Neurons transmit electrical signals via chemical and electrical synapses.
The three types of muscle found in the human body are the smooth, the striated and the cardiac muscle.
Olfactory receptors produce electric signals when stimulated by odors.
The main parts of the human brain are the brain stem, the cerebellum, the diencephalon, and the cerebrum, which is divided into lobes.
Taste receptors convert chemical stimuli into electric signals.
The skin is the soft outer covering of our body, its three layers are the epidermis, the dermis and the hypodermis.
The central nervous system consists of the brain and the spinal cord, the peripheral nervous system consists of nerves and ganglia.
The main parts of the human brain are the brain stem, the cerebellum, the diencephalon, and the cerebrum.
Connective tissues include loose and dense connective tissues, adipose tissue, blood, tendon and bone tissue.
Human activity increases the greenhouse effect and leads to global warming.
The ozone layer filters the Sun´s harmful UV radiation, therefore it is indispensable for life on Earth.
The Earth’s magnetic North and South poles are located near the geographic North and South poles.
The longest part of the digestive system, where most of the digestion and absorption takes place.
Stratovolcanoes consist of layers of volcanic ash, debris and lava.
Wealthy citizens in ancient Rome owned large houses with varied layouts of several rooms.
The 900 years old Benedictine abbey is situated in Melk, on the right bank of the Danube.
The average house in Ancient Greece had a rectangular, geometrical floor plan and two stories.
This animation compares the life cycles of mosses and ferns, helping to understand the general life cycle of plants.
This animation explains transparency and opacity, the principle of radiography, and the light-absorbing properties of materials.
The first commercially successful technique of photography was invented by the French Louis Daguerre.