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The Heart <3 composed mostly of muscle hollow organ—size of clenched fist enclosed in a protective sac of tissue called
Pericardium two thin layers of epithelial and connective tissue that
surround a thick layer of muscle called Myocardium contractions of the Myocardium (heartbeat) pump
blood through the circulatory system heart muscle contracts an average of 72 times a
minute—pumps 70 mL of blood the Septum divides the right side of the heart from the
left and prevents Oxygen-poor blood from mixing with Oxygen-rich blood
Heart—valves
four chambers-two upper chambers (left and right atria) and two lower chambers (left and right ventricles)
right atrium has thinner walls and is larger than the left
the left ventricle is the strongest and largest chamber in the heart
Heart—valves four types of valves:
Tricuspid valve- separates the right atrium from the right ventricle and regulates blood flow between them
Pulmonary valve- separates the right ventricle from the left pulmonary artery and controls blood flow from each other
Mitral valve- separates the left ventricle from the left atrium
Aortic valve- separates the left ventricle from the Aorta and controls the blood flow from the ventricle into the rest of the body
Heart—arteries arteries push blood through the blood
vessels when the heart relaxes from its contractions
arteries transport Oxygen-rich blood to the capillaries where exchange of CO2 and Oxygen takes place
Heart—arteries
arteries of the heart:Pulmonary artery- carries deoxygenated blood
from the right side of the heart to the lungs for purification, it also divides into right and left branch
Aorta-main artery of the heart which carries oxygenated blood to the rest of the body; branches off to smaller arteries that supply blood for the body
Coronary arteries- attached to the heart and supply blood to heart muscles
Heart—veins
veins are like arteries but do not transport blood at high pressure
after the exchange of CO2 and O, the blood containing waste products is received by the veins
Pulmonary vein- carries oxygenated blood from the lungs to the left side of the heart
Heart—veins
all four pulmonary veins pour oxygenated blood into the left atrium (two left and two right)Venae Cavae- two large veins carry
deoxygenated blood from the body to the heartSuperior Venae Cavae- brings deoxygenated
blood from parts above heart into the right atrium
Inferior Venae Cavae- brings blood from the parts below the heart to the right atrium
Blood Vessels Three types of blood vessels:
ArteriesCapillariesVein
Arteries: the largest vessels that carry blood from the heart to the tissues.
Except for the pulmonary and umbilical arteries, all arteries carry oxygen loaded blood.
Arteries have thick walls to withstand the pressure from the heart when it contracts and pushes blood into them.
Blood Vessels
Arteries have three layers….Adventitia: outside layer; elastic to
allow the arteries to expand under pressure.
Media: middle layer; contracts to regulate the diameter
Endothelium: inside layer; smooth lining to allow blood to flow
Blood Vessels Aorta: Largest vessel leaving the left ventricle and leads down to
the rest of the arteries. Arterioles: small vessels that branch off from the arteries and
lead to the capillaries Capillaries: Smallest, “side-streets”. The walls are only one cell
thick. These are the main vessels that nutrients and oxygen is brought to tissues.
Veins: After passing through the capillary system, blood returns to the heart for oxygen
Blood flows against gravity through the veins. Large veins, like in the leg, have valves that push the blood
towards the heart. Exercising helps keep the blood from accumulating in one spot,
which produces a blood clot.
Blood Pressure Blood Pressure ~ the force of blood
against the walls of the arteries. Systolic pressure: the pressure as the
heart beats Diastolic pressure: the pressure as the
heart relaxes between beats Equation: systolic/diastolic mmHg
(millimeters of mercury) the normal or “desired” number is 120/80
mmHg
Blood Plasma
Blood Plasma-55% of blood is plasma. Plasma is 90% water and
10% dissolved gasses, salts, nutrients, enzymes, hormones, waste products, and proteins.
Plasma proteins:Albumins- helps regulate osmotic pressure and
blood volume, and transports substancesGlobulins- transports substances, and fights viral
and bacterial infectionsFibrinogen- gives blood the ability to clot
Blood Cells Red Blood Cells
1 milliliter of blood has about 5 million red blood cells
Red blood cells transport oxygenThey get their red color from hemoglobin (iron-
containing protein that binds to oxygen in the lungs and transports it to tissue throughout the body)
They are disk-shaped cells without a nucleus made from cells in red bone marrow
Red blood cells last for about 120 days before they are destroyed in the spleen
Blood Cells White Blood Cells
less common, out numbered almost 1000 to 1guard against infections, fight parasites, attack
bacteriathey can slip out of capillaries and fight
infections throughout the bodythe body can increase the number of white
blood cells when fightinghave nuclei and are made in bone marrowlive for days, months, even years
Blood Cells
Plateletsthere are about 150,000 to 350,000
platelets per micro literblood clotting is made possible by
plasma proteins and plateletsthey aren't actually cells, but cell
fragments produced in bone marrow
Diseases 2 Types
Present at BirthAcquired
Aortic AneurysmBulging in the wall of the aorta (largest artery)Caused by a tear or defect in the aortic wallCan be a complication of other diseases such as high
blood pressure Angina
Pain or discomfort in the chest area caused by leakage in the blood vessels leading to the heart
Pain lasts usually about 10 minutes
Diseases Arrhythmia
Irregularity in the heart rhythm, varies from very slow to very fast
Can occur at any point in life Atherosclerosis
The hardening of the arterial wall because of plaque or artheroma
Plaque is composed of cholesterol, calcium, and fatty deposits
Can slow or stop blood circulationThere is a sharp pain in the affected area
Diseases High Blood Pressure
When the systolic pressure Is over 140 mmHg and disastolic pressure is over 90 mmHg
Caused by heredity or unhealthy lifestyle habits such as heavy drinking and smoking
Peripheral Vascular Diseasea disorder in the blood vesselscaused by fatty acid deposits in the arteries of
the leg portioncan be hereditary or acquired by unhealthy living
Diseases
Ways to Prevent Circulatory Diseases:Do not Smoke or use any other
nicotine sourceExercise consistentlyEat HealthyGet enough sleep each 24-hoursAvoid high amounts of stress
Overview Three Major Parts
The Heart The Blood The Blood Vessels
The Heart removes waste materials and pumps and circulates blood The Blood has the oxygen and nutrients necessary for cell survival The Blood Vessels transport blood to and from the heart The Circulatory System is the main transportation and cooling
system of the body It is basically like the roads in cities used to transports goods and
other important materials. When your heart beats, it forces the oxygen-rich blood through the
circulatory system