the beginning of veins
describe the walls of capilleries
they are only one cell thick, substances can easily get through them and into the blood or out
what does the tricuspid valve do?
prevents backflow into the right atrium
what does the semilunar valve do?
prevents backflow into heart
what does the bicuspid valve do?
prevents backflow into the left atrium
describe bloodflow in the heart.
from the body through the vena cava, into the right atrium, past the tricuspid valve, into the right ventricle, past teh semilunar valve and through the pulmonary artery, into the lungs, from the lungs through the pulmonary vein, into the left atrium, past the bicuspid valve, into the left ventricle, past the semilunar valve and out through the aorta.
what is lung circuit in the circulatory system called?
pulmonary circuit
what is the body circuit in the circulatory system called?
systemic circuit
where does the systemic circuit transport blood?
pumps to the head, trunk, limbs and back to heart
where does the pulmonary circuit transport blood?
pumps to the lungs and back to the hearts
which side of the heart is the blood oxygenated on and which is it deoxygenated on?
oxygenated -systemic- left
deoxygenated -pulmonary- right
what are three advantages of the double circulation system?
separation of oxygen rich and oxygen poor blood
blood pressure can be kept high
single circulation - blood pumped from heart around the body and back to the heart, restricts metabolism
what are the three subsystems in the systemic circuit called?
coronary circulation, hepatic portal circulation, renal ciculation
what is the coronary circulation system?
coronary arteries branch at aorta - supply blood to heart, coronary vein drains blood back into right atrium
what does a blockage in the coronary artery result in?
a heart attack
what is the renal circulation system?
supplies blood to the kidney
what percentage of blood flows to the kidneys?
nearly one fourth of the blood that is pumped into the aorta flows to the kidneys
what is the hepatic portal circulation stystem?
connects intestines with the liver, nutrients are transported to the liver, the portal system begins and ends in the capilleries.
what controls the heartbeat?
a pacemaker
what does a pacemaker do?
sends electrical signals to cardiac muscles
what makes the heart beat sounds?
the opening and closing of heart valves
what speeds up and slows down heartbeat?
the brain
what is blood pressure?
the force exerted by the blood against the walls of the blood vessels
what measures blood pressure?
sphygmomanometer - measures the amount of pressure to stop the flow of blood
what effect does nicotine have on the heart?
increases pressure and heart rate
what does carbon monoxide do?
reduces the amount of oxygen in blood
what effects can smoking have on a person?
increases blood clots, causes lung cancer, bronchitis
by how many years is life expectancy shortened by cigarettes?
10-15 years
what effect does diet have on your heart?
fats are high in cholesterol which causes blockages, high salts can cause high blood pressure, obesity causes high blood pressure and heart attacks
what effect does exercise have on your heart?
enlarges and strengthens your heart, improves blood circulation
describe how a pacemaker controls your heart rate?
pacemaker (SA node) pulses, atria contracts, ventricle contracts
why would your heart rate increase?
exercise, temperature, emotions
why would your heart rate decrease?
relaxation, sleep, alcohol
what is diastole?
heart chambers relax
what is systole?
heart chambers contract
what are the three stages of heartbeat?
- atria diastole - atria fill with blood
- atrial systole - blood is pumped to ventricle
- ventricular systole - blood pumped out of heart
describe the pathway of deoxygenated blood?
enters heart through vena cava, enters right atrium, chamber contracts and forces blood into the tricuspid valve, vena cava closes, blood enters the right ventricle, tricuspid valve closes, chamber contracts forcing blood through the semilunar valve and out through the pulmonary artery.
describe the pathway of oxygenated blood?
enters through the pulmonary vein into left atrium, pumped through the bicuspid valve into left ventricle, chamber contracts and the bicuspid valve closes, blood is pumped through the semilunar valve into the aorta
what does the acronym LORD stand for?
Left
Oxygenated
Right
Deoxygenated
what is a portal system?
a pathway that begins and ends in capilleries
what is a pulse?
the alternate expansion and contraction of the arteries
what is the average pulse rate for adults?
72 beats per minute
what is the typical blood pressure for adults?
120 over 80 (written as a fraction)
