heart and blood vessels & blood Flashcards
what is the heart?
The heart is an organ that pumps blood around the body in a
double circulatory system
in the double circulatory system what does the right ventricle do?
pumps deoxygenated blood to the lungs where gas exchange takes place .The blood then returns to the heart
in the double circulatory system what does the left ventricle do?
The left ventricle pumps oxygenated blood around the rest of the body . The blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again
what are the walls of the heart mostly made of?
muscle tissue
why does the heart have valves?
to prevent the back flow of blood
what four chambers does the heart have and what is found at the top and bottom?
-at the top you can find the right and left atrium
-at the bottom you can find the right and left ventricle
the side of the heart is opposite -right side is left , left side is right
what is the natural resting heart rate controlled by?
a group of cells located in the right atrium that act as a pacemaker
1)where does blood flow into the two atria(plural of atrium) from ?
the vena cava and pulmonary artery
2) the atria contracts pushing blood into?
the ventricles
3)the ventricles contract forcing blood into where?
the pulmonary artery and the aorta and out of the heart
4) the blood then flows to the organs through what?
the arteries and returns through the veins
the atria fills again and the whole cycle starts over
why do coronary arteries branch off the aorta and surround the heart?
to make sure that it gets all the oxygenated blood it needs
what is the function of the lungs?
to get the oxygen that we need from the air into our bloodstream where it can be transported to the rest of the body
how does air pass into the lungs? why does the trachea have rings of cartilage ?
through a tube called trachea
rings of cartilage prevent the trachea from collapsing during inhalation
the trachea then splits into two smaller tubes called bronchi with one passing to each lung . what does this further divide to ?
to smaller tubes called bronchioles
finally , what do bronchioles end in ?
tiny air sacs called alveoli
trachea->bronchi->bronchioles->alveoli
what happens in the alveoli ?
site of gas exchange
what adaptations do alveoli have for effective gas exchange ?
- one cell thick creates a short diffusion pathway
- many alveoli mean that lungs have huge surface area
-very good blood supply
by breathing we also increase the rate of diffusion .
what does breathing bring?
fresh oxygen into the alveoli and takes away the carbon dioxide .This makes the concentration gradient high for these gases . that increases the rate of diffusion
what does the systematic circulation carry?
the newly oxygenated blood from the heart to deliver oxygen to respiring tissues in the rest of the body
what does the pulmonary circulation carry?
deoxygenated blood to the lungs to exchange carbon dioxide for oxygen
what are artificial pacemakers?
Artificial pacemakers are electrical devices used to correct irregularities in
the heart rate.
the circulatory system
-blood is pumped from the heart to the lungs where it collects oxygen
-blood then returns to the heart and is pumped around the whole body where it delivers the oxygen to the body cells
breaths per minute
breaths per minute = number of breaths divided by number of minutes
