UNIT 4

THE HUMAN BODY

health

exercise

walk

Ride a bike

swim

run

Get enough sleep

Eat a balanced diet

Proteins

Minerals

Fats

Vitamins

carbohydrates

Keep clean

brush teeth to remove plaque

Wash hands before eating

ING

ES

TIO

N

DIG

ES

TIO

NIn te stomach the food

mixes with gastric juices and turns into a thick liquid. The thick

liquid travels to the small intestine where

the food is broken down even more. A

BS

OR

PT

ION

The liver and the pancreas send juices to the smal intestine so that our body can now absorb the nutrients in the food.

ELI

MIN

AT

ION The remains of the

food that our body can’t use go tothe large intestines. Here our body has its last chance to take water from the food. The remains finally leave our body through the anus

The digestive process starts in the mouth. We chew our food and mix the food with the saliva. Our food passes to the oesophagus and then to our stomach.

THE DIGESTION PROCESS

mouth

oesophagus

liver

stomach

pancreas Largeintestine

Smallintestine

anus

THE DIGESTIVE SYSTEM

The excretory system

kidneys

Renal artery

Renal vein

ureters

bladder

urethra

The excretory system

The kidneys clean the waste from our blood. This waste combines with water to make urine. Urine goes down the ureters, and collects in the bladder.When the bladder starts to get full, the body tell us that it’s time to go to the toilet.Urine then leaves the body through the urethra.

The respiratory system

When we inhale, air enters our body through our nose and mouth. Tiny hairs inside the nose trap dust particles and clean the air.The air then passes through the pharynx and larynx as it goes down to the trachea.The trachea divides into two parts called bronchi. The air travels down the bronchi into the lungs.The bronchi divide into small tubes called bronchioles. At the end are alveoli which are covered in blood vessels.Here , the oxygen in the air is absorbed into the blood. Waste carbon dioxide passes from the blood to the alveoli.This exchange the gases is called respiration.

THE RESPIRATORY SYSTEM

nose

mouth

pharynx

larynx

trachea

bronchi

lung

bronchioles

diaphragmalveoli

large with thick walls carry oxygenated blood from the heart to the rest of the body.

thinner walls carry blood back to the heart.

tiny connect arteries and veins

yellowish liquid made up of 90% water carries

nutrients and waste products

carry oxygen and carbon dioxide contain haemoglobin

fight infection

join together when the body is losing blood

Pumps the blood around the body.

THE CIRCULATORY SYSTEM

aorta Pulmonary artery

Pulmonary vein

Left atrium

Left ventricle

Right ventricle

Right atrium

Complete the following sentences.

Red blood cells carry

__________________________________________________________________________

_______.

The blood gets oxygen from the ___________________________________.

Blood carries ___________________________ from the small intestine.

____________________ blood cells fight germs.

Blood travels to all parts of the ___________________________.

The liquid part of blood is called __________________________.

________________ blood cells give blood its colour.

________________ form blood clots.

REVISION

Nutrition is a very complex process in humans.

Four body systems have to work together to perform the process.

• The digestive system breaks down the food into nutrients.

• The circulatory system takes the nutrients and oxygen to all parts of the body.

• The respiratory system obtains oxygen from the air. Oxygen is necessary for the

transformation of the nutrients into energy.

• The excretory system eliminates harmful waste produced in the process