Topic 2: Systems in the human body

CORE CONTENT:

[Note: The intention of this topic is to provide learners with an overview of the structure and functions of organs and systems in the human body]

Body systems

• the human body consists of several integrated systems working together including the following

• digestive system: breaks down food into dissolved nutrients that can be absorbed into the blood stream and transported to cells throughout the body

-- the main processes include ingestion, digestion absorption and egestion

-- the main components include the mouth, oesophagus, stomach, intestines, liver

-- health issues include ulcers, anorexia nervosa, diarrhoea, liver cirrhosis

• circulatory system: brings nutrients and oxygen to cells and removes waste products

-- the main processes include circulating blood between heart and lungs, and circulating blood between the heart and the rest of the body

-- the main components include the heart, blood vessels (arteries, veins, capillaries), blood

-- health issues include high blood pressure, heart attacks, strokes

• respiratory system: is responsible for supplying oxygen to the body and for removing carbon dioxide

-- the main processes include breathing (inhalation and exhalation), gaseous exchange (diffusion) and respiration

-- the main components include the nose and mouth, trachea and other air passageways, lungs, blood

-- health issues include asthma, lung cancer, bronchitis, asbestosis

• musculoskeletal system: muscles produce body movement. The skeleton protects the body, provides support and enables movement

-- the main processes include contraction and relaxation of muscles, locomotion and movement

-- the main components include the muscles, bones, cartilage, tendons, ligaments

-- health issues include rickets, arthritis, osteoporosis

• excretory system: removes waste from the blood and regulates the body’s fluids

-- the main processes include filtration, absorption, diffusion, excretion

-- the main components include the kidneys, bladder, ureters

-- health issues include kidney failure, bladder infection, kidney stones

• nervous system: receives and helps the body respond to stimuli

-- the main processes include hearing, seeing, feeling, tasting, smelling, sending and receiving impulses, regulating temperature

-- the main components include the brain, spinal cord, nerves, ears, nose, eyes, skin, tongue

-- health issues include deafness, blindness, short sightedness, effects of drugs and alcohol on the brain

• reproductive system: produces sex cells for the purpose of continuation of the species

-- the main processes include growth, cell division, maturation, copulation, ejaculation, ovulation, menstruation, fertilisation, implantation

-- the main components include testes, ovaries, uterus

-- health issues include infertility, foetal alcohol syndrome, STDs