the human circulatory system explained for grade 11 learners

1. THE HUMAN
CIRCULATORY SYSTEM:
HEART AND ASSOCIATED VESSELS
For Grade 11

2. The circulatory systems has two
distinct circuits:


Pulmonary circuit
Systemic circuit

3. 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.

4.  Connects
arteries and veins.
 facilitates the exchange of substances in the
capillaries and the interstitial tissue fluid.

5. 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)

6. FUNCTIONS OF blood vessels
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.
 Main

7. 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 oxygenpoor 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.

9. CIRCULATORY SYSTEM: HEART AND
VESSELS
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.

10. 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.

11. 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.

12. 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.

14. 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.

15. 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.

16. References for slide

Guestbca131b. (2012). Received from
slideshare.http://www.slideshare.net/guestbca131b/theheart-and-cardiac-cycle.

Thelawofscience.( 2012) received from slideshare.
http://www.slideshare.net/thelawofscience/circulatorysystem-10946147

Medicineppt. (2011). Received from slideshare.
http://www.slideshare.net/medicineppt/heart-powerpointpresentation-template

Tctp-cp-science. (2011) received from slideshare.
http://www.slideshare.net/tctp-cp-science/circulatorysystem-tctp

Debdstein. (2013). Received from slideshare.
http://www.slideshare.net/debdstein/circulation-humanheart-shortened-and-revised