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 SystemClosed system – blood is in tubesConsists of:

Heart

BloodBlood vessels – arteries, veins, capillaries

Blood VesselsArteries - carry blood away from the heart

to all parts of bodyexpansion and contraction of artery is the pulse

– corresponds to the number of heartbeatsCapillaries – smallest vessels

one cell layer thicksite of exchange between blood and body

tissues Veins – bring blood back to the heart

Contain valves which stop blood from flowing backwards

HeartMuscular pump that is responsible for

circulating blood throughout the bodyA. Structure of the Heart

4 chambers – right and left side of the heart separated by the septum

Heart2 upper chambers – Atria

Right atrium receives deoxygenated blood from the body

Left atrium receives oxygenated blood from the lungs

2 lower chambers – VentriclesRight ventricle sends deoxygenated blood to the

lungsLeft ventricle sends oxygenated blood to the

body**Ventricular walls contain thicker muscles

HeartB. 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

HeartC. Blood PressureThe pressure exerted on the walls of the

arteries from the pumping action of the heart is referred to as blood pressure.

100-140 Systolic Pressure on the ventricles during contraction60-80 Diastolic Pressure in the ventricle during relaxation

HeartD. Pathways of CirculationSystemic: from the heart to the rest of the

body and backPulmonary: from the right ventricle

lungsleft atriumCoronary: from the heart to the blood vessels

that supply the heart muscle with oxygenated blood.

Diseases or Homeostatic failure of the circulatory systemTransport Disorders – diseases of the

heart and blood vessels are called cardiovascular diseases1. 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 systemBlood 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.