From Atom to Organism
Division of Labour between the different organ systems
The Skeletal System: The skeletal system of the average human being
consists of 206 bones. The main purposes the of skeletal system are to provide
the body with structure. The bones also provide protection to the body’s vital
organs such as the lungs, heart and brain. The skeletal system also provides movement
to the body with joints.
Circulatory System: The
circulatory system of the human body consists of the heart, arteries, veins and
capillaries. The primary function of the circulatory system is to transport oxygenated
blood around the body to vital organs such as the heart, brain liver, kidneys
and lungs. The circulatory system also transports key nutrients around the
body, such as amino acids. Carbon dioxide, blood cells and hormones are also
transported through the Circulatory System.
Muscular System: Containing
visceral, cardiac and skeletal muscles this system allows movement of the body,
maintaining a posture and circulating blood throughout the body. Visceral
Muscles are involuntary controlled muscles that operate the stomach, bladder
and blood vessels. Cardiac Muscles are another type of involuntary muscle that
controls the heart. Skeletal Muscles are voluntarily controlled muscles attached
to the bones which allow movement of the body when contraction occurs.
Digestive System: The organs that
make up the digestive system are the mouth, oesophagus, stomach, small
intestine, large intestine, the rectum and the anus. Digestion starts in the
mouth where we chew the food to break up into smaller pieces and mixed with
saliva to make the digestion process easier. Food then travels down the oesophagus
and into the stomach, here food is partially digested with the churning of the
stomach muscles and then the release of acids and enzymes further break the
food down chemically. From the stomach, food then travels to the small
intestine. The small intestine absorbs the nutrients and minerals from the food
into the body. The final stage of the digestion occurs in the large intestine,
here the water from the already digested food is absorbed by the body and any
remaining indigestible food exits the body via the anus and then the rectum.
Urinary System: This
system is responsible for removing excess and unneeded materials from the body
fluids of person to prevent damage to the body. The organs that make up the urinary
system are the kidneys, ureters, urinary bladder and the urethra. The function
of the kidneys are to filter wastes and from the blood to produce urine (these
wastes being metabolic wastes excess ions). This urine is carried from the kidneys
to the urinary bladder by the ureters. The ureters are a pair of tubes and
their sole purpose is to transport the urine from the kidneys to the urinary
bladder. The urinary bladder is a sack that is used to store and accumulate
urine until full. The average person’s
bladder can hold between 600 and 800 millilitres of urine. When the urinary
bladder is full, urine passes through the urethra, which is a tube that carries
the urine out of the body. In a male the urethra ends at the tip of the penis
and in a woman directly below the clitoris.
Nervous System: Consisting of the
brain, spinal cord, sensory organs and all the nerves in the body. As a system
combined the nervous system allows us to control, feel and think. The brain is
like a computer to our body, sending electrical signals to control our body.
The spinal cord carries these electrical signals around our body so we can move
System: The human reproductive system allows us to
reproduce and create offspring. Male and Females do not share the same
reproductive system. The male produces sperm which travels into the female via
the vagina which will then fertilise the egg. The male reproductive system
contains the penis, scrotum, testes, the epididymis, spermatic cords, seminal
vesicles, ejaculatory duct, urethra, prostate, Cowper’s gland & the penis.
The female reproductive system consists of the ovaries, fallopian tubes,
uterus, vagina, vulva, breasts and the mammary glands.
Lymphatic System: Also known as the
immune system, this system is responsible for our bodies defence against
pathogenic viruses, fungi, bacteria & parasites. Our body works around the
clock to attack and keep these harmful agents at bay.