Blood Vessels, Heart, Gaseous Exchange

Question 1

Arteries

Answer 1

• take blood from heart to organs

- thick walls made from muscles and elastic fibres

Question 2

Veins

Answer 2

• takes blood from your organs to your heart

- thinner walls and valves to prevent backflow

Question 3

Capillaries

Answer 3

• allow substances needed by the cells to pass out of the blood
• allow substances produced by the cells to pass into blood
• narrow, thin-walled blood vessels

Question 4

The heart pumps blood around the body in a _____

Answer 4

-double circulatory system

Question 5

What are the four chambers in the heart ?

Answer 5

• left and right ATRIA, which RECEIVE BLOOD from VEINS

- left and right VENTRICLES, which PUMP BLOOD OUT INTO ARTERIES

Question 6

How does the heart pump blood around body

Answer 6

1) Blood enters heart through the ATRIA
2) Atria contracts and forces blood into VENTRICLES
3) ventricles contract and force blood OUT OF HEART
4) VALVES Make sure blood flows in the correct direction

Question 7

Where is the group of cells that control the natural resting heart rate ?

Answer 7

-in the right atrium, acts as a pacemaker

Question 8

Gaseous exchange

Answer 8

1) Heart sends blood to lungs via PULMONARY ARTERY
2) Air obtained by breathing reaches lungs through TRACHEA, has rings of CARTILAGE to prevent it from collapsing
3) trachea divides into two tubes- BRONCHI
4) these divide to form BRONCHIOLES, and they divide into tiny air sacs called ALVEOLI
5) blood is taken back to heart through PULMONARY VEIN

Question 9

How are alveoli adapted for exchanging oxygen and co2

Answer 9

• large, moist SA
• rich blood supply
• close to blood capillaries, so distance for gases to diffuse is small

Question 10

How is the pulmonary artery unusual

Answer 10

-carries deoxygenated blood