The Human Body
The Human Body
By
Letisha, Shelly, Nicita
and Rebecca
Contents 
The human lungs
Did you know ?
We take in about 20,000 breaths
a day .An adults lungs hold 5 litre
The Lungs
Though the right lung has three lobes, the left lung, with a cleft to accommodate the heart, has only two. The two branches of the trachea, called bronchi, subdivide within the lobes into smaller and smaller air vessels. They terminate in alveoli, tiny air sacs surrounded by capillaries. When the alveoli inflate with inhaled air, oxygen diffuses into the blood in the capillaries to be pumped by the heart to the tissues of the body, and carbon dioxide diffuses out of the blood into the lungs, where it is exhaled.
Did you know ?
You have two lungs one on each
side of your chest. You can feel
them fill with air as you breath in.
Structure of the eye
The nerve signals that pass to the brain. A mesh of blood vessels, the choroid, supplies the retina with oxygen and sugar. Left: Lacrimal entering the eye is controlled by the pupil, which dilates and contracts accordingly. The cornea and lens, whose shape is adjusted by the ciliary body, focus the light on t retina, where receptors glands secrete tears that wash foreign bodies out of the eye and keep the tube from drying out. Blinking compresses and releases the lacrimal sac, creating a suction that pulls
Did you know ?
The iris is the colour part of
the eye .The most common
colour is brown then blue.
The kidneys
Kidney
Approximately one million nephrons (right) compose each bean-shaped kidney (left). The filtration unit of the nephron, called the glomerulus, regulates the concentration within the body of important substances such as potassium, calcium, and hydrogen, and removes substances not produced by the body such as drugs and food additives. The filtrate, urine, leaves the nephron through a long tubule and collecting duct. Chemical signals triggered by the body's need for water and salt cause the walls of the tubule to become more or less permeable to these substances, which are reabsorbed accordingly from the urine.
Did you know ?
You have two kidneys one on both
sides of your back bone at about
waist level.
The human heart
Human Heart
The heart is a dual pump, circulating blood through two separate closed systems. Oxygen-carrying blood leaves the left ventricle through the aorta. It circulates through the body and returns, deoxygenated, to the right auricle via the superior and inferior venae cavae. The right ventricle pumps this blood through the pulmonary artery to the lungs, where it exchanges carbon dioxide for oxygen. Oxygenated blood then returns to the left auricle of the heart, ready for arterial circulation, through the pulmonary veins.
Structure of the ear
Designated as outer ear structures are the visible part of the ear, called the auricle, and the waxy, dirt-trapping auditory canal which conveys changes in air pressure and sound waves to the eardrum. The eardrum, or membrane, begins the middle ear, which also comprises the eustachian tube and the three vibrating bones of the ear: malleus, incus, and stapes. The cochlea and semicircular canals make up the inner ear. Information passes from the inner ear to the brain via the auditory nerve.
