Body Systems - Year 8

Study for year 8 body systems

cell

the basic building block of organisms

tissue

a group of similar cells working together form this

organ system

a group of organs function to perform a role form this

respiration

a chemical reaction in our cells that produces energy; breathing for humans

glucose and oxygen

what respiration uses to create energy

water and carbon dioxide

waste products of respiration

digestion

the process where nutrients and energy are extracted from the food we eat

mechanical digestion

occurs when food is physically broken down or mashed

into smaller pieces

chemical digestion

occurs when special chemicals

called enzymes chemically break down food.

canine

teeth with the role of biting, ripping and tearing food

incisors

teeth with the role of cutting food

molars

teeth with the role of grinding

mouth

where digestion begins. The tongue, saliva and teeth begin digestion

oesophagus

the tube connecting the mouth and stomach

stomach

a j-shaped organ in which muscles churn food, mixing it with gastric juices including enzymes and acid to form chime

pancreas

produces chemicals to break down food and neutralise stomach acid which are released into the small intestine. Also produces insulin.

liver

produces bile which neutralises stomach acid and breaks down fat, also clears the blood of waste products

gallbladder

stores bile from the liver to be released into the small intestine

small intestine

where most food is digested and nutrients are absorbed through its walls. Lined with villi

large intestine

absorbs excess water, salts and remaining minerals to make faeces

rectum

the part of the large intestine that stores faeces before they leave the body

villi

these line the walls of the small intestine to increase its surface area and allow for better absorption

anus

where stools from the rectum are expelled

blood

a liquid that carries water, oxygen and nutrients around the body

red blood cells

component of blood carrying oxygen

haemoglobin

a substance that attracts and carries oxygen - carried by red blood cells

white blood cells

part of blood responsible for fighting bacteria and viruses

platelets

part of blood responsible for helping blood clot

plasma

the clear yellow liquid in which platelets, red and white blood cells are suspended

heart

the organ responsible for pumping blood

blood vessels

these tubes carry blood around the body

oxygenated

blood rich in oxygen

deoxygenated

blood with most of its oxygen removed

arteries

carry blood away from the heart to organs

veins

carry blood back to the heart

capillaries

fine, one cell thick blood vessels allowing for exchange of gases, nutrients and waste products

valves

structures that prevent a flow of blood in the wrong direction

circulatory system

a system made up of the heart, arteries, veins and capillaries

respiratory system

a system mainly comprised of the lungs

trachea

the scientific term for the windpipe

nose

part of the respiratory system which warms, filters and moistens the inhaled air

pharynx

connects the nose and mouth to the oesophagus

epiglottis

a flap of tissue that stops food entering the trachea

larynx

the scientific term for the voice box, also helps stop food entering the trachea

bronchi

the two main branches of the trachea (a left and right bronchus)

broncioles

the finer tubes that bronchi branch into

alveoli

sacs which are one cell thick allowing for gas exchange takes place in the lungs

diaphragm

a sheet of muscle separating the chest from the abdomen allowing us to breathe

excretion

the process in which waste is removed from the body

kidneys

the organs responsible for filtering your blood

nephrons

the tiny filtration units inside kidneys

urine

the waste liquid produced by the kidneys

ureters

tubes connecting kidneys to the bladder

bladder

a muscular storage bag which holds urine

urethra

a passage which allows urine to exit the body

right atrium

the first chamber where deoxygenated blood flows into the heart

vena cava

deoxygenated blood flows into the heart through this

aorta

oxygenated blood leaves the heart through this

pulmonary vein

oxygenated blood enters the heart from the lungs through this

left atrium

the first chamber of the heart oxygenated blood flows into

right ventricle

where blood flows into after the right atrium

left ventricle

where blood flows into after the left atrium

pulmonary artery

deoxygenated blood flows out of the heart, to the lungs through this

septum

separates the left and right sides of the heart

left

muscle on this side of the heart is thicker