THE HUMAN CIRCULATORY SYSTEM: HEART AND ASSOCIATED VESSELS

For Grade 11

DOUBLE CIRCULATION

The circulatory systems has two distinct circuits:

Pulmonary circuit Systemic circuit

DOUBLE CIRCULATION

Pulmonary circuit

The heart pumps deoxygenated blood to the lungs and oxygenated blood back to the heart.

Systemic circuit

The heart pumps oxygenated blood to the somatic cells and deoxygenated blood back to the heart.

FUNCTIONS OF CAPILLARIES

Connects arteries and veins. facilitates the exchange of substances in the

capillaries and the interstitial tissue fluid.

FUNCTIONS OF blood vessels Arteries: transport oxygenated blood except

for the pulmonary artery. Veins : transports deoxygenated blood

except for the pulmonary vein.

Other veins: Renal vein (kidney) Hepatic vein (liver)

Other arteries: Renal artery (kidney) Hepatic artery (liver)

FUNCTIONS OF blood vessels Main artery is called the Aorta –

pumping oxygenated blood from heart to rest of body.

Main vein is called the vena cava –

pumping deoxygenated blood towards the heart from the rest of the body.

CIRCULATORY SYSTEM: HEART AND VESSELS Mammals have a four-chambered heart with

two atria and two ventricles The left side of the heart pumps and receives

only oxygen-rich blood, while the right side receives and pumps only oxygen-poor blood

The mammalian cardiovascular system meets the body’s continuous demand for O2.

Blood begins its flow when deoxygenated blood flow from the body into the right atrium.

Blood then flows from the right atrium into the right ventricle through the tricuspid valve.

The blood is then pumped into lungs, through the semilunar valve via the pulmonary artery.

In the lungs, the blood loads O2 and unloads CO2.Oxygen-rich blood from the lungs enters the heart via the pulmonary vein at the left atrium Blood flows into the left ventricle through the bicuspid valve.

This blood is then pumped through semilunar valve into the aorta with takes blood to the entire body.

CIRCULATORY SYSTEM: HEART AND VESSELS

CIRCULATORY SYSTEM: HEART AND VESSELS Deoxygenated blood returns to the heart through the superior vena cava (blood from head, neck, and forelimbs) and inferior vena cava (this blood is from the trunk and hind limbs)

The superior vena cava and inferior vena cava flow into the right atrium.

The atrioventricular (AV) valves (tricuspid and bicuspid valves) separate each atrium and ventricle

The semilunar valves control blood flow to the aorta and the pulmonary artery.

CARDIAC CYCLE

cardiac cycle:The heart contracts and relaxes in a rhythmic cycle.Systole: The contraction, or pumping, phase is called… Diastole:The relaxation, or filling, phase.pulse :Is the heart rate, is the number of beats per minute.

MAINTAINING THE HEART’S RHYTHMIC BEAT

cardiac muscle cells contract without any signal from the nervous system

The sinoatrial (SA) node, or pacemaker, sets the rate and timing at which cardiac muscle cells contract.

Impulses from the SA node travel to the Atrioventricular (AV) node

At the AV node, the impulses are delayed and then travel to the Purkinje fibers that make the ventricles contract.

HEART AND CIRCULATORY SYSTEM DISEASES

Cardiovascular diseases:

Atherosclerosis, just one of the many Cardiovascular diseases, are caused by the build-up of plaque (fat) deposits within the arteries.

HEART AND CIRCULATORY SYSTEM DISEASES Heart attack: Is the death of cardiac muscle tissue

caused by blockage of one or more coronary arteries. Stroke

Is the death of nervous tissue in the brain, usually caused by a rupture or blockage of arteries in the head.. Hypertension:

High blood pressure, causes atherosclerosis and gives a high risk of a

heart attack and/or a stroke. Hypertension can also be prevented by living a very healthy lifestyle and/or medication.

References for slide Guestbca131b. (2012). Received from

slideshare.http://www.slideshare.net/guestbca131b/the-heart-and-cardiac-cycle.

Thelawofscience.( 2012) received from slideshare. http://www.slideshare.net/thelawofscience/circulatory-system-10946147

Medicineppt. (2011). Received from slideshare. http://www.slideshare.net/medicineppt/heart-powerpoint-presentation-template

Tctp-cp-science. (2011) received from slideshare. http://www.slideshare.net/tctp-cp-science/circulatory-system-tctp

Debdstein. (2013). Received from slideshare. http://www.slideshare.net/debdstein/circulation-human-heart-shortened-and-revised