Circulatory System

The human body contains ________ of cells.

• A

  thousands

• B

  millions

• C

  billions

• D

  trillions

Tags

NGSS.MS-LS1-1

Which of these best describes circulation?

• A

  the process by which food is turned into energy

• B

  the flow of blood throughout the body

• C

  the strength of muscles and bones

• D

  the ability to think and dream

The main organ of the circulatory system is the

• A

  liver.

• B

  brain.

• C

  heart.

• D

  spleen

The heart is about the size of a

• A

  fist.

• B

  quarter.

• C

  football.

• D

  ring finger.

Which of these is true?

• A

  Both veins and arteries carry oxygen-rich blood.

• B

  Both veins and arteries carry oxygen-poor blood.

• C

  Veins carry oxygen-poor blood, and arteries carry oxygen-rich blood

• D

  Veins carry oxygen-rich blood, and arteries carry oxygen-poor blood.

Plasma is

• A

  the clear liquid part of blood.

• B

  the compound that makes blood red.

• C

  a type of blood cell that fights infection.

• D

  a type of blood cell that carries carbon dioxide

What is the function of platelets?

• A

  They reduce pain and inflammation.

• B

  They kill bacteria in the blood.

• C

  They give you energy.

• D

  They help blood clot.

Red blood cells carry ________ around the body.

• A

  platelets

• B

  oxygen

• C

  aortas

• D

  veins

Tags

NGSS.MS-LS1-2

NGSS.MS-LS1-3

The human heart beats about ________ times a day.

• A

  1,000

• B

  10,000

• C

  100,000

• D

  1,000,000

What is homeostasis?

• A

  a state of balance in the body

• B

  a way to measure physical fitness

• C

  the amount of oxygen in the blood

• D

  the number of times the heart beats