Transcript Circulatory System Notes

Human Transport System
How does the circulatory system help
maintain homeostasis?
It transports nutrients and other
essential materials, such as oxygen,
to cells and removes waste
products.
What other human systems work with the
circulatory in maintaining homeostasis?
 Respiratory
 Excretory
 Digestive
Human Circulatory System
 Closed system – blood is in tubes
 Consists of:
 Heart
 Blood
 Blood vessels – arteries, veins, capillaries
Blood Vessels
 Arteries - carry blood away from the heart to all parts of
body
 expansion and contraction of artery is the pulse – corresponds
to the number of heartbeats
 Capillaries – smallest vessels
 one cell layer thick
 site of exchange between blood and body tissues
 Veins – bring blood back to the heart
 Contain valves which stop blood from flowing backwards
Heart
 Muscular pump that is responsible for circulating blood
throughout the body
A. Structure of the Heart
 4 chambers – right and left side of the heart separated by the
septum
Heart
 2 upper chambers – Atria
 Right atrium receives deoxygenated blood from the body
 Left atrium receives oxygenated blood from the lungs
 2 lower chambers – Ventricles
 Right ventricle sends deoxygenated blood to the lungs
 Left ventricle sends oxygenated blood to the body
 **Ventricular walls contain thicker muscles
Heart
B. Valves prevent backflow of blood in chambers of the
heart. The closing of valves creates “lub-dub” sound of
heartbeat.
 Tricuspid valve - located between the right atrium and right
ventricle
 Mitral valve - located between the left atrium and left
ventricle
Heart
C. Blood Pressure
 The pressure exerted on the walls of the arteries from the
pumping action of the heart is referred to as blood pressure.
100-140
60-80
Systolic Pressure on the ventricles during contraction
Diastolic Pressure in the ventricle during relaxation
Heart
D. Pathways of Circulation
 Systemic: from the heart to the rest of the body and back
 Pulmonary: from the right ventricle lungsleft atrium
 Coronary: from the heart to the blood vessels that supply the
heart muscle with oxygenated blood.
Diseases or Homeostatic failure of the
circulatory system
 Transport Disorders – diseases of the heart and blood
vessels are called cardiovascular diseases
 1. Hypertension is also known as high blood pressure. This
condition damages the heart and the wall of the blood vessels.
Risk factors include stress, diet, heredity, cigarette smoking and
aging.
Diseases or Homeostatic failure of the
circulatory system
 2. Angina Pectoris is a temporary narrowing of the coronary
arteries causing temporary shortages of oxygen to the heart.
This results in severe chest pain that may radiate down the left
arm and into the jaw.
 3. Coronary thrombosis (heart attack) is a blockage in the
coronary artery or its branches. The blockage deprives the
heart muscle of oxygen and subsequently damages it.
Diseases or Homeostatic failure of the
circulatory system
 4. Strokes are the result of blood clots that block blood vessels
from bringing blood to the brain. Brain cells begin to die from
a lack of oxygen. Ruptures in these same blood vessels may also
cause strokes.
Diseases or Homeostatic failure of the
circulatory system
 Blood Disorders
 Leukemia is a form of cancer in which the bone marrow
produces abnormally large numbers of white blood cells.
 Anemia is a condition in which the blood cannot carry
sufficient amounts of oxygen to the body cells.
 Sickle cell anemia is a genetic disorder resulting in
misshapen red blood cells due to an alteration in the
hemoglobin.
 Iron deficiency anemia is the result of low iron in the
diet resulting in a decrease in the number of red blood cells.