Unit 5 – P3
By Jess Ross
Respiratory system

The respiratory system is made up of organs that help the body to breathe that is its main function. The lungs are the main organs of the respiratory system. In the lungs oxygen is taken into the body and carbon dioxide is breathed out. The red blood cells are responsible for picking up the oxygen in the lungs and carrying the oxygen to all the body cells that need it. The red blood cells drop off the oxygen to the body cells, then pick up the carbon dioxide which is a waste gas product produced by our cells. The red blood cells transport the carbon dioxide back to the lungs and we breathe it out when we exhale.
Renal system
The renal system (also known as the urinary system) consists of the kidneys, urethras, urinary bladder, and urethra. The kidneys filter the blood to remove wastes and produce urine. The urethras, urinary bladder, and urethra together form the urinary tract, which acts as a plumbing system to drain urine from the kidneys, store it, and then release it during urination. Besides filtering and eliminating wastes from the body, the urinary system also maintains the homeostasis of water, ions, pH, blood pressure, calcium and red blood cells. Within the system renal veins take blood from the kidneys straight into the vena cava, the main within the body.

Nervous system
The nervous system comprises the central nervous system (the brain and spinal cord) and the peripheral nervous system, the nerves running to and from the brain (cranial nerves) and spinal cord (spinal nerves). A chain of ganglia runs close to the spinal cord and is associated with the automatic nervous system, which controls internal organs. Automatic nerve fibres are also contained within the peripheral nerve. The main function of the nervous system is to coordinate all of the body's activities. It controls not only the maintenance of normal functions but also the body's ability to cope with emergency situations.

Endocrine system
This is a collection of ductless glands scattered throughout the body. Endocrine glands pass their secretions (hormones) directly into the blood stream so they are always adjacent to blood vessels. The endocrine system plays a role in regulating mood, growth and development, tissue function, metabolism, and sexual function and reproductive processes. In general, the endocrine system is in charge of body processes that happen slowly, such as cell growth. Faster processes like breathing and body movement are controlled by the nervous system. But even though the nervous system and endocrine system are separate systems, they often work together to help the body function properly.

Reproductive system
Male and females have different reproductive organs, as these serve different purposes. The female reproductive system compromises of two ovaries, each with emerging oviduct (fallopian tube) connecting to the thick walled uterus (womb). The neck of the uterus protrudes into the muscular vagina and this opens to the exterior at the vulva. The main function of the female reproduction system is to give women the ability to produce ova (an ovum is one egg, ova means multiple eggs) to be fertilized by sperm. They also provide a place for the fetus (baby) to grow and develop. Other structures such as the breasts give the mother the ability to feed and nourish a baby after birth.

The male reproductive system consists of two testes which hang in a sac the scrotum, just outside the abdomen, and are connected by long tubes to the urethra. The urethra is much longer than the female and enclosed in an organ called the penis. Two pairs of glands pour their secretions into the vasa deferentia, close to the bladder. A single ring shaped gland, called the prostate gland, also adds secretions and is located around the upper part of the urethra, just below the bladder. The urethra and vasa deferentia unite within the prostate gland. The male reproductive system is used to produce millions of sperm and the Seminal Vesicle is used to create liquid called semen. The sperm are formed in the two testes. The sperm travel to the penis via the Ductus deferens. It meets with the seminal vesicle and the white liquid known as semen is used as a lubricant for the sperm cells to reach and fertilise the egg.

Lymphatic system
The lymphatic system is a system of thin tubes and lymph nodes that run throughout the body. These tubes are called lymph vessels or lymphatic vessels. The lymph system is an important part of our immune system. It plays a role in fighting bacteria and other infections and destroying old or abnormal cells, such as cancer cells. The lymphatic system is similar to the blood circulation. The lymph vessels branch through all parts of the body like the arteries and veins that carry blood. But the lymphatic system tubes are much finer and carry colorless liquid called lymph. Lymph contains a high number of a type of white blood cells called lymphocytes that fight infection and destroy damaged or abnormal cells. The main function of the lymphatic system is to collect and transport tissue fluids from the intercellular spaces in all the tissues of the body, back to the veins in the blood system.

Musculo – skeletal system The bones of the skeleton and their attached striated muscles form this system. Striated muscle fibres are bound together to form muscles that pull bones into different positions by contracting. Muscles never push so an opposite muscle is required to return bones back to their original shape. The systems main functions are to provide mechanical support through a framework of bones and providing movement through contraction of muscles. Another important function is the system has a protective role because bone structures such as the ribs protect vital organs such as the heart and kidneys. Finally, the system has a metabolic function because Bones serve as a reservoir for calcium and phosphorus, essential minerals for various cellular activities throughout the body.

Immune system
The immune system is placed all around the body and isn’t specifically in the same place like other systems such as the digestive. It is a collection of cells, tissues and proteins that protect the body from invasion of harmful microorganisms. Its main function s to protect the body from harmful disease and infections by creating antibodies.