nikoniko

The heartbeat is initiated by specialized cells called

• the atrioventricular code

• the superior vena cava

• the sinoatrial code

• tricuspid valve

Arteries 

• carry blood from lungs to the muscles

• carry blood through organs of the body

• carry blood from the heart to organs of the body

• carry blood from organs back to heart

Veins

• carry blood from the heart to organs of the body

• carry blood from organs back to heart

• carry blood from lungs to the muscles

• carry blood through organs of the body

Capillaries

• carry blood from the heart to organs of the body

• carry blood from organs back to heart

• carry blood from lungs to the muscles

• carry blood through organs of the body

Which is not a main component of the human circulatory system ?

• lungs

• heart

• blood

• blood vessels

What helps keep blood flowing onwards away from the heart in the artery ?

• valves

• elastic fibres

• contraction of skeletal muscles

• having a wide lumen

 The term lumen refers to 

• the outside space of a tubular structure

• the inside space of a tubular structure

• the inner layer of cells in blood vessels

• the fluid that is transported through capillary walls

  Choose the correct sequence to correspond with the following 

            brain・heart・lung・liver・kidney

• cerebral・cardiac・pulmonary・hepatic・renal

• cerebral ・cardiac ・hepatic・pulmonary・renal

• cerebral・cardiac・renal ・pulmonary・hepatic

• cerebral・cardiac・pulmonary・renal・hepatic

The internal environment

• refers to the environment outside the cells but inside of the body

• is the environment inside cells, outside the nucleus within the cytoplasm

• refers to the interstitial fluid and the intracellular environment

• refers to the environment outside the cells but inside of the body

Extracellular fluid consists of 

• red blood cells, white blood cells, and plasma

• blood cells and tissue fluid

• interstitial fluid and plasma

• blood plasma and intracellular fluid