Healthcare test #4 Flashcards
(111 cards)
The cardiovascular system
The organ system that is made up of the heart, the blood, and the blood vessels
The circulatory system connects all parts of the body.
left and right
Oxygenated blood is shown in red (left side of body). Deoxygenated blood is shown in blue (right side of body).
Function of the circulatory system
To transport substances around the body
To move nutrients to all of the body’s cells
Regulation of body temperature
Transport of disease-fighting white blood cells to areas of the body where they are needed (i.e. viruses/bacteria)
How is this done?
Blood flows through lungs, picks up oxygen, then flows to heart to pump to body to deliver it to active cells
Parts of the Cardiovascular (circulatory) system
4 parts of the circulatory system: blood, heart, and blood vessels, lungs
Heart pumps blood through large vessels (arteries) AWAY from heart to body
Blood exchanges substances, in smallest vessels (capillaries), with surrounding tissues
Blood then flows into larger vessels (veins) and returns TO the heart
Blood then goes to lungs for more oxygen, back to heart and cycle continues
The Heart
Located slightly left of middle of the chest -about the size of your fist (weighs 9 oz)
Protected by sternum
Surrounded by pericardium
Muscular part is myocardium (cardiac muscle) coronary artery supplies heart with O2, cardiac vein removes CO2
Has 4 chambers – 2 atria and 2 ventricles
3 Layers of the Heart
pericardium, myocardium, endocardium
Chambers of the Heart
Atria (atrium)– 2 top chambers;
-right atrium gets deoxygenated blood from the vena cava from body
-left atrium gets oxygenated blood from the pulmonary vein from the lungs
Ventricles – 2 lower chambers receive blood from atria
-right ventricle pumps deoxygenated blood to the pulmonary artery to lungs for oxygen
- left ventricle (thicker) pumps oxygenated blood to the aorta to send to the body and cells
Myocardium
Specialized muscle tissue (cardiac muscle) that forms the heart. The heart is considered a “double pump” that is divided into right and left sides.
Pulmonary Circulation
The main function of the right side of the heart is to pump deoxygenated blood, which has just returned from the body, and is going to the lungs.
Systemic Circulation
The role of the left side of the heart is to pump oxygenated blood, which has just returned from the lungs, and is going to the rest of the body.
Blood Flow Through the Heart
Blood is delivered to the right atrium from the superior and inferior vena cava.
It passes through the tricuspid valve and enters the right ventricle.
From there, the blood is pumped through the pulmonary semilunar valve and out through the pulmonary arteries to the lungs
The blood returns from the lungs through the pulmonary veins to the left atrium.
It then passes through the bicuspid valve and enters into the left ventricle.
The blood is then pumped out through the aortic semilunar valve into the aorta and throughout the systemic circulation.
Arteries
Blood vessel
Elastic blood vessels that carry blood AWAY from the heart
Artery expands with surge of blood during contraction of ventricles, then snaps back during relaxation of ventricles
Under a great amount of pressure
Have thicker walls to withstand pressure; will spurt when cut
Can vary in size
Veins
Blood vessels
Elastic blood vessels that carry blood TOWARD the heart
Can’t contract to help move blood back to heart
Have one-way valves to prevent blood from flowing backward
Blood is at a lower pressure
Thinner wall than arteries
Can vary in size
Capillaries
Blood vessel
Extremely small blood vessels located within the tissues of the body
Fine network
Transports blood from arteries to veins
Exchange O2 with CO2 and nutrients with waste
Thin walled
Allow substances to diffuse between the blood and other body fluids and tissues
Artioles
Arterioles are small vessels in the blood circulation system that branch out from arteries (that came from lungs) and lead to capillaries, where gas exchange eventually occurs. Surrounded by smooth muscle, arterioles are the primary site of vascular resistance.
Venules
Small blood vessels that branch out from capillaries and lead to veins with deoxygenated blood used by cells that are sent to lung for oxygen.
Pulmonary arteries
One of the main vessels of the heart
transport deoxygenated blood out of heart to the lungs to pick up oxygen
Pulmonary veins
One of the main vessels of the heart
bring oxygenated blood back to the heart to be pumped out to the body
Aorta
One of the main vessels of the heart
largest blood vessel (artery) in body; where all blood going to the body tissues leaves the heart (brachiocephalic, common carotid, subclavian)
Vena cava
One of the main vessels of the heart
largest vein in the body carrying blood back to heart from body (superior vena cava from top half of body and inferior vena cava from bottom half)
Valves of the Heart
Valves control the flow of blood through the heart in the correct direction
4 valves of the heart:
2 Atrioventricular valves (AV valves)
1.Tricuspid valve (3 flaps)- between the right atrium and right ventricle
2. Bicuspid valve (2 flaps and called mitral valve) between the left atrium and left ventricle
2 Semi-Lunar valves
Pulmonary valve- between the right ventricle and the pulmonary artery
Aortic valve -between the left ventricle and the aorta
Varicose Veins
Varicose Veins occur when valves become faulty and blood begins to pool in areas of the veins.
If the walls of the vein become stretched and less flexible (elastic), the valves can weaken. A weakened valve can allow blood to leak backward and eventually flow in the opposite direction. When this occurs, blood can accumulate in the vein(s), which then become enlarged and swollen.
Compression socks and clothes
help blood flow
Blood
A type of connective tissue that circulates throughout body (about 9 pints at a time)
Both fluid and solid portion
It consists of four components:
Plasma 🡪 55% of blood volume
red blood cells (erythrocytes) 🡪 44% of blood
white blood cells (leukocytes) 🡪1%
Platelets (thrombocytes) 🡪0.5%
Red Blood Cells
Erythrocytes
perform the most important
blood duty
Specialized for oxygen transport
A single drop of blood contains
millions of red blood cells which are
constantly traveling through your body delivering oxygen/nutrients and removing waste/CO2
Contain hemoglobin (protein) which allows cells to pick up oxygen and also transports some of the carbon dioxide waste (iron helps hemoglobin)
RBCs are the most plentiful of the body’s blood cells.