heart and blood vessels & blood

Question 1

what is the heart?

Answer 1

The heart is an organ that pumps blood around the body in a
double circulatory system

Question 2

in the double circulatory system what does the right ventricle do?

Answer 2

pumps deoxygenated blood to the lungs where gas exchange takes place .The blood then returns to the heart

Question 3

in the double circulatory system what does the left ventricle do?

Answer 3

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

Question 4

what are the walls of the heart mostly made of?

Answer 4

muscle tissue

Question 5

why does the heart have valves?

Answer 5

to prevent the back flow of blood

Question 6

what four chambers does the heart have and what is found at the top and bottom?

Answer 6

-at the top you can find the right and left atrium
-at the bottom you can find the right and left ventricle

Question 7

the side of the heart is opposite -right side is left , left side is right
what is the natural resting heart rate controlled by?

Answer 7

a group of cells located in the right atrium that act as a pacemaker

Question 8

1)where does blood flow into the two atria(plural of atrium) from ?

Answer 8

the vena cava and pulmonary artery

Question 9

2) the atria contracts pushing blood into?

Answer 9

the ventricles

Question 10

3)the ventricles contract forcing blood into where?

Answer 10

the pulmonary artery and the aorta and out of the heart

Question 11

4) the blood then flows to the organs through what?

Answer 11

the arteries and returns through the veins
the atria fills again and the whole cycle starts over

Question 12

why do coronary arteries branch off the aorta and surround the heart?

Answer 12

to make sure that it gets all the oxygenated blood it needs

Question 13

what is the function of the lungs?

Answer 13

to get the oxygen that we need from the air into our bloodstream where it can be transported to the rest of the body

Question 14

how does air pass into the lungs? why does the trachea have rings of cartilage ?

Answer 14

through a tube called trachea
rings of cartilage prevent the trachea from collapsing during inhalation

Question 15

the trachea then splits into two smaller tubes called bronchi with one passing to each lung . what does this further divide to ?

Answer 15

to smaller tubes called bronchioles

Question 16

finally , what do bronchioles end in ?

Answer 16

tiny air sacs called alveoli
trachea->bronchi->bronchioles->alveoli

Question 17

what happens in the alveoli ?

Answer 17

site of gas exchange

Question 18

what adaptations do alveoli have for effective gas exchange ?

Answer 18

• one cell thick creates a short diffusion pathway
• many alveoli mean that lungs have huge surface area
  -very good blood supply

Question 19

by breathing we also increase the rate of diffusion .
what does breathing bring?

Answer 19

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

Question 20

what does the systematic circulation carry?

Answer 20

the newly oxygenated blood from the heart to deliver oxygen to respiring tissues in the rest of the body

Question 21

what does the pulmonary circulation carry?

Answer 21

deoxygenated blood to the lungs to exchange carbon dioxide for oxygen

Question 22

what are artificial pacemakers?

Answer 22

Artificial pacemakers are electrical devices used to correct irregularities in
the heart rate.

Question 23

the circulatory system

Answer 23

-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

Question 24

breaths per minute

Answer 24

breaths per minute = number of breaths divided by number of minutes